BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention generally relate to an electrochemical processing system and methods for electrochemically depositing conductive materials on substrates.
2. Description of the Related Art
Metallization of sub-quarter micron sized features is a foundational technology for present and future generations of integrated circuit manufacturing processes. More particularly, in devices such as ultra large scale integration-type devices, i.e., devices having integrated circuits with more than a million logic gates, the multilevel interconnects that lie at the heart of these devices are generally formed by filling high aspect ratio, i.e., greater than about 4:1, interconnect features with a conductive material, such as copper or aluminum. Conventionally, deposition techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD) have been used to fill these interconnect features. However, as the interconnect sizes decrease and aspect ratios increase, void-free interconnect feature fill via conventional metallization techniques becomes increasingly difficult. Therefore, plating techniques, i.e., electrochemical plating (ECP) and electroless plating, have emerged as promising processes for void free filling of sub-quarter micron sized high aspect ratio interconnect features in integrated circuit manufacturing processes.
In an ECP process, for example, sub-quarter micron sized high aspect ratio features formed into the surface of a substrate (or a layer deposited thereon) may be efficiently filled with a conductive material, such as copper. ECP plating processes are generally two stage processes, wherein a seed layer is first formed over the surface features of the substrate, and then the surface features of the substrate are exposed to an electrolyte solution, while an electrical bias is applied between the seed layer and a copper anode positioned within the electrolyte solution. The electrolyte solution generally contains ions to be plated onto the surface of the substrate, and therefore, the application of the electrical bias causes these ions to be urged out of the electrolyte solution and to be plated onto the biased seed layer, thus depositing a layer of the ions on the substrate surface that may fill the features. Electrolyte solutions also include chemical components to improve ion transition into and out of the electrolyte solution, to improve deposition rates, and to develop desired deposition profiles.
However, electrolyte solutions are sensitive to the changes in the levels of components of the composition. Minor changes in the compositions may result in compositions having variable deposition rates and less than desirable deposition profiles. Prior processes for introducing chemical components to electrolyte compositions have less than desired results, including concentration spikes and non-uniformity of electrolyte composition at the point of use. The prior processes can result in less than desirous deposition results, and excess use of electrolyte composition, which can result in increase cost of consumables and operation costs.
Additionally, previous systems for precisely measuring volumes to be added to electrolyte solutions have utilized fixed volumes of deliveries, which are unsuitable for effectively and efficiently instituting changes in constituent composition of electrolyte solutions without hardware modification.
- SUMMARY OF THE INVENTION
Therefore, there is a need for an improved electrochemical plating system configured to provide electrolyte compositions for an electrochemical plating process.
Embodiments of the invention generally provide an electrochemical processing system configured to provide measured amounts of chemical components, electrolyte compositions, or both for a plating process or other chemical processes including surface preparation processes, such as substrate cleaning, etching or deoxidizing. In one aspect, a method is provided for supplying a fluid to a substrate processing apparatus including measuring a first level in the vessel with a first ultrasonic signal to provide a first volume measurement, delivering at least one chemical component to the vessel, measuring a second level in the vessel with a second ultrasonic signal to provide a second volume measurement, determining the difference in volume between the first volume measurement and the second volume measurement, comparing the difference in volume with a pre-determined value, and discharging chemical components from the vessel to the substrate processing apparatus.
In another aspect, a method is provided for electroplating at least one layer onto a surface of a substrate surface including positioning the substrate in a plating cell on a unitary system platform for a plating technique, supplying an electrolyte composition to the plating cell by supplying an electrolyte and an amount of one or more chemical components, wherein the amount of one or more chemical components are provided by measuring the first level of a vessel with a first ultrasonic signal to provide a first volume measurement, delivering at least one chemical component to the vessel, measuring a second level in the vessel with a second ultrasonic signal to provide a second volume measurement, determining the difference in volume between the first volume measurement and the second volume measurement, comparing the difference in volume with a pre-determined value, and discharging chemical components from the vessel to the plating cell, and depositing a conductive material from the electrolyte composition to the surface of the substrate.
In another aspect, an electrochemical processing system is provided including a system platform having one or more processing cells positioned thereon, at least one robot positioned to transfer substrates between the one or more processing cells, and a fluid delivery system in fluid communication with each of the one or more processing cells, the fluid delivery system including one or more chemical component sources, a metering pump in fluid communication with each of the chemical component sources, an electrolyte source in fluid communication with the metering pump, and a vessel in fluid communication with the metering pump at an input and with the one or more processing cells at an output, the vessel comprising a charging cell, an ultrasonic sensor, and a controller.
BRIEF DESCRIPTION OF THE DRAWINGS
In another aspect, an electrochemical processing system is provided including a processing system base having one or more process cell locations thereon, at least two electrochemical plating cells positioned at two of the process cell locations, at least one spin rinse dry cell positioned at one of the process cell locations, at least one substrate bevel clean cell positioned at another one of the process cell locations, and a fluid delivery system in fluid communication with each of the one or more processing cells, the fluid delivery system including one or more chemical component sources, a metering pump in fluid communication with each of the chemical component sources, a first virgin electrolyte source in fluid communication with the metering pump, and a vessel in fluid communication with the metering pump at an input and with one or more processing cells at an output, the vessel comprising a charging cell, an ultrasonic sensor, and a controller.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a top plan view of one embodiment of an electrochemical plating system of the invention;
FIG. 2A is a partial sectional view of one embodiment of an electrochemical process cell;
FIG. 2B is a partial sectional view of another embodiment of an electrochemical process cell;
FIG. 3 is a schematic diagram of one embodiment of a plating solution delivery system;
FIG. 4A is a schematic diagram of one embodiment of a volume measurement device;
FIG. 4B is a perspective view of one embodiment of a volume measurement device;
FIG. 5 is a partial sectional view of one embodiment of a process cell configured to remove deposited material from an edge of a substrate;
FIG. 6 is a partial sectional view of one embodiment of a process cell configured to spin, rinse and dry a substrate; and
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 7 is a flow diagram illustrating one embodiment of a process for monitoring chemical component volume.
Embodiments of the invention generally provide an electrochemical plating system configured to plate conductive materials, such as metals, on a semiconductor substrate using a device for accurately measuring component quantities, for example, for use in apparatus implementing multiple chemistries on a single plating platform. Embodiments of the invention contemplate that the measurement device may be used for measuring, adding, or mixing chemical components for various plating processes, including, but not limited to direct plating on a barrier layer, alloy plating, alloy plating combined with convention metal plating, plating on a thin seed layer, optimized feature fill and bulk fill plating, plating multiple layers with minimal defects, or any other plating process where more than one chemistry may be beneficial to a plating process.
While the following description of the volume measurement device is directed to use in an electrochemical processing system (ECP), the invention contemplates the use of the invention where precise volumes of liquids may be added to form processing composition. For example the volume measurement device may be used in combination with chemical mechanical polishing apparatus, such as the Mirra® Mesa™ polishing system and the Reflexion™ processing system, commercially available from Applied Materials, Inc., of Santa Clara, Calif., wet clean process apparatus, such as the Tempest™ wet clean apparatus available from Applied Materials, Inc., of Santa Clara, Calif., and other liquid processing systems.
