US20120193693A1 - Magnetic random access memory and a method of fabricating the same - Google Patents
Magnetic random access memory and a method of fabricating the same Download PDFInfo
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- US20120193693A1 US20120193693A1 US13/235,272 US201113235272A US2012193693A1 US 20120193693 A1 US20120193693 A1 US 20120193693A1 US 201113235272 A US201113235272 A US 201113235272A US 2012193693 A1 US2012193693 A1 US 2012193693A1
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C11/02—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements
- G11C11/16—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C11/02—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements
- G11C11/16—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect
- G11C11/161—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C11/02—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements
- G11C11/16—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using magnetic elements using elements in which the storage effect is based on magnetic spin effect
- G11C11/165—Auxiliary circuits
- G11C11/1659—Cell access
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B61/00—Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
- H10B61/20—Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices comprising components having three or more electrodes, e.g. transistors
- H10B61/22—Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices comprising components having three or more electrodes, e.g. transistors of the field-effect transistor [FET] type
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N50/00—Galvanomagnetic devices
- H10N50/01—Manufacture or treatment
Definitions
- Embodiments described herein generally relate to a magnetic random access memory device and a method of fabricating the magnetic random access memory device.
- MRAMs Magnetic Random Access Memories
- TMR Tunneling Magneto Resistive
- a film may not be formed evenly and a seam or void may be generated inside some contact plugs.
- the contact plugs and magneto resistive elements on the contact plugs lose their surface flatness, causing a problem of degrading the reliability of the magneto resistive elements.
- FIG. 1 is a cross-sectional view showing a memory cell in a magnetic random access memory according to a first embodiment
- FIG. 2 is a cross-sectional view showing the memory cell in the magnetic random access memory according to the first embodiment
- FIGS. 3A-3D are cross-sectional views showing a method of fabricating the magnetic random access memory according to the first embodiment.
- FIGS. 4A-4D are cross-sectional views showing the method of fabricating the magnetic random access memory according to the first embodiment
- FIGS. 5A-5D are cross-sectional views showing the method of fabricating the magnetic random access memory according to the first embodiment
- FIG. 6 is a cross-sectional view showing a method of fabricating a magnetic random access memory according to a second embodiment
- FIG. 7 is a cross-sectional view showing a magnetic random access memory according to a third embodiment
- FIGS. 8A-8C are cross-sectional views showing a method of fabricating the magnetic random access memory according to the third embodiment.
- magnetic random access memory device including a semiconductor substrate, a selection transistor provided on the semiconductor substrate, the selection transistor including a diffusion layer on a surface area of the semiconductor substrate, a contact plug provided on the diffusion layer, an amorphous film provided on the contact plug, a lower electrode provided on the amorphous film, a first magnetic layer provided on the lower electrode, a nonmagnetic layer provided on the first magnetic layer, a second magnetic layer provided on the nonmagnetic layer, an upper electrode provided on the second magnetic layer, and a sidewall contact film provided on the contact plug, the sidewall contact film being in contact with a sidewall of the lower electrode.
- FIGS. 1 and 2 are cross-sectional views showing a memory cell in the magnetic random access memory according to the first embodiment, taken along a line parallel to the bit line direction.
- Each select transistor includes a source layer S, a drain layer D, a gate insulating film 2 , and a gate electrode 3 . Meanwhile, each pair of select transistors share a drain layer D with each other. That is, the select transistors are adjacent to each other with the drain layer D in between.
- a p-type silicon substrate for example is used for the semiconductor substrate 1 .
- the source layer S and the drain layer D are provided in upper layer portions of the semiconductor substrate 1 and are n-type diffusion layers for example.
- the drain layer D is constituted with an extension layer 5 and a high-concentration layer 6 .
- the gate insulating films 2 and the gate electrodes 3 are provided in order on the semiconductor substrate 1 .
- a silicon oxide film for example is used for each gate insulating film 2 .
- a polycrystalline silicon film or the like for example is used for each gate electrode 3 .
- Word lines 4 are provided on the gate electrodes 3 .
- a conductive film made of W or the like for example is used for each gate electrode 3 .
- First protection films 7 are provided on the semiconductor substrate 1 in such a manner as to cover the gate insulating films 2 and the gate electrodes 3 .
- An insulating film such as a silicon nitride film for example is used for each first protection film 7 .
- the width of each first protection film 7 in the bit line direction is approximately 40 nm for example, and the film thickness of the first protection film 7 from the top of the word line is approximately 50 nm for example.
- Second protection films 8 are provided on the semiconductor substrate 1 in such a manner as to be in contact with the first protection films 7 .
- An insulating film such as a silicon nitride film for example is used for each second protection film 8 .
- a barrier metal film (not illustrated) is provided on the source layer S, the drain layer D, and the second protection films 8 .
- a conductive film such as a single layer film made of Ti, TiN, or the like or a laminate film made of Ti and TiN for example is used for the barrier metal film.
- the barrier metal film prevents direct contact between the semiconductor substrate 1 and each contact plug 9 to be described below, thereby suppressing the diffusion of a metal such as W for example used for the contact plug 9 into the semiconductor substrate 1 . Accordingly, the barrier metal film can protect the semiconductor substrate 1 from the contact plug 9 .
- the contact plug 9 is provided on the barrier metal film in such a manner as to be buried between the paired select transistors. W, Cu, or the like for example is used for the contact plug 9 .
- the contact plug 9 is electrically connected to the drain layer D via the barrier metal film.
- the contact plug 9 is electrically insulated from the word lines 4 since the first protection films 7 and the second protection films 8 are provided as insulating films between the contact plug 9 and the word lines 4 .
- a seam 10 may exist in the contact plug 9 in some cases. For this reason, the surface flatness of the contact plug 9 may not always be excellent.
- the width of the contact plug 9 in the bit line direction is approximately 50 nm for example, and the film thickness is approximately 200 nm for example.
- An amorphous film 11 is provided on one of the first protection films 7 and the contact plug 9 .
- An amorphous silicon oxide film for example is used for the amorphous film 11 . It is possible to use some other film such as a metal film as long as the material is amorphous.
- the film thickness of the amorphous film 11 is approximately 100 to 200 nm for example. Using the amorphous film 11 eliminates the influence of the seam 10 in the contact plug 9 . Thus, an amorphous film 11 with excellent surface flatness can be obtained even when the flatness of the contact plug 9 is poor.
- the surface flatness of the amorphous film 11 is Ra which is equal to 0.2 nm or less for example. Note that the amorphous film 11 may be provided only on the contact plug 9 .
- a magneto resistive element 18 is provided on the amorphous film 11 .
- the magneto resistive element 18 refers to an element with a structure in which a lower electrode 13 , a first magnetic layer 14 , a nonmagnetic layer 15 , a second magnetic layer 16 , and an upper electrode 17 are stacked in the order.
- the lower electrode 13 is provided on the amorphous film 11 .
- a conductive film containing at least one of Pt, Ir, Ru, Cu, W, Ta, Ti, Al, Hf, and Sr, a mixture containing at least one of these materials, a nitride containing at least one of the materials, a nitride containing the mixture, or the like is used for the lower electrode 13 .
- the film thickness of the lower electrode 13 is approximately 15 nm for example.
- the first magnetic layer 14 is provided on the lower electrode 13 .
- the first magnetic layer 14 is a perpendicular magnetization film for example whose magnetization is oriented substantially perpendicular to the film surface, and is a free layer in which the magnetization orientation is variable.
- An ordered alloy layer for example is used for the first magnetic layer 14 .
- FePd, FePt, CoPt, CoPd, or the like is used for the layer, but the material is not limited to these materials.
