TW201932298A - Plasma erosion resistant thin film coating for high temperature application - Google Patents

Abstract

An article such as a susceptor includes a body of a thermally conductive semimetal coated by a first protective layer and a second protective layer over a surface of the body. The first protective layer is a thermally conductive ceramic. The second protective layer covers the first protective layer and is a plasma resistant ceramic thin film that is resistant to cracking at temperatures of 650 degrees Celsius.

Description

Plasma-resistant coating for high temperature applications

This patent application claims the benefit of U.S. Provisional Application No. 61/984,691, filed on Apr. 25, 2014.

In general, embodiments of the present invention pertain to protective chamber components that are often exposed to high temperatures and direct or distal plasma environments.

In the semiconductor industry, components are fabricated by a number of process processes that produce structures that are ever-decreasing in size. Certain process processes, such as plasma etching and plasma cleaning processes, expose the substrate to a high speed plasma stream to etch or clean the substrate. The plasma can be highly aggressive and can erode the process chamber and other surfaces that are exposed to the plasma. Therefore, plasma spray protective coatings are commonly used to protect process chamber components from erosion.

Some process processes are performed at high temperatures (eg, temperatures in excess of 400 ° C). Conventional plasma sprayed protective coatings may not be suitable for use with certain chamber components used in the above processes.

In an exemplary embodiment, the article includes a body having a thermally conductive semi-metal. The article further includes a first protective layer on the surface of the body, the first protective layer being a thermally conductive ceramic. The article further includes a second protective layer on the first protective layer, and the second protective layer includes a plasma-resistant ceramic film resistant to cracking at a temperature of 650 °C.

In another exemplary embodiment, a method includes providing an article comprising a thermally conductive semi-metallic body. The method further includes depositing a first protective layer on the surface of the thermally conductive semi-metallic body, the first protective layer being a thermally conductive ceramic. The method further includes performing ion assisted deposition to deposit a second protective layer on the first protective layer, the second protective layer comprising a plasma resistant ceramic film resistant to cracking at a temperature of 650 °C.

In another exemplary embodiment, the susceptor of the atomic layer deposition chamber includes a graphite body. The pedestal further includes a first protective layer on the surface of the graphite body, and the first protective layer includes tantalum carbide. The pedestal further includes a second protective layer on the first protective layer, the second protective layer comprising a plasma-resistant ceramic film resistant to cracking at a temperature of 650 ° C, wherein the second protective layer comprises a selected from the group consisting of Er ₃ Al ₅ O ₁₂ , Y ₃ A group of ceramics composed of Al ₅ O ₁₂ and YF ₃ .

Embodiments of the present invention provide articles having a thin film protective layer on one or more surfaces of an article (e.g., chamber components for an atomic layer deposition (ALD) chamber). The protective layer can have a thickness of less than about 50 microns and can provide plasma erosion resistance to protect the article. The chamber components can be exposed to high temperatures during wafer processing. For example, the chamber components can be exposed to temperatures in excess of 450 °C. A film protective layer capable of resisting or effectively immunizing these high temperature cracks is formed in the above manner. The thin film protective layer can be a dense, conformal film deposited on a heated substrate using ion assisted deposition (IAD). The thin film protective layer may be formed of Y ₃ Al ₅ O ₁₂ , Er ₃ Al ₅ O ₁₂ or YF ₃ . The improved corrosion resistance provided by the film protective layer improves the life of the article while reducing maintenance and manufacturing costs.

1 is a cross-sectional view of a process chamber 100 having one or more chamber components coated with a thin film protective layer in accordance with an embodiment of the present invention. The process chamber 100 can be an ALD process chamber. In one embodiment, the process chamber 100 utilizes a remote plasma unit to deliver fluorine radicals (F*) into the process chamber 100 for chamber cleaning. Alternatively, the embodiments described herein can be used with other types of process chambers.

The process chamber 100 can be used in a high temperature ALD process. For example, the process chamber 100 can be used for the deposition of titanium nitride (TiN). The TiN deposition process is typically performed in an ALD process at 450 ° C or above. Another exemplary high temperature ALD process is the deposition of dichlorosilane (DCS) tungsten telluride. The DCS antimony tungsten process is performed by the reaction of WF ₆ , DCS and SiH ₄ at a temperature of about 500-600 ° C. Other high temperature ALD processes can be performed by the process chamber 100.

Examples of chamber components that may include a thin film protective layer include a pedestal 134, a chamber body 105, a showerhead 110, and the like. The thin film protective layer described in more detail below may include Y ₃ Al ₅ O ₁₂ (YAG), Er ₃ Al ₅ O ₁₂ (EAG), and/or YF ₃ . In some embodiments, the thin film protective layer can also include other ceramics. Furthermore, the thin film protective layer can be one of the layers of the protective layer stack. The pedestal 134 has a thin film protective layer (second protective layer 136) as described in accordance with one embodiment. However, it should be understood that any of the other chamber components (eg, those listed above) may also include a thin film protective layer.

In one embodiment, the process chamber 100 includes a chamber body 105 enclosing an interior space 106 and a showerhead 110. The chamber body 105 can be constructed of aluminum, stainless steel, or other suitable material. The chamber body 105 generally includes a side wall and a bottom. Any of the showerhead 110, the sidewalls, and/or the bottom may include a thin film protective layer.

The chamber discharge device 125 and one or more discharge ports 137 may exhaust the exhaust gases into the interior space 106 of the chamber. The bleed enthalpy 137 can be coupled to a pumping system that includes one or more pumps 160 and a throttle valve 156 and/or gate valve 154 for venting and regulating the pressure of the interior space 106 of the process chamber 100.