FIG. 1 is a top plan view of one embodiment of an electrochemical processing system (ECP) 100 of the present invention. ECP system 100 generally includes a processing base 113 having a robot 120 centrally positioned thereon. The robot 120 generally includes one or more robot arms 122, 124 configured to support substrates thereon. Additionally, the robot 120 and the accompanying blades 122, 124 are generally configured extend, rotate, and vertically move so that the robot 120 may insert and remove substrates to and from a plurality of processing locations 102, 104, 106, 108, 110, 112, 114, 116 positioned on the base 113.
ECP system 100 further includes a factory interface (FI) 130. FI 130 generally includes at least one FI robot 132 positioned adjacent a side of the FI that is adjacent the processing base 113. This position of robot 132 allows the robot to access substrate cassettes l34 to retrieve a substrate 126 therefrom and then deliver the substrate 126 to one of processing cells 114, 116 to initiate a processing sequence. Similarly, robot 132 may be used to retrieve substrates from one of the processing cells 114, 116 after a substrate processing sequence is complete. In this situation robot 132 may deliver the substrate 126 back to one of the cassettes 134 for removal from the system 100. Additionally, robot 132 is also configured to access an anneal chamber 135 positioned in communication with FI 130. The anneal chamber 135 generally includes a two position annealing chamber, wherein a cooling plate-or position 136 and a heating plate or position 137 are positioned adjacently with a substrate transfer robot 140 positioned proximate thereto, e.g., between the two stations. The robot 140 is generally configured to move substrates between the respective heating 137 and cooling plates 136.
Generally, process locations 102, 104, 106, 108, 110, 112, 114, 116 may be any number of processing cells utilized in an electrochemical plating platform. More particularly, the process locations may be configured as electrochemical plating cells, rinsing cells, bevel clean cells, spin rinse dry cells, substrate surface cleaning cells, electroless plating cells, metrology inspection stations, and other cells or processes that may be beneficially used in conjunction with a plating platform.
FIG. 2A is a cross sectional view of one embodiment of a processing cell (FIG. 2A illustrates an exemplary electrochemical plating cell) that may be implemented in any one of processing locations 102, 104, 106, 108, 110, 112, 114, 116 of processing system 100 as shown in FIG. 1. Generally, however, the exemplary processing system 100 is configured to include four electrochemical plating cells at processing locations 102, 104, 112, and 110. Processing locations 106 and 108 are generally configured as edge bead removal or bevel clean chambers. Further, processing locations 114 and 116 are generally configured as substrate surface cleaning chambers and spin rinse dry chambers, which may be positioned in a stacked manner, i.e., one above the other. However, the invention is not intended to be limited to any particular order or arrangement of cells, as various combinations and arrangements may be implemented without departing from the scope of the invention.
Returning to FIG. 2A, the electrochemical processing cell 150 generally includes a head assembly 211, an anode assembly 220, an inner basin 272, and an outer basin 240. The outer basin 240 is coupled to a base 160 and circumscribes the inner basin 272. The inner and outer basins 272, 240 are typically fabricated from an electrically insulative material compatible with process chemistries, for example, ceramics, plastics, plexiglass (acrylic), lexane, PVC, CPVC or PVDF. Alternatively, the inner and outer basins 272, 240 may be made from a metal, such as stainless steel, nickel or titanium, which is coated with an insulating layer, such as Teflon®, fluoropolymer, PVDF, plastic, rubber and other combinations of materials compatible with plating fluids and can be electrically insulated from the electrodes (i.e., the anode and cathode of the electroplating system). The inner basin 272 is typically configured to conform to the substrate plating surface and the shape of the substrate being processed through the system, generally having a circular or rectangular shape. In one embodiment, the inner basin 272 is a cylindrical ceramic tube having an inner diameter that has about the same dimension as or slightly larger than the diameter of a substrate being plated in the cell 150. The outer basin 272 generally includes a channel 248 for catching plating fluids flowing out of the inner basin 272. The outer basin 272 also has a drain 218 formed therethrough that couples the channel 248 to a reclamation system for processing, recycling and/or disposal of used plating fluids.
The head assembly 211 is mounted to a head assembly frame 252. The head assembly frame 252 includes a mounting post 254 and a cantilever arm 256. The mounting post 254 is coupled to the base 160 and the cantilever arm 256 extends laterally from an upper portion of the mounting post 254 and is generally adapted to rotate about a vertical axis of the mounting post 254 to allow movement of the head assembly 211 over or clear of the basins 240, 272. The head assembly 211 is generally attached to a mounting plate 260 disposed at the distal end of the cantilever arm 256. The lower end of the cantilever arm 256 is connected to a cantilever arm actuator 268, such as a pneumatic cylinder, mounted on the mounting post 254. The cantilever arm actuator 268 provides pivotal movement of the cantilever arm 256 with respect to the joint between the cantilever arm 256 and the mounting post 254. When the cantilever arm actuator 268 is retracted, the cantilever arm 256 moves the head assembly 211 away from the anode assembly 220 disposed in the inner basin 272 to provide the spacing required to remove and/or replace the anode assembly 220 from the first process cell 150. When the cantilever arm actuator 268 is extended, the cantilever arm 256 moves the head assembly 211 axially toward the anode assembly 220 to position the substrate in the head assembly 211 in a processing position. The head assembly 211 may also tilt to orientate a substrate held therein in at an angle from horizontal.
The head assembly 211 generally includes a substrate holder assembly 250 and a substrate assembly actuator 258. The substrate assembly actuator 258 is mounted onto the mounting plate 260, and includes a head assembly shaft 262 that extends downwardly through the mounting plate 260. The lower end of the head assembly shaft 262 is connected to the substrate holder assembly 250 to position the substrate holder assembly 250 in a processing position and in a substrate loading position. The substrate assembly actuator 258 additionally may be configured to provide rotary motion to the head assembly 211. In one embodiment, the head assembly 211 is rotated between about 2 rpm and about 50 rpm during an electroplating process, and may be rotated between about 5 and about 20 rpm. The head assembly 211 can also be rotated as the head assembly 211 is lowered to position the substrate in contact with the plating solution in the process cell as well as when the head assembly 211 is raised to remove the substrate from the plating solution in the process cell. The head assembly 211 may be rotated at a high speed (i.e., >20 rpm) after the head assembly 211 is lifted from the process cell to enhance removal of residual plating solution from the head assembly 211 and substrate.
The substrate holder assembly 250 generally includes a thrust plate 264 and a cathode contact ring 266. The cathode contact ring 266 is configured to electrically contact the surface of the substrate to be plated. Typically, the substrate has a seed layer of metal, such as copper, deposited on the feature side of the substrate. A power source 246 is coupled between the cathode contact ring 266 and the anode assembly 220 and provides an electrical bias that drives the plating process.
