Processing fitting for processing chamber with protective coating

Abstract

Embodiments described herein generally relate to a method and apparatus for manufacturing a chamber component for a plasma processing chamber. In one embodiment, there is provided a chamber component for use in a plasma processing chamber, the chamber component comprising: a metal substrate material comprising a rough non-planar first surface, where the rough non-planar surface has an Ra surface roughness of between 4 microinches and 80 microinches; a planar silica coating formed over the rough non-planar surface, in which the planar silica coating has: a surface having an Ra surface roughness less than an Ra surface roughness of the rough non-planar surface; a thickness between about 0.2 microns and about 10 microns; a porosity of less than 1% by volume and containing less than 2E12 atoms per cm2 of aluminum.

Description

[0001] This application is a divisional application of the invention patent application with application date of May 21, 2019, application number 201980037849.7, and name “Processing accessories for a processing chamber with a protective coating”. Technical Field

[0002] The present disclosure generally relates to tools and components for plasma processing chamber equipment. More specifically, the present disclosure relates to a method for manufacturing plasma processing chamber components that are resistant to corrosive plasma environments. Background Art

[0003] Semiconductor processing involves many different chemical and physical processes that create tiny integrated circuits on a substrate. The material layers that make up the integrated circuits are created by chemical vapor deposition, physical vapor deposition, epitaxial growth, and the like. Some of the material layers are patterned using photoresist masks and wet or dry etching techniques. The substrate used to form the integrated circuits can be silicon, gallium arsenide, indium phosphide, glass, or other suitable materials.

[0004] A typical semiconductor processing chamber includes a chamber body defining a processing region, a gas distribution assembly adapted to supply gas from a gas supply into the processing region, a gas energizer (e.g., a plasma generator) for energizing the processing gas to process a substrate located on a substrate support assembly, and a gas exhaust. During plasma processing, the energized gas is typically composed of ions and highly reactive species that etch and corrode exposed portions of processing chamber components, such as an electrostatic chuck that holds the substrate during processing. In addition, processing byproducts are typically deposited on chamber components, which are typically cleaned periodically with highly reactive fluorine. In-situ cleaning procedures for removing processing byproducts from the chamber body may further erode the integrity of processing chamber components. Attacks from reactive species during processing and cleaning can shorten the useful life of chamber components and increase maintenance frequency. In addition, flakes from eroded portions of chamber components may become a source of particulate contamination during substrate processing. Furthermore, trace metals from the base material of the chamber components may leach out of the chamber components and contaminate the substrate. Therefore, chamber components are typically replaced after multiple processing cycles and before the chamber components provide inconsistent or undesirable properties 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 throughput.

[0005] Therefore, a need exists for an improved method for forming chamber components that are more resistant to plasma processing chamber environments. Summary of the invention

[0006] Embodiments described herein generally relate to a method and apparatus for manufacturing a chamber component for a plasma processing chamber. In one embodiment, a chamber component for use in a plasma processing chamber is provided, the chamber component comprising: a metal substrate material, the metal substrate material comprising a rough non-planar first surface, wherein the rough non-planar surface has a surface roughness Ra between 4 micro-inches and 80 micro-inches; a planar silicon dioxide coating formed on the rough non-planar surface, wherein the planar silicon dioxide coating has: a surface having a surface roughness Ra less than the surface roughness Ra of the rough non-planar surface; a thickness between about 0.2 microns and about 10 microns; a porosity of less than 1% by volume, and containing less than 2E 12 Atom / cm 2 of aluminum. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Thus, the manner in which the above-described features of the present disclosure may be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be obtained by reference to the embodiments, some of which are shown in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure and are therefore not to be considered limiting of its scope, as the present disclosure may admit to other equally effective embodiments.

[0008] Figure 1A A cross-sectional view of one embodiment of a plasma processing chamber component that may be used within the processing chamber is shown.

[0009] Figure 1B yes Figure 1A A magnified view of plasma processing chamber components.