The showerhead 110 can be supported by the sidewall of the chamber body 105. The showerhead 110 (or cover) can be opened to allow access to the interior space 106 of the process chamber 100 and can provide a seal to the process chamber 100 when closed. The showerhead 110 can include a gas distribution plate and one or more nozzles 122, 123, 124. The showerhead 110 can be made of aluminum, stainless steel or other suitable material. Alternatively, in certain embodiments, the showerhead 110 can be replaced by a cover and a nozzle.

The gas panel 152 can provide process and/or cleaning gas to the interior space 106 through the showerhead 110 through one or more gas delivery lines 138-146. Examples of process gases that can be used to perform a CVD operation to deposit a layer on a substrate include NH ₃ , TiCl ₄ , tetrakis(dimethylamino)titanium (TDMAT), WF ₆ , DCS, SiH _{4 ,} and the like, depending on the deposition to be performed. Floor. A remote plasma source (RPS) 150 can generate fluorine radicals (F*) during the cleaning process and can transport fluorine radicals through one or more gas delivery lines 138-146. The gas delivery lines 138-146, the discharge weir 137, and the showerhead 110 may be covered by a dome 180, which may be aluminum or another suitable material.

The chamber components, such as the inner wall of the chamber body 105, the showerhead 110, the pedestal 134, and the like, accumulate a layer of deposited material during processing. To mitigate changes in deposition properties and particulate contamination, the deposited layer can be periodically cleaned from the chamber components using a remote plasma cleaning process. Examples of cleaning gases that can be used to clean deposited materials from the surface of the chamber components include halogen-containing gases (such as C ₂ F ₆ , SF ₆ , SiCl ₄ , HBr, NF ₃ , CF ₄ , CHF ₃ , CH ₂ F ₃ , F). , NF ₃ , Cl ₂ , CCl ₄ , BCl ₃ and SiF _{4 ,} etc.) with other gases (such as O ₂ or N ₂ O). Examples of carrier gases include N ₂ , He, Ar, and other gases that are inert to the cleaning gas (eg, non-reactive gases). In one embodiment, NF ₃ and Ar are used to perform a plasma cleaning process.

The pedestal 134 is disposed in the interior space 106 of the process chamber 100 and below the showerhead 110 and supported by the pedestal 132. The susceptor 134 holds one or more substrates during processing. The pedestal 134 is configured to rotate around the center during the ALD process to ensure uniform distribution of process gases that interact with one or more substrates. The uniform distribution described above improves the thickness uniformity of the layers deposited on one or more substrates.

The pedestal 134 is configured to be heated throughout the process and maintain uniform heat throughout the susceptor 134. Therefore, the susceptor 134 may have a body composed of a heat conductive material that is highly resistant to thermal shock. In one embodiment, the body is a semi-metallic material such as graphite. The pedestal 134 may also have a body comprised of other materials having high thermal shock resistance (eg, glass-carbon).

The pedestal 134 has a plurality of recesses. Each recess is approximately equal to the size of the substrate (eg, wafer) held in the recess. The substrate may be vacuum attached (clamped) to the pedestal 134 during processing.

In one embodiment, the body of the pedestal 134 has a first protective layer 135 on at least one surface and a second protective layer 136 over the first protective layer 135. In one embodiment, the first protective layer is SiC and the second protective layer is one of Y ₃ Al ₅ O ₁₂ (YAG), Er ₃ Al ₅ O ₁₂ (EAG) or YF ₃ . In another embodiment, the pedestal 134 has only a single protective layer, and the single protective layer is one of Y ₃ Al ₅ O ₁₂ (YAG), Er ₃ Al ₅ O ₁₂ (EAG), or YF ₃ . In other embodiments, an additional protective layer can also be applied. An exemplary pedestal is illustrated in more detail with reference to Figures 2A-2B.

In one embodiment, one or more heating elements 130 are disposed below the pedestal 134. One or more thermal shields may also be disposed adjacent the heating element 130 to protect components that should not be heated to high temperatures. In one embodiment, the heating element 130 is a resistive or inductive heating element. In another embodiment, the heating element is a radiant heating bulb. In certain embodiments, the heating element 130 can heat the susceptor 134 to a temperature of up to 700 ° C or higher.

FIG. 2A depicts an exemplary susceptor 200 for an ALD chamber. The susceptor 200 has a thin film protective coating. In one embodiment, the thin film protective coating coats only the upper surface of the pedestal. Alternatively, the thin film protective coating coats the upper and lower surfaces of the pedestal. A thin film protective layer may also coat the sidewalls of the pedestal. The purpose of the susceptor 200 is to support and uniformly heat a plurality of wafers simultaneously. The susceptor 200 can be heated radiatively using a resistive heating element or bulb. The susceptor 200 is coated along the supported wafer by atomic single layer deposition (ALD) or other CVD process during processing. In order to increase the mean time between cleanings (MTBC), the susceptor 200 should be periodically cleaned to avoid peeling of the coating due to internal film stress developed during subsequent processing. The susceptor 200 can be cleaned by either thermal or remote plasma processing. In the distal plasma cleaning example using NF ₃ , fluorine radicals (F*) are generated distally and transported into the process zone to remove the deposited film. However, F* at high temperatures will also etch the susceptor material (eg, CVD SiC and graphite). Therefore, a protective coating that is corrosion resistant to the applied chemical is applied. The protective coating also allows for "over-etching" for a period of time to ensure removal of the deposited film as a whole.

In one embodiment, the susceptor 200 includes a semi-metallic thermally conductive mount, such as graphite. The susceptor 200 can have a disk-like profile that is large enough to support multiple substrates (eg, multiple wafers). In one embodiment, the base has a diameter of more than 1 meter.

The susceptor 200 can include one or more recesses (also referred to as recesses) 201-206, each of which can be configured to support a wafer or other substrate during processing. In the depicted example, base 200 includes six recesses 201-206. However, other pedestals may have more or fewer recesses.