The thrust plate 264 and the cathode contact ring 266 are suspended from a hanger plate 236. The hanger plate 236 is coupled to the head assembly shaft 262. The cathode contact ring 266 is coupled to the hanger plate 236 by hanger pins 238. The hanger pins 238 allows the cathode contact ring 266 when mated against the inner basin 272, to move to closer to the hanger plate 236, thus allowing the substrate held by the thrust plate 264 to be sandwiched between the hanger plate 236 and thrust plate 264 during processing, thereby ensuring good electrical contact between the seed layer of the substrate and the cathode contact ring 266.
The anode assembly 220 is generally positioned within a lower portion of the inner basin 272 below the substrate holder assembly 250. The anode assembly 220 generally includes one or more anodes 244 and a diffusion plate 222. The anode 244 is typically disposed in the lower end of the inner basin 272 and the diffusion plate 222 is disposed between the anode 244 and the substrate held by the substrate holder assembly 250 at the top of the inner basin 272. The anode 244 and diffusion plate 222 are generally maintained in a spaced-apart relation by insulative spacer 224. The diffusion plate 222 is typically attached to and substantially spans the inner opening of the inner basin 272. The diffusion plate 222 is generally permeable to the plating solution and is typically fabricated from a plastic or ceramic material, for example an olefin such as a spunbonded polyester film: The diffusion plate 222 generally operates as a fluid flow restrictor to improve flow uniformity across the surface of the substrate 126 being plated. The diffusion plate 222 also operates to damp electrical variations in the electrochemical cell, i.e., to control electrical flux, which improves plating uniformity. Alternatively, the diffusion plate 222 may be: fabricated from a hydrophilic plastic, such as treated PE, PVDF, PP, or other porous or permeable material that provides electrically resistive damping characteristics.
The anode assembly 220 may include a consumable anode 244 that serves as a metal source for the plating process. Alternatively, the anode 244 may be a non-consumable anode, and the metal to be electroplated is supplied within the plating solution from the plating solution delivery system 111. The anode assembly 220 may be a self-enclosed module having a porous enclosure preferably made of the same metal as the metal to be electroplated, such as copper. Alternatively, the enclosure may be fabricated from porous materials, such as ceramics or polymeric membranes. Exemplary consumable and non-consumable anodes include copper/doped copper and platinum, respectively. The anode 244 is typically metal particles, wires, and/or a perforated sheet and is typically manufactured from the material to be deposited on the substrate, such as copper, aluminum, gold, silver, platinum, tungsten, copper phosphate, noble metal or other materials which can be electrochemically deposited on the substrate. The anode 244 may be porous, perforated, permeable or otherwise configured to allow passage of the plating solution therethrough. Alternatively, the anode 244 may be solid. As compared to a non-consumable anode, the consumable (i.e., soluble) anode provides gas-generation-free plating solution and minimizes the need to constantly replenish the metal in the plating solution. In the embodiment depicted in FIG. 2A, the anode 244 is a solid copper disk.
An electrolyte inlet 216 is formed through the inner basin 272 and is coupled to the plating solution delivery system 111. The plating solution entering the inner basin 272 through the electrolyte inlet 216 flows through or around the anode assembly 220 upward toward the surface of the substrate 126 positioned on the upper end of the inner basin 272. The plating solution flows across the substrate's surface and through slots (not shown) in the cathode contact ring 266 to a passage formed in the outer bas in 240. The bias applied by the power source 246 between the substrate (through the cathode contact ring 266) and the anodes 244 causes metal ions from the plating fluids and/or anode to deposit on the surface of the substrate. Examples of process cells that may be adapted to benefit from the invention are described in U.S. patent application Ser. No. 09/905,513, filed Jul. 13, 2001, and in U.S. patent application Ser. No. 10/061,126, filed Jan. 30, 2002, both of which incorporated by reference in their entireties.
FIG. 2B is partial sectional view of another embodiment of an exemplary processing cell, and more particularly, an exemplary electrochemical plating cell 200. The electrochemical plating cell 200 generally includes an outer basin 201 and an inner basin 202 positioned within outer basin 201. Inner basin 202 is generally configured to contain a plating solution that is used to plate a metal, e.g., copper, onto a substrate during an electrochemical plating process. During the plating process, the plating solution is generally continuously supplied to inner basin 202 (at about 1 gallon per minute for a 10 liter plating cell, for example), and therefore, the plating solution continually overflows the uppermost point of inner basin 202 and runs into outer basin 201. The overflow plating solution is then collected by outer basin 201 and drained therefrom for recirculation into inner basin 202. Plating cell 200 is generally positioned at a tilt angle, i.e., the frame portion 203 of plating cell 200 is generally elevated on one side such that the components of plating cell 200 are tilted between about 3° and about 30°. Therefore, in order to contain an adequate depth of plating solution within inner basin 202 during plating operations, the uppermost portion of basin 202 may be extended upward on one side of plating cell 200, such that the uppermost point of inner basin 202 is generally horizontal and allows for contiguous overflow of the plating solution supplied thereto around the perimeter of basin 202.
The frame member 203 of plating cell 200 generally includes an annular base member 204 secured to frame member 203. Since frame member 203 is elevated on one side, the upper surface of base member 204 is generally tilted from the horizontal at an angle that corresponds to the angle of frame member 203 relative to a horizontal position. Base member 204 includes an annular or disk shaped recess formed therein, the annular recess being configured to receive a disk shaped anode member 205. Base member 204 further includes a plurality of fluid inlets/drains 209 positioned on a lower surface thereof. Each of the fluid inlets/drains 209 are generally configured to individually supply or drain a fluid to or from either the anode compartment or the cathode compartment of plating cell 200. Anode member 205 generally includes a plurality of slots 207 formed therethrough, wherein the slots 207 are generally positioned in parallel orientation with each other across the surface of the anode 205. The parallel orientation allows for dense fluids generated at the anode surface to flow downwardly across the anode surface and into one of the slots 207. Plating cell 200 further includes a membrane support assembly 206. Membrane support assembly 206 is generally secured at an outer periphery thereof to base member 204, and includes an interior region configured to allow fluids to pass therethrough. A membrane 208 is stretched across the support 206 and operates to fluidly separate a catholyte chamber and anolyte chamber portions of the plating cell. The membrane support assembly may include an o-ring type seal positioned near a perimeter of the membrane, wherein the seal is configured to prevent fluids from traveling from one side of the membrane secured on the membrane support 206 to the other side of the membrane. A diffusion plate 210 is positioned above the membrane 208 and is configured similarly to diffusion plate 222 illustrated in FIG. 2A.