[0010] Figure 2 A plasma processing system is shown schematically.

[0011] Figure 3 is a table of data showing testing of plasma resistant coatings on chamber components as described herein.

[0012] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are shared by the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0013] Figure 1A A cross-sectional view of one embodiment of a plasma processing chamber component 100 that may be used within a processing chamber is shown. Figure 1B yes Figure 1A FIG. 1 is an enlarged view of a plasma processing chamber component 100. Although the chamber component 100 is Figure 1A1 as having a rectangular cross-section, but for purposes of discussion it is understood that the chamber component 100 may take the form of any chamber component 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 core, a plasma shield, a pedestal, a substrate support assembly, a showerhead, a gas nozzle, and the like.

[0014] The chamber component 100 has at least one exposed surface 114 that is exposed to a plasma environment within a processing chamber when in 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 pits and valleys of the non-planar surface 106 (e.g., planarizes the non-planar surface 106) to produce a smoother surface than the non-planar surface 106.

[0015] The body 102 of the chamber component 100 is a metal material, such as aluminum, stainless steel and alloys thereof, or a ceramic material. The plasma resistant coating 104 is a fully crystallized silicon dioxide material (e.g., silicon dioxide (SiO2)) material. The thickness 116 of the plasma resistant coating 104 is about 0.2 micrometers (μm) to about 10 μm or more. The plasma resistant coating 104 has a porosity of less than about 1% by volume. The outer surface 112 is processed to an average surface roughness (Ra) of about 4 microinches (μ") to about 80 μ". However, the Ra of the plasma resistant coating 104 is less than the Ra of the outer surface 112.

[0016] The plasma resistant coating 104 is applied using a technique such as coating, painting, or spraying the outer surface 112 with a silicon dioxide material. Next, the plasma resistant coating 104 is annealed by placing the coated chamber component 100 in a furnace. Heating relaxes surface tension in the plasma resistant coating 104, which makes the plasma resistant coating 104 conformal or flat and smooth. The heating may be performed at a temperature of about 200 degrees Celsius or less. The heating may be performed for about one hour.

[0017] Figure 2A plasma processing system 200 is schematically shown. The plasma processing system 200 includes a chamber body 225 defining a processing space 241. The chamber body 225 includes a sealable slit valve channel 224 to allow a substrate 201 to enter and exit the processing space 241. The chamber body 225 includes a sidewall 226 and a lid 243. The sidewall 226 and the lid 243 can be made of a metal or ceramic material and include a plasma resistant coating 104 as 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.

[0018] The antenna assembly 270 includes one or more coil antennas disposed coaxially with an axis of symmetry 273 (eg, a longitudinal axis) of the plasma processing system 200. Figure 2 As shown, the plasma processing system 200 includes an outer coil antenna 271 and an inner coil antenna 272 disposed on the cover 243. In one embodiment, the coil antennas 271, 272 can be independently controlled. It should be noted that even though two coaxial antennas are described in the plasma processing system 200, other configurations are also contemplated, such as one coil antenna, three or more coil antenna configurations.

[0019] The inner coil antenna 272 includes one or more electrical conductors that are wound into a spiral shape with a small pitch and form an inner antenna space 274. When current flows through the one or more electrical conductors, a magnetic field is established in the inner antenna space 274 of the inner coil antenna 272. As discussed below, embodiments of the present disclosure provide a chamber extension space within the inner antenna space 274 of the inner coil antenna 272 to generate plasma using the magnetic field in the inner antenna space 274.

[0020] It should be noted that the inner coil antenna 272 and the outer coil antenna 271 may have other shapes depending on the application, such as to match a certain 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 space in a super rectangular shape.

[0021] The plasma processing system 200 further includes a substrate support 240 disposed in the processing space 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 source 220 and a matching network 221 may be connected to the substrate support 240. The bias power source 220 provides a bias potential to the plasma generated in the processing space 241.