The recesses 201-206 each include a number of surface features. Examples of surface features in the recess 201 include an outer ring 208, a plurality of humps 206, and a groove or gas passage between the humps 206. In some embodiments, the features have a height of between about 10 and 80 microns.

In one embodiment, the susceptor 200 further includes a CVD deposited SiC or SiN layer on one or more surfaces of the thermally conductive semi-metal base. The recesses 201-206 and surface features, such as the humps 206 and the outer ring 208, are fluidly coupled to the heat transfer (or backside) gas source (eg, He) through the bore of the bore in the susceptor 200. In operation, the backside gas inlet channel can be provided under controlled pressure to assist in heat transfer between the susceptor 200 and the substrate.

The recess and surface features can be formed in the body of the susceptor 200 prior to depositing the first protective layer. Alternatively, recesses and/or surface features may be formed in the first protective layer after the first protective layer is deposited over. The second protective layer can be a conformal thin film protective layer conformal to the recess and surface features. Alternatively, surface features can be formed in the second protective layer. Therefore, all surface features, such as humps 206 and outer ring 208, are present on the surface of the second protective layer. In one embodiment, the second protective layer has a thickness of between about 5 and 50 microns. In another embodiment, the second protective layer has a thickness of less than 20 microns. In another embodiment, the second protective layer has a thickness of up to 1000 microns.

The base 200 additionally includes a lift pin hole 210. For example, the base 200 can include three lift pin holes that support a lift pin (eg, an Al ₂ O ₃ lift pin). The lift pins can load the wafer onto the susceptor 200 and unload the wafer from the susceptor 200. The base 200 can include a recess 215 that can be used to clamp the base to the axis of rotation. The recess 215 can include a bore 220 that can be used to mechanically secure the base 200 to the rotating shaft.

FIG. 2B depicts an enlarged cross-sectional view of the susceptor 200 having the insertion hole of the plasma resistant socket 250. IAD and PVD are line of sight processes. Therefore, the thin film protective coating may not have the interior of the holes in the susceptor, such as the lift pin holes 210, the holes 220, or the x-holes. In one embodiment, a preliminary aperture having an oversized size is formed in the pedestal. A plasma resistant socket (eg, plasma resistant socket 250) can be separately fabricated and inserted into oversized holes. The plasma resistant socket 250 can be press mounted (eg, mechanically pressed) into an oversized hole. The plasma resistant socket 250 may be formed from a block of sintered plasma resistant ceramic material, such as AlN, Y ₂ O ₃ , a ceramic compound comprising a solid-solution of Y ₄ Al ₂ O ₉ and Y ₂ O ₃ -ZrO ₂ or another rare earth oxide .

The plasma resistant socket 250 itself may have a final hole at the center of the plasma resistant socket 250, wherein the final hole has a desired diameter. The CVD deposited layer and/or thin film protective layer may be coated only with the pedestal, or both the pedestal and the plasma resistant socket 250. In one embodiment, the CVD deposited layer is deposited prior to insertion into the plasma resistant socket 250. A thin film protective layer can then be deposited after insertion of the plasma resistant socket 250. The thin film protective layer can fill and/or any gap between the outer wall of the bridge socket 250 and the initial hole inserted into the socket 250. In some instances, the thin film protective layer may not be thick enough to bridge the gap between the socket and the initial hole inserted into the socket. Thus, a CVD coating can be deposited after insertion into the socket to bridge any gaps. A thin film protective layer can then be deposited over the CVD coating.

In one embodiment, the bottom of the plasma resistant socket is narrower than the top of the plasma resistant socket (as shown). This allows the plasma resistant socket to be pressed into a predetermined depth of the base 200.

Figures 3-5 depict cross-sectional side views of articles (e.g., chamber components) covered by one or more thin film protective layers. 3 depicts a cross-sectional side view of one embodiment of an article 300 having a first protective layer 330 and a second protective layer 308. The first protective layer can be SiC, SiN or another ceramic material. The first protective layer 330 may have been deposited onto the body 305 by a CVD process. The first protective layer can have a thickness of up to 200 microns. In one embodiment, the first protective layer is about 5 to 100 microns thick.

The second protective layer 308 may be a ceramic thin film protective layer applied to the first protective layer 330 by IAD. Two exemplary IAD processes that can be used to deposit the second protective layer 308 include electron beam IAD (EB-IAD) and ion beam sputtering IAD (IBS-IAD). The second protective layer 308 can serve as a top coat and can serve as a corrosion resistant barrier layer and seal the exposed surface of the first protective layer 330 (eg, sealing the inner surface of the first protective layer 330 from cracking and holes).

The second protective layer 308 deposited by the IAD can have relatively low film stress (e.g., film stress caused by plasma spray or sputtering). The second protective layer 308 of IAD deposition may additionally have a porosity of less than 1% and a porosity of less than about 0.1% in certain embodiments. Therefore, the protective layer of IAD deposition is a dense structure, which has an implementation advantage applied to the chamber components. Additionally, the IAD deposited second protective layer 308 can be deposited without first roughening the first protective layer 330 or performing other time consuming surface preparation steps.

Examples of ceramics that can be used to form the second protective layer 308 include Y ₃ Al ₅ O ₁₂ (YAG), Er ₃ Al ₅ O ₁₂ (EAG), and YF ₃ . Another exemplary ceramic that can be applied is Y ₄ Al ₂ O ₉ (YAM). Any of the ceramics shown above may include minor amounts of other materials such as ZrO ₂ , Al ₂ O ₃ , SiO ₂ , B ₂ O ₃ , Er ₂ O ₃ , Nd ₂ O ₃ , Nb ₂ O ₅ , CeO ₂ , Sm. ₂ O ₃ , Yb ₂ O ₃ or other oxides.