In operation, assuming a tilted implementation is utilized, the plating cell 200 will generally immerse a substrate into a plating solution contained within inner basin 202. Once the substrate is immersed in the plating solution, which generally contains copper sulfate, chlorine, and one or more of a plurality of organic plating chemical components (levelers, suppressors, accelerators, etc.) configured to control plating parameters, an electrical bias is applied between a seed layer on the substrate and the anode 205 positioned in the plating cell. The electrical bias is generally configured to cause metal ions moving through the plating solution to deposit on the cathodic substrate surface. In this embodiment of the plating cell 200, separate fluid solutions are supplied to the volume above the membrane 208 and the volume below the membrane 208. Generally, the volume above the membrane is designated the cathode compartment or region, as this region is where the cathode electrode or plating electrode is positioned. Similarly, the volume below the membrane 208 is generally designated the anode compartment or region, as this is the region where the anode is located. The respective anode and cathode regions are generally fluidly isolated from each other via membrane 208 (which is generally an ionic membrane). Thus, the fluid supplied to the cathode compartment is generally a plating solution containing all the required constituents to support plating operations, while the fluid supplied to the anode compartment is generally a solution that does not contain the plating solution chemical components that are present in the cathode chamber, e.g., copper sulfate solutions, for example. Additional detail with respect to the configuration and operation of the exemplary plating cell illustrated in FIG. 2B may be found in commonly assigned U.S. patent application Ser. No. 10/268,284, entitled “Electrochemical Processing Cell”, filed on Oct. 9, 2002.
FIG. 3 is a schematic diagram of one embodiment of the plating solution delivery system 111. The plating solution delivery system 111 is generally configured to supply a plating solution to each processing location on system 100 that requires the solution. More particularly, the plating solution delivery system is further configured to supply a different plating solution or chemistry to each of the processing locations. For example, the delivery system may provide a first plating solution or chemistry to processing locations 110, 112, while providing a different plating solution or chemistry to processing locations 102, 104. The individual plating solutions are generally isolated for use with a single plating cell, and therefore, there are no cross contamination issues with the different chemistries. However, embodiments of the invention contemplate that more than one cell may share a common chemistry that is different from another chemistry that is supplied to another plating cell on the system. These features are advantageous, as the ability to provide multiple chemistries to a single processing platform allows for multiple chemistry plating processes on a single platform.
In another embodiment of the invention, a first plating solution and a separate and different second plating solution can be provided sequentially to a single plating cell. Typically, providing two separate chemistries to a single plating cell requires the plating cell to be drained and/or purged between the respective chemistries; however, a mixed ratio of less than about 10 percent first plating solution to the second plating solution should not be detrimental to film properties.
More particularly, the plating solution delivery system 111 typically includes a plurality of chemical component sources 302 and at least one electrolyte source 304 that are fluidly coupled to each of the processing cells of system 100 via a valve manifold 332. Typically, the chemical component sources 302 include an accelerator source 306, a leveler source 308, and a suppressor source 310. The accelerator source 306 is adapted to provide an accelerator material that typically adsorbs on the surface of the substrate and locally accelerates the electrical current at a given voltage where they adsorb. Examples of accelerators include sulfide-based molecules. The leveler source 308 is adapted to provide a leveler material that operates to facilitate planar plating. Examples of levelers are nitrogen containing long chain polymers. The suppressor source 310 is adapted to provide suppressor materials that tend to reduce electrical current at the sites where they adsorb (typically the upper edges/corners of high aspect ratio features). Therefore, suppressors slow the plating process at those locations, thereby reducing premature closure of the feature before the feature is completely filled and minimizing detrimental void formation. Examples of suppressors include polymers of polyethylene glycol, mixtures of ethylene oxides and propylene oxides, or copolymers of ethylene oxides and propylene oxides.
In order to prevent situations where a chemical component source runs out and to minimize chemical component waste during containers replacement, each of the chemical component sources 302 generally includes a bulk or larger storage container coupled to a smaller buffer container 316. The buffer container 316 is generally filled from the containers 306, 308, and 310, and therefore, the containers 306, 308, and 310, may be removed for replacement without affecting the operation of the fluid delivery system, as the associated buffer container may supply the particular chemical component to the system while the containers are being replaced. The volume of the buffer container 316 is typically much less than the volume of the containers 306, 308, and 310. The containers 306, 308, and 310 are sized to contain enough chemical components for 10 to 12 hours of uninterrupted operation. This provides sufficient time for operators to replace the containers when the containers are empty. If the buffer container was not present and uninterrupted operation was still desired, the containers would have to be replaced prior to being empty, thus resulting in significant chemical component waste.
In the embodiment depicted in FIGS. 3, 4A, and 4B, the fluid delivery system includes a volume measurement module 312 coupled between the plurality of chemical component sources 302 and the plurality of processing cells (not shown). The volume measurement module 312 generally includes at least a vessel 610, an ultrasonic sensor 620 disposed in a position to monitor the level or volume in the vessel 610, a controller 630 coupled to the ultrasonic sensor 620, a liquid inlet port 315, a liquid outlet port 340, a purge port 317, a gas inlet 640, and a vent 313. The volume measurement module 312 may be adapted to receive liquids from one or more sources and adapted for providing volumes of individual liquids and mixtures of liquids.
The vessel 610 may comprise any container adapted for repeated fluid flow therethrough and may be of any shape or configuration. Typically, the vessel 610 includes a cylindrical volumetric shape having multiple fluid inlets and outlets. The vessel 610 may be of any material inert to the fluids being flowed therethrough including stainless steel, glass, and plastic. All components of the volume measurement module 312 may comprise plastic. If redundant sensors are used, such as optical sensors, the vessel 610 preferably comprises a transparent material to the optical measurement device or an independent visual scale of volume disposed on the vessel surface, such as graduated volume markings. The volume may vary on the amount of chemical components to be charged to an electrolyte solution, and may comprise between about 1 milliliters and about 1000 milliliters in volume, such as between about 4 ml and about 120 ml. An example of the vessel 610 is a charge tube having a 1.375 inch outer diameter with a 7.5 inch height, with 4 or 5 inlets and outlets.
The ultrasonic sensor 620 may be a fixed level sensor disposed along a vertical axis of the circumference or side of the vessel 610. The ultrasonic sensor may also be a variable level sensor and disposed vertically displaced from a central axis of the vessel 610 to read the surface level of any liquid disposed in the vessel 610. For example, the ultrasonic sensor may be disposed on the top of the vessel 610 as shown in FIGS. 4A and 4B. An example of a variable level ultrasonic sensor includes the FM-600 and FM-900 series of ultrasonic sensors commercially available from Hyde Park Electronics of Dayton, Ohio, having a 10-0V analog output and an 18 mm outer diameter. In operation, the variable level ultrasonic sensor emits an ultrasonic signal, reads any reflecting or returning signal, or echo, of the emitted ultrasonic signal, to determine a level in the container, converts the level reading to a voltage, and sends an analog voltage signal to a controller 630. Alternatively, the signal may be a serial communications signal (i.e., RS-232, RS-485, etc.), or a well-known industrial protocol bus signal, such as the General Purpose Interface Bus (GPIB). The sensor may be used to measure the amount of liquid in the vessel 610 during filling the vessel 610, after an amount of liquid has been metered in the vessel 610, or during the discharge of the liquid to the desired process or cell. Alternatively, a pressure sensor positioned or coupled fluidically to the bottom of the vessel 610 to sense the liquid column pressure head of the vessel 610 may be used to measure the volume in the vessel 610. An example of a pressure sensor is a model 209, part 2091001EG1M2805, pressure sensor from Setra Systems, Inc., of Boxborough, Md.
