TWI710472B - 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 corrosion resistant thin film coating for high temperature applications

This patent application claims the benefits of U.S. Provisional Application No. 61/984,691 filed on April 25, 2014 in accordance with the Patent Law.

Generally speaking, the embodiments of the present invention relate to protective chamber components that are often exposed to high temperatures and direct or remote plasma environments.

In the semiconductor industry, devices are manufactured by a large number of process processes that produce structures that are always reduced in size. Certain process processes (such as plasma etching and plasma cleaning processes) expose the substrate to a high-speed plasma flow to etch or clean the substrate. The plasma can be highly aggressive and can erode the process chamber and other surfaces exposed to the plasma. Therefore, plasma sprayed protective coatings are often used to protect process chamber components from corrosion.

Some process treatments are performed at high temperatures (for example, temperatures exceeding 400°C). Traditional plasma sprayed protective coatings may not be suitable for certain chamber components used in the above processes.

In an exemplary embodiment, the article includes a body with a thermally conductive semi-metal. The object further includes a first protective layer on the surface of the main body, and the first protective layer is a thermally conductive ceramic. The object further includes a second protective layer on the first protective layer, and the second protective layer includes a plasma resistant ceramic film that can resist cracking at a temperature of 650°C.

In another exemplary embodiment, a method includes providing an article including a thermally conductive semi-metal body. The method further includes depositing a first protective layer on the surface of the thermally conductive semi-metal body, and the first protective layer is 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 includes a plasma resistant ceramic film that can resist cracking at a temperature of 650°C.

In another exemplary embodiment, the base of the atomic layer deposition chamber includes a graphite body. The base further includes a first protective layer on the surface of the graphite body, and the first protective layer includes silicon carbide. The base further includes a second protective layer on the first protective layer. The second protective layer includes a plasma-resistant ceramic film that can resist cracking at a temperature of 650° C., and the second protective layer includes Er ₃ Al ₅ O ₁₂ , Y ₃ Al ₅ O ₁₂ and YF ₃ constitute the group of ceramics.

Embodiments of the present invention provide an object having a thin film protective layer on one or more surfaces of the object (for example, a chamber component used in an atomic layer deposition (ALD) chamber). The protective layer may have a thickness of less than about 50 microns, and may provide plasma erosion resistance to protect the object. The chamber components can be exposed to high temperatures during wafer processing. For example, the chamber components can be exposed to temperatures exceeding 450°C. In the above-mentioned manner, a thin-film protective layer capable of resisting or effectively immune to rupture at these high temperatures is formed. The thin-film protective layer may be a dense, conformal thin film deposited on a heating 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 thin-film protective layer can improve the service life of the object while reducing maintenance and manufacturing costs.

FIG. 1 is a cross-sectional view of a process chamber 100. The process chamber 100 has one or more chamber components coated with a thin film protective layer according to an embodiment of the present invention. The process chamber 100 may be an ALD process chamber. In one embodiment, the process chamber 100 utilizes a remote plasma unit to transport fluorine radicals (F*) into the process chamber 100 for chamber cleaning. Alternatively, the embodiments described herein can be used in 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 usually an ALD process performed at a temperature of 450°C or higher. Another exemplary high-temperature ALD process is the deposition of dichlorosilane (DCS) tungsten silicide. The DCS tungsten silicide 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 base 134, a chamber body 105, a shower head 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 may also include other ceramics. In addition, the thin-film protective layer may be one layer in the protective layer stack. According to the description of one embodiment, the base 134 has a thin-film protective layer (the second protective layer 136). However, it should be understood that any of the other chamber components (e.g., those listed above) may also include a thin film protective layer.

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

The chamber exhaust device 125 and one or more exhaust ports 137 can exhaust the exhaust gas from the inner space 106 of the chamber. The exhaust port 137 can be connected to a pumping system, which includes one or more pumps 160 and a throttle valve 156 and/or a gate valve 154 for emptying and adjusting the pressure of the internal space 106 of the process chamber 100.