The body 305 and/or the first protective layer 330 of the article 300 can include one or more surface features. For the pedestal, the surface features may include recesses, humps, sealing strips, gas passages, helium holes, and the like. For the showerhead, the surface features may include hundreds or thousands of gas distribution holes, divots or bumps surrounding the gas distribution holes, and the like. Other chamber components may have other surface features.

The second protective layer 308 can conform to the surface features of the body 305 and the first protective layer 330. For example, the second protective layer 308 can maintain a relative shape of the upper surface of the first protective layer 330 (eg, a shape that exposes features in the first protective layer 330). Additionally, the second protective layer 308 can be thin enough to not plug the holes in the body 305 and/or the first protective layer 330. The second protective layer can have a thickness of less than 1000 microns. In one embodiment, the second protective layer 308 has a thickness of less than about 20 microns. In a further embodiment, the second protective layer has a thickness between about 0.5 microns and about 7 microns.

In an alternate embodiment, the first protective layer 330 can be omitted. Thus, only a single Y ₃ Al ₅ O ₁₂ (YAG), Er ₃ Al ₅ O ₁₂ (EAG), YF ₃ or Y ₄ Al ₂ O ₉ (YAM) protective layer can be deposited on one or more surfaces of the body 305. .
Table 1: Material properties of YAM, YF ₃ , YAG and EAG deposited by IAD

Table 1 shows the material properties of YAM deposited, YAM, YF ₃ , YAG and EAG. As shown, the 5 micron (μm) IAD deposited YAM coating has a breakdown voltage of 695 volts (V). The 5 μm IAD deposited YF ₃ coating has a breakdown voltage of 522 V. The 5 μm IAD deposited YAG coating has a breakdown voltage of 1080 V. The 5 μm IAD deposited EAG coating has a breakdown voltage of 900 V.

The dielectric constant of YF ₃ on 1.6 mm alumina is about 9.2, the dielectric constant of YAG film is about 9.76, and the dielectric constant of EAG film is about 9.54. About YF ₃ film on 1.6 mm alumina For 9E-4, the YAG film has a loss tangent of about 4E-4, while the EAG film has a loss tangent of about 4E-4. The thermal conductivity of the YAG film is about 20.1 W/mK, while the thermal conductivity of the EAG film is about 19.2 W/mK.

For each of the labeled ceramic materials, the adhesion strength of the thin film protective layer to the alumina substrate can be higher than 27 megapascals (MPa). The adhesion strength can be determined by measuring the force used to separate the protective layer of the film from the substrate.

Sealing measurements utilize the sealing capabilities achievable with a thin film protective layer. As shown in the table, the He leakage rate of about 2.6E-9 cubic centimeters (cm ³ /s) per second can be achieved by using YF ₃ , and the He leakage rate of about 4.4E-10 can be achieved by YAG, and the EAG can be achieved by using EAG. A He leakage rate of about 9.5E-10 was achieved. A lower He leakage rate represents an improved seal. The exemplary film protective layers each have a He leakage rate lower than typical Al ₂ O ₃ .

Y ₃ Al ₅ O ₁₂ , Y ₄ Al ₂ O ₉ , Er ₃ Al ₅ O ₁₂ and YF ₃ each have a hardness which is resistant to abrasion during plasma treatment. As shown, YF ₃ has a Vickers hardness (5 Kgf) of about 3.411 billion Pascals (GPa), YAG has a hardness of about 8.5 GPa, and EAG has a hardness of about 9.057 GPa. The measured wear rate of YAG is about 0.28 nm (nm/RFhr) per RF, while the EAG wear rate is about 0.176 nm/RFhr.

It is noted that in certain embodiments, Y ₃ Al ₅ O ₁₂ , Y ₄ Al ₂ O ₉ , Er ₃ A _l5 O ₁₂ and YF ₃ may be modified such that the properties and characteristics of the material indicated above may vary up to 30%. Therefore, it should be understood that the values described for the properties of these materials are exemplary achievable values. The ceramic film protective layer described herein should not be construed as being limited to the value provided.

4 depicts a cross-sectional side view of an embodiment of article 400 having a thin film protective layer stack 406 deposited on body 405 of article 400. In an alternate embodiment, the thin film protective layer stack 406 can be deposited on the first protective layer of SiC or SiN.

One or more thin film protective layers (such as first layer 408 and/or second layer 410) in thin film protective layer stack 406 can be one of YAG, YAM, EAG, or YF ₃ . In addition, some of the protective layers may include Er ₂ O ₃ , Gd ₂ O ₃ , Gd ₃ Al ₅ O ₁₂ or a solid-solution including Y ₄ Al ₂ O ₉ and Y ₂ O ₃ -ZrO ₂ (solid- Solution) of a ceramic compound. In one embodiment, the same ceramic material is not used for two adjacent thin film protective layers. However, in another embodiment, adjacent layers may be constructed of the same ceramic.

FIG. 5 depicts a cross-sectional side view of another embodiment of article 500 having a thin film protective layer stack 506 deposited on body 505 of article 500. Alternatively, the thin film protective layer stack 506 can be deposited on the SiC or SiN layer. Object 500 is similar to article 400 except that thin film protective layer stack 506 has four thin film protective layers 508, 510, 515, 518.

Thin film protective layer stacks (eg, those described) can have any number of thin film protective layers. The thin film protective layers in the stack may each have the same thickness or may have different thicknesses. Each of the film protective layers can have a thickness of less than about 50 microns and a thickness of less than about 10 microns in certain embodiments. In one example, the first layer 408 can have a thickness of 3 microns and the second layer 410 can have a thickness of 3 microns. In another example, the first layer 508 can be a YAG layer having a thickness of 2 microns, the second layer 510 can be a compound ceramic layer having a thickness of 1 micron, and the third layer 515 can be a YAG layer having a thickness of 1 micron, and The fourth layer 518 can be a compound ceramic layer having a thickness of 1 micron.