A temperature measurement device (not shown), such as a thermistor, may also be disposed on or adjacent the vessel 610 for measuring the temperature inside the vessel 610. The temperature measurement device may be positioned to measure the non-liquid filled volume of the vessel 610, such as at top of the vessel 610 near the vent 313. The temperature measurement device may be integrated into the ultrasonic sensor 620 or disposed in an external spaced relationship from the ultrasonic sensor 620. The temperature measurement device may be adapted to provide data to sensor 620 or the controller 630 to compensate for changes in the velocity of sound with temperature and provide a more accurate measurement of the level and volume of any chemical components or liquids in the vessel 610. When the temperature measurement signal is routed to the ultrasonic sensor 620 prior to the controller 630, the ultrasonic signal can be compensated for temperature variances represented by the temperature measurement signal to form a temperature-corrected output signal from the sensor 620 to the controller 630. One example of a thermistor comprises an epoxy thermistor with a protruding heads having two leads connected to the thermistor and the two leads seated in a polymeric sheath, such as a Peek Tubing, and sealed from exposure by an epoxy, such as Masterbond EP21AR Epoxy.
A controller 630 may be coupled to the sensor 620, or any other sensors including the temperature measurement device, to receive signals therefrom. The controller 630 may be any suitable controller capable of receiving signals from the sensor 620 and calculating a volume for effectively determining the fluctuating state of liquid volume in the vessel 610 for one or more steps. The controller 630 may be an independent controller or integrated in part of whole in any controller used to monitor and control the processing apparatus. For some embodiments, the controller may be a programmable logic controller (PLC) or a rack-mounted personal computer (PC). In one example, the controller 630 may comprise a central processing unit (CPU), memory, and interface circuitry. The CPU may be one of any form of computer processor that can be used in an industrial setting. The memory may be one or more of readily available computer-readable medium, such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote.
A first liquid inlet port 315 is coupled to a chemical component dosing pump 311 disposed between the volume measurement module 312 and the chemical component sources 306, 308, and 310. The chemical component dosing pump 311 provides the chemical components to the vessel 610 via the pump line 319 and may also be adapted to provide additional liquids, such as electrolyte 304, deionized water, 342, and/or a purge gas 344. The chemical component dosing pump 311 may be a rotary metering pump, a solenoid metering pump, a diaphragm pump, a syringe, a peristaltic pump, a piston pump, or other positive displacement volumetric device. The chemical component dosing pump 311 may used in conjunction with the volume measurement device 312 and/or the controller described herein as well as used singularly or coupled to a flow sensor. For example, in one embodiment, the chemical component dosing pump 311 includes a rotating and reciprocating ceramic piston that drives 0.32 ml per cycle of a predetermined chemical component. Alternatively, the dosing pump 311 may be replaced by pressurized fluid delivery process or a vacuum delivery system, which draws chemical components into the module 312 by a vacuum source at port 313 or another port. The electrolyte source 304 may also be fluidly coupled to the vessel 610 by the dosing pump 311.
A first outlet port 330 of the volume measurement module 312 is generally coupled to the processing cells via valve or valve manifold 332 by an output line 340. Chemical components (i.e., at least one or more accelerators, levelers and/or suppressors) may be mixed or delivered for combining with an electrolyte flowing through a first delivery line 350 from the electrolyte source 304, to form the first br second plating solutions as desired. The purge port 317 is generally coupled to the vessel 610 by the valve or manifold 335 electrolyte source 304. The purge port 317 may be used to purge vessel 610 when necessary to recover from chemical component delivery errors that are detected by the volume measurement module 312.
A first gas inlet line 640 may be used to couple a purge/processing gas source 660 to the vessel 610. The purge/processing gas generally comprises a pressurized inert gas to purge gas disposed in portions of the vessel 610 not containing a liquid. The pressurized inert gas may be adapted to provide inert gases of variable pressures based on the use of the inert gases. The purge/processing gas may also be used to assist in evacuating the liquid volume from the vessel 610 to the processing cells. A vent line 313 may also be used to allow removal of gases in the vessel 610, such as residual gases, contaminant gases, or “head” gases, for example, during a purge process or during volumetric fill in the vessel 610. The purging of contaminant gases is believed to minimize ultrasonic measurement variations.
While the volume measurement module 312 is described herein for processing chemical components for electrolyte solutions, the invention contemplates that the volume measurement module 312 may be used for processing additional liquids used in plating operations, including electrolytes, cleaning agents, such as water, etchants as described herein, or dissolving agents as described herein, among others.
In operation, the volume measurement module 312 receives, measures, and discharges chemical components to an electrolyte for use in a plating process. A purge gas from source 660 is introduced into the vessel 610 to remove gases therefrom by vent 313. The sensor 620 then measures the level of any fluids located in the vessel 610. Chemical components are then introduced from the sources 306, 308, 310, through the buffer container 316 to the dosing pump 311 and through the dosing pump line 319 into the vessel 610. The sensor 620 measures the level of the liquid in the vessel 610 either continuously, periodically, or as a level sensor until a specified volume is measured. The vent 313 is closed, the first outlet port 330 is opened and a pressurized gas from the inert gas source 660 or electrolyte from source 304 is introduced into the vessel 610 to discharge liquids therefrom. The sensor 620 may also measure the discharging liquid volume.
While not shown, the invention also contemplates additional components using in fluid systems, including bypass valves, purge valves, flow controllers, and/or temperature controllers.
In another embodiment of the invention the fluid delivery system may be configured to provide a second completely different plating solution and associated chemical components. As such, while not shown, multiple volume measurement modules 312 may be disposed in the system to connect to one or more of the plating cells to provide the necessary plating solutions. For example, in this embodiment a different base electrolyte solution (similar to the solution contained in container 304) may be implemented to provide the processing system 100 with the ability, for example, to use plating solutions from two separate manufacturers. Further, an additional set of chemical component containers may also be implemented to correspond with the second base plating solution. Therefore, this embodiment of the invention allows for a first chemistry (a chemistry provided by a first manufacturer) to be provided to one or more plating cells of system 100, while a second chemistry (a chemistry provided by a second manufacturer) is provided to one or more plating cells of system 100. Each of the respective chemistries will generally have their own associated chemical components, however, cross dosing of the chemistries from a single chemical component source or sources is not beyond the scope of the invention.
In order to implement the fluid delivery system capable of providing two separate chemistries from separate base electrolytes, a duplicate of the fluid delivery system illustrated in FIG. 3 is connected to the processing system. More particularly, the fluid delivery system illustrated in FIG. 3 is generally modified to include a second set of chemical component containers 302 and separate sources for virgin makeup solution/base electrolyte 304 are also provided. The additional hardware is set up in the same configuration as the hardware illustrated in FIG. 3, however, the second fluid delivery system is generally in parallel with the illustrated or first fluid delivery system. Thus, with this configuration implemented, either base chemistry with any combination of the available chemical components may be provided to any one or more of the processing cells of system 100.