[0022] In the illustrated embodiment, the substrate support 240 is surrounded by an annular cathode liner 256. A plasma containment screen or baffle 252 covers the top of the cathode liner 256 and covers the outer peripheral portion of the substrate support 240. The substrate support 240 may contain materials that are incompatible or vulnerable to corrosive plasma processing environments, and the cathode liner 256 and baffle 252 isolate the substrate support 240 from the plasma and contain the plasma in the processing space 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 in the processing space 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.

[0023] The plasma shield 250 is disposed on top of the substrate support 240 to control the spatial distribution of charged and neutral species of the plasma on the surface of the substrate 201. In one embodiment, the plasma shield 250 includes a substantially planar member electrically isolated from the chamber wall and includes a plurality of holes extending vertically through the planar member. The plasma shield 250 may include a high purity plasma resistant coating 104 as described above, which resists the processing environment within the processing space 241.

[0024] The cover 243 has an opening 244 to allow one or more process gases to enter. In one embodiment, the opening 244 may be disposed near a central axis of the plasma processing system 200, which corresponds to the center of the substrate 201 being processed.

[0025] The plasma processing system 200 includes a chamber extension 251 disposed on a cover 243 that covers an 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 space 242 in fluid communication with the processing space 241 via the opening 244.

[0026] The plasma processing system 200 includes a gas distribution showerhead, shown as a baffle nozzle assembly 255 disposed adjacent to the opening 244 in the processing volume 241 and the extension volume 242. The baffle nozzle assembly 255 directs one or more processing gases into the processing volume 241 through the extension volume 242. In one embodiment, the baffle nozzle assembly 255 has a bypass path that allows the processing gas to enter the processing volume 241 without passing through the extension volume 242. The baffle nozzle assembly 255 is made of aluminum and includes the plasma resistant coating 104 as described above.

[0027] Because the extension space 242 is within the inner antenna space 274, the process gas in the extension space 242 is exposed to the magnetic field of the inner coil antenna 272 before entering the process space 241. The use of the extension space 242 increases the plasma intensity within the process space 241 without increasing the power applied to the inner coil antenna 272 or the outer coil antenna 271.

[0028] The plasma processing system 200 includes a pump 230 and a throttle valve 235 to provide vacuum and exhaust the processing space 241. The throttle valve 235 may include a gate valve core 254. The gate valve core 254 may be made of aluminum. The plasma processing system 200 further includes a cooler 245 to control 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 operated to control the pressure within the chamber body 225.

[0029] The plasma processing system 200 also includes a gas delivery system 202 to provide one or more processing gases to the processing space 241. The gas delivery system 202 is located in a housing 205, which is disposed directly adjacent to the chamber body 225 (such as below the chamber body 225). The gas delivery system 202 selectively couples one or more gas sources located in one or more gas panels 204 to a baffle nozzle assembly 255 to provide processing gases to the chamber body 225. The gas delivery system 202 is connected to the baffle nozzle assembly 255 to provide gas to the processing space 241. The housing 205 is located near the chamber body 225 to reduce gas conversion time, minimize gas usage, and minimize gas waste when changing gases.

[0030] The plasma processing system 200 further includes a lift system 227 for raising and lowering a substrate support 240 that supports the substrate 201 in the chamber body 225 .

[0031] In the illustrated embodiment, the chamber body 225 is protected by a lower liner 222 and an upper liner 223, which may be aluminum and include a plasma resistant coating 104 as described above.

[0032] The gas delivery system 202 can be used to supply at least two different gas mixtures to the chamber body 225 at an instantaneous rate, as further described below. In an optional embodiment, the plasma processing system 200 can include a spectral monitor that is operable to measure the depth of the etched trenches and the thickness of the deposited films as the trenches are formed in the chamber body 225, and has the ability to use other spectral features to determine the status of the reactor. The plasma processing system 200 can accommodate a variety of substrate sizes, such as substrates up to about 300 mm in diameter or larger.