The choice of the number of ceramic layers and the composition used for the ceramic layer can be based on the desired application and/or type of article to be coated. The EAG, YAG and YF ₃ thin film protective layers formed by IAD generally have an amorphous structure. Conversely, IAD deposited compound ceramics and Er ₂ O ₃ layers typically have crystalline or nanocrystalline structures. Crystalline and nanocrystalline structural ceramic layers are generally more resistant to corrosion than amorphous ceramic layers. However, in some instances, a thin film ceramic layer having a crystalline structure or a nanocrystalline structure may undergo sporadic vertical rupture (approximately in the film thickness direction and substantially perpendicular to the coated surface.) The above vertical rupture can be caused by lattice mismatch and can be the point of attack of the plasma chemistry. The mismatch in the coefficient of thermal expansion between the film protective layer and the substrate to which the film protective layer is applied each time the article is heated and cooled causes stress on the film protective layer. The above stresses will be concentrated in the vertical rupture. This causes the film protective layer to eventually peel off from the substrate coated by the film protective layer. Conversely, if there is no vertical rupture, the stress will approximately disperse evenly across the film.

Thus, in one embodiment, the first layer 408 of the thin film protective layer stack 406 is an amorphous ceramic such as YAG or EAG, and the second layer 410 of the thin film protective layer stack 406 is a crystalline or nanocrystalline ceramic. (such as ceramic compounds or Er ₂ O ₃ ). In the above embodiments, the second layer 410 can provide greater plasma resistance relative to the first layer 408. By forming the second layer 410 on the first layer 408 rather than directly on the body 405 (or SiC or SiN protective layer), the first layer 408 acts as a buffer to minimize lattice mismatch of subsequent layers. Therefore, the life of the second layer 410 can be increased.

In another example, the host, Y ₃ Al ₅ O ₁₂ (YAG), Y ₄ A _l2 O ₉ , Er ₂ O ₃ , Gd ₂ O ₃ , Er ₃ Al ₅ O ₁₂ , Gd ₃ Al ₅ O ₁₂ , The ceramic compounds including the solid-solution of Y ₄ Al ₂ O ₉ and Y ₂ O ₃ -ZrO ₂ may each have different coefficients of thermal expansion. The greater the mismatch in the coefficient of thermal expansion between two adjacent materials, the greater the likelihood that one of these materials will ultimately rupture, peel, or otherwise lose bond with other materials. The protective layer stacks 406, 506 can be formed in the manner described above to minimize the mismatch in the coefficient of thermal expansion between adjacent layers (or between the layers and the bodies 405, 505). For example, body 505 can be graphite, and EAG can have a coefficient of thermal expansion that is closest to the coefficient of thermal expansion of graphite, followed by a coefficient of thermal expansion of YAG, followed by a coefficient of thermal expansion of the compound ceramic. Thus, in one embodiment, the first layer 508 can be an EAG, the second layer 510 can be a YAG, and the third layer 515 can be a compound ceramic.

In another example, the layers in the protective layer stack 506 can be alternating layers of two different ceramics. For example, a first layer 508 and the third layer 515 may be a YAG, and the second layer 510 and fourth layer 518 may EAG or YF _3. The alternating layers described above may provide advantages similar to those set forth above, in which one of the materials used in the alternating layers is amorphous and the other material used in the alternating layers is crystalline or nanocrystalline.

In another example, a thin film coating having a discernable color can be deposited at a location in the thin film protective layer stack 406 or 506. For example, a thin film coating having a discernible color can be deposited on the bottom of the film stack. For example, a thin film coating having a discernible color can be Er ₂ O ₃ or SmO ₂ . When the technician sees a discernable color, he or she can be alerted that the pedestal should be replaced or refreshed.

In some embodiments, one or more of the thin film protective layer stacks 406, 506 are transition layers formed using heat treatment. If the bodies 405, 505 are ceramic bodies, a high temperature heat treatment can be performed to promote interdiffusion between the film protective layer and the body. In addition, heat treatment may be performed to promote interdiffusion between adjacent thin film protective layers or between thick protective layers and thin film protective layers. It is worth noting that the transition layer can be a non-porous layer. The transition layer acts as a diffusion bond between the two ceramics and provides improved adhesion between adjacent ceramics. This can help to avoid cracking, flaking or stripping of the protective layer during the plasma treatment process.

The heat treatment can be a heat treatment that lasts up to about 24 hours (e.g., in one embodiment, 3-6 hours) up to about 1400-1600 °C. This can result in an interdiffusion layer between the first film protective layer and one or more of the adjacent ceramic body, thick protective layer or second film protective layer.

FIG. 6 depicts one embodiment of a process 600 for forming one or more protective layers on an article. At block 605 of process 600, a pedestal is provided. The pedestal can be used in an ALD process chamber. In one embodiment, the susceptor has a thermally conductive semi-metallic body (a semi-metallic body having good thermal conductivity). In one embodiment, the thermally conductive semi-metallic body is a graphite body. Alternatively, a non-thermally conductive pedestal can be provided. The non-thermally conductive pedestal may have a body composed of carbon-glass. In other embodiments, items other than the base may be provided. For example, an aluminum showerhead for an ALD process chamber can be provided.

In one embodiment, at block 608, the plasma-resistant ceramic socket is inserted into a hole in the base. The plasma resistant ceramic socket can be pressed into the hole. In an alternate embodiment, the plasma-resistant ceramic socket is inserted into the hole in the base after the block of text 610. In another embodiment, no plasma resistant ceramic socket is inserted into the hole in the base.

At block 610, a CVD process is performed to deposit a first protective layer on the provided pedestal. In one embodiment, the first protective layer covers only the plasma facing surface of the pedestal. In another embodiment, the first protective layer covers the front and back sides of the base. In another embodiment, the first protective layer covers the front, back and sides of the base. In one embodiment, the first protective layer is SiC. Alternatively, the first protective layer can be SiN or another suitable material. The first protective layer can have a thickness of up to about 200 microns. The surface features of the pedestal can be processed into the graphite. In one embodiment, the first protective layer is ground after deposition.