The valve manifold 332 is typically configured to interface with a bank of valves 334. Each valve of the valve bank 334 may be selectively opened or closed to direct fluid from the valve manifold 332 to one of the process cells of the plating system 100. The valve manifold 332 and valve bank 334 may optionally be-configured to support selective fluid delivery to additional number of process cells. In the embodiment depicted in FIG. 3, the valve manifold 332 and valve bank 334 include a sample port 336 that allows different combinations of chemistries or component thereof utilized in the system 100 to be sampled without interrupting processing.
In some embodiments, it may be desirable to purge the volume measurement module 312, output line 340 and/or valve manifold 332. To facilitate such purging, the plating solution delivery system 111 is configured to supply at least one of a cleaning and/or purging fluid. In the embodiment depicted in FIG. 3, the plating solution delivery system 111 includes a deionized water source 342 and a non-reactive gas source 344 coupled to the first delivery line 350. The non-reactive gas source 344 may supply a non-reactive gas, such as an inert gas, air or nitrogen through the first and second delivery lines 350 and 352 to flush out the valve manifold 332. Deionized water may be provided from the deionized water source 342 to flush out the valve manifold 332 in addition to, or in place of non-reactive gas. Electrolyte from the electrolyte sources 304 may also be utilized as a purge medium.
In an alternative embodiment of the system, a second delivery line 352 is tied between the first gas delivery line 350 and the dosing pump 311. A purge fluid of a purge liquid includes at least one of an electrolyte, deionized water or other suitable liquid from the respective sources, such as 304 and 342, may be diverted from the first delivery line 350 through the second gas delivery line 352, and through the dosing pump 311 to the volume measurement module 312. A purge fluid of a purge gas, such as nitrogen gas, from the respective sources 344 may be diverted from the first delivery line 350 through the second gas delivery line 352 and purge gas line 351 to the volume measurement module 312. The purge fluid is driven through the volume measurement module 312 and out the output line 340 to the valve manifold 332. The valve bank 334 typically directs the purge fluid out a drain port 338 to the reclaimation system 232. The various other valves, regulators and other flow control devices have not been described and/or shown for the sake of brevity.
In one embodiment of the invention, chemical components for a first chemistry may be provided to promote feature filling of copper on a semiconductor substrate. The first chemistry may include between about 30 and about 65 g/l of copper, between about 35 and about 85 ppm of chlorine, between about 20 and about 40 g/l of acid, between about 4 and about 7.5 ml/L of accelerator, between about 1 and 5 ml/L of suppressor, and no leveler. The chemical components for the first chemistry is delivered from the valve manifold 332 to a first plating cell 150 to enable features disposed on the substrate to be substantially filled with metal. As the first chemistry generally does not completely fill the feature and has an inherently slow deposition rate, the first chemistry may be optimized to enhance the gap fill performance and the defect ratio of the deposited layer.
A second chemistry makeup with a different chemistry from the first chemistry may be provided to another plating cell on system 100 via valve manifold 332, wherein the second chemistry is configured to promote planar bulk deposition of copper on a substrate. The second chemistry may include between about 35 and about 60 g/l of copper, between about 60 and about 80 ppm of chlorine, between about 20 and about 40 g/l of acid, between about 4 and about 7.5 ml/L of accelerator, between about 1 and about 4 ml/L of suppressor, and between about 6 and about 10 ml/L of leveler, for example. The chemical components for the second chemistry is delivered from the valve manifold 332 to the second process cell to enable an efficient bulk metal deposition process to be performed over the metal deposited during the feature fill and planarization deposition step to fill the remaining portion of the feature. Since the second chemistry generally fills the upper portion of the features, the second chemistry may be optimized to enhance the planarization of the deposited material without substantially impacting substrate throughput. Thus, the two step, different chemistry deposition process allows for both rapid deposition and good planarity of deposited films to be realized. The two chemistries may be provided sequentially from the same volume measurement module 312.
When utilized with a process cell requiring anolyte solutions such as the process cell 200 of FIG. 2B, the plating solution delivery system 111 generally includes an anolyte fluid circuit 380 that is coupled to the inlet 209 of the plating cell 200. The anolyte fluid circuit 380 may include a plurality of chemical component sources 382 coupled by a dosing pump 384 to a manifold 386 that directs chemical components (typically not utilized) selectively metering from one or more of the sources 382 and combined with an anolyte in the manifold 386 to those process cells (such as the cell 200) requiring anolyte solution during the plating process. The anolyte may be provided by an anolyte source 388 and a volume measurement module may be used to provide the selectively metering chemical components.
FIG. 5 depicts one embodiment of a process cell 400 configured to remove deposited material from an edge of a substrate 402. The process cell 400 includes a housing 404 having a substrate chuck 406 disposed therein. The substrate chuck 406 includes a plurality of arms, shown as 408A-C, extending from a central hub 410. Each arm 408A-C includes a substrate clamp 412 disposed at a distal end of the arm. The hub 410 is coupled by a shaft 414 to a motor 416 disposed outside of the housing 404. The motor 416 is adapted to rotate the chuck 406 and substrate 402 disposed thereon during processing. During processing, the substrate 402 is rotated while an etchant is delivered from an etchant source 418 to the substrate's edge. The etchant is typically delivered to the substrate's edge through a plurality of upper nozzles 420 positioned within the housing 404 in an orientation that directs the etchant flowing therefrom in a radially outward direction against the substrate's surface. The process cell 400 may also include a plurality of lower nozzles 422 coupled to the etchant source 418 and adapted to direct etchant to the substrate's edge on the side of the substrate opposite the upper nozzle 420. The etchant is typically delivered to the substrate 402 while the substrate rotates between about 100 to about 1,000 rpm. The nozzles 420, 422 are typically configured to direct the etchant at the substrate in a substantially tangential direction, typically with an angle of about 10 to about 70 degrees, or alternatively, between about 10 and about 30 degrees, wherein the angle is defined as being between the substrate surface and the direction or longitudinal axis of the fluid flow or dispensing nozzle. In one embodiment, the etchant is a combination of an acid and oxidizer, such as sulfuric acid, nitric acid, citric acid, or phosphoric acid combined with hydrogen peroxide, which removes deposited copper from the exclusion zone of the substrate (generally the outer annulus of the substrate surface, which is generally about 2 mm or 3 mm wide.
After the deposited material has been removed from the substrate's edge, deionized water or other cleaning agent is provided through the nozzles 420, 422 to clean the substrate's surface. The substrate 402 is typically rotated at approximately 200 rpm to remove etchant, deionized water and other impurities from the respective upper and lower surfaces of the substrate 402. The various fluids dispended during processing are drained from the housing 404 through a port 425 formed in the bottom of the housing 404. Two process cells configured to remove deposited material from the edge of the substrate which may be adapted to benefit from the invention are described in U.S. patent application Ser. No. 09/350,212, filed Jul. 9, 1999, and U.S. patent application Ser. No. 09/614,406, filed Jul. 12, 2000, both of which are hereby incorporated by reference in their entireties.
