CN102222738A - Method for manufacturing GaN (gallium nitride) substrate material - Google Patents

Method for manufacturing GaN (gallium nitride) substrate material Download PDF

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Publication number
CN102222738A
CN102222738A CN2011101710220A CN201110171022A CN102222738A CN 102222738 A CN102222738 A CN 102222738A CN 2011101710220 A CN2011101710220 A CN 2011101710220A CN 201110171022 A CN201110171022 A CN 201110171022A CN 102222738 A CN102222738 A CN 102222738A
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China
Prior art keywords
resilient coating
gallium nitride
manufacture method
backing material
etching
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CN2011101710220A
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张汝京
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XI'AN SHENGUANG ANRUI OPTOELECTRONIC TECHNOLOGY Co Ltd
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XI'AN SHENGUANG ANRUI OPTOELECTRONIC TECHNOLOGY Co Ltd
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Abstract

The invention discloses a method for manufacturing a GaN (gallium nitride) substrate material, comprising the following steps: providing a substrate; forming a buffer layer on the substrate; etching the buffer layer, so that a plurality of grooves are formed on the buffer layer; forming a second buffer layer, wherein the second buffer layer covers the surface of one side with the grooves on the buffer layer, thus cavities are formed in the second buffer layer in the grooves; forming a GaN layer on the second buffer layer; and eliminating the substrate, the first buffer layer and the second buffer layer. Due to the existence of the cavities, the dislocation density of the GaN layer is reduced and the stress in the GaN layer is released, thereby forming the GaN layer with fewer defects.