At block 615, the susceptor is heated to a temperature above 200 °C. For example, the susceptor can be heated to a temperature of 200-400 °C. In one embodiment, the susceptor is heated to a temperature of 300 °C.

At block 620, when the susceptor is heated, the IAD is performed to deposit a second protective layer on one or more surfaces of the first protective layer. In one embodiment, the second protective layer covers only the plasma facing surface of the first protective layer. In another embodiment, the second protective layer covers the first protective layer on the front and back sides of the pedestal. In another embodiment, the second protective layer covers each surface of the first protective layer. In one embodiment, oxygen and/or argon ions are directed to the susceptor by an ion gun prior to IAD deposition. Oxygen and argon ions can burn off any surface organic contaminants on the first protective layer and dissipate any residual particles.

The two types of IAD that can be performed include EB-IAD and IBS-IAD. The EB-IAD can be performed by evaporation. The IBS-IAD can be performed by sputtering a solid target material. The second protective layer may be Y ₃ Al ₅ O ₁₂ , Y ₄ Al ₂ O ₉ , Er ₃ Al ₅ O ₁₂ or YF ₃ . The second protective layer can be amorphous and resistant to cracking at temperatures of 450 °C. In one embodiment, the protective layer may not experience any cracking after repeated thermal cycling up to 550 °C. In a further embodiment, the second protective layer resists cracking at temperatures up to 650 °C. The second protective layer is resistant to cracking, and although the second protective layer is deposited on the first protective layer and the pedestal, both the first protective layer and the pedestal have different coefficients of thermal expansion from the second protective layer.

The deposition rate of the second protective layer can be about 1-8 angstroms per second and can be varied by adjusting the deposition parameters. In one embodiment, the deposition rate is 1-2 angstroms per second (A/s). The deposition rate can also be altered during the deposition process. In one embodiment, an initial deposition rate of about 0.25-1 A/s is used to achieve a conformal good adhesion coating on the substrate. Next, a deposition rate of 2-10 A/s was used to achieve a thicker coating in a shorter and more cost effective coating.

The second protective layer can be a film protective layer that is very conformal, uniform in thickness, and well adhered to the deposited material. In one embodiment, the second protective layer has a thickness of less than 1000 microns. In a further embodiment, the second protective layer has a thickness of from 5 to 50 microns. In still further embodiments, the thickness of the second protective layer is less than 20 microns.

At block 625, a decision is made as to whether any additional protective layers (e.g., any additional thin film protective layers) are deposited. If an additional protective layer is about to be deposited, the process continues to block 630. At block 630, another protective layer is formed on the second protective layer using the IAD.

In one embodiment, the other protective layer is composed of a ceramic different from the ceramic of the second protective layer. In one embodiment, the other protective layer is Y ₃ Al ₅ O ₁₂ , Y ₄ Al ₂ O ₉ , Er ₂ O ₃ , Gd ₂ O ₃ , Er ₃ Al ₅ O ₁₂ , Gd ₃ Al ₅ O ₁₂ , YF ₃ or one of a solid-solution ceramic compound of Y ₄ Al ₂ O ₉ and Y ₂ O ₃ -ZrO ₂ .

In another embodiment, the other protective layer is comprised of the same ceramic as the ceramic of the second protective layer. For example, the mask can be placed on the pedestal after the second protective layer is formed. The mask can have an opening in which features such as a humour and seal will be formed on the base (eg, in a recess in the base). Additional protective layers can then be deposited to form these features. In one embodiment, the features (eg, ridges) have a height of 10-20 microns.

The method then returns to block 625. If no additional thin film protective layer is applied at block 625, the process is terminated.

Figure 7A depicts a deposition mechanism suitable for use in a variety of deposition techniques utilizing energy particles, such as ion assisted deposition (IAD). Exemplary IAD methods include deposition processes incorporating ion bombardment, such as evaporation in the presence of ion bombardment (such as activated reactive evaporation (ARE) or EB-IAD) and sputtering (eg, IBS-IAD) ) to form a plasma resistant coating as described herein. Any of the IAD methods can be performed in the presence of a reactive gas species such as O ₂ , N ₂ , halogen, and the like.

As shown, a thin film protective layer 715 is formed by accumulating deposition material 702 in the presence of energy particles 703 (eg, ions). Deposited material 702 includes atoms, ions, free radicals, or a mixture of the foregoing. The energy particles 703 can collide and compress the film protective layer 715 as the film protective layer 715 is formed.

In one embodiment, the thin film protective layer 715 is formed using IAD as described previously herein. Figure 7B depicts a schematic of an IAD deposition apparatus. As shown, material source 752 (also referred to as the target body) provides a flow of deposition material 702 while energy particle source 755 provides a flow of energy particles 703 that both collide with object 750 throughout the IAD process. The energy particle source 755 can be an oxygen or other ion source. The energy particle source 755 can also provide other types of energy particles, such as inert radicals, neutron atoms, and nano-sized particles from a particle-generating source (such as from a plasma, a reactive gas, or from a source of material that provides a deposition material). . The source of material (e.g., target body) 752 for providing deposition material 702 can be a ceramic agglomerate that corresponds to the same ceramic that will form the thin film protective layer 715. For example, the material source may be a ceramic compound agglomerate, or a YAG, Er ₂ O ₃ , Gd ₂ O ₃ , Er ₃ Al ₅ O ₁₂ , YF ₃ or Gd ₃ Al ₅ O ₁₂ agglomerate. The IAD can utilize one or more plasmas or beams to provide a source of material and an ion source of energy. Alternatively, the source of material can be a metal.

