Adjustment measures for ALD productivity

Abstract

A deposition method and apparatus for conditioning a process kit to extend the life of the process kit is described, wherein a nitride film formed on the process kit is exposed to a conditioning process including nitrogen and hydrogen radicals to condition the nitride film to reduce particle contamination from the process kit.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to apparatus and methods for conditioning process chamber parts. In particular, embodiments of the present disclosure relate to methods and apparatus for nitride deposition with improved productivity. [Background technology]

[0002] Atomic layer deposition (ALD) process chambers used to deposit some types of nitride films require frequent cleaning and maintenance. The mean number of wafers between cleanings (MWBC) is low due to the characteristics of the deposition material on the process kit (e.g., consumable parts used in the deposition chamber). The process kit includes, but is not limited to, removable deposition chamber elements that come into contact with reactive chemicals during processing. For example, the chamber showerhead, pumping liner, pump shield, etc.

[0003] During processing, ALD tantalum nitride (TaN) is deposited on the wafer as well as the process kit. The wafer temperature differs from the process kit temperature, with the wafer temperature being higher than the process kit. Due at least in part to this temperature difference, the TaN deposited on the process kit differs from the film deposited on the wafer. The TaN on the process kit has a lower density and higher impurity levels. The TaN formed is powdery, which creates particle issues. There are no known in-situ cleaning processes capable of cleaning the ALD TaN from the process kit, and cleaning and maintenance require significant equipment downtime.

[0004] Additionally, plasma-based processes are prone to increased particle contamination due to plasma-induced stress buildup in the chamber body. The particle lifetime of a process kit in a plasma process is approximately 20% of that of a thermal process chamber.

[0005] Therefore, there is a need for a method and apparatus for extending the mean number of wafers between cleaning (MWBC) of a nitride deposition process. Summary of the Invention

[0006] One or more embodiments of the present disclosure relate to a deposition method that includes exposing a process kit in a process chamber having a nitride film thereon to a conditioning process including nitrogen radicals and hydrogen radicals to form a conditioned nitride film. A nitride layer is deposited on a plurality of wafers in the process chamber.

[0007] An additional embodiment of the present disclosure relates to a deposition method that includes processing a plurality of wafers in a process chamber to deposit tantalum nitride (TaN) on the wafers and depositing a nitride film on a process kit in the process chamber, the nitride film having a thickness of 9 g / cm 3 After processing multiple wafers, the process kit is conditioned using a conditioning process that exposes the process kit to nitrogen and hydrogen radicals to reduce the density of the nitride film to 9 g / cm. 3 The stress is increased to ultra high, producing a nitride film with compressive stress.

[0008] A further embodiment of the present disclosure relates to a non-transitory computer-readable medium comprising instructions that, when executed by a controller of a processing chamber, cause the processing chamber to perform operations of exposing a substrate to deposition process conditions to deposit a nitride film and exposing a process kit in the process chamber to a conditioning process.

[0009] In order that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above will be obtained with reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure and should not be considered as limiting the scope of the present disclosure, since the present disclosure may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a schematic diagram of a process chamber according to one or more embodiments of the present disclosure. [Figure 2] 1 is a flow diagram of a process method according to one or more embodiments of the present disclosure. [Figure 3A] FIG. 2 is an expanded view of region 155 of FIG. 1 before a conditioning process in accordance with one or more embodiments of the present disclosure. [Figure 3B] FIG. 3B is the diagram of FIG. 3A after an adjustment process according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Before describing several example embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description. The present disclosure is capable of other embodiments and of being practiced and carried out in various ways.

[0012] The term "substrate," as used herein and in the appended claims, refers to a surface or portion of a surface upon which a process acts. It will also be understood by those skilled in the art that a reference to a substrate can refer to only a portion of a substrate, unless the context clearly indicates otherwise. Additionally, a reference to depositing on a substrate can refer to both a bare substrate and a substrate upon which one or more thin films or features have been deposited or formed.

[0013] As used herein, "substrate" refers to a substrate or material surface formed on a substrate on which a film treatment is performed during a manufacturing process. For example, substrate surfaces on which treatment can be performed include silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other material such as metals, metal nitrides, alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, electron beam cure, and / or bake the substrate surface. In addition to performing film treatments directly on the surface of the substrate itself, in the present disclosure, any of the disclosed film treatment steps may also be performed on an underlying layer formed on the substrate, as disclosed in more detail below, and the term "substrate surface" is intended to include the underlying layer as the context indicates. Thus, for example, if a film / layer or partial film / layer is deposited on a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0014] Embodiments of the present disclosure relate to methods of using conditioning procedures to improve film properties of films formed on process kits. Some embodiments of the present disclosure perform conditioning procedures on one or more of a chamber showerhead, a pumping liner, a chamber isolator, or an edge ring. Some embodiments of the present disclosure advantageously provide methods for improving adhesion of films to process kits during deposition. One or more embodiments advantageously provide methods for reducing particle contamination from films formed on process kits. Some embodiments advantageously provide methods for extending the mean number of wafers between cleanings (MWBC) for nitride deposition processes.