The shower head 110 can be supported by the side wall of the chamber body 105. The shower head 110 (or cover) can be opened to allow access to the inner space 106 of the process chamber 100, and can provide a seal to the process chamber 100 when closed. The shower head 110 may include a gas distribution plate and one or more nozzles 122, 123, and 124. The spray head 110 may be made of aluminum, stainless steel or other suitable materials. Alternatively, in some embodiments, the spray head 110 can be replaced by a cap and a nozzle.

The gas panel 152 can provide process and/or cleaning gas to the internal space 106 through the shower head 110 through one or more gas delivery lines 138-146. Examples of process gases that can be used to perform CVD operations to deposit layers on substrates include NH ₃ , TiCl ₄ , tetrakis (dimethylamino) titanium (TDMAT), WF ₆ , DCS, SiH _4, etc., depending on the type of deposition to be deposited Floor. The remote plasma source (RPS) 150 can generate fluorine radicals (F*) during the cleaning process, and can transport the fluorine radicals through one or more gas delivery lines 138-146. The gas delivery lines 138-146, the discharge port 137, and the nozzle 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 shower head 110, the base 134, etc., accumulate the deposited material layer during the processing. In order to slow down changes in deposition properties and particle contamination, a remote plasma cleaning process can be used to periodically clean the deposited layers from the chamber components. Examples of cleaning gases that can be used to clean the deposited materials from the surface of the chamber component 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.) and other gases (such as O ₂ or N ₂ O). Examples of the carrier gas include N ₂ , He, Ar, and other gases that are inert to the cleaning gas (for example, non-reactive gases). In one embodiment, NF ₃ and Ar are used to perform the plasma cleaning process.

The base 134 is disposed in the inner space 106 of the process chamber 100 under the shower head 110 and supported by the base 132. The susceptor 134 holds one or more substrates during processing. The susceptor 134 is configured to rotate around the center during the ALD process to ensure uniform distribution of the process gas interacting with one or more substrates. The above-mentioned uniform distribution improves the thickness uniformity of the layers deposited on one or more substrates.

The susceptor 134 is configured to be heated during processing and maintain uniform heat throughout the susceptor 134. Therefore, the base 134 may have a main body composed of a thermally conductive material with high resistance to thermal shock. In one embodiment, the body is a semi-metallic material, such as graphite. The base 134 may also have a main body made of other materials with high thermal shock resistance (for example, glass-carbon).

The base 134 has a plurality of recesses. Each recess is approximately equal to the size of the substrate (for example, wafer) held in the recess. During the processing, the substrate can be vacuum attached (clamped) to the susceptor 134.

In one embodiment, the main body of the base 134 has a first protective layer 135 on at least one surface and a second protective layer 136 on 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 base 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. Refer to Figures 2A-2B to illustrate an exemplary base in more detail.

In one embodiment, one or more heating elements 130 are disposed under the base 134. One or more heat shields may also be arranged near the heating element 130 to protect parts that should not be heated to high temperatures. In one embodiment, the heating element 130 is a resistive or induction heating element. In another embodiment, the heating element is a radiant heating bulb. In some embodiments, the heating element 130 can heat the susceptor 134 to a temperature as high as 700°C or higher.

Figure 2A depicts an exemplary susceptor 200 for an ALD chamber. The base 200 has a thin film protective coating. In one embodiment, the thin film protective coating only coats the upper surface of the base. Alternatively, a thin-film protective coating coats the upper and lower surfaces of the base. The thin film protective layer can also coat the sidewall of the base. The purpose of the susceptor 200 is to support and uniformly heat multiple wafers at the same time. The base 200 may be radiatively heated by a resistive heating element or a bulb. During the processing, the susceptor 200 is coated along the supported wafer through atomic monolayer deposition (ALD) or other CVD processes. In order to increase the mean time between cleaning (MTBC), the susceptor 200 should be cleaned periodically to prevent the coating from peeling off due to internal film stress developed during subsequent processing. The base 200 can be cleaned by either thermal or remote plasma processing. In the remote plasma cleaning example using NF ₃ , fluorine radicals (F*) are generated remotely and transported into the process area to remove the deposited film. However, F* at high temperatures will also corrode the base material (for example, CVD SiC and graphite). Therefore, a protective coating that is corrosion resistant to the applied chemicals is applied. The protective coating also allows a period of "over-etching" to ensure removal of the entire deposited film.