Reactive species can also be provided during the deposition of the plasma resistant coating. In one embodiment, the energy particles 703 comprise at least one of a non-reactive species (eg, Ar) or a reactive species (eg, O). In further embodiments, reactive species such as CO and halogen (Cl, F, Br, etc.) may also be introduced during the plasma resistant coating formation to further increase the selectivity to remove most of the weakly bonded bonds to The tendency of the thin film protective layer 715 to deposit material.

The energy particles 703 can be controlled by an energy ion (or other particulate) source 755 independently of other deposition parameters in an IAD process. The energy (eg, rate), density, and angle of incidence of the energy ion flux can be adjusted to control the composition, structure, crystallographic orientation, and grain size of the thin film protective layer. Additional parameters that can be adjusted are the temperature of the object during deposition and the deposition period.

Ion-assisted energy is utilized to densify the coating and accelerate material deposition on the surface of the substrate. Both the voltage and current of the ion source can be utilized to change the ion assist energy. Voltage and current can be adjusted to achieve high and low coating densities, control coating stress, and coating crystallinity. The ion assist energy ranges from about 50 to 500 V and is about 1 to 50 amps (A). Ion-assisted energy can also be utilized to deliberately change the stoichiometry of the coating. For example, a metal target can be applied during the deposition process and converted to a metal oxide.

The coating temperature can be controlled by heating the deposition chamber and/or substrate with a heater and by adjusting the deposition rate. The temperature of the substrate (object) during deposition can be roughly divided into low temperature (about 120-150 ° C, typically room temperature in one embodiment) and high temperature (in one embodiment, about 270 ° C or higher). In one embodiment, a deposition temperature of about 300 ° C is used. Alternatively, a higher (e.g., up to 450 °C) or lower (e.g., as low as room temperature) deposition temperature can be applied. The deposition temperature can be applied to adjust film stress, crystallinity, and other coating properties.

The working distance is the distance between the electron beam (or ion beam) gun and the substrate. The working distance can be varied to achieve the coating with the highest uniformity. In addition, the working distance can affect the deposition rate and density of the coating.

The deposition angle is the angle between the electron beam (or ion beam) and the substrate. The deposition angle can be varied by changing the position and/or orientation of the substrate. By optimizing the deposition angle, a uniform coating of three-dimensional geometry can be achieved.

EB-IAD and IBS-IAD deposition are suitable for a wide range of surface conditions. However, an abrasive surface is preferred to achieve a uniform coating coverage. A variety of fixtures can be used to hold the substrate during the IAD deposition process.

Figure 8 depicts the corrosion rate of a thin film protective layer formed in accordance with an embodiment of the present invention. Figure 8 shows the corrosion rate of the thin film protective layer when exposed to NF ₃ plasma chemistry. As shown, the IAD deposited thin film protective layer shows more improved corrosion resistance than SiC. For example, SiC shows a corrosion rate of more than 2.5 μm (μm/RFHr) per RF hour. Conversely, the IAG, YAG, and YF ₃ thin film protective layers deposited by IAD exhibited corrosion rates below 0.2 μm/RFHr.

The foregoing description has set forth various specific embodiments, such as the specific embodiments, However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without the specific details. In other instances, conventional components or methods have not been described in detail or exist in a simple text block diagram format to avoid unnecessarily interfering with the present invention. Therefore, the specific details presented are merely exemplary. Particular embodiments may be distinguished from these exemplary details and are still considered to be within the scope of the invention.

References to "one embodiment" or "an embodiment" are intended to mean that a particular feature, structure, or characteristic is described in the at least one embodiment. Thus, the appearance of the phrase "in one embodiment" or "in an embodiment" In addition, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". When the term "about" or "approximately" is used herein, it is intended to mean that the nominal numerical value presented is within ±30%.

Although the operations of the methods herein are illustrated and described in a particular order, the order of operation of the various methods can be modified so that some operations can be performed in the reverse order or some of the operations of the at least some of the operations can be performed in conjunction with other operations. In another embodiment, the instructions or sub-operations of the unique operation may be in an intermittent and/or alternating manner.

The above description is intended to be illustrative, and not restrictive. Many other embodiments are known to those skilled in the art after reading and understanding the above description. The scope of the invention should be determined by the scope of the appended claims and the full scope of the equivalents.

100‧‧‧Processing chamber

105‧‧‧ Chamber body

106‧‧‧Internal space

110‧‧‧ sprinkler

122, 123, 124‧ ‧ nozzle

125‧‧‧Cell discharge device

130‧‧‧heating elements

132‧‧‧Base

134, 200‧‧‧ pedestal

135, 330‧‧‧ first protective layer

136, 308‧‧‧ second protective layer

137‧‧‧Emissions

138, 140, 142, 144, 146‧‧ gas pipelines

150‧‧‧Remote plasma source

152‧‧‧ gas panel

154‧‧‧ gate valve

156‧‧‧ throttle valve

160‧‧‧ pump

201, 202, 203, 204, 205, 206, 215‧ ‧ recess

208‧‧‧ outer ring

210‧‧‧Uplift hole

220‧‧‧ hole

250‧‧‧Pure-resistant socket

300, 400, 500, 750‧‧‧ objects

305, 405, 505‧‧‧ subjects

406, 506‧‧ ‧ film protective layer stacking

408, 508‧‧‧ first floor

410, 510‧‧‧ second floor

515‧‧‧ third floor

518‧‧‧ fourth floor

600‧‧‧Process

605, 608, 610, 615, 620, 625, 630 ‧ ‧ text blocks

702‧‧‧deposited materials

703‧‧‧ energy particles

715‧‧‧film protective layer

752‧‧‧Material source

755‧‧‧Energy particle source

The present invention is described by way of example, and not by way of limitation, It should be noted that the different element symbols of the "one" or "one" embodiment are not necessarily directed to the same embodiment, and the above-described element symbols mean at least one.

