Process chamber process kit with protective coating - Patent application

Abstract

To provide a plasma processing chamber component that is resistant to a corrosive plasma environment, and an apparatus.SOLUTION: In a plasma processing system, a chamber component used within a plasma processing chamber is provided, the chamber component including: a metallic base material comprising a roughened non-planar first surface, the roughened non-planar surface having a surface roughness Ra of 4 micro-inches to 80 micro-inches; and a planar silica coating formed over the roughened non-planar surface, the planar silica coating having a surface that has a surface roughness Ra that is less than the surface roughness Ra of the roughened non-planar surface, a thickness of about 0.2 microns to about 10 microns, and less than 1% porosity by volume, and containing less than 2E12atoms / cm2 of aluminum.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001]

[0001] This disclosure relates generally to tools and components for use in plasma processing chamber apparatus. More particularly, this disclosure relates to methods for manufacturing plasma processing chamber components that are resistant to corrosive plasma environments. [Background technology]

[0002]

[0001] Semiconductor processing involves a variety of chemical and physical processes by which minute integrated circuits are fabricated on a substrate. The layers of materials that make up an integrated circuit are fabricated by chemical vapor deposition, physical vapor deposition, epitaxial growth, etc. Some of the layers of material are patterned using photoresist masks and wet or dry etching techniques. The substrates utilized to form integrated circuits can be silicon, gallium arsenide, indium phosphide, glass, or other suitable materials.

[0003] A typical semiconductor processing chamber includes a chamber body defining a process zone, a gas distribution assembly adapted to deliver gas from a gas supply to the process zone, a gas energizer, e.g., a plasma generator, utilized to energize process gases for processing a substrate disposed on a substrate support assembly, and a gas exhaust. During plasma processing, the energized gases are often composed of ions and reactive species that etch and erode exposed portions of processing chamber components, such as an electrostatic chuck that holds the substrate during processing. Furthermore, processing by-products often deposit on chamber components that are routinely cleaned with reactive fluorine. In-situ cleaning procedures used to remove processing by-products from within the chamber body can further erode the integrity of processing chamber components. Attack from reactive species during processing and cleaning shortens the lifespan of chamber components and increases maintenance frequency. Furthermore, flakes from eroded portions of chamber components can cause particulate contamination during substrate processing. Furthermore, trace metals from the base material of chamber components can leach from the chamber components and contaminate substrates. Therefore, chamber components are typically replaced after several process cycles and before they begin to provide inconsistent or undesirable performance during substrate processing. However, frequent replacement of chamber components shortens the useful life of the processing chamber, increases chamber downtime, increases maintenance frequency, and reduces substrate yield.

[0004]

[0003] Therefore, there is a need for improved methods for forming chamber components that are more resistant to the plasma processing chamber environment. Summary of the Invention

[0005]

[0004] Embodiments described herein generally relate to methods and apparatus for manufacturing chamber components for plasma processing chambers. In one embodiment, a chamber component for use in a plasma processing chamber is provided, the chamber component comprising: a metal-based material including a rough, non-planar first surface having an Ra surface roughness of between 4 microinches and 80 microinches; a planar silica coating formed on the rough, non-planar surface, the planar silica coating having an Ra surface roughness less than the Ra surface roughness of the rough, non-planar surface; a thickness of between about 0.2 microns and about 10 microns; a porosity of less than 1% by volume; and a porosity of 2E12 atoms / cm 2 and a planar silica coating containing less than 1000 ppm of aluminum.