[0033] The plasma resistant coating 104 described above can be used to manufacture various chamber components in the above-mentioned processing system 200. These chamber components are often exposed to the plasma processing environment. For example, the plasma resistant coating 104 can be applied to the chamber body 225, the upper liner 223 of the chamber body, the lower liner 222 of the chamber body, the plasma door 224 of the chamber body, the cathode liner 256, the gas ring of the chamber cover, the throttle valve core 254, the plasma shield 250, the baffle nozzle assembly 255, the baffle 252 and the pedestal or substrate support 240.

[0034] Figure 3 3 is a data table 300 showing testing of the plasma resistant coating 104 on the chamber component 100. The testing of the plasma resistant coating 104 showed low levels of trace metals in or on the plasma resistant coating 104. This demonstrates that the plasma resistant coating 104 effectively blocks metal atoms from leaching from the body 102 of the chamber component 100 into the coating 104. For example, the aluminum concentration in the plasma resistant coating 104 is less than about 2E 12 Atoms / cm2 (atoms / cm 2 ). Many other trace metals are present in or on the plasma resistant coating 104, but are below critical levels.

[0035] The disclosed processing chamber and components thereof can be used in one or more substrate processing operations. The following description provides one such exemplary process, but other processes are contemplated.

[0036] In one example, a processing chamber such as chamber body 225 is treated with H2 plasma without a substrate placed therein. Plasma treatment of chamber body 225 prior to introduction of a substrate into the chamber may be referred to as Plasma Every Wafer (PEW). Plasma treatment of a processing chamber or PEW may include introducing one or more gases such as O2, N2, NH3, Ar, H2, He, or a combination thereof into chamber body 225, and exciting 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 chamber body 225, and the plasma is formed in a remote plasma source outside chamber body 225.

[0037] In one embodiment, NH3 and Ar gases are introduced into the chamber body 225. In another embodiment, O2 and H2 gases are introduced into the chamber body 225. In another embodiment, O2 and Ar gases 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. The step of plasma treating the chamber body 225 prior to introducing the substrate typically involves introducing or forming a plasma containing oxygen or nitrogen gas in the processing chamber.

[0038] In some embodiments, one or more gases are excited by an RF power source. The RF power may be pulsed at a duty cycle of 2% to 70% and may be in a range of about 100 W to about 2500 W. The RF power may be a continuous wave ranging from about 100 W to about 2500 W. The chamber body 225 may have a chamber pressure ranging from about 10 millitorr (mT) to about 200 mTorr during plasma processing of the chamber body 225. The processing temperature, which may be the temperature of a substrate support pedestal such as substrate support 240, may have a range from 20 degrees Celsius to about 500 degrees Celsius.

[0039] Thereafter, the substrate (optionally with a gate stack thereon) is treated by a hydrogen-containing plasma within the chamber body 225. The hydrogen-containing plasma treatment of the substrate may include introducing a hydrogen-containing gas (such as H2 gas), or a hydrogen-containing gas and an inert gas (such as Ar gas) into the chamber body 225, and exciting the H2 gas or H2 / Ar gas to form a hydrogen-containing plasma. Ar gas may be added to the H2 gas to improve the life of the chamber body 225 (further mitigating hydrogen-containing plasma erosion of components inside the chamber body 225) and to adjust the H* radical concentration. In some embodiments, the H2 gas or H2 / Ar gas is excited by an RF power source (such as the RF power source 215). The RF power may be pulsed at a duty cycle of 2% to 60%, and may have a range from about 100 W to about 2500 W. The RF power may be a continuous wave ranging from about 100 W to about 2500 W. During the hydrogen-containing plasma treatment of the substrate, the chamber body 225 may have a chamber pressure ranging from about 10 mT to about 200 mT. The treatment temperature (which may be the temperature of the substrate support) may have a range from 20° C. to about 500° C. The substrate may be treated with the hydrogen-containing plasma for about 10 to 360 seconds. In one embodiment, the chamber pressure is about 100 mT, H2 gas flows into the chamber body 225 at about 25 standard cubic centimeters per minute (sccm), and Ar gas flows into the chamber body 225 at about 975 sccm, the RF power is about 500 W, the treatment temperature is about 400° C., and the substrate is treated with the hydrogen-containing plasma for about 30 to 90 seconds. After the substrate is treated with the hydrogen-containing plasma, the substrate may be removed from the chamber body 225.