- the film thickness is approximately 6 nm for example.
- the first magnetic layer 14 may be a plane magnetization film whose magnetization is oriented in parallel to the film surface.
- the nonmagnetic layer 15 is provided on the first magnetic layer 14 as a tunneling barrier film.
- the nonmagnetic layer 15 is an oxide material with a NaCl structure for example. MgO, CaO, SrO, TiO, VO, NbO, or the like is used for the nonmagnetic layer 15 . Some other material such as Al 2 O 3 for example may be used instead.
- the film thickness of the nonmagnetic layer 15 is approximately 10 nm for example.
- the second magnetic layer 16 is provided on the nonmagnetic layer 15 .
- the second magnetic layer 16 is a perpendicular magnetization film for example whose magnetization is oriented substantially perpendicular to the film surface, and is a pinned layer in which the magnetization orientation is fixed to one direction.
- a film of an alloy such as CoCr, CoPt, FePt, FePd, or CoPd is used for the second magnetic layer 16 .
- a laminate film of Co/Pd, Co/Pt, or Co/Ru may be used for the second magnetic layer 16 .
- the second magnetic layer 16 may be a plane magnetization film whose magnetization is oriented parallel to the film surface. When the second magnetic layer 16 is a pinned layer, the film thickness is approximately 30 nm for example.
- the upper electrode 17 is provided on the second magnetic layer 16 .
- a single layer film of Ta or a laminate film of Ta/TiAlN is used for the upper electrode 17 .
- Some other film such as a single layer film of Ta, TiAl x N y , TiN, WN, or W or a laminate film of these materials for example may be used for the upper electrode 17 .
- the film thickness of the upper electrode 17 is approximately 100 nm for example.
- the upper electrode 17 functions not only as an electrode but also as a hard mask.
- a sidewall mask 19 is provided in contact with the side surface of each of the upper electrode 17 , the second magnetic layer 16 , the nonmagnetic layer 15 , and the first magnetic layer 14 .
- the bottom surface of the sidewall mask 19 is lower than the bottom surface of the nonmagnetic layer 15 , but higher than the bottom surface of the lower electrode 13 . Meanwhile, as shown in FIG. 2 , when the bottom surface of the sidewall mask 19 is lower than the top surface of the lower electrode 13 , a first sidewall contact 20 is not in contact with the side surface of the first magnetic layer 14 , thereby preventing magnetic field leakage from the first magnetic layer 14 . Note that the bottom surface of the sidewall mask 19 may be lower than the bottom surface of the second magnetic layer 16 , but higher than the bottom surface of the nonmagnetic layer 15 .
- the sidewall mask 19 functions to prevent electrical connection between the first sidewall contact 20 to be described below and the upper electrode 17 .
- the sidewall mask 19 also functions as a hard mask.
- PCVD Physical Vapor Deposition
- ALD Atomic Layer Deposition
- sputtering and PeALD (Plasma enhanced ALD) are suitable deposition methods for the sidewall mask 19 .
- deposition at or below 300° C. can reduce damage on the MTJ element.
- the first sidewall contact 20 is provided on the contact plug 9 while being in contact with the side walls of the amorphous film 11 and lower electrode 13 . Accordingly, the contact plug 9 and the side surface of the lower electrode are electrically connected to each other. TiN for example is used for the first sidewall contact 20 . Note that part of the first sidewall contact 20 connected to the side surface of the lower electrode 13 may be provided on the first protection layer 7 as shown in FIG. 1 .
- ALD, sputtering, and PeALD are suitable deposition methods for the sidewall contact 20 . Moreover, deposition at or below 300° C. can reduce damage on the MTJ element.
- the laminate structure is formed to include the free layer, the nonmagnetic layer, and the pinned layer in the order from the top layer.
- the laminate structure may be formed to include the pinned layer, the nonmagnetic layer, and the free layer in this order from the top layer, in which case appropriate materials should be selected for the upper and lower electrodes.
- FIGS. 3A to 5D a method of fabricating the magnetic random access memory according to the first embodiment will be described below by using FIGS. 3A to 5D .
- gate insulating films 2 and gate electrodes 3 are formed on a semiconductor substrate 1 .
- word lines 4 are formed on the gate electrodes 3 .
- a protection film is deposited covering the semiconductor substrate 1 , the gate insulating films 2 , the gate electrodes 3 , and the word lines 4 , and is then etched back by RIE (Reactive Ion Etching) or the like to form first protection films 7 . Thereafter, with the first protection films 7 as masks, ions are implanted to form extension layers 5 as diffusion layers in upper layer portions of the semiconductor substrate 1 .
- RIE Reactive Ion Etching
- another protection film is deposited on the semiconductor substrate 1 in such a manner as to be in contact with the first protection films 7 , and is then etched back by RIE or the like to form second protection films 8 .
- the etching is performed until the top surfaces of the first protection films 7 are exposed for example.
- ions are implanted to form high-concentration layers 6 as diffusion layers in upper portions of the extension layers 5 in the upper layer portions of the semiconductor substrate 1 .
- a barrier metal film (not illustrated) is formed on the semiconductor substrate 1 .
- a W film is deposited to be embedded as a contact plug material onto the barrier metal film by CVD (Chemical Vapor Deposition).
- the contact plug material is polished through CMP (Chemical Mechanical Polishing) until the top surfaces of the first protection films 7 are exposed to thereby form contact plugs 9 .
- the top surface of each contact plug 9 is made lower than the top surface of each first protection film 7 .
- a seam 10 may be formed in the contact plug 9 in some cases, possibly leading to poor flatness of the contact plug 9 .
- an amorphous silicon oxide film is formed by plasma DVD for example on the first protection films 7 and the contact plug 9 as an amorphous film 11 .
- a seam 12 may be formed in the top surface of the amorphous film 11 in some cases.
- the top surface of the amorphous film 11 is planarized through CMP to remove the seam 12 in the top surface of the amorphous film 11 .
- this allows each magneto resistive element 18 to be formed on a flat surface of the amorphous film 11 .
- the amorphous film 11 may be filled in the seam 10 .
- FIG. 4A an amorphous silicon oxide film is formed by plasma DVD for example on the first protection films 7 and the contact plug 9 as an amorphous film 11 .
- a seam 12 may be formed in the top surface of the amorphous film 11 in some cases.
- the top surface of the amorphous film 11 is planarized through CMP to remove the seam 12 in the top surface of the amorphous film 11 .
- the above-mentioned magneto resistive element 18 formed of a lower electrode 13 , a first magnetic layer 14 , a nonmagnetic layer 15 , a second magnetic layer 16 , and an upper electrode 17 is provided on the amorphous film 11 . Thereafter, a silicon oxide film (not illustrated) is formed by CVD on the upper electrode 17 as a hard mask.
- the upper electrode 17 is etched by RIE.
- the silicon oxide film and the upper electrode 17 are etched by RIE, IBE (Ion Beam Etching), or the like.
- the RIE may be performed under a high-temperature condition of approximately 150 to 300° C. in particular. Note that the etching may be stopped at the top surface of the nonmagnetic layer 15 or of the lower electrode 13 .
- a sidewall mask material is formed by the aforementioned PCVD, ALD, sputtering, or PeALD in such a manner as to cover the magneto resistive element 18 .
- the sidewall mask material is etched back to expose the top surface of the upper electrode 17 , thereby forming each sidewall mask 19 as shown in FIG. 5A .
- the sidewall mask material on the first magnetic layer 14 is etched as well.
- the first magnetic layer 14 , the lower electrode 13 , and the amorphous film are etched to expose the contact plug 9 and the first protection films 7 .