In one embodiment, the base 200 includes a semi-metal thermally conductive base, such as graphite. The susceptor 200 may have a disk-like shape large enough to support multiple substrates (for example, multiple wafers). In one embodiment, the diameter of the base exceeds 1 meter.

The susceptor 200 may include one or more recesses (also referred to as recesses) 201-206, each of which may be provided to support wafers or other substrates during processing. In the depicted example, the base 200 includes 6 recesses 201-206. However, other bases 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 ridges 206, and grooves or gas passages between the ridges 206. In some embodiments, the height of the feature is about 10-80 microns.

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

The recesses and surface features can be formed in the main body of the base 200 before depositing the first protective layer. Alternatively, the recesses and/or surface features may be formed in the first protective layer after the first protective layer is deposited thereon. The second protective layer can be a conformal thin-film protective layer conformal to the recesses and surface features. Alternatively, surface features can be formed in the second protective layer. Therefore, all surface features (such as bumps 206 and outer ring 208) exist on the surface of the second protective layer. In one embodiment, the thickness of the second protective layer is about 5-50 microns. In another embodiment, the thickness of the second protective layer is less than 20 microns. In another embodiment, the thickness of the second protective layer is up to 1000 microns.

The base 200 additionally includes a lifting pin hole 210. For example, the base 200 may include three lifting pin holes for supporting lifting pins (for example, Al ₂ O ₃ lifting pins). The lifting pins can load wafers onto the susceptor 200 and unload the wafers from the susceptor 200. The base 200 may include a recess 215, and the recess 215 may be used to clamp the base to the rotating shaft. The recess 215 may include a hole 220, which may be used to mechanically fix the base 200 to the rotating shaft.

FIG. 2B depicts an enlarged cross-sectional view of the base 200 with the insertion hole of the plasma resistant socket 250. IAD and PVD are line of sight (line of sight) processes. Therefore, the thin film protective coating may not coat the inside of the holes in the base (such as the lifting pin holes 210, the holes 220, or the helium gas holes). In one embodiment, a preliminary hole having an excessively large size is formed in the base. The plasma resistant socket (for example, the plasma resistant socket 250) can be separately manufactured and inserted into the oversized hole. The plasma resistant socket 250 may be press-installed (for example, mechanically pressed) into the oversized hole. The plasma-resistant socket 250 may be formed of a sintered plasma-resistant ceramic material block, such as AlN, Y ₂ O ₃ , a solid-solution ceramic compound including 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 the thin film protective layer may only coat the base, or coat both the base and the plasma resistant socket 250. In one embodiment, the CVD deposited layer is deposited before insertion into the plasma resistant socket 250. Then a thin film protective layer can be deposited after inserting the plasma resistant socket 250. The film protection layer can fill and/or bridge any gap between the outer wall of the socket 250 and the initial hole inserted into the socket 250. In some instances, the protective film layer may not be thick enough to bridge the gap between the socket and the initial hole inserted into the socket. Therefore, a CVD coating can be deposited after insertion into the socket to bridge any gaps. A thin protective layer can then be deposited on 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 and installed into the predetermined depth of the base 200.

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

The second protective layer 308 may be a ceramic thin film protective layer applied to the first protective layer 330 using 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 be used as a top coating, and can be used as a corrosion-resistant barrier layer, and seals the exposed surface of the first protective layer 330 (for example, seals internal surface cracks and holes in the first protective layer 330).