[0006]

[0005] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly summarized above can be made by 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 therefore should not be considered as limiting its scope, since the present disclosure may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0007] [Figure 1A] 1 illustrates a cross-sectional view of one embodiment of a plasma processing chamber component that may be used in the processing chamber. [Figure 1B] FIG. 1B is an enlarged view of the plasma processing chamber components of FIG. 1A. [Figure 2] 1 illustrates a schematic representation of a plasma processing system. [Figure 3] 1 is a data sheet showing testing of a plasma resistant coating on a chamber component as described herein. DETAILED DESCRIPTION OF THE INVENTION

[0008]

[0010] For ease of understanding, identical elements common to the figures have been designated using identical reference numerals where possible. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0009]

[0011] FIG. 1A shows a cross-sectional view of one embodiment of a plasma processing chamber component 100 that may be used in a processing chamber. FIG. 1B shows an enlarged view of the plasma processing chamber component 100 of FIG. 1A. For purposes of discussion, the chamber component 100 is shown in FIG. 1A as having a rectangular cross-section, but it is understood that the chamber component 100 can take the form of any chamber part, including, but not limited to, a chamber body, a chamber body upper liner, a chamber body lower liner, a chamber body plasma door, a cathode liner, a chamber lid gas ring, a throttle gate valve spool, a plasma screen, a pedestal, a substrate support assembly, a showerhead, a gas nozzle, etc.

[0010]

[0012] The chamber component 100 has at least one exposed surface 114 that is exposed to a plasma environment in a processing chamber during use. The chamber component 100 includes a body 102 having a plasma-resistant coating 104 disposed on an outer surface 112 of a non-planar (rough) surface 106 of the body 102. The plasma-resistant coating 104 fills in depressions and valleys in the non-planar surface 106 (e.g., flattens the non-planar surface 106), creating a much smoother surface than the non-planar surface 106.

[0011]

[0013] The body 102 of the chamber component 100 is a metallic material, such as aluminum, stainless steel, and alloys thereof, or a ceramic material. The plasma-resistant coating 104 is a fully crystallized silica material (e.g., silicon dioxide (SiO2)). The thickness 116 of the plasma-resistant coating 104 is about 0.2 microns (μm) to about 10 μm, or greater. The plasma-resistant coating 104 has a porosity of less than about 1% by volume. The outer surface 112 is finished to an average surface roughness (Ra) of about 4 microinches (μ") to about 80 μ". However, the plasma-resistant coating 104 has an Ra that is less than the Ra of the outer surface 112.

[0012]

[0014] The plasma resistant coating 104 is applied using techniques such as painting, sprinkling, or spraying a silica material onto the exterior surface 112. The plasma resistant coating 104 is then annealed by placing the coated chamber component 100 in a furnace. The heating relieves the surface tension of the plasma resistant coating 104, causing the plasma resistant coating 104 to become conformal or flat and smooth. The heating can be to a temperature of about 200 degrees Celsius or less. The heating can be performed for about one hour.

[0013]

[0015] FIG. 2 schematically illustrates a plasma processing system 200. The plasma processing system 200 includes a chamber body 225 that defines a processing volume 241. The chamber body 225 includes a sealable slit valve tunnel 224 to allow passage of the substrate 201 into and out of the processing volume 241. The chamber body 225 includes a sidewall 226 and a lid 243. The sidewall 226 and the lid 243 may be fabricated from a metal or ceramic material and may include the plasma-resistant coating 104 described herein. The plasma processing system 200 further includes an antenna assembly 270 disposed on the lid 243 of the chamber body 225. A radio frequency (RF) power source 215 and a matching network 217 are coupled to the antenna assembly 270 to provide energy for plasma generation.

[0014]

[0016] The antenna assembly 270 includes one or more coil antennas arranged coaxially with an axis of symmetry 273 (e.g., a longitudinal axis) of the plasma processing system 200. As shown in FIG. 2, the plasma processing system 200 includes an outer coil antenna 271 and an inner coil antenna 272 arranged on the lid 243. In one embodiment, the coil antennas 271, 272 can be independently controlled. It should be noted that while two coaxial antennas are depicted in the plasma processing system 200, other configurations are contemplated, such as a single coil antenna, three or more coil antenna configurations, etc.

[0015]

[0017] The inner coil antenna 272 includes one or more conductors that are helically wound with a small pitch and form an inner antenna volume 274. When a current is passed through the one or more conductors, a magnetic field is established in the inner antenna volume 274 of the inner coil antenna 272. As discussed below, embodiments of the present disclosure provide a chamber extension volume within the inner antenna volume 274 to generate a plasma using the magnetic field within the inner antenna volume 274 of the inner coil antenna 272.