- the second magnetic layer 16 , the nonmagnetic layer 15 , the first magnetic layer 14 , and part of the lower electrode 13 may be etched and the sidewall mask 19 may be formed thereafter.
- the lower electrode 13 and the amorphous film 11 are etched using the upper electrode 17 and the sidewall mask 19 as masks.
- a TiN film for example is deposited as a sidewall contact material through CVD, ALD, or sputtering for example in such a manner as to cover the contact plug 9 , the first protection films 7 , the amorphous film 11 , the sidewall mask 19 , and the magneto resistive element 18 .
- the sidewall contact material is etched back by IBE or RIE to expose the upper electrode 17 .
- a first sidewall contact 20 that is in contact with the side surfaces of the lower electrode 13 and first magnetic layer 14 is formed on the contact plug 9 .
- the first sidewall contact 20 is configured to electrically connect the contact plug 9 and the side surfaces of the lower electrode 13 and first magnetic layer 14 .
- the first sidewall contact 20 is formed in contact with the side surface of the lower electrode 13 but not in contact with the side surface of the first magnetic layer 14 .
- the first sidewall contact 20 can prevent magnetic field leakage from the first magnetic layer 14 , which in turn prevents deterioration in the magnetization property of the magneto resistive element 18 .
- a third protection film (not illustrated) is formed covering the top surfaces of the contact plug 9 and first protection films 7 , as well as the first sidewall contact 20 , the sidewall mask 19 , and the upper electrode 17 .
- the third protection film is a single layer film made of any of Si x N y , Al 2 O 3 , SiO 2 , SiAlO, TiO 2 , and ZrO 2 , or a laminated film of two or more of these materials.
- a first interlayer insulator ILD 1 is deposited on the third protection film. Then, the first interlayer insulator ILD 1 and the third protection film are polished through CMP until the top surface of the upper electrode is exposed. In this process, the top surface of the interlayer insulator ILD 1 is made lower than the top surface of the upper electrode 17 . Then, a local wiring LIC is formed covering the top surface of the upper electrode 17 , and thereafter a second interlayer insulator ILD 2 is deposited covering the local wiring LIC. Subsequently, a source line contact SC, a bit line contact BC (not illustrated), a source line SL, and a bit line BL (not illustrated) are formed. As a result, a magnetic random access memory according to the first embodiment is formed as illustrated.
- the amorphous film 11 having excellent surface flatness is provided on the contact plug 9 and the first protection film 7 , and the magneto resistive element 18 is provided on the amorphous film 11 .
- the magneto resistive element 18 is provided without any stepped portion. Accordingly, a magnetic random access memory can be obtained without reliability degradation.
- the sidewall contact material is deposited covering the contact plug 9 , the first protection films 7 , the amorphous film 11 , and the magneto resistive element 18 , and then etched back to form the first sidewall contact 20 that electrically connects the contact plug 9 and the side surface of the lower electrode 13 with each other.
- the electrical connection between the first sidewall contact 20 and the side surface of the lower electrode 13 can be controlled and maintained in a preferable state.
- FIG. 6 is a cross-sectional view showing a method of fabricating the magnetic random access memory according to the second embodiment.
- portions that are identical to those in the configuration of the magnetic random access memory of the first embodiment shown in FIG. 1 are denoted by the same reference signs, and detailed description thereof is omitted.
- the first sidewall contact 20 is formed by depositing a sidewall contact material to cover the first protection films 7 , the contact plug 9 , the amorphous film 11 , the magneto resistive element 18 , and the sidewall mask 19 and then etching back the sidewall contact material.
- the first sidewall contact 20 is formed by subjecting the contact plug 9 to physical etching to deposit a sidewall contact material onto the contact plug 9 .
- select transistors are formed on a semiconductor substrate 1 , and then an amorphous film 11 , a magneto resistive element 18 , and a sidewall mask 19 are formed on a contact plug 9 and a first protection film 7 .
- the contact plug 9 is processed by a physical process such as ion milling. The process is performed until a contact plug material deposited onto the contact plug 9 by the sputtering effect comes into contact with the side surface of the lower electrode 13 . Consequently, a first sidewall contact 20 is formed which electrically connects the contact plug 9 and the side surface of the lower electrode to each other, as shown in FIG. 6 .
- the contact plug 9 and the first sidewall contact 20 are made of the same material such as W for example.
- the material of the first protection film 7 which is SiN for example, is deposited onto the side surfaces of the amorphous film 11 and lower electrode 13 as a deposition layer 21 .
- the material of the first sidewall contact 20 and the material of the deposition layer 21 both contain part of the material of the first protection layer and part of the material of the contact plug 9 .
- IBE may be performed as the physical process.
- RIE may be performed under a high-bias condition to process the contact plug 9 .
- the amorphous film 11 having excellent surface flatness is provided on the contact plug 9 and the first protection film 7 , and the magneto resistive element 18 is provided on the amorphous film 11 .
- the magneto resistive element 18 is provided without any stepped portion. Accordingly, a magnetic random access memory can be obtained without reliability degradation.
- the first sidewall contact 20 is formed without depositing the sidewall contact material used in the first embodiment.
- use of the method of fabricating a magnetic random access memory according to the second embodiment makes it possible to reduce the number of fabrication steps and therefore lowers the fabrication cost.
- FIG. 7 is a cross-sectional view showing the magnetic random access memory according to the third embodiment.
- portions that are identical to those in the configuration of the magnetic random access memory of the first embodiment shown in FIG. 1 are denoted by the same reference signs, and detailed description thereof is omitted.
- the third embodiment differs from the first embodiment in that a metal film 22 is provided between the contact plug 9 and first protection film 7 and the amorphous film 11 shown in FIG. 1 .
- the first sidewall contact 20 is mainly made of the material of the metal film 22 .
- the first sidewall contact 20 also contains the material of the contact plug 9 and the material of the first protection film 7 .
- a second sidewall contact 23 may be provided in contact with the first sidewall contact 20 .
- the composition of the second sidewall contact 23 is mainly the same as that of the material of the contact plug 9 .
- the material of the contact plug 9 contains part of the material of the contact plug 9 and part of the material of the first protection film 7 .
- FIG. 8 is a cross-sectional view showing a method of fabricating the magnetic random access memory according to the third embodiment.
- select transistors, first protection films 7 , and a contact plug 9 are formed on a semiconductor substrate 1 .
- a metal film 22 is formed on the first protection films 7 and the contact plug 9 .
- the metal film 22 may be filled in the seam 10 .
- a metal such as Ta, Pt, TiN, W, or TiAlN for example is used for the metal film 22 .
- the surface flatness of the metal film 22 is affected by the contact plug 9 and therefore may not always be excellent.
- an amorphous film 11 is formed on the metal film 22 .
- a magneto resistive element 18 and a sidewall mask 19 are formed on the amorphous film 11 .
- the amorphous film 11 is etched until the metal film 22 is exposed.
- the metal film 22 is processed by a physical process such as ion milling.
- a metal having the same composition as the metal film 22 is deposited on the contact plug 9 .
- a first sidewall contact 20 is formed on the contact plug 9 in such a manner as to be in contact with the side surface of the lower electrode 13 .
- the contact plug 9 may also be subjected to a physical process to deposit a contact plug material onto the first sidewall contact 20 and form a second sidewall contact 23 made of W for example.
- a deposition layer 21 of SiN for example, which is as the material of the first protection film 7 is deposited on the first sidewall contact 20 .
- the amorphous film 11 having excellent surface flatness is provided on the metal film 22 , and the magneto resistive element 18 is provided on the amorphous film 11 .