[0040] It is contemplated that other and further processes may be performed within the chamber body 225. Furthermore, it is contemplated that the coated chamber components may be used with other and additional processes.

[0041] Through the above examples and explanations, the features and spirit of the embodiments of the present disclosure are described. Those skilled in the art will easily observe that many modifications and changes can be made. Therefore, the above disclosure should be interpreted as being limited only by the boundaries of the attached claims.

Claims

1. A chamber component for a processing chamber, comprising: A substrate material comprising a roughened surface, wherein the roughened surface has an average surface roughness (Ra) in a range of 4 microinches to 80 microinches; and A silicon dioxide coating is formed on the rough surface, wherein: The formed silicon dioxide coating has a surface having an Ra smaller than the Ra of the rough surface; and The formed silicon dioxide coating blocks atoms from filtering out of the substrate material and entering the formed silicon dioxide coating, so that the surface of the formed silicon dioxide coating contains less than 2E 12 Atom / cm 2 of metal.

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

3. The chamber component of claim 1, wherein the metal is at least a part of the composition of the substrate material.

4. The chamber component of claim 1, wherein the substrate material comprises a gas distribution showerhead, a nozzle assembly, or a baffle. 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 roughened surface is a metal surface.

8. The chamber component of claim 1, wherein the surface of the formed silicon dioxide coating contains more than 0 atoms / cm 2 of metal.

9. The chamber component of claim 1, wherein: The rough surface includes pits, and the silicon dioxide coating fills the pits.

10. The chamber component of any one of claims 1-9, wherein the silicon dioxide coating has a thickness in the range of 0.2 microns to 10 microns.

11. The chamber component of claim 10, wherein the silicon dioxide coating has a porosity of less than 1% by volume.

12. A chamber component for a processing chamber, comprising: A body comprising a roughened surface, wherein the roughened surface has an average surface roughness (Ra) in a range of 4 microinches to 80 microinches; and A silicon dioxide coating is formed on the rough surface, wherein: The silica coating blocks atoms from filtering out of the main body and entering the silica coating, so that the surface of the silica coating contains less than 2E 12 Atom / cm 2 of metal.

13. The chamber component of claim 12, wherein a surface of the silicon dioxide coating has an Ra smaller than the Ra of the roughened surface.

14. The chamber component of claim 12, wherein the body comprises a gas distribution showerhead or nozzle assembly.

15. The chamber component of claim 12, wherein the body comprises a baffle.

16. A processing chamber comprising: a chamber body defining a processing space; a substrate support disposed in the processing space; a gas inlet opening for allowing gas to flow into the processing space; One or more chamber components, each comprising: A body comprising a roughened surface, wherein the roughened surface has an average surface roughness (Ra) in a range of 4 microinches to 80 microinches; and A silicon dioxide coating is formed on the rough surface, wherein: The silica coating blocks atoms from filtering out of the main body and entering the silica coating, so that the surface of the silica coating contains less than 2E 12 Atom / cm 2 of metal.

17. The processing chamber of claim 16, wherein the substrate material comprises aluminum and the metal is aluminum.

18. The processing chamber of claim 16, wherein the metal is at least a part of the composition of the substrate material.

19. The processing chamber of claim 16, wherein a surface of the silicon dioxide coating has an Ra smaller than the Ra of the roughened surface.

20. The processing chamber of any of claims 16-19, wherein the silica coating has a thickness in a range of 0.2 microns to 10 microns, and the silica coating has a porosity of less than 1% by volume.

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