Description

The manufacture method of gallium nitride backing material
Technical field
The present invention relates to the semiconductor light emitting field, particularly relate to a kind of manufacture method of gallium nitride backing material.
Background technology
Light-emitting diode is applied to various fields owing to have long, low power consumption and other advantages of life-span, and especially along with its illumination performance index day by day significantly improves, light-emitting diode is commonly used for light-emitting device at lighting field.Wherein, be the III-V compound semiconductor of representative with gallium nitride (GaN) because have that band gap is wide, luminous efficiency is high, characteristics such as electronics saturation drift velocity height, chemical property are stable, in the high-luminance light field of electronic devices huge application potential is arranged, caused people's extensive concern.
See also Fig. 1, Fig. 1 is a kind of cross-sectional view of light-emitting diode of prior art.Described light-emitting diode comprises substrate 11, resilient coating (buffer layer) 12, N type contact layer (N contact layer) 13, N type cover layer (N active layer) 14, active layer (light emitting layers) 15, P type cover layer (P active layer) 16, P type contact layer (P contact layer) 17, the positive electrode 18 that is connected with described P type contact layer 17 and the negative electrode 19 that is connected with described N type contact layer 13.Described light-emitting diode is that two heterogeneous (wherein double-heterostructure comprises for Double Heterogeneous, the DH) light-emitting diode of structure: N type cover layer 14, active layer 15 and P type cover layer 16.Described active layer 15 is the luminescent layer of described light-emitting diode.Described N type cover layer 14 is a N type doped gallium nitride layer, and described P type cover layer 16 is a P type doped gallium nitride layer.Similarly, U.S. Pat 5777350 has also been announced a kind of nitride semiconductor photogenerator.
Yet, because gallium nitride body monocrystalline is difficult to acquisition, so the growth of gallium nitride material is at present mainly passed through at sapphire (Sapphire, Al 2O 3) means of carrying out heteroepitaxy on the substrate obtain, topmost growth technology has metal oxide chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE) and halide vapour phase epitaxy (HVPE) etc.But, because Sapphire Substrate and epitaxial layer of gallium nitride exist very big lattice mismatch (lattice mismatch) and heat expansion mismatch, so can in epitaxial layer of gallium nitride, introduce a large amount of dislocation (dislocation) inevitably, reduce the internal quantum efficiency of device.
Therefore, be necessary to provide a kind of manufacture method of gallium nitride backing material, to form high-quality gallium nitride backing material.
Summary of the invention
The invention provides a kind of manufacture method of gallium nitride backing material, to form few, the high-quality gallium nitride backing material of defective.
For solving the problems of the technologies described above, the invention provides a kind of manufacture method of gallium nitride backing material, comprising: a substrate is provided; On described substrate, form first resilient coating; Described first resilient coating of etching makes described first buffer-layer surface form a plurality of grooves; Form second resilient coating, described second resilient coating covers the surface that described first resilient coating has groove one side, makes to be formed with the cavity in second resilient coating in the described groove; On described second resilient coating, form gallium nitride layer; Remove described substrate, first resilient coating and second resilient coating.
Optionally, in the manufacture method of described gallium nitride backing material, the depth-width ratio of described groove was more than or equal to 1.2: 1.
Optionally, in the manufacture method of described gallium nitride backing material, adopt described first resilient coating of mode etching of no mask inductive couple plasma reactive ion etching.
Optionally, in the manufacture method of described gallium nitride backing material, in the step of described first resilient coating of etching, etching gas is the mixture of boron chloride and chlorine, chamber pressure is 5~100mTorr, and backplane power is 200~400W, and coil power is 100~200W.
Optionally, in the manufacture method of described gallium nitride backing material, utilize the mode of metallo-organic compound chemical vapour deposition (CVD) on described substrate, to form first resilient coating.
Optionally, in the manufacture method of described gallium nitride backing material, form in the step of first resilient coating, chamber pressure is 100~600Torr, and temperature is 500~800 ℃.
Optionally, in the manufacture method of described gallium nitride backing material, utilize the mode of metallo-organic compound chemical vapour deposition (CVD) to form second resilient coating.
Optionally, in the manufacture method of described gallium nitride backing material, form in the step of second resilient coating, chamber pressure is 100~1000mTorr, and temperature is 800~1000 ℃.
Optionally, in the manufacture method of described gallium nitride backing material, utilize the mode of metallo-organic compound chemical vapour deposition (CVD) to form described gallium nitride layer.
Optionally, in the manufacture method of described gallium nitride backing material, form in the step of described gallium nitride layer, chamber pressure is 400~760Torr, and temperature is 800~1400 ℃.