- the magneto resistive element 18 is provided without any stepped portion. Accordingly, a magnetic random access memory can be obtained without reliability degradation.
- the metal film 22 which has a large contact area with the contact plug 9 , is provided on the contact plug 9 and the first protection film 7 . Accordingly, it is possible to maintain excellent electrical connection between the contact plug 9 and the first sidewall contact 20 .
- the metal film is subjected to a physical process to form the first sidewall contact 20 that electrically connects the contact plug 9 and the side surface of the lower electrode 13 with each other.
- the electrical connection between the first sidewall contact 20 and the side surface of the lower electrode 13 can be controlled and maintained in a preferable state.
- planar select transistors are formed on the semiconductor substrate 1 .
- three-dimensional select transistors such as FINFETs (Fin Field Effect Transistors) for example may be provided instead of the planar transistors.
- first to third embodiments have been described on the assumption that a free layer is used for the first magnetic layer 14 and a pinned layer is used for the second magnetic layer 16 .
- a pinned layer may be used for the first magnetic layer 14 and a free layer may be used for the second magnetic layer 16 instead.
- an alignment control film may be provided between the lower electrode 13 and the first magnetic layer 14 .
- a film made of Pt, Ir, Ru, or the like, or a laminate film made of these atoms for example is used for the alignment control film.
- a magnetization adjustment layer may be provided between the second magnetic layer 16 and the upper electrode 17 .
- the magnetization adjustment layer is an antiferromagnetic film provided to adjust magnetic field leakage from the pinned layer, suppress a magnetic influence on the free layer, and also fix the magnetization orientation of the pinned layer to a predetermined one orientation.
- An alloy of Mn with Fe, Ni, Pt, Pd, Ru, Os, or Ir, namely FeMn, NiMn, PtMn, PdMn, PtPdMn, RuMn, OsMn, IrMn, CrPtMn, or the like for example is used for the magnetization adjustment layer.
Abstract
An aspect of the present embodiment, there is provided magnetic random access memory device including a semiconductor substrate, a selection transistor on the semiconductor substrate, the selection transistor including a diffusion layer, a contact plug on diffusion layer, an amorphous film on the contact plug, a lower electrode provided on the amorphous film, a first magnetic layer, a nonmagnetic layer, a second magnetic layer, an upper electrode stacked in an order and a sidewall contact film on the contact plug, the sidewall contact film being in contact with a sidewall of the upper electrode.
Description
- This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2011-021210, filed on Feb. 2, 2011, the entire contents of which are incorporated herein by reference.
- Embodiments described herein generally relate to a magnetic random access memory device and a method of fabricating the magnetic random access memory device.
- Recent years, MRAMs (Magnetic Random Access Memories) utilizing a TMR (Tunneling Magneto Resistive) effect have been developed. Having large magnetic resistance change ratios, magneto resistive elements including MTJs (Magnetic Tunnel Junctions) are used in MRAMs.
- With the miniaturization of memory cells in MRAMs, a structure in which magneto resistive elements are provided on contact plugs is now being studied. In such a structure, the reliability of each magneto resistive element depends on the flatness of the corresponding contact plug.
- Meanwhile, in the process of forming contact plugs in contact holes by CVD or the like, a film may not be formed evenly and a seam or void may be generated inside some contact plugs.
- In this case, the contact plugs and magneto resistive elements on the contact plugs lose their surface flatness, causing a problem of degrading the reliability of the magneto resistive elements.
-
FIG. 1 is a cross-sectional view showing a memory cell in a magnetic random access memory according to a first embodiment; -
FIG. 2 is a cross-sectional view showing the memory cell in the magnetic random access memory according to the first embodiment; -
FIGS. 3A-3D are cross-sectional views showing a method of fabricating the magnetic random access memory according to the first embodiment. -
FIGS. 4A-4D are cross-sectional views showing the method of fabricating the magnetic random access memory according to the first embodiment; -
FIGS. 5A-5D are cross-sectional views showing the method of fabricating the magnetic random access memory according to the first embodiment; -
FIG. 6 is a cross-sectional view showing a method of fabricating a magnetic random access memory according to a second embodiment; -
FIG. 7 is a cross-sectional view showing a magnetic random access memory according to a third embodiment; -
FIGS. 8A-8C are cross-sectional views showing a method of fabricating the magnetic random access memory according to the third embodiment. - An aspect of the present embodiment, there is provided magnetic random access memory device including a semiconductor substrate, a selection transistor provided on the semiconductor substrate, the selection transistor including a diffusion layer on a surface area of the semiconductor substrate, a contact plug provided on the diffusion layer, an amorphous film provided on the contact plug, a lower electrode provided on the amorphous film, a first magnetic layer provided on the lower electrode, a nonmagnetic layer provided on the first magnetic layer, a second magnetic layer provided on the nonmagnetic layer, an upper electrode provided on the second magnetic layer, and a sidewall contact film provided on the contact plug, the sidewall contact film being in contact with a sidewall of the lower electrode.
- Hereinbelow, embodiments will be described with reference to the drawings.
- A magnetic random access memory according to a first embodiment will be described below.
FIGS. 1 and 2 are cross-sectional views showing a memory cell in the magnetic random access memory according to the first embodiment, taken along a line parallel to the bit line direction. - As shown in
FIG. 1 , a plurality of select transistors are provided on asemiconductor substrate 1. Each select transistor includes a source layer S, a drain layer D, agate insulating film 2, and agate electrode 3. Meanwhile, each pair of select transistors share a drain layer D with each other. That is, the select transistors are adjacent to each other with the drain layer D in between. - A p-type silicon substrate for example is used for the
semiconductor substrate 1. The source layer S and the drain layer D are provided in upper layer portions of thesemiconductor substrate 1 and are n-type diffusion layers for example. The drain layer D is constituted with anextension layer 5 and a high-concentration layer 6. - The
gate insulating films 2 and thegate electrodes 3 are provided in order on thesemiconductor substrate 1. A silicon oxide film for example is used for eachgate insulating film 2. A polycrystalline silicon film or the like for example is used for eachgate electrode 3.Word lines 4 are provided on thegate electrodes 3. A conductive film made of W or the like for example is used for eachgate electrode 3. -
First protection films 7 are provided on thesemiconductor substrate 1 in such a manner as to cover thegate insulating films 2 and thegate electrodes 3. An insulating film such as a silicon nitride film for example is used for eachfirst protection film 7. The width of eachfirst protection film 7 in the bit line direction is approximately 40 nm for example, and the film thickness of thefirst protection film 7 from the top of the word line is approximately 50 nm for example.Second protection films 8 are provided on thesemiconductor substrate 1 in such a manner as to be in contact with thefirst protection films 7. An insulating film such as a silicon nitride film for example is used for eachsecond protection film 8. - A barrier metal film (not illustrated) is provided on the source layer S, the drain layer D, and the