[0016]

[0018] It should be noted that the inner coil antenna 272 and the outer coil antenna 271 may have other shapes depending on the application, for example, to match a particular shape of the chamber wall or to achieve symmetry or asymmetry within the chamber body 225. In one embodiment, the inner coil antenna 272 and the outer coil antenna 271 may form an inner antenna volume in the shape of a super-rectangular prism.

[0017]

[0019] The plasma processing system 200 further includes a substrate support 240 disposed within the process volume 241. The substrate support 240 supports the substrate 201 during processing. In one embodiment, the substrate support 240 is an electrostatic chuck. A bias power supply 220 and a matching network 221 may be connected to the substrate support 240. The bias power supply 220 provides a bias potential to the plasma generated within the process volume 241.

[0018]

[0020] In the illustrated embodiment, the substrate support 240 is surrounded by a ring-shaped cathode liner 256. A plasma containment screen or baffle 252 covers the top of the cathode liner 256 and covers a peripheral portion of the substrate support 240. The substrate support 240 may comprise a material that is incompatible or weak in the corrosive plasma processing environment, and the cathode liner 256 and baffle 252 isolate the substrate support 240 from the plasma and contain the plasma within the process volume 241, respectively. In one embodiment, the cathode liner 256 and baffle 252 may include a high-purity plasma-resistant coating 104 that is resistant to the plasma contained within the process volume 241. The plasma-resistant coating 104 on the cathode liner 256 and baffle 252 as described above improves the service life of the cathode liner 256 and baffle 252.

[0019]

[0021] A plasma screen 250 is disposed on top of the substrate support 240 to control the spatial distribution of charged and neutral species of the plasma across the surface of the substrate 201. In one embodiment, the plasma screen 250 comprises a substantially planar member electrically insulated from the chamber walls and includes a plurality of apertures extending vertically through the planar member. The plasma screen 250 may include a high-purity plasma-resistant coating 104, as described above, that is resistant to the process environment within the processing volume 241.

[0020]

[0022] The lid 243 has an opening 244 to allow the entry of one or more process gases. In one embodiment, the opening 244 may be located near a central axis of the plasma processing system 200 corresponding to the center of the substrate 201 being processed.

[0021]

[0023] The plasma processing system 200 includes a chamber extension 251 disposed on the lid 243 over the opening 244. In one embodiment, the chamber extension 251 is disposed inside the coil antenna of the antenna assembly 270. The chamber extension 251 defines an extension volume 242 in fluid communication with the processing volume 241 through the opening 244.

[0022]

[0024] The plasma processing system 200 includes a gas distribution showerhead, shown as a baffle nozzle assembly 255, positioned adjacent the opening 244 of the process volume 241 and the expansion volume 242. The baffle nozzle assembly 255 directs one or more process gases through the expansion volume 242 and into the process volume 241. In one embodiment, the baffle nozzle assembly 255 has a bypass path that allows the process gases to enter the process volume 241 without passing through the expansion volume 242. The baffle nozzle assembly 255 may be fabricated from aluminum and may include a plasma-resistant coating 104 as described above.

[0023]

[0025] Because the expansion volume 242 is within the inner antenna volume 274, the process gas within the expansion volume 242 is exposed to the magnetic field of the inner coil antenna 272 before entering the process volume 241. The use of the expansion volume 242 increases the plasma intensity within the process volume 241 without increasing the power applied to the inner coil antenna 272 or the outer coil antenna 271.

[0024]

[0026] The plasma processing system 200 includes a pump 230 and a throttle valve 235 for providing a vacuum and evacuating the processing volume 241. The throttle valve 235 may include a gate valve spool 254. The gate valve spool 254 may be fabricated from aluminum. The plasma processing system 200 further includes a chiller 245 for controlling the temperature of the plasma processing system 200. The throttle valve 235 may be disposed between the pump 230 and the chamber body 225 and may be operable to control the pressure within the chamber body 225.