Figure 1 depicts a cross-sectional view of one embodiment of a process chamber.

Figure 2A depicts a susceptor for atomic layer deposition (ALD) with a thin film protective coating on one surface.

Figure 2B depicts an enlarged cross-sectional view of a susceptor for an atomic layer deposition chamber having a plasma resistant socket embedded in the hole.

Figures 3-5 depict cross-sectional side views of an exemplary article having a stack of protective layers on a surface.

Figure 6 depicts one embodiment of a process for forming one or more protective layers on an article.

Figure 7A depicts a deposition mechanism suitable for a variety of deposition techniques utilizing energy particles, such as ion assisted deposition (IAD).

Figure 7B depicts a schematic of an IAD deposition apparatus.

Figure 8 depicts the corrosion rate of a thin film protective layer formed in accordance with an embodiment of the present invention.

Domestic deposit information (please note in the order of the depository, date, number)
no

Foreign deposit information (please note in the order of country, organization, date, number)
no

Claims (20)

An object, including: a body comprising a thermally conductive material, wherein the body comprises a hole; a plasma resistant socket, the plasma resistant socket is inserted into the hole; a first protective layer, the first protective layer is located on a surface of the body, the first protective layer is a thermally conductive ceramic; A second protective layer is disposed on the first protective layer, and the second protective layer comprises a plasma-resistant ceramic film that resists cracking at a temperature of up to 650 °C. The article of claim 1 wherein the thermally conductive material comprises graphite. The article of claim 1 wherein the thermally conductive material comprises a thermally conductive semimetal and the first protective layer comprises tantalum carbide. The article of claim 1, wherein the object is a susceptor for an atomic layer deposition chamber. The article of claim 1, wherein the second protective layer comprises a ceramic selected from the group consisting of Er ₃ Al ₅ O ₁₂ , Y ₃ Al ₅ O ₁₂ and YF ₃ . The article of claim 1, wherein the second protective layer has a thickness of 5 to 50 microns. The article of claim 1, wherein the plasma resistant socket is composed of a sintered ceramic comprising AlN, Y ₂ O ₃ or a Y ₄ Al ₂ O ₉ and a Y ₂ O ₃ -ZrO ₂ At least one of a solid-solution ceramic compound. The article of claim 1, wherein a first diameter of the hole corresponds to an outer diameter of the plasma receptacle, and wherein the plasma resistant socket includes a second hole, the second hole having a smaller than the first diameter a second diameter. The object of claim 1, wherein: The first protective layer does not cover the plasma resistant socket; and The second protective layer covers the plasma resistant socket. The object of claim 1, wherein: A bottom of the plasma resistant socket has a smaller outer diameter than a top of the plasma resistant socket. The object of claim 1, wherein: a gap between an outer wall of the plasma resistant socket and a wall of the hole inserted into the plasma resistant socket; and The first protective layer covers the plasma resistant socket and at least partially fills the gap between the wall of the hole and the outer wall of the plasma resistant socket. A method comprising the following steps: Drilling a hole in a heat conducting body; Inserting a plasma resistant socket into the hole; Depositing a first protective layer on a surface of the thermally conductive body, the first protective layer being a thermally conductive ceramic; Ion-assisted deposition is performed to deposit a second protective layer on the first protective layer, the second protective layer comprising a plasma-resistant ceramic film that resists cracking at temperatures up to 650 °C. The method of claim 12, further comprising the steps of: Heating the heat conducting body to a temperature of about 200-400 ° C; and The ion assisted deposition is performed when the thermally conductive body and the first protective layer are heated. The method of claim 12, wherein the step of depositing the first protective layer comprises the step of performing a chemical vapor deposition process. The method of claim 12, wherein the thermally conductive body comprises a susceptor for an atomic layer deposition chamber, the thermally conductive body comprises graphite, the first protective layer comprises tantalum carbide, and the second protective layer comprises a A ceramic selected from the group consisting of Er ₃ Al ₅ O ₁₂ , Y ₃ Al ₅ O ₁₂ and YF ₃ . The method of claim 12, wherein the second protective layer has a thickness of 5 to 50 microns. The method of claim 12, wherein the plasma resistant socket is inserted into the hole after depositing the first protective layer and before performing the ion assisted deposition step. The method of claim 12, wherein the plasma resistant socket is comprised of a sintered ceramic comprising AlN, Y ₂ O ₃ or a Y ₄ Al ₂ O ₉ and a Y ₂ O ₃ -ZrO ₂ At least one of a solid-solution ceramic compound, and wherein the plasma resistant socket includes an additional aperture having a diameter that is smaller than the aperture of the plasma resistant socket. The method of claim 12, wherein the plasma resistant socket is inserted into the hole prior to depositing the first protective layer, wherein an outer wall of the plasma resistant socket and a wall of the hole inserted into the plasma resistant socket There is a gap therebetween, and wherein the first protective layer covers the plasma resistant socket and at least partially fills the gap between the wall of the hole and the outer wall of the plasma resistant socket. A component for an atomic layer deposition chamber, comprising: a graphite body; a plurality of holes in the graphite body; a plurality of plasma resistant sockets, wherein the plurality of plasma resistant sockets are each inserted into one of the plurality of holes; a first protective layer, the first protective layer is disposed on a surface of the graphite body, the first protective layer includes tantalum carbide; and a second protective layer is disposed on the first protective layer, The second protective layer comprises a plasma-resistant ceramic film that resists cracking at a temperature of up to 650 ° C, wherein the second protective layer comprises an oxide layer selected from the group consisting of Er ₃ Al ₅ O ₁₂ and Y ₃ Al ₅ O ₁₂ a ceramic of the group of YF ₃ ; wherein at least one of the first protective layer or the second protective layer covers the plurality of plasma resistant sockets.