second protection films 8. A conductive film such as a single layer film made of Ti, TiN, or the like or a laminate film made of Ti and TiN for example is used for the barrier metal film. The barrier metal film prevents direct contact between thesemiconductor substrate 1 and eachcontact plug 9 to be described below, thereby suppressing the diffusion of a metal such as W for example used for thecontact plug 9 into thesemiconductor substrate 1. Accordingly, the barrier metal film can protect thesemiconductor substrate 1 from thecontact plug 9. - The
contact plug 9 is provided on the barrier metal film in such a manner as to be buried between the paired select transistors. W, Cu, or the like for example is used for thecontact plug 9. Thecontact plug 9 is electrically connected to the drain layer D via the barrier metal film. Moreover, thecontact plug 9 is electrically insulated from theword lines 4 since thefirst protection films 7 and thesecond protection films 8 are provided as insulating films between thecontact plug 9 and theword lines 4. Aseam 10 may exist in thecontact plug 9 in some cases. For this reason, the surface flatness of thecontact plug 9 may not always be excellent. The width of thecontact plug 9 in the bit line direction is approximately 50 nm for example, and the film thickness is approximately 200 nm for example. - An
amorphous film 11 is provided on one of thefirst protection films 7 and thecontact plug 9. An amorphous silicon oxide film for example is used for theamorphous film 11. It is possible to use some other film such as a metal film as long as the material is amorphous. The film thickness of theamorphous film 11 is approximately 100 to 200 nm for example. Using theamorphous film 11 eliminates the influence of theseam 10 in thecontact plug 9. Thus, anamorphous film 11 with excellent surface flatness can be obtained even when the flatness of thecontact plug 9 is poor. The surface flatness of theamorphous film 11 is Ra which is equal to 0.2 nm or less for example. Note that theamorphous film 11 may be provided only on thecontact plug 9. - A magneto
resistive element 18 is provided on theamorphous film 11. The magnetoresistive element 18 refers to an element with a structure in which alower electrode 13, a firstmagnetic layer 14, anonmagnetic layer 15, a secondmagnetic layer 16, and anupper electrode 17 are stacked in the order. - The
lower electrode 13 is provided on theamorphous film 11. A conductive film containing at least one of Pt, Ir, Ru, Cu, W, Ta, Ti, Al, Hf, and Sr, a mixture containing at least one of these materials, a nitride containing at least one of the materials, a nitride containing the mixture, or the like is used for thelower electrode 13. The film thickness of thelower electrode 13 is approximately 15 nm for example. - The first
magnetic layer 14 is provided on thelower electrode 13. The firstmagnetic layer 14 is a perpendicular magnetization film for example whose magnetization is oriented substantially perpendicular to the film surface, and is a free layer in which the magnetization orientation is variable. An ordered alloy layer for example is used for the firstmagnetic layer 14. FePd, FePt, CoPt, CoPd, or the like is used for the layer, but the material is not limited to these materials. When the firstmagnetic layer 14 is a free layer, the film thickness is approximately 6 nm for example. - Note that the first
magnetic layer 14 may be a plane magnetization film whose magnetization is oriented in parallel to the film surface. - The
nonmagnetic layer 15 is provided on the firstmagnetic layer 14 as a tunneling barrier film. Thenonmagnetic layer 15 is an oxide material with a NaCl structure for example. MgO, CaO, SrO, TiO, VO, NbO, or the like is used for thenonmagnetic layer 15. Some other material such as Al2O3 for example may be used instead. The film thickness of thenonmagnetic layer 15 is approximately 10 nm for example. - The second
magnetic layer 16 is provided on thenonmagnetic layer 15. The secondmagnetic layer 16 is a perpendicular magnetization film for example whose magnetization is oriented substantially perpendicular to the film surface, and is a pinned layer in which the magnetization orientation is fixed to one direction. A film of an alloy such as CoCr, CoPt, FePt, FePd, or CoPd is used for the secondmagnetic layer 16. Alternatively, a laminate film of Co/Pd, Co/Pt, or Co/Ru may be used for the secondmagnetic layer 16. Note that the secondmagnetic layer 16 may be a plane magnetization film whose magnetization is oriented parallel to the film surface. When the secondmagnetic layer 16 is a pinned layer, the film thickness is approximately 30 nm for example. - The
upper electrode 17 is provided on the secondmagnetic layer 16. A single layer film of Ta or a laminate film of Ta/TiAlN is used for theupper electrode 17. Some other film such as a single layer film of Ta, TiAlxNy, TiN, WN, or W or a laminate film of these materials for example may be used for theupper electrode 17. The film thickness of theupper electrode 17 is approximately 100 nm for example. Theupper electrode 17 functions not only as an electrode but also as a hard mask. Asidewall mask 19 is provided in contact with the side surface of each of theupper electrode 17, the secondmagnetic layer 16, thenonmagnetic layer 15, and the firstmagnetic layer 14. The bottom surface of thesidewall mask 19 is lower than the bottom surface of thenonmagnetic layer 15, but higher than the bottom surface of thelower electrode 13. Meanwhile, as shown inFIG. 2 , when the bottom surface of thesidewall mask 19 is lower than the top surface of thelower electrode 13, afirst sidewall contact 20 is not in contact with the side surface of the firstmagnetic layer 14, thereby preventing magnetic field leakage from the firstmagnetic layer 14. Note that the bottom surface of thesidewall mask 19 may be lower than the bottom surface of the secondmagnetic layer 16, but higher than the bottom surface of thenonmagnetic layer 15. - An insulating film of SiN or the like for example is used for the
sidewall mask 19. Thesidewall mask 19 functions to prevent electrical connection between thefirst sidewall contact 20 to be described below and theupper electrode 17. Thesidewall mask 19 also functions as a hard mask. PCVD (Plasma Chemical Vapor Deposition), ALD (Atomic Layer Deposition), sputtering, and PeALD (Plasma enhanced ALD) are suitable deposition methods for thesidewall mask 19. Moreover, deposition at or below 300° C. can reduce damage on the MTJ element. - The
first sidewall contact 20 is provided on thecontact plug 9 while being in contact with the side walls of theamorphous film 11 andlower electrode 13. Accordingly, thecontact plug 9 and the side surface of the lower electrode are electrically connected to each other. TiN for example is used for thefirst sidewall contact 20. Note that part of thefirst sidewall contact 20 connected to the side surface of thelower electrode 13 may be provided on thefirst protection layer 7 as shown inFIG. 1 . ALD, sputtering, and PeALD are suitable deposition methods for thesidewall contact 20. Moreover, deposition at or below 300° C. can reduce damage on the MTJ element. - In the embodiment, the laminate structure is formed to include the free layer, the nonmagnetic layer, and the pinned layer in the order from the top layer. Note, however, that the laminate structure may be formed to include the pinned layer, the nonmagnetic layer, and the free layer in this order from the top layer, in which case appropriate materials should be selected for the upper and lower electrodes.