FIG. 6 is a partial sectional view of a process cell 500 configured to spin, rinse and dry a substrate 502 after processing. The process cell 500 includes a housing 504 having a substrate chuck 506 disposed therein. The substrate chuck 506 includes a plurality of arms, shown as 508A-C, extending from a central hub 510. Each arm 508A-C includes a substrate clamp 512 disposed at a distal end of the arm. The hub 512 is coupled by a shaft 514 to a motor 516 disposed outside of the housing 504. The motor 516 is adapted to rotate the chuck 506 and substrate 502 disposed thereon during processing. During processing, the substrate is rotated while a cleaning agent, such as deionized water or alcohol, is delivered from a fluid source 518 to the upper side of the substrate 502 from a plurality of upper nozzles 520 positioned within the housing 504 above the chuck 506. The backside of the substrate 502 is treated with at least one of a cleaning agent or a dissolving agent dispensed from a plurality of lower nozzles 522 disposed below the chuck 506 and coupled to the fluid source 518. Examples of dissolving agents include hydrochloric acid, sulfuric acid, phosphoric acid, hydrofluoric acid among others. The fluids are typically delivered to the substrate while the substrate rotates between about 4 to about 4,000 rpm.
After the deposited material has been removed from the substrate's edge, deionized water or other cleaning agent is provided through the nozzles 520, 522 to clean the substrate's surface. The substrate 502 is typically rotated at approximately 100 to about 5000 rpm to dry the substrate while removing liquids and other impurities from the respective upper and lower surfaces of the substrate 502. The various fluids dispended during processing are drained from the housing 504 through a port 524 formed in the bottom of the housing 504. One process cell configured to clean and dry the substrate which may be adapted to benefit from the invention is described in U.S. Pat. No. 6,290,865, issued Sep. 18, 2001, which is hereby incorporated by reference in its entirety.
In operation, embodiments of the invention generally provide a plating system having multiple plating cells on a single integrated platform, wherein a fluid delivery system for the plating system is capable of providing multiple chemistries to the plating cells. More particularly, for example, assuming that four individual plating cells are positioned on a common system platform, then the fluid delivery system of the invention is capable of providing a different chemistry to each of the four plating cells. The different chemistries may include different base solutions or virgin makeup solutions, and further, may include various chemical components at various amounts, including absence of selected chemical components.
Multiple chemistry capability for a single platform has advantages in several areas of semiconductor processing. For example, the ability to provide multiple chemistries to multiple plating cells on a unitary platform allows for a single plating system take advantage of positive characteristics of multiple chemistries in a single platform on a single substrate. Multiple chemistry capability has application, for example, to feature fill and bulk fill process, as a first plating solution or chemistry may be tailored to a feature full process (low defect, but slow deposition rate process), while a second solution may be tailored to a feature bulk fill process (a more rapid deposition process that may be implemented once the feature is primarily filled by the first process). Additionally, a multiple chemistry plating system would facilitate plating directly on barrier layers, as a first plating chemistry could be used to facilitate adhesion of a first material to the barrier layer, and then a second chemistry could be used plate a second material over the first material layer on top of the barrier layer and fill the features without encountering barrier layer plating adhesion challenges. Further, a multiple chemistry system would also be beneficial to an alloy plating process, wherein a first chemistry could be used to plate the alloy layer and then a second chemistry could be used to plate a different layer or another alloy layer over the previously deposited layer. Further still, a multiple chemistry process could be used to substantially improve defect ratios in semiconductor substrate plating processes via utilization of a first chemistry configured to plate a first layer with minimal defects, and then a second chemistry configured to plate a second layer over the first layer with minimal defects in manner that optimizes throughput.
Exemplary Method of the Volume Measurement Module
FIG. 7 is a flow diagram illustration one embodiment of an exemplary method 700 for monitoring and controlling the volume of a liquid in the volume measurement module 312 to the process cells described herein. The method may be monitored and controlled by controller 630 as described herein as well as by any other controller use on the system 100.
The process begins by confirming that chemical components are primed to be delivered to the vessel 610 of the volume measurement module 312 at step 710. The confirmation may be achieved, for example, by a proximity, flow, level, or pressure sensor disposed in the chemical component sources 306, 308, 310, or buffer container 316, in the line between the dosing pump 311 and the chemical component sources 306, 308, 310, or buffer container 316, or a sensor disposed in or adjacent the dosing pump 311.
A volume of initial fluid is introduced into the vessel 610 at step 720. The electrolyte, for example, catholyte, or deionized water, may be introduced into the vessel 610, such as less than about 10 ml, for example, between about 1 and about 2 ml, at step 720. A purge gas of an inert gas, such as nitrogen, is introduced into the vessel 610 to remove any gas, such as head gas, disposed in the vessel 610 and discharged from the vessel 610 through the vent 313 at step 730.
The ultrasonic sensor 620 measures the initial volume of any liquid in the volume at step 740. For example, an ultrasonic sensor 620 emits an ultrasonic signal into the vessel 610. The ultrasonic signal then contacts the volume of liquid and a reflection signal is generated. The ultrasonic sensor has a receiver to sense reflective signal and based upon a determination of signal intensity and/or duration between emission and reception of the signal, produce an electronic signal, such as a voltage measurement, representative of liquid level in the vessel 610. The electronic signal is typically the average of several hundred reading taken over approximately a time span, for example, between about 1 to 2 second time span. The multiple readings are believed to average out random errors. The ultrasonic sensor 620 may be programmed to average multiple reading for example, averaging between 2 and about 1000 readings. The controller 630 may also be programmed to average signals received from the ultrasonic sensor 620.
The electronic signal is then sent to the controller 630 as an analog signal, which is then converted by the controller into a volume measurement by use of a prior calibration, a pre-selected value, or database of pre-calculated to pre-measured volumes. Circuitry on the ultrasonic sensor or controller may comprise any combination of analog to digital (A/D) converters, digital signal processing (DSP) circuits and communication circuits to convert the signals to a format suitable by the CPU of the controller. The initial fluid introduced in step 720 may be used to provide sufficient signal feedback to establish an initial level measurement.
Alternatively, if a temperature measuring device, such as a thermistor, is used with the ultrasonic sensor, the thermistor measures the temperature of the non-liquid filled portion of the vessel 610 to compensate or correct for the changes in the velocity of sound with temperature prior to calculating the liquid level in the vessel 610.
One or more chemical components, either concurrently or sequentially, are introduced into the vessel 610 at step 750. The introduced chemical components level in the vessel 610 is then measured at step 760. The chemical components levels may be measured as described in step 740.