Optionally, in the manufacture method of described gallium nitride backing material, the material of described substrate is sapphire, carborundum, silicon, zinc oxide, GaAs or spinelle.
Optionally, in the manufacture method of described gallium nitride backing material, the step of removing described substrate, first resilient coating and second resilient coating comprises: utilize the mode of laser lift-off or wet etching to remove described substrate; And utilize the mode of grinding to remove first resilient coating and second resilient coating.
Optionally, in the manufacture method of described gallium nitride backing material, the etching liquid that described wet-etching technology adopts is the mixed liquor of sulfuric acid and phosphoric acid.
Compared with prior art, the present invention is formed with a plurality of grooves on the surface of contiguous second resilient coating of described first resilient coating, on described first resilient coating, form second resilient coating afterwards, make and be formed with the cavity in second resilient coating in the described groove, because the existence in described cavity, dislocation in the gallium nitride layer of follow-up formation is absorbed (dislocation trapping), thereby reduced the dislocation density (dislocation density) of gallium nitride layer, discharge the stress in the gallium nitride layer, can form less, the high-quality gallium nitride layer of defective thus.
Description of drawings
Fig. 1 is a kind of cross-sectional view of light-emitting diode of prior art.
Fig. 2 is the flow chart of the manufacture method of gallium nitride backing material of the present invention.
Fig. 3 is each step schematic diagram of the manufacture method of gallium nitride backing material of the present invention to Fig. 8.
Fig. 9 is the vertical view of groove of the present invention.
Figure 10 is the enlarged diagram that the manufacture method of gallium nitride backing material of the present invention forms empty step.
Embodiment
Core concept of the present invention is, be formed with a plurality of grooves by surface at contiguous second resilient coating of described first resilient coating, on described first resilient coating, form second resilient coating afterwards, make and be formed with the cavity in second resilient coating in the described groove, because the existence in described cavity, the dislocation in the gallium nitride layer of follow-up formation is absorbed, thereby has reduced the dislocation density of gallium nitride layer, discharge the stress in the gallium nitride layer, can form less, the high-quality gallium nitride layer of defective thus.
See also Fig. 2, it is the flow chart of the manufacture method of gallium nitride backing material of the present invention.The manufacture method of described gallium nitride backing material may further comprise the steps:
Step S10 a: substrate is provided;
Step S20: on described substrate, form first resilient coating;
Step S30: described first resilient coating of etching makes described first buffer-layer surface form a plurality of grooves;
Step S40: form second resilient coating, described second resilient coating covers the surface that described first resilient coating has groove one side, makes to be formed with the cavity in second resilient coating in the described groove;
Step S50: on described second resilient coating, form gallium nitride layer;
Step S60: remove described substrate, first resilient coating and second resilient coating.
To Fig. 8, describe the manufacture method of gallium nitride backing material of the present invention below in conjunction with Fig. 3 in detail.
As shown in Figure 3, at first, provide a substrate 100.The material of described substrate 100 can be sapphire, carborundum (SiC), silicon, zinc oxide (ZnO), GaAs (GaAs), spinelle (MgAL 2O 4), and lattice constant is near the monocrystalline nitride of nitride-based semiconductor.Preferably, described substrate 100 is Sapphire Substrate or silicon substrate.Before forming first resilient coating 110, one deck aln layer 101 of can on described substrate 100, growing earlier.
As shown in Figure 4, then, go up formation first resilient coating 110 at described substrate 100 (being aln layer 101 in the present embodiment).Described first resilient coating 110 can adopt the manufacture method of prior art to form, and forms as the method that adopts the metallo-organic compound chemical vapour deposition (CVD).
In the present embodiment, form in the step of described first resilient coating 110, chamber pressure for example is 100~600Torr, and temperature is 500~800 ℃, and the thickness of described first resilient coating 110 for example is 1~10 μ m.Owing to have very big lattice mismatch (lattice mismatch) and heat expansion mismatch between the described substrate 100 and first resilient coating 110, so can in first resilient coating 110, introduce a large amount of dislocations (dislocation) 111 inevitably.
As shown in Figure 5, then, adopt described first resilient coating 110 of mode etching of no mask inductive couple plasma reactive ion etching, because it is very fast that first resilient coating 110 has the regional etch rate of dislocation, and dislocation-free zone etch rate is relatively slow, therefore forms a plurality of groove 110a on the surface of described first resilient coating 110.