- Next, a method of fabricating the magnetic random access memory according to the first embodiment will be described below by using
FIGS. 3A to 5D . - As shown in
FIG. 3A ,gate insulating films 2 andgate electrodes 3 are formed on asemiconductor substrate 1. Then,word lines 4 are formed on thegate electrodes 3. - Next, as shown in
FIG. 3B , a protection film is deposited covering thesemiconductor substrate 1, thegate insulating films 2, thegate electrodes 3, and theword lines 4, and is then etched back by RIE (Reactive Ion Etching) or the like to formfirst protection films 7. Thereafter, with thefirst protection films 7 as masks, ions are implanted to form extension layers 5 as diffusion layers in upper layer portions of thesemiconductor substrate 1. - Next, as shown in
FIG. 3C , another protection film is deposited on thesemiconductor substrate 1 in such a manner as to be in contact with thefirst protection films 7, and is then etched back by RIE or the like to formsecond protection films 8. In this event, the etching is performed until the top surfaces of thefirst protection films 7 are exposed for example. Thereafter, with thesecond protection films 8 as masks, ions are implanted to form high-concentration layers 6 as diffusion layers in upper portions of the extension layers 5 in the upper layer portions of thesemiconductor substrate 1. - Next, a barrier metal film (not illustrated) is formed on the
semiconductor substrate 1. Then, as shown inFIG. 3D , a W film is deposited to be embedded as a contact plug material onto the barrier metal film by CVD (Chemical Vapor Deposition). Thereafter, the contact plug material is polished through CMP (Chemical Mechanical Polishing) until the top surfaces of thefirst protection films 7 are exposed to thereby form contact plugs 9. Here, the top surface of eachcontact plug 9 is made lower than the top surface of eachfirst protection film 7. In this process, aseam 10 may be formed in thecontact plug 9 in some cases, possibly leading to poor flatness of thecontact plug 9. - Next, as shown in
FIG. 4A , an amorphous silicon oxide film is formed by plasma DVD for example on thefirst protection films 7 and thecontact plug 9 as anamorphous film 11. In this process, aseam 12 may be formed in the top surface of theamorphous film 11 in some cases. Then, as shown inFIG. 4B , the top surface of theamorphous film 11 is planarized through CMP to remove theseam 12 in the top surface of theamorphous film 11. As described below, this allows each magnetoresistive element 18 to be formed on a flat surface of theamorphous film 11. In this process, theamorphous film 11 may be filled in theseam 10. Then, as shown inFIG. 4C , the above-mentioned magnetoresistive element 18 formed of alower electrode 13, a firstmagnetic layer 14, anonmagnetic layer 15, a secondmagnetic layer 16, and anupper electrode 17 is provided on theamorphous film 11. Thereafter, a silicon oxide film (not illustrated) is formed by CVD on theupper electrode 17 as a hard mask. - Next, with the silicon oxide film (not illustrated) on the
upper electrode 17 as a mask, theupper electrode 17 is etched by RIE. Then, as shown inFIG. 4D , with the silicon oxide film and theupper electrode 17 as masks, the secondmagnetic layer 16, thenonmagnetic layer 15, and part of the firstmagnetic layer 14 are etched by RIE, IBE (Ion Beam Etching), or the like. The RIE may be performed under a high-temperature condition of approximately 150 to 300° C. in particular. Note that the etching may be stopped at the top surface of thenonmagnetic layer 15 or of thelower electrode 13. - Next, a sidewall mask material is formed by the aforementioned PCVD, ALD, sputtering, or PeALD in such a manner as to cover the magneto
resistive element 18. Then, the sidewall mask material is etched back to expose the top surface of theupper electrode 17, thereby forming eachsidewall mask 19 as shown inFIG. 5A . In this process, the sidewall mask material on the firstmagnetic layer 14 is etched as well. - Next, as shown in
FIG. 5B , with the upper electrode and thesidewall mask 19 as masks, the firstmagnetic layer 14, thelower electrode 13, and the amorphous film are etched to expose thecontact plug 9 and thefirst protection films 7. - Note that before forming the
sidewall mask 19, the secondmagnetic layer 16, thenonmagnetic layer 15, the firstmagnetic layer 14, and part of thelower electrode 13 may be etched and thesidewall mask 19 may be formed thereafter. In this case, thelower electrode 13 and theamorphous film 11 are etched using theupper electrode 17 and thesidewall mask 19 as masks. - Next, as shown in
FIG. 5C , a TiN film for example is deposited as a sidewall contact material through CVD, ALD, or sputtering for example in such a manner as to cover thecontact plug 9, thefirst protection films 7, theamorphous film 11, thesidewall mask 19, and the magnetoresistive element 18. - Next, as shown in
FIG. 5D , the sidewall contact material is etched back by IBE or RIE to expose theupper electrode 17. As a result, afirst sidewall contact 20 that is in contact with the side surfaces of thelower electrode 13 and firstmagnetic layer 14 is formed on thecontact plug 9. Thefirst sidewall contact 20 is configured to electrically connect thecontact plug 9 and the side surfaces of thelower electrode 13 and firstmagnetic layer 14. Note that when the bottom surface of thesidewall mask 19 is lower than the top surface of thelower electrode 13, thefirst sidewall contact 20 is formed in contact with the side surface of thelower electrode 13 but not in contact with the side surface of the firstmagnetic layer 14. In this case, thefirst sidewall contact 20 can prevent magnetic field leakage from the firstmagnetic layer 14, which in turn prevents deterioration in the magnetization property of the magnetoresistive element 18. - Next, a third protection film (not illustrated) is formed covering the top surfaces of the
contact plug 9 andfirst protection films 7, as well as thefirst sidewall contact 20, thesidewall mask 19, and theupper electrode 17. The third protection film is a single layer film made of any of SixNy, Al2O3, SiO2, SiAlO, TiO2, and ZrO2, or a laminated film of two or more of these materials. - Next, a first interlayer insulator ILD1 is deposited on the third protection film. Then, the first interlayer insulator ILD1 and the third protection film are polished through CMP until the top surface of the upper electrode is exposed. In this process, the top surface of the interlayer insulator ILD1 is made lower than the top surface of the
upper electrode 17. Then, a local wiring LIC is formed covering the top surface of theupper electrode 17, and thereafter a second interlayer insulator ILD2 is deposited covering the local wiring LIC. Subsequently, a source line contact SC, a bit line contact BC (not illustrated), a source line SL, and a bit line BL (not illustrated) are formed. As a result, a magnetic random access memory according to the first embodiment is formed as illustrated. - As described above, in the first embodiment, the
amorphous film 11 having excellent surface flatness is provided on thecontact plug 9 and thefirst protection film 7, and the magnetoresistive element 18 is provided on theamorphous film 11. Hence, the magnetoresistive element 18 is provided without any stepped portion. Accordingly, a magnetic random access memory can be obtained without reliability degradation. - Further, in the first embodiment, the sidewall contact material is deposited covering the
contact plug 9, thefirst protection films 7, theamorphous film 11, and the magnetoresistive element 18, and then etched back to form thefirst sidewall contact 20 that electrically connects thecontact plug 9 and the side surface of thelower electrode 13 with each other. Hence, by changing the film thickness of the sidewall contact material, the electrical connection between thefirst sidewall contact 20 and the side surface of thelower electrode 13 can be controlled and maintained in a preferable state. - A method of fabricating a magnetic random access memory according to a second embodiment of the invention will be described by using
FIG. 6 .FIG. 6 is a cross-sectional view showing a method of fabricating the magnetic random access memory according to the second embodiment. In the configuration of the second embodiment, portions that are identical to those in the configuration of the magnetic random access memory of the first embodiment shown inFIG. 1 are denoted by the same reference signs, and detailed description thereof is omitted. - In the first embodiment, the
first sidewall contact 20 is formed by depositing a sidewall contact material to cover thefirst protection films 7, thecontact plug 9, theamorphous film 11, the magnetoresistive element 18, and thesidewall mask 19 and then etching back the sidewall contact material. In the second embodiment, thefirst sidewall contact 20 is formed by subjecting thecontact plug 9 to physical etching to deposit a sidewall contact material onto thecontact plug 9. - Like the first embodiment, as shown in
FIGS. 3A to 4D , select transistors are formed on asemiconductor substrate 1, and then anamorphous film 11, a magnetoresistive element 18, and asidewall mask 19 are formed on acontact plug 9 and afirst protection film 7. - Next, the
contact plug 9 is processed by a physical process such as ion milling. The process is performed until a contact plug material deposited onto thecontact plug 9 by the sputtering effect comes into contact with the side surface of thelower electrode 13. Consequently, afirst sidewall contact 20 is formed which electrically connects thecontact plug 9 and the side surface of the lower electrode to each other, as shown inFIG. 6 . In this case, thecontact plug 9 and thefirst sidewall contact 20 are made of the same material such as W for example. Meanwhile, when thefirst protection film 7 is subjected to the physical process, the material of thefirst protection film 7, which is SiN for example, is deposited onto the side surfaces of theamorphous film 11 andlower electrode 13 as adeposition layer 21. Note that the material of thefirst sidewall contact 20 and the material of thedeposition layer 21 both contain part of the material of the first protection layer and part of the material of thecontact plug 9. Incidentally, IBE may be performed as the physical process. Moreover, instead of the physical process, RIE may be performed under a high-bias condition to process thecontact plug 9. - Thereafter, the same processes as the first embodiment are performed to form the magnetic random access memory.