[0015] Some embodiments of the present disclosure use a mixed ammonia, hydrogen, and argon plasma treatment to condition the chamber body to increase the density of films deposited on the process kit by changing the film composition. In some embodiments, films deposited on the process kit are treated to increase the film density. In some embodiments, the treatment process causes the film material to have a more neutral film stress. Some embodiments improve the film properties of the material deposited on the process kit, resulting in improved adhesion to the process kit over time. In some embodiments, adhesion is improved by reducing particle formation in the chamber over time due to delamination, cracks from the stress film, and / or showerhead peeling. In some embodiments, process particle performance is improved to extend the particle lifetime of the process kit. In some embodiments, particle performance is defined by particle adders greater than 32 nm. In some embodiments, particle performance is in the range of fewer than five particle adders (particles added by the process on the wafer) greater than 32 nm in size. In some embodiments, particles are measured using a surface inspection system using, for example, light scattering. In some embodiments, particles are measured using a scanning electron microscope (SEM) to determine particle size based on image analysis. In some embodiments, particle maps and bin sizes are determined by optically measuring surface topography aberrations, which indicate defects on the wafer surface. At smaller particle sizes, the measured particles may be wafer defects rather than process-added particles, and an SEM can be used to observe the top of the wafer before or after receiving a defect map from another technique. In some embodiments, SEM images are taken at locations on the defect map at one or more magnifications and scrutinized for particle presence, correct bin size, particle morphology, and / or particle composition.

[0016] In some embodiments, ammonia (NH3) / hydrogen (H2) / argon (Ar) plasma treatment at various powers, process gas flow ratios, and / or treatment times improves film density and / or particle performance. Nitridation of ALD nitride films (e.g., TaN) deposited on a process kit transforms tensile, low-density, loose films into denser, more stress-neutral films. Unless otherwise indicated, those skilled in the art will recognize that the use of terms such as "tantalum nitride" or chemical formulas such as "TaN" identifies the elemental components of the presented material and does not imply a specific stoichiometric relationship of the components. For example, TaN refers to a film having tantalum and nitrogen atoms unless otherwise indicated. In an example using a specific stoichiometry, a low-density, tensile film containing TaN is reformed into a denser, more stress-neutral Ta3N5 film.

[0017] During deposition, films deposited on a process kit typically have high impurities and form powdery materials that can cause particle issues and reduce the MWBC of the chamber during production. Some embodiments of the present disclosure periodically modify the properties of films deposited on a process kit during kit life to help the film remain adhered to the process kit, making the film denser and / or more stress-neutral, and therefore less likely to develop defects that cause particle issues.

[0018] FIG. 1 illustrates a process chamber 100, and FIG. 2 illustrates a process method 200 according to some embodiments of the present disclosure. The process chamber 100 illustrated in FIG. 1 includes a chamber body 110, a showerhead 120 (or other gas distribution plate), a confinement ring 125 (which may be omitted), a pedestal 130 (or other substrate support), and a wafer 140. The process kit 150 in FIG. 1 includes the pedestal 130 and the confinement ring 125. The process kit 150, having a nitride film 160 thereon, is exposed to a conditioning process 210 to form a conditioned nitride film 165. The conditioning process in some embodiments includes nitrogen radicals and hydrogen radicals. The method 200 further includes a deposition process 220 in which a nitride layer 170 is deposited on multiple wafers 140 in the process chamber 100. In some embodiments, the multiple wafers 140 are processed individually. In some embodiments, deposition is performed on more than one wafer at a time.

[0019] During the deposition process 220 in which the nitride layer 170 is formed on the wafer 140 surface, some material deposits on the process kit 150 (e.g., the showerhead 120 and / or the confinement ring 125) as a nitride film 160. The nitride film 160 that forms on the process kit 150 has different properties than the nitride layer 170 that is formed on the wafer 140. Without being bound to any particular theory of operation, the difference in properties between the nitride film 160 and the nitride layer 170 is due, among other things, to the temperature difference between the wafer 140 and the process kit 150.