In the present embodiment, in etching process, etching gas for example is boron chloride (BCl 3) and chlorine (Cl 2) mixture, chamber pressure is 5~100mTorr, backplane power is 200 to 400 watts, coil power is 100 to 200 watts, the flow of boron chloride is 5~50sccn, the flow of chlorine is 10~100sccm.Preferably, as Fig. 6 and shown in Figure 9, the depth-width ratio of described groove 110a was more than or equal to 1.2: 1, and the height of described groove 110a (being meant maximum height in the present embodiment) H is 1~3 μ m, the width W of described groove 110a is 1~2 μ m, and the length L of described groove 110a is 1~10 μ m.The density of described groove 110a is more than or equal to 10 8/ cm 2, can be formed with a cavity 121 in each groove 110a, corresponding, the density in cavity 121 is also more than or equal to 10 8/ cm 2, the density of the linear dislocation of epitaxial loayer can be reduced to 10 at least 7/ cm 2Below.
As shown in Figure 6, on described first resilient coating 110, form after the groove 110a, a side surface that has groove 110a at described first resilient coating 110 forms second resilient coating 120, described second resilient coating 120 can adopt the manufacture method of prior art to form, and forms as the method that adopts the metallo-organic compound chemical vapour deposition (CVD).In conjunction with shown in Figure 10, because due to the characteristic of depositing operation, in the process that forms described second resilient coating 120, (near last second resilient coating of the relatively easy covering recess sidewall) can't complete filling be arrived in the groove center, progressively deposition along with second resilient coating, wherein be formed centrally the cavity and tend towards stability gradually in the top, level and smooth and the center has second resilient coating 120 in cavity until the final top that formed.
Wherein, it is hundreds of to dusts up to ten thousand that the thickness of described first resilient coating 110 and second resilient coating 120 is generally, and material is generally gallium nitride or aluminium nitride (AlN).Preferably, when described substrate 100 was Sapphire Substrate, described first resilient coating 110 and second resilient coating 120 were gallium nitride (LT GaN) layer of growth under the cryogenic conditions; When described substrate 100 was silicon substrate, described first resilient coating 110 and second resilient coating 120 were aln layer; Again or, when described substrate 100 is silicon substrate, elder generation is growth one deck aln layer 101 on described substrate 100, form first resilient coating 110 and second resilient coating 120 then on described aln layer 101, described first resilient coating 110 and second resilient coating 120 are all selected the gallium nitride of growth under the cryogenic conditions for use.In the process that forms described second resilient coating 120, make to be filled in the second interior resilient coating 120 of described groove 110a to have formed cavity 121.
As shown in Figure 7, form after described second resilient coating 120, on described second resilient coating 120, form gallium nitride layer 130.Because described empty 121 existence, linear dislocation in the gallium nitride layer 130 is terminated in these cavities, and promptly the dislocation in the gallium nitride layer 130 is absorbed, thereby has reduced the dislocation density of gallium nitride layer 130, discharge the stress in the gallium nitride layer 130, can form the less gallium nitride layer of defective thus.
In the present embodiment, can utilize the mode of metallo-organic compound chemical vapour deposition (CVD) (MOCVD) on resilient coating 110, to form gallium nitride layer 130.Wherein, described MOCVD technology can adopt higher temperature and lower chamber pressure, with the deposition rate of quickening MOCVD technology, and then enhances productivity.For example, the temperature of described MOCVD technology is 800~1400 ℃, and chamber pressure is 400~760torr, and deposition rate can be greater than 10 μ m/hour.Preferably, the thickness of described gallium nitride layer 130 is 100 μ m~10cm.
As shown in Figure 8, on described second resilient coating 120, form after the gallium nitride layer 130, can directly remove substrate 100, first resilient coating 110 and second resilient coating 120, and only keep few, the high-quality gallium nitride layer 130 of defective.Described gallium nitride layer 130 can be used as backing material, is used to make devices such as light-emitting diode.
In the present embodiment, removing step can carry out in two steps: at first, can utilize the mode of laser lift-off (laser lift-off) or wet etching to remove substrate 100, described laser lift-off focuses on a certain interface, utilize high temperature that the material of focusing place is melted, thereby substrate 100 is peeled off, and the etching liquid that described wet-etching technology adopts is sulfuric acid and phosphoric acid mixed liquor; Then, can utilize the mode of grinding to remove first resilient coating 110 and second resilient coating 120, thereby only keep few, the high-quality gallium nitride layer of defective; Certainly, in other specific embodiment of the present invention, also can utilize the mode of laser lift-off or wet etching to remove substrate 100 and partial buffer layer earlier, and then remove remaining resilient coating.
Under situation without departing from the spirit and scope of the present invention, can also constitute many very embodiment of big difference that have.Should be appreciated that except as defined by the appended claims, the present invention is not limited at the specific embodiment described in the specification.