[0025]

[0027] The plasma processing system 200 also includes a gas supply system 202 for supplying one or more process gases to the process volume 241. The gas supply system 202 is disposed within a housing 205 disposed directly adjacent, such as below, the chamber body 225. The gas supply system 202 selectively couples one or more gas sources disposed in one or more gas panels 204 to a baffle nozzle assembly 255 to supply process gases to the chamber body 225. The gas supply system 202 is connected to the baffle nozzle assembly 255 to supply gases to the process volume 241. The housing 205 is disposed in close proximity to the chamber body 225 to reduce gas transition times when changing gases, minimize gas usage, and minimize gas waste.

[0026]

[0028] The plasma processing system 200 further includes a lift system 227 for raising and lowering a substrate support 240 that supports the substrate 201 within the chamber body 225 .

[0027]

[0029] In the embodiment shown, the chamber body 225 may be aluminum and is protected by a lower liner 222 and an upper liner 223 which may include a plasma resistant coating 104 as described above.

[0028]

[0030] Gas delivery system 202 can be used to supply at least two different gas mixtures at instantaneous rates to chamber body 225, as described further below. In an optional embodiment, plasma processing system 200 can include a spectral monitor operable to measure the depth of the etched trench and the deposited film thickness as the trench is formed in chamber body 225, and capable of using other spectral features to determine reactor conditions. Plasma processing system 200 can accommodate a variety of substrate sizes, for example, substrate diameters up to about 300 mm or larger.

[0029]

[0031] Various chamber components of the processing system 200 described above can be fabricated using the plasma-resistant coating 104 described above. These chamber components are frequently exposed to plasma processing environments. For example, the plasma-resistant coating 104 can be applied to the chamber body 225, the chamber body upper liner 223, the chamber body lower liner 222, the chamber body plasma door 224, the cathode liner 256, the chamber lid gas ring, the throttle gate valve spool 254, the plasma screen 250, the baffle nozzle assembly 255, the baffle 252, and the pedestal or substrate support 240.

[0030]

[0032] FIG. 3 is a data sheet 300 showing testing of the plasma resistant coating 104 on the chamber component 100. Testing of the plasma resistant coating 104 showed low levels of trace metals in or on the plasma resistant coating 104. This proves that the plasma resistant coating 104 effectively prevents metal atoms from the body 102 of the chamber component 100 from leaching into the coating 104. For example, the aluminum concentration in the plasma resistant coating 104 is about 2E12 atoms per square centimeter (atoms / cm 2 ) Many other trace metals were present in or on the plasma resistant coating 104, but below critical levels.

[0031]

[0033] The disclosed process chamber and its components can be used in one or more substrate processing steps. The following description provides one such exemplary process, although other processes are contemplated.

[0032]

[0034] In one example, a process chamber, such as the chamber body 225, is treated with H plasma without a substrate disposed therein. Plasma treatment of the chamber body 225 before a substrate is introduced into the chamber may be referred to as Plasma Every Wafer (PEW). Plasma treatment of the process chamber, or PEW, may include introducing one or more gases, such as O, N, NH, Ar, H, He, or a combination thereof, into the chamber body 225 and energizing the one or more gases to form a plasma. Alternatively, PEW may include introducing a plasma containing radicals and / or ions of oxygen, nitrogen, hydrogen, ammonia, hydroxide, or a combination thereof, into the chamber body 225, where the plasma is formed in a remote plasma source outside the chamber body 225.

[0033]

[0035] In one embodiment, NH3 gas and Ar gas are introduced into the chamber body 225. In another embodiment, O2 gas and H2 gas are introduced into the chamber body 225. In another embodiment, O2 gas and Ar gas are introduced into the chamber body 225. In another embodiment, O2 gas is introduced into the chamber body 225. In yet another embodiment, N2 gas is introduced into the chamber body 225. Typically, plasma treating the chamber body 225 prior to introducing the substrate includes introducing or forming a plasma comprising oxygen or nitrogen into the process chamber.