[0020] FIG. 3A shows an expanded view of region 155 before conditioning process 210, and FIG. 3B shows the view of FIG. 3A after conditioning process 210. In FIG. 3A, nitride film 160 formed on process kit 150 has a relatively low density and is under tensile stress. In some embodiments, conditioning process 210 increases the density of nitride film 160 to form conditioned nitride film 165, as shown in FIG. 3B. Conditioned nitride film 165 may also be referred to as a densified nitride film.

[0021] In some embodiments, nitride film 160 is formed in process kit 150 during a nitride deposition process to form a nitride layer on one or more wafers. In some embodiments, the nitride layer is deposited by one or more of chemical vapor deposition (CVD) or atomic layer deposition. In some embodiments, the nitride layer and nitride film are deposited by atomic layer deposition. In some embodiments, the nitride layer is deposited on multiple wafers simultaneously or sequentially.

[0022] In some embodiments, the nitride film 160 deposited in the process kit 150 includes one or more of tantalum nitride (TaN), titanium nitride (TiN), manganese nitride (MnN), tungsten nitride (WN), ruthenium tantalum nitride (RuTaN), or niobium nitride (NbN). In some embodiments, the nitride film 160 deposited in the process kit 150 includes or consists essentially of tantalum nitride (TaN). As used in this manner, the term “consisting essentially of” means that the composition of the film is, on an atomic basis, 90%, 92.5%, 95%, 98%, 99% or more, or 99% of the sum of the listed elements. In some embodiments, the nitride film 160 deposited in the process kit 150 includes or consists essentially of titanium nitride. In some embodiments, the nitride film 160 deposited in the process kit 150 includes or consists essentially of niobium nitride.

[0023] In some embodiments, the nitride film 160 comprises tantalum nitride that has a relatively low density under tensile stress. As used in this manner, the term "relatively low density" refers to a tantalum nitride film having a density of 8 g / cm3 or less prior to the conditioning process. 3 , 7.5g / cm 3 , 7g / cm 3 , 6.5g / cm 3 , 6g / cm 3 , 5.5g / cm 3 , or 5g / cm 3 This means that:

[0024] In some embodiments, the tantalum nitride film formed on the process kit has a thickness of 5 g / cm 2 prior to the conditioning process. 3 ~6.5g / cm 3 In some embodiments, the nitride film 160 formed on the process kit before the conditioning process comprises tantalum nitride, which has tensile stress. In some embodiments, ellipsometry is used to measure the differential stress of a deposited film with a known thickness (measured by XRF). The ALD TaN film before treatment is highly tensile, with tensile stress ranging from 100 MPa to 1500 MPa. In some embodiments, after treatment, the ALD Ta3N5 film is more stress-neutral / compressive. In some embodiments, the stress of the treated film is in the range of 0 to -500 MPa. In some embodiments, ellipsometry is used to measure the radius of curvature of the wafer before and after film deposition. The curvature delta is used to calculate film stress, with the film thickness known.

[0025] The conditioning process 210 transforms the nitride film 160 into a conditioned nitride film 165. In some embodiments, the conditioned nitride film 165 has a thickness of 9 g / cm 3 , 9.5g / cm 3 , or 10 g / cm 3 In some embodiments, the conditioned nitride film 165 has a density of 9 g / cm or greater. 3 ~10.5g / cm 3 or 9.5g / cm 3 ~10g / cm 3 Tantalum nitride has a density in the range of .

[0026] In some embodiments, the conditioned nitride film has a compressive stress, hi some embodiments, the compressive stress is in the range of about 0 to about -500 MPa, as measured by ellipsometry.

[0027] In some embodiments, the conditioning process includes nitrogen radicals and hydrogen radicals. In some embodiments, the nitrogen radicals and hydrogen radicals are formed by passing a conditioning gas through a hot wire. In some embodiments, the nitrogen radicals and hydrogen radicals are formed in a plasma generated from the conditioning gas. In some embodiments, the plasma is a direct plasma. In some embodiments, the plasma is a remote plasma.

[0028] In some embodiments, the tuning gas includes one or more of ammonia (NH), hydrazine (N2H4), nitrogen (N2), hydrogen (H2), or argon (Ar). In some embodiments, the tuning gas includes one or more of ammonia (NH3), hydrazine (N2H4), nitrogen (N2), hydrogen (H2), or argon (Ar), provided that each of nitrogen (N2), hydrogen (H2), or argon (Ar) is used with at least one additional gas species to provide nitrogen and hydrogen radicals. In some embodiments, the tuning gas includes an ammonia hydrogen compound (azane). In some embodiments, the tuning gas includes one or more of diazane (hydrazine), triazane (N3H5), diazene (N2H2), or triazene (N3H3). In some embodiments, the tuning gas includes at least one species having both nitrogen and hydrogen atoms. In some embodiments, the conditioning gas comprises or consists essentially of ammonia (NH). As used in this context, the term "consisting essentially of" means that the active species in the conditioning gas are 95%, 98%, 99%, 99.5%, or greater, on a molecular basis, of the listed species, or of the sum of the listed species, not counting inert or diluent species. In some embodiments, the conditioning gas comprises or consists essentially of hydrazine (NH). In some embodiments, the conditioning gas comprises or consists essentially of ammonia and hydrogen (H). In some embodiments, the conditioning gas comprises or consists essentially of hydrogen (H) and nitrogen (N).