Claims (13)

1. the manufacture method of a gallium nitride backing material is characterized in that, comprising:
One substrate is provided;
On described substrate, form first resilient coating;
Described first resilient coating of etching makes described first buffer-layer surface form a plurality of grooves;
Form second resilient coating, described second resilient coating covers the surface that described first resilient coating has groove one side, makes to be formed with the cavity in second resilient coating in the described groove;
On described second resilient coating, form gallium nitride layer;
Remove described substrate, first resilient coating and second resilient coating.
2. the manufacture method of gallium nitride backing material as claimed in claim 1 is characterized in that, the depth-width ratio of described groove was more than or equal to 1.2: 1.
3. the manufacture method of gallium nitride backing material as claimed in claim 1 or 2 is characterized in that, adopts described first resilient coating of mode etching of no mask inductive couple plasma reactive ion etching.
4. the manufacture method of gallium nitride backing material as claimed in claim 3 is characterized in that, in the step of described first resilient coating of etching, etching gas is the mixture of boron chloride and chlorine, chamber pressure is 5~100mTorr, and backplane power is 200~400W, and coil power is 100~200W.
5. the manufacture method of gallium nitride backing material as claimed in claim 1 or 2 is characterized in that, utilizes the mode of metallo-organic compound chemical vapour deposition (CVD) to form first resilient coating on described substrate.
6. the manufacture method of gallium nitride backing material as claimed in claim 5 is characterized in that, forms in the step of first resilient coating, and chamber pressure is 100~600Torr, and temperature is 500~800 ℃.
7. the manufacture method of gallium nitride backing material as claimed in claim 1 or 2 is characterized in that, utilizes the mode of metallo-organic compound chemical vapour deposition (CVD) to form second resilient coating.
8. the manufacture method of gallium nitride backing material as claimed in claim 7 is characterized in that, forms in the step of second resilient coating, and chamber pressure is 100~1000mTorr, and temperature is 800~1000 ℃.
9. the manufacture method of gallium nitride backing material as claimed in claim 1 or 2 is characterized in that, utilizes the mode of metallo-organic compound chemical vapour deposition (CVD) to form gallium nitride layer on described second resilient coating.
10. the manufacture method of gallium nitride backing material as claimed in claim 9 is characterized in that, forms in the step of described gallium nitride layer, and chamber pressure is 400~760Torr, and temperature is 800~1400 ℃.
11. the manufacture method of gallium nitride backing material as claimed in claim 1 is characterized in that, the material of described substrate is sapphire, carborundum, silicon, zinc oxide, GaAs or spinelle.
12. the manufacture method of gallium nitride backing material as claimed in claim 1 is characterized in that, the step of removing described substrate, first resilient coating and second resilient coating comprises:
Utilize the mode of laser lift-off or wet etching to remove described substrate; And
Utilize the mode of grinding to remove first resilient coating and second resilient coating.
13. the manufacture method of gallium nitride backing material as claimed in claim 12 is characterized in that, the etching liquid that described wet-etching technology adopts is the mixed liquor of sulfuric acid and phosphoric acid.
CN2011101710220A 2011-06-23 2011-06-23 Method for manufacturing GaN (gallium nitride) substrate material Pending CN102222738A (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103390699A (en) * 2012-05-09 2013-11-13 华夏光股份有限公司 Light-emitting diode and manufacturing method thereof
CN103887379A (en) * 2014-03-28 2014-06-25 西安神光皓瑞光电科技有限公司 Method for reducing GaN epitaxial defects through wet etching
CN104037290A (en) * 2014-05-23 2014-09-10 南昌大学 Epitaxy structure of AlyInxGa1-x-yN film, and growth method
CN105552182A (en) * 2016-03-09 2016-05-04 太原理工大学 Preparation method of high-luminous-efficiency gallium-nitride-based LED epitaxial wafer
CN106435721A (en) * 2016-09-22 2017-02-22 东莞市联洲知识产权运营管理有限公司 GaAs/Si epitaxial material preparation method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6380108B1 (en) * 1999-12-21 2002-04-30 North Carolina State University Pendeoepitaxial methods of fabricating gallium nitride semiconductor layers on weak posts, and gallium nitride semiconductor structures fabricated thereby

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6380108B1 (en) * 1999-12-21 2002-04-30 North Carolina State University Pendeoepitaxial methods of fabricating gallium nitride semiconductor layers on weak posts, and gallium nitride semiconductor structures fabricated thereby

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103390699A (en) * 2012-05-09 2013-11-13 华夏光股份有限公司 Light-emitting diode and manufacturing method thereof
CN103887379A (en) * 2014-03-28 2014-06-25 西安神光皓瑞光电科技有限公司 Method for reducing GaN epitaxial defects through wet etching
CN104037290A (en) * 2014-05-23 2014-09-10 南昌大学 Epitaxy structure of AlyInxGa1-x-yN film, and growth method
CN104037290B (en) * 2014-05-23 2017-01-18 南昌大学 Epitaxy structure of AlyInxGa1-x-yN film, and growth method
CN105552182A (en) * 2016-03-09 2016-05-04 太原理工大学 Preparation method of high-luminous-efficiency gallium-nitride-based LED epitaxial wafer
CN106435721A (en) * 2016-09-22 2017-02-22 东莞市联洲知识产权运营管理有限公司 GaAs/Si epitaxial material preparation method

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Application publication date: 20111019