The volume of the chemical components as determined by the controller 630 is compared with a pre-determined or pre-selected value at step 770. If the calculated volume does not achieve the desired pre-determined or pre-selected value, chemical components are continued to be supplied to the vessel 610. The chemical components may be provided periodically or continuously to the vessel 610. Volume calculations may be made periodically or continuously during filling of the vessel 610. The comparison of values may be used to determine whether the delivery accuracy from the pump 311 is correct, and if not, the components in the vessel 610, may be discharge to a drain via line 317. The predetermined value may be the estimated volume provided by an upstream metering pump, such as pump 311, or other delivery mechanism. The predetermined value may also be stored electronically in a database for comparison or the controller 630 might be able to directly compare values from a sensor on the pump 311 to the volume measured in the vessel 610.
The process may be repeated for each chemical component introduced into the vessel 610, so that a final discharge volume may comprise one or more chemical components that have been pre-mixed before discharge to the appropriate line, process cell, or storage unit. For example, the dosing pump 311 may provide a metered amount of liquid to the vessel 610, a level measurement may be taken for each metered amount or after a series of metered amount to verify the amount of liquid provided.
The process may be performed statically or dynamically. In a static process, the vessel 610 is filled with a first quantity of fluid and a measurement is taken of the volume prior to the addition of any additional liquids. This can be used to verify the volume metered out by the dosing pump 311. In a static process, steps 750-770 are performed separately. In a dynamic process, the vessel is continuously filled with a liquid and the level is continuously of periodically measured until a desired level is reached. In the dynamic process, step 750-770 are performed concurrently.
If the calculated volume achieves the desired pre-determined or pre-selected value, the contents in the vessel 610 may be discharged at step 780. The discharge of the contents may be provided by closing the vent 313 of the vessel 610 remaining open during filling of the vessel 610, opening an outlet, and pressurizing the liquid from the vessel 610. The liquid may be discharged by supplying pressurized purge gas, such as nitrogen, by the use of deionized water, or by an amount of electrolyte, such as catholyte, provided to the vessel 610.
Optionally, after discharge of the liquids from the vessel 610, the vessel 610 may be rinsed by electrolyte, such as the catholyte, or deionized water at step 790 prior to initiation of the next sequence.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
|REFERENCE NUMERALS |
| ||ECP System ||100 |
| ||Process Location ||102 |
| ||Process Location ||104 |
| ||Process Location ||106 |
| ||Process Location ||108 |
| ||Process Location ||110 |
| ||Delivery System ||111 |
| ||Process Location ||112 |
| ||Processing Base ||113 |
| ||Process Location ||114 |
| ||Process Location ||116 |
| ||Robot ||120 |
| ||Robot Arms ||122 |
| ||Robot Arms ||124 |
| ||Substrate ||126 |
| ||Factory Interface (F1) ||130 |
| ||F1 Robot ||132 |
| ||Substrate Cassettes ||134 |
| ||Anneal Chamber ||135 |
| ||Cooling Plate Position ||136 |
| ||Heating Plate Position ||137 |
| ||Processing Cell ||150 |
| ||Base ||160 |
| ||Plating Cell ||200 |
| ||Outer Basin ||201 |
| ||Inner Basin ||202 |
| ||Frame Portion ||203 |
| ||Base Member ||204 |
| ||Anode Member ||205 |
| ||Support Assembly ||206 |
| ||Slots ||207 |
| ||Membrane ||208 |
| ||Fluid Inlet/Drains ||209 |
| ||Diffusion Plate ||210 |
| ||Head Assembly ||211 |
| ||Electrolyte Inlet ||216 |
| ||Drain ||218 |
| ||Anode Assembly ||220 |
| ||Diffusion Plate ||222 |
| ||Insulative Spacer ||224 |
| ||System ||232 |
| ||Hanger Plate ||236 |
| ||Hanger Pins ||238 |
| ||Basins ||240 |
| ||Anodes ||244 |
| ||Power Source ||246 |
| ||Channel ||248 |
| ||Holder Assembly ||250 |
| ||Assembly Frame ||252 |
| ||Mounting Post ||254 |
| ||Cantilever Arm ||256 |
| ||Assembly Actuator ||258 |
| ||Mounting Plate ||260 |
| ||Assembly Shaft ||262 |
| ||Thrust Plate ||264 |
| ||Contact Ring ||266 |
| ||Arm Actuator ||268 |
| ||Inner Basin ||272 |
| ||Component Sources ||302 |
| ||Electrolyte Source ||304 |
| ||Accelerator Source ||306 |
| ||Leveler Source ||308 |
| ||Suppressor Source ||310 |
| ||Volume Measurement Module ||312 |
| ||Vent ||313 |
| ||Liquid Inlet Port ||315 |
| ||Buffer Container ||316 |
| ||Purge Port ||317 |
| ||Pump Line ||319 |
| ||First Outlet Port ||330 |
| ||Valve Manifold ||332 |
| ||Valve Bank ||334 |
| ||Port ||336 |
| ||Drain Port ||338 |
| ||Output Line ||340 |
| ||Water Source ||342 |
| ||Gas Source ||344 |
| ||Delivery Lines ||350, 352 |
| ||Circuit ||380 |
| ||Sources ||382 |
| ||Dosing Pump ||384 |
| ||Anolyte Source ||388 |
| ||Process Cell ||400 |
| ||Substrate ||402 |
| ||Housing ||404 |
| ||Substrate Chuck ||406 |
| ||Arms ||408A-C |
| ||Central Hub ||410 |
| ||Clamp ||412 |
| ||Shaft ||414 |
| ||Motor ||416 |
| ||Etchant Source ||418 |
| ||Nozzles ||420, 422 |
| ||Port ||425 |
| ||Process Cell ||500 |
| ||Substrate ||502 |
| ||Housing ||504 |
| ||Chuck ||506 |
| ||Arms ||508A-C |
| ||Central Hub ||510 |
| ||Clamp or Hub ||512 |
| ||Shaft ||514 |
| ||Motor ||516 |
| ||Fluid Source ||518 |
| ||Upper Nozzles ||520 |
| ||Lower Nozzles ||522 |
| ||Port ||524 |
| ||Vessel ||610 |
| ||Vent ||613 |
| ||Sensor ||620 |
| ||Controller ||630 |
| ||Gas Inlet Line ||640 |
| ||Gas Source ||660 |
| ||Priming Additive for Delivery to a Vessel ||710 |
| ||Introducing a Volume of Initial Liquid to the ||720 |
| ||Vessel |
| ||Purging the Vessel of any Resident Gases ||730 |
| ||Measuring the Initial Level/Volume of Any ||740 |
| ||Liquid Disposed in the Vessel by an |
| ||Ulatrasonic Sensor |
| ||Introducing One or More Additives into the ||750 |
| ||Vessel |
| ||Measuring the Level/Volume of Additives ||760 |
| ||Disposed in the Vessel by an Ulatrasonic |
| ||Sensor |
| ||Comparing the Level/Volume of the Initial ||770 |
| ||Additives Level/Volume to a Pre-Selected |
| ||Value to Determine Process Volume |
| ||Discharging the Additives from the Vessel ||780 |
| ||Optionally, Cleaning the Vessel ||790 |
| || |