[0029] In some embodiments, the conditioning gas comprises ammonia (NH), hydrogen (H), and argon (Ar). In some embodiments, the conditioning gas consists essentially of ammonia (NH), hydrogen (H), and argon (Ar). In some embodiments, the ratio of ammonia:hydrogen:argon (NH:H:Ar) is in the range of 0.9-1.1 NH:0.9-1.1 H:0.9-1.1 Ar. In some embodiments, the ratio of ammonia:hydrogen:argon (NH:H:Ar) is about 1:1:1. In some embodiments, the ratio of ammonia:hydrogen:argon (NH:H:Ar) is in the range of 1-20 NH:1-20 H:1 Ar, or in the range of 1-10:1-10:1, or in the range of 10:10:0.1-10. In some embodiments, the amounts of ammonia (NH3) and hydrogen (H2) are within ±10% relative to one another, and argon (Ar) is a diluent in any amount suitable to provide sufficient reactive species to the process chamber.

[0030] In some embodiments, the tuning gas comprises a plasma having a frequency in the range of about 2 MHz to 100 MHz, 13.56 MHz to 60 MHz, or 13.56 MHz to 40 MHz. In some embodiments, the tuning gas comprises a plasma having a pressure in the range of about 0.5 Torr to about 25 Torr, or in the range of about 1 Torr to 15 Torr, or in the range of about 1.5 Torr to 10 Torr. In some embodiments, the tuning gas comprises a plasma, and the tuning process is carried out in 5 minutes or less.

[0031] Referring to FIG. 2 , after the conditioning process 210, a nitride layer is deposited 220 on one or more wafers (substrates). The number of wafers deposited before reconditioning the process kit 150 depends, for example, on the conditioning process parameters, deposition parameters, and nitride layer composition used. In some embodiments, the number of wafers between reconditioning using the conditioning process 210 ranges from 5 to 50 wafers. In some embodiments, following the method 200 extends the lifetime of the process kit 150 by at least 5 times compared to a process kit in which the conditioning process 210 is not performed. In some embodiments, the lifetime of a process kit is defined as the number of wafers that can be processed between cleaning or preventative maintenance. For a given process, a typical reference lifetime ranges from <1K to 10K.

[0032] Some embodiments of the method begin with a seasoning process 205 to season the process kit 150. The seasoning process 205 of some embodiments prepares the process kit 150 for use using a deposition process 220 followed by a conditioning process 210. In some embodiments, the process kit 150 undergoes the seasoning process 205 before being installed in a deposition chamber. In some embodiments, the seasoning process 205 includes a form of deposition process followed by a form of conditioning process. In some embodiments, the seasoning process includes a form of deposition process, and the method 200 moves to the conditioning process 210 as the next step to condition and complete the seasoning process. In some embodiments, the seasoning process includes a form of conditioning process, after the seasoning process 205, the method 200 continues to the deposition process 220 by following optional path 222.

[0033] Referring to FIG. 1 , an additional embodiment of the present disclosure relates to a process chamber 100 for performing the methods described herein. FIG. 1 illustrates a chamber 100 that can be used to process substrates in accordance with one or more embodiments of the present disclosure. The process chamber 100 includes at least one controller 190 configured to control various components of the chamber 100. In some embodiments, there are multiple processors connected to the process chamber 100, with a primary control processor coupled to each of the separate processors to control the chamber 100. The controller 190 can be one of any form of general-purpose computer processor, microcontroller, microprocessor, etc. that can be used in an industrial setting to control various chambers and sub-processors.

[0034] In some embodiments, controller 190 has a processor 192 (also referred to as a CPU), memory 194 coupled to processor 192, input / output devices 196 coupled to processor 192, and support circuits 198 for communication between various electronic components. In some embodiments, memory 194 includes one or more of temporary memory (e.g., random access memory) or non-temporary memory (e.g., storage).