[0034]

[0036] In some embodiments, the one or more gases are energized by an RF power source. The RF power may be pulsed with a duty cycle of 2% to 70% and may range from about 100 W to about 2500 W. The RF power may be continuous wave in the range of about 100 W to about 2500 W. The chamber body 225 may have a chamber pressure in the range of about 10 milliTorr (mT) to about 200 mT during plasma processing of the chamber body 225. The process temperature, which may be the temperature of a substrate support pedestal, such as the substrate support 240, may range from 20° C. to about 500° C.

[0035]

[0037] The substrate (optionally having a gate stack thereon) is then treated with a hydrogen-containing plasma in the chamber body 225. The hydrogen-containing plasma treatment of the substrate may include introducing a hydrogen-containing gas, such as H gas, or a hydrogen-containing gas and an inert gas, such as Ar gas, into the chamber body 225 and energizing the H gas or H gas / Ar gas to form a hydrogen-containing plasma. This may improve the service life of the chamber body 225 (further mitigating hydrogen-containing plasma attack of components within the chamber body 225) and may also reduce the hydrogen-containing plasma attack of the H * To adjust the radical concentration, Ar gas can be added to the H gas. In some embodiments, the H gas or H gas / Ar gas is energized by an RF power source, such as the RF power source 215. The RF power may be pulsed with a duty cycle of 2% to 60% and may range from about 100 W to about 2500 W. The RF power may be continuous wave in the range of about 100 W to about 2500 W. The chamber body 225 may have a chamber pressure in the range of about 10 mT to about 200 mT during the hydrogen-containing plasma treatment of the substrate. The process temperature, which may be the temperature of the substrate support, may range from 20° C. to about 500° C. The substrate may be treated with the hydrogen-containing plasma for about 10 seconds to 360 seconds. In one embodiment, the chamber pressure is about 100 mT, H gas is flowed into the chamber body 225 at about 25 standard cubic centimeters per minute (sccm), Ar gas is flowed into the chamber body 225 at about 975 sccm, the RF power is about 500 W, the process temperature is about 400° C., and the substrate is treated with the hydrogen-containing plasma for about 30-90 seconds. After the substrate has been treated with the hydrogen-containing plasma, the substrate may be removed from the chamber body 225.

[0036]

[0038] It is contemplated that other additional processes may be performed within the chamber body 225. Additionally, it is contemplated that the coated chamber components may be utilized in conjunction with other additional processes.

[0037]

[0039] The above examples and explanations are used to explain the features and spirit of the embodiments of the present disclosure. Those skilled in the art will readily appreciate that numerous modifications and variations may be made. Accordingly, the above disclosure should be construed as limited only by the scope of the appended claims.

Claims

1. 1. A chamber component for use in a processing chamber, comprising: a base material including a rough surface, the rough surface having an average surface roughness (Ra) in the range of 4 microinches to 80 microinches; a silica coating formed on the roughened surface; and Including, the formed silica coating has a surface with an Ra less than the Ra of the rough surface; and The formed silica coating is 2E １２ atoms / cm ２ less than aluminum, a thickness in the range of 0.2 microns to 10 microns, and a porosity of less than 1% by volume to prevent leaching of atoms from the base material into the formed silica coating. Chamber components.

2. The chamber component of claim 1 , wherein the base material comprises aluminum.

3. The chamber component of claim 1 , wherein the aluminum comprises at least a portion of the composition of the base material.

4. The chamber component of claim 1 , wherein the base material comprises a gas distribution showerhead, a nozzle assembly, or a baffle.

5. The chamber component of claim 1 , wherein the base material comprises a liner.

6. The chamber component of claim 5 , wherein the liner comprises a cathode liner.

7. The chamber component of claim 1 , wherein the rough surface is a metal surface.

8. The surface of the formed silica coating has a surface roughness of at least 1E １０ atoms / cm ２ The chamber component of claim 1 , wherein the aluminum comprises:

9. The chamber component of claim 1 , wherein the roughened surface comprises depressions, and the silica coating fills the depressions.