- As described above, in the second embodiment, the
amorphous film 11 having excellent surface flatness is provided on thecontact plug 9 and thefirst protection film 7, and the magnetoresistive element 18 is provided on theamorphous film 11. Hence, the magnetoresistive element 18 is provided without any stepped portion. Accordingly, a magnetic random access memory can be obtained without reliability degradation. - Further, in the second embodiment, the
first sidewall contact 20 is formed without depositing the sidewall contact material used in the first embodiment. In other words, use of the method of fabricating a magnetic random access memory according to the second embodiment makes it possible to reduce the number of fabrication steps and therefore lowers the fabrication cost. - A magnetic random access memory according to a third embodiment will be described by using
FIG. 7 .FIG. 7 is a cross-sectional view showing the magnetic random access memory according to the third embodiment. In the configuration of the third embodiment, portions that are identical to those in the configuration of the magnetic random access memory of the first embodiment shown inFIG. 1 are denoted by the same reference signs, and detailed description thereof is omitted. - The third embodiment differs from the first embodiment in that a
metal film 22 is provided between thecontact plug 9 andfirst protection film 7 and theamorphous film 11 shown inFIG. 1 . In this case, thefirst sidewall contact 20 is mainly made of the material of themetal film 22. In addition, thefirst sidewall contact 20 also contains the material of thecontact plug 9 and the material of thefirst protection film 7. Note that asecond sidewall contact 23 may be provided in contact with thefirst sidewall contact 20. The composition of thesecond sidewall contact 23 is mainly the same as that of the material of thecontact plug 9. The material of thecontact plug 9 contains part of the material of thecontact plug 9 and part of the material of thefirst protection film 7. - A method of fabricating the magnetic random access memory according to the third embodiment will be described by using
FIG. 8 .FIG. 8 is a cross-sectional view showing a method of fabricating the magnetic random access memory according to the third embodiment. - Like the first embodiment, as shown in
FIGS. 3A to 3D , select transistors,first protection films 7, and acontact plug 9 are formed on asemiconductor substrate 1. - Next, as shown in
FIG. 8A , ametal film 22 is formed on thefirst protection films 7 and thecontact plug 9. In this process, themetal film 22 may be filled in theseam 10. A metal such as Ta, Pt, TiN, W, or TiAlN for example is used for themetal film 22. The surface flatness of themetal film 22 is affected by thecontact plug 9 and therefore may not always be excellent. - Next, as shown in
FIG. 8B , anamorphous film 11 is formed on themetal film 22. Then, like the first embodiment, a magnetoresistive element 18 and asidewall mask 19 are formed on theamorphous film 11. Further, with theupper electrode 17 and thesidewall mask 19 as masks, theamorphous film 11 is etched until themetal film 22 is exposed. - Next, as shown in
FIG. 8C , themetal film 22 is processed by a physical process such as ion milling. By the sputtering effect, a metal having the same composition as themetal film 22 is deposited on thecontact plug 9. As a result, afirst sidewall contact 20 is formed on thecontact plug 9 in such a manner as to be in contact with the side surface of thelower electrode 13. Note that when thefirst sidewall contact 20 is not in contact with the side surface of thelower electrode 13, thecontact plug 9 may also be subjected to a physical process to deposit a contact plug material onto thefirst sidewall contact 20 and form asecond sidewall contact 23 made of W for example. This makes it possible to maintain excellent electrical connection between thecontact plug 9 and the side surface of thelower electrode 13. In a case where thefirst protection film 7 is processed, adeposition layer 21 of SiN for example, which is as the material of thefirst protection film 7, is deposited on thefirst sidewall contact 20. - Thereafter, the same process steps as the first embodiment are performed to form the magnetic random access memory.
- As described above, in the third embodiment, the
amorphous film 11 having excellent surface flatness is provided on themetal film 22, and the magnetoresistive element 18 is provided on theamorphous film 11. Hence, the magnetoresistive element 18 is provided without any stepped portion. Accordingly, a magnetic random access memory can be obtained without reliability degradation. - Further, in the third embodiment, the
metal film 22, which has a large contact area with thecontact plug 9, is provided on thecontact plug 9 and thefirst protection film 7. Accordingly, it is possible to maintain excellent electrical connection between thecontact plug 9 and thefirst sidewall contact 20. - Furthermore, in the third embodiment, the metal film is subjected to a physical process to form the
first sidewall contact 20 that electrically connects thecontact plug 9 and the side surface of thelower electrode 13 with each other. Hence, by changing the film thickness of themetal film 22, the electrical connection between thefirst sidewall contact 20 and the side surface of thelower electrode 13 can be controlled and maintained in a preferable state. - The foregoing first to third embodiments have been described on the assumption that planar select transistors are formed on the
semiconductor substrate 1. However, three-dimensional select transistors such as FINFETs (Fin Field Effect Transistors) for example may be provided instead of the planar transistors. - The foregoing first to third embodiments have been described on the assumption that a free layer is used for the first
magnetic layer 14 and a pinned layer is used for the secondmagnetic layer 16. However, a pinned layer may be used for the firstmagnetic layer 14 and a free layer may be used for the secondmagnetic layer 16 instead. - In the foregoing first to third embodiments, an alignment control film may be provided between the
lower electrode 13 and the firstmagnetic layer 14. A film made of Pt, Ir, Ru, or the like, or a laminate film made of these atoms for example is used for the alignment control film. - In the foregoing first to third embodiments, a magnetization adjustment layer may be provided between the second
magnetic layer 16 and theupper electrode 17. The magnetization adjustment layer is an antiferromagnetic film provided to adjust magnetic field leakage from the pinned layer, suppress a magnetic influence on the free layer, and also fix the magnetization orientation of the pinned layer to a predetermined one orientation. An alloy of Mn with Fe, Ni, Pt, Pd, Ru, Os, or Ir, namely FeMn, NiMn, PtMn, PdMn, PtPdMn, RuMn, OsMn, IrMn, CrPtMn, or the like for example is used for the magnetization adjustment layer. - While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Claims (20)
1. A magnetic random access memory, comprising:
a semiconductor substrate;
a selection transistor provided on the semiconductor substrate, the selection transistor including a diffusion layer on a surface area of the semiconductor substrate;
a contact plug provided on the diffusion layer;
an amorphous film provided on the contact plug;
a lower electrode provided on the amorphous film;
a first magnetic layer provided on the lower electrode;
a nonmagnetic layer provided on the first magnetic layer;
a second magnetic layer provided on the nonmagnetic layer;
an upper electrode provided on the second magnetic layer; and
a sidewall contact film provided on the contact plug, the sidewall contact film being in contact with a sidewall of the lower electrode.
2. The magnetic random access memory of claim 1 , further comprising:
a sidewall mask being in contact with sidewalls of the upper electrode, the second magnetic layer and the nonmagnetic layer, a height of a bottom surface of the sidewall mask being lower than a height of a bottom surface of the second magnetic layer and being higher than a height of a bottom surface of the nonmagnetic layer.
3. The magnetic random access memory of claim 1 , wherein
a sidewall mask is in contact with the sidewalls of the upper electrode, the second magnetic layer and the nonmagnetic layer, and a sidewall of the first magnetic layer, a height of a bottom surface of the sidewall mask being lower than the height of the bottom surface of the nonmagnetic layer and being higher than a height of a bottom surface of the first magnetic layer.