[0035] The processor's memory 194 or computer-readable medium may be one or more of readily available memory such as random access memory (RAM), read-only memory (ROM), a floppy disk, a hard disk, or any other form of local or remote digital storage. The memory 194 may hold a set of instructions operable by the processor 192 to control system parameters and components. Support circuits 198 are coupled to the processor 192 for supporting the processor in a conventional manner. The circuits may include, for example, cache, power supplies, clock circuits, input / output circuits, subsystems, etc.

[0036] The processes can generally be stored in memory as software routines that, when executed by a processor, cause the process chamber to perform the processes of the present disclosure. The software routines can also be stored and / or executed by a second processor (not shown) located remotely from the hardware being controlled by the processor. Some or all of the methods of the present disclosure can also be performed in hardware. Thus, the processes can be implemented in software and executed using a computer system, implemented in hardware, for example, as an application-specific integrated circuit or other type of hardware implementation, or implemented as a combination of software and hardware. The software routines, when executed by a processor, transform a general-purpose computer into a special-purpose computer (controller) that controls chamber operation to perform the processes.

[0037] In some embodiments, the controller 190 has one or more configurations for executing individual processes or subprocesses to perform a method. In some embodiments, the controller 190 is connected to and configured to operate intermediate components to perform the functions of a method. For example, the controller 190 of some embodiments is connected to and configured to control one or more of gas valves, actuators, motors, slit valves, vacuum controls, etc.

[0038] The controller 190 of some embodiments has one or more configurations selected from a configuration for exposing a substrate to deposition process conditions to deposit a nitride film and a configuration for exposing a process kit of a process chamber to a conditioning process. A non-transitory computer-readable medium comprising instructions that, when executed by a controller of a processing chamber, cause the processing chamber to perform operations of exposing a substrate to deposition process conditions to deposit a nitride film and exposing a process kit of a process chamber to a conditioning process.

[0039] References throughout this specification to "one embodiment," "an embodiment," "one or more embodiments," or "one embodiment" mean that a particular feature, structure, material, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of phrases such as "in one or more embodiments," "an embodiment," "in one embodiment," or "in one embodiment" in various places throughout this specification do not necessarily refer to the same embodiment of the present disclosure. Moreover, particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0040] Although the present disclosure herein has been described with reference to particular embodiments, those skilled in the art will recognize that the described embodiments are merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and apparatus without departing from the spirit and scope of the present disclosure. Accordingly, the present disclosure may include modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. exposing a process kit in a process chamber having a nitride film thereon comprising one or more of tantalum nitride (TaN), ruthenium tantalum nitride (RuTaN), manganese nitride (MnN), tungsten nitride (WN), or niobium nitride (NbN) to a conditioning process when no wafer is present in the process chamber; The nitride film on the process kit has a tensile stress in the range of 100 MPa to 1500 MPa as measured using ellipsometry, and the conditioning process includes exposing the process kit to a conditioning gas, the conditioning gas consisting essentially of ammonia, hydrogen, and argon (NH 3 : H 2 a ratio of nitrogen radicals and hydrogen radicals in the atmosphere (Ar) is in the range of 0.9-1.1:0.9-1.1:0.9-1.1; the conditioning process includes nitrogen radicals and hydrogen radicals to form a conditioned nitride film; the conditioning process increases the density of the nitride film on the process kit; and the nitride film has a density of 8 g / cm 3 The nitride film has a density of 10 g / cm 3 or greater, wherein the conditioning process changes the stress of the tensile-stressed nitride film to a conditioned film having a compressive stress in the range of 0 MPa to −500 MPa as measured by ellipsometry, and increases the lifetime of the process kit by at least 5 times compared to a process without the conditioning process; further depositing a nitride layer on the plurality of wafers in the process chamber; A deposition method comprising:

2. 10. The method of claim 1, wherein the conditioned nitride film comprises tantalum nitride (TaN).

3. The method of claim 1 , wherein the nitride layer on the plurality of wafers is deposited by atomic layer deposition.

4. The method of claim 3 , wherein the nitride film on the process kit is formed during deposition of the nitride layer on the plurality of wafers.

5. 10. The method of claim 1, wherein the conditioning process comprises a plasma formed from the conditioning gas, the conditioning gas comprising at least one plasma species having nitrogen and hydrogen atoms.

6. The method of claim 5, wherein the plasma has a frequency in the range of 13.56 to 40 MHz.

7. The method of claim 5, wherein the plasma has a pressure in the range of 1.5 to 10 Torr.

8. The method of claim 5 , wherein the conditioning process is performed in 5 minutes or less.

9. 10. The method of claim 1, wherein the plurality of wafers is in the range of 5 to 50 wafers prior to further exposure to the conditioning process.

10. The method of claim 1 , wherein the process kit includes one or more of a showerhead, a pumping liner, or an edge ring.

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