10. 1. A method for manufacturing a component, comprising: depositing a layer of silica on a surface of a body of the chamber component; annealing the silica layer to reduce surface tension in the silica layer; Including, the surface is a rough surface having an average surface roughness (Ra) in the range of 4 microinches to 80 microinches, and the depositing step comprises: painting, sprinkling, or spraying a layer of said silica onto said surface; and placing said body and said layer of silica in a furnace; Including, The annealing step comprises: Heat at a temperature of 200 degrees Celsius or less for approximately 1 hour. Including, the layer of silica has a surface with an Ra that is less than the Ra of the surface of the body; and The silica layer is 2E １２ atoms / cm ２ less than aluminum, a thickness in the range of 0.2 microns to 10 microns, and a porosity of less than 1% by volume to prevent leaching of atoms from the body into the silica layer. method.

11. The method of claim 10 , wherein the surface of the body comprises depressions, and the deposition of the layer of silica fills the depressions.

12. The method of claim 10 , wherein the body comprises aluminum.

13. 1. A method for manufacturing a component, comprising: forming a chamber component body from a material including a roughened surface having an average surface roughness (Ra) in the range of 4 microinches to 80 microinches; depositing a layer of silica on the surface of the body; heating the layer of silica and the material; Including, the silica layer has a surface with an Ra less than the Ra of the rough surface; and The silica layer is 2E １２ atoms / cm ２ less than aluminum, a thickness in the range of 0.2 microns to 10 microns, and a porosity of less than 1% by volume to prevent leaching of atoms from the body into the silica layer. method.

14. The method of claim 13 wherein the material is aluminum.

15. 14. The method of claim 13, wherein the layer of silica and the material are heated for about 1 hour.

16. 16. The method of claim 15, wherein the heating is to a temperature of 200 degrees Celsius or less.

17. The method of claim 13 , wherein the depositing comprises painting, sprinkling, or spraying the layer of silica onto the surface of the body.

18. The rough surface is a metal surface, and the surface of the silica layer has a surface roughness of at least 1E １０ atoms / cm ２ 18. The method of claim 10, wherein the aluminum is

19. Disposing a chamber component as part of a process chamber, the chamber component comprising: a base material including a rough surface having an average surface roughness (Ra) in the range of 4 microinches to 80 microinches; a planar silica coating formed on the roughened surface, the planar silica coating having a surface with an Ra smaller than the Ra of the roughened surface; Including, The planar silica coating is 2E １２ atoms / cm ２ disposing a chamber component having less than 1000 nm of aluminum, a thickness in the range of 0.2 microns to 10 microns, and a porosity of less than 1% by volume to prevent leaching of atoms from the base material into the planar silica coating; Plasma treating the process chamber with a nitrogen or oxygen containing plasma; placing a substrate having a stack disposed thereon into the process chamber; Plasma treating the stack disposed on the substrate; A method comprising:

20. The method of claim 19 , wherein the base material comprises aluminum.

21. 20. The method of claim 19, wherein the nitrogen or oxygen containing plasma is formed by introducing one or more gases into the process chamber and energizing the one or more gases.

22. The one or more gases are O ２ , N ２ , N.H. ３ , Ar, H ２ , He, or a combination thereof.

23. 20. The method of claim 19, wherein plasma treating the stack comprises treating the stack with a plasma containing ammonia.

24. 24. The method of claim 23, wherein forming the ammonia-containing plasma further comprises introducing a hydrogen-containing gas and an inert gas into the process chamber and energizing the hydrogen-containing gas and the inert gas.

25. 20. The method of claim 19, wherein plasma treating the stack comprises treating the stack with a nitrogen-containing plasma.

26. The rough surface is a metal surface, and the surface of the planar silica coating has a surface roughness of at least 1E １０ atoms / cm ２ 26. The method of any one of claims 19 to 25, wherein the aluminum is

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