4. The magnetic random access memory of claim 1 , wherein
a sidewall mask being in contact with the sidewalls of the upper electrode, the second magnetic layer, the nonmagnetic layer, the first magnetic layer, and a portion of the sidewall of the lower electrode, a height of a bottom surface of the sidewall mask is lower than the height of the bottom surface of the first magnetic layer and is higher than a height of a bottom surface of the lower electrode.
5. The magnetic random access memory of claim 1 , wherein
the sidewall contact film is composed of a titanium nitride film.
6. The magnetic random access memory of claim 1 , wherein
a seam is provided in the contact plug and the amorphous film is provided in at least a portion of the seam.
7. The magnetic random access memory of claim 1 , wherein
a surface asperity of the amorphous film is 0.2 nm or less.
8. The magnetic random access memory of claim 1 , further comprising;
a metal film provided between the contact plug and the amorphous film, the sidewall contact film including metal composing the metal film.
9. The magnetic random access memory of claim 8 , wherein
the sidewall contact film is constituted with a first sidewall contact film and a second sidewall contact film, the first sidewall contact film is in contact with the sidewall of lower electrode and the second sidewall contact film is in contact with a sidewall of the first sidewall contact film.
10. The magnetic random access memory of claim 9 , wherein
the second sidewall contact film includes metal composing the contact plug.
11. The magnetic random access memory of claim 8 , wherein
the first sidewall contact film is composed of a titanium nitride film.
12. The magnetic random access memory of claim 8 , wherein
the seam is provided in the contact plug and the metal film is provided in at least a portion of the seam.
13. A method of fabricating a magnetic random access memory, comprising;
providing a selection transistor on a semiconductor substrate, the selection transistor including a diffusion layer on a surface of the semiconductor substrate;
providing a contact plug on the diffusion layer;
providing an amorphous film on the contact plug;
polishing a surface of the amorphous film;
providing a lower electrode on the amorphous film;
providing a first magnetic layer on the lower electrode;
providing a nonmagnetic layer on the first magnetic layer;
providing a second magnetic layer on the nonmagnetic layer;
providing an upper electrode on the second magnetic layer;
etching the upper electrode and the second magnetic layer as a first step;
providing a sidewall mask to cover sidewalls of the upper electrode and the second magnetic layer;
etching the nonmagnetic layer, the first magnetic layer, the lower electrode and the amorphous film until exposing a surface of the contact plug as a second step so as to provide a magneto resistive element including the lower electrode, the first magnetic layer, the nonmagnetic layer, the second magnetic layer and the upper electrode; and
providing a sidewall contact on sidewalls of the magneto resistive element and the amorphous film so as to be in contact with the contact plug and the lower electrode.
14. A method of claim 13 , wherein
etching as the first step further includes etching the nonmagnetic layer, etching as the second step includes other than etching the nonmagnetic layer, and the sidewall mask further covers a sidewall of the nonmagnetic layer.
15. A method of claim 14 , wherein
etching as the first step further includes etching the nonmagnetic layer and the first magnetic layer, etching as the second step includes other than etching the nonmagnetic layer and the first magnetic layer, and the sidewall mask further covers the sidewall of the nonmagnetic layer and a sidewall of the first magnetic layer.
16. A method of claim 14 , wherein
etching as the first step further includes etching the nonmagnetic layer, the first magnetic layer and a portion of the lower electrode, etching as the second step includes other than etching the nonmagnetic layer, the first magnetic layer and the portion of the lower electrode, and the sidewall mask covers the sidewalls of the nonmagnetic layer and the first magnetic layer, and a sidewall of the lower electrode.
17. A method of claim 13 , wherein
providing the sidewall contact is constituted with providing a sidewall material which covers the magneto resistive element, and etching the sidewall material on the magneto resistive element.
18. A method of claim 13 , wherein
providing the sidewall contact is constituted with etching the first magnetic layer, the lower electrode and the amorphous film until exposing the surface of the contact plug, and etching the contact plug so as to provide a material of the contact plug to the sidewall of the lower electrode.
19. A method of claim 18 , wherein
etching the first magnetic layer, the lower electrode and the amorphous film, and etching the contact plug so as to provide a material of the contact plug are seriously performed.
20. A method of fabricating a magnetic random access memory, comprising;
providing a selection transistor on a semiconductor substrate, the selection transistor including a diffusion layer on a surface of the semiconductor substrate;
providing a contact plug on the diffusion layer;
providing a metal film on the contact plug;
providing an amorphous film on the metal film;
polishing a surface of the amorphous film;
providing a lower electrode on the amorphous film;
providing a first magnetic layer on the lower electrode;
providing a nonmagnetic layer on the first magnetic layer;
providing a second magnetic layer on the nonmagnetic layer;
providing an upper electrode on the second magnetic layer;
etching the upper electrode, the second magnetic layer and the nonmagnetic layer;
providing a sidewall mask to cover sidewalls of the upper electrode, the second magnetic layer and the nonmagnetic layer;
etching the first magnetic layer, the lower electrode and the amorphous film until exposing a surface of the contact plug;
etching the metal film so as to provide a first sidewall contact containing same metal as the metal film on a sidewall of the lower electrode on the metal film;
etching the contact plug to provide a second sidewall contact being in contact with the first sidewall contact on the contact plug.
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US (2) | US20120193693A1 (en) |
JP (1) | JP2012160671A (en) |
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6714444B2 (en) * | 2002-08-06 | 2004-03-30 | Grandis, Inc. | Magnetic element utilizing spin transfer and an MRAM device using the magnetic element |
US7860351B2 (en) * | 2005-03-25 | 2010-12-28 | Sony Corporation | Spin-injection magnetoresistance effect element |
US8000126B2 (en) * | 2007-01-11 | 2011-08-16 | Renesas Electronics Corporation | Semiconductor device with recording layer containing indium, germanium, antimony and tellurium |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3873015B2 (en) | 2002-09-30 | 2007-01-24 | 株式会社東芝 | Magnetic memory |
JP2004214459A (en) | 2003-01-06 | 2004-07-29 | Sony Corp | Nonvolatile magnetic memory and its fabricating process |
KR100552690B1 (en) * | 2003-09-26 | 2006-02-20 | 삼성전자주식회사 | Magnetic random access memory comprising MTJ layer having uniform tunneling film in thickness and method of manufacturing the same |
JP2005183579A (en) | 2003-12-18 | 2005-07-07 | Canon Inc | Manufacturing method for semiconductor device, and the semiconductor device |
KR100719345B1 (en) * | 2005-04-18 | 2007-05-17 | 삼성전자주식회사 | Methods of forming a magnetic memory device |
-
2011
- 2011-02-02 JP JP2011021210A patent/JP2012160671A/en active Pending
- 2011-09-16 US US13/235,272 patent/US20120193693A1/en not_active Abandoned
-
2013
- 2013-10-10 US US14/051,404 patent/US9076720B2/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6714444B2 (en) * | 2002-08-06 | 2004-03-30 | Grandis, Inc. | Magnetic element utilizing spin transfer and an MRAM device using the magnetic element |
US7860351B2 (en) * | 2005-03-25 | 2010-12-28 | Sony Corporation | Spin-injection magnetoresistance effect element |
US8000126B2 (en) * | 2007-01-11 | 2011-08-16 | Renesas Electronics Corporation | Semiconductor device with recording layer containing indium, germanium, antimony and tellurium |
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US9076720B2 (en) | 2015-07-07 |
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