The second protective layer 308 deposited by the IAD may have a relatively low film stress (for example, relative to the film stress caused by plasma spraying or sputtering). The second protective layer 308 deposited by the IAD may additionally have a porosity lower than 1%, and the porosity is lower than about 0.1% in some embodiments. Therefore, the protective layer deposited by the IAD is a dense structure, which has the advantage of being applied to the chamber components. In addition, the second protective layer 308 deposited by IAD 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 used is Y ₄ Al ₂ O ₉ (YAM). Any of the ceramics shown above may include trace 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 main body 305 and/or the first protective layer 330 of the object 300 may include one or more surface features. For the base, the surface features may include recesses, ridges, sealing tapes, gas channels, helium holes, and so on. For the shower head, the surface features may include hundreds or thousands of gas distribution holes, divots or bumps surrounding the gas distribution holes, and so on. Other chamber components may have other surface features.

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

表1：IAD沉積之YAM、YF₃ 、YAG與EAG的材料性質In an alternative embodiment, the first protective layer 330 may be omitted. Therefore, 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 main body 305 .

Table 1: Material properties of YAM, YF ₃ , YAG and EAG deposited by IAD

Table 1 shows the material properties of YAM, YF ₃ , YAG and EAG deposited by IAD. As shown in the table, the YAM coating deposited by the 5 micron (µm) IAD has a breakdown voltage of 695 volts (V). The YF ₃ coating deposited by the 5 µm IAD has a breakdown voltage of 522 V. The YAG coating deposited by 5 µm IAD has a breakdown voltage of 1080 V. The EAG coating deposited by 5 µm IAD 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. The dielectric constant of YF ₃ film on 1.6 mm alumina is about For 9E-4, the loss tangent of YAG film is about 4E-4, and the loss tangent of EAG film is 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 marked ceramic material, 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 thin film protective layer from the substrate.

Tightness measurement utilizes the sealing ability achievable by the thin film protective layer. As shown in the table, the He leakage rate of about 2.6E-9 cubic centimeters per second (cm ³ /s) can be achieved with YF ₃ , the He leakage rate of about 4.4E-10 can be achieved with YAG, and the He leakage rate of about 4.4E-10 can be achieved with EAG. A He leakage rate of about 9.5E-10 is achieved. A lower He leakage rate represents an improved seal. The exemplary thin-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 that can resist abrasion during plasma treatment. As shown in the table, YF ₃ has a Vickers hardness (5 Kgf) of about 3.411 gigapascals (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 nanometers per radio frequency (nm/RFhr), while the wear rate of EAG 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 material is shown risen above characteristic properties may vary up to 30%. Therefore, it should be understood that the values described in these material properties are achievable values for demonstration. The ceramic thin film protective layer described herein should not be interpreted as being limited to the values provided.

FIG. 4 depicts a cross-sectional side view of an embodiment of the object 400. The object 400 has a thin film protective layer stack 406 deposited on the main body 405 of the object 400. In an alternative embodiment, the thin-film protective layer stack 406 may be deposited on the first protective layer of SiC or SiN.

A thin film protection layer stack or a plurality of thin film protection layer 406 (such as the first layer 408 and / or the second layer 410) may be a YAG, YAM, EAG one or YF _3. In addition, some of these 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 solution) 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 composed of the same ceramic.

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

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

The selection of the number of ceramic layers and the composition of the ceramic layers can be based on the desired application and/or type of the article to be coated. The EAG, YAG and YF ₃ thin film protective layers formed by IAD usually have an amorphous structure. On the contrary, the compound ceramic and Er ₂ O ₃ layer deposited by IAD usually have a crystalline or nanocrystalline structure. Crystalline and nanocrystalline structured 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 experience occasional vertical cracking (cracking that proceeds approximately in the film thickness direction and approximately perpendicular to the coated surface). The above-mentioned vertical fracture can be caused by lattice mismatch, and can be an attack point of plasma chemicals. Each time an object is heated and cooled, the mismatch of the thermal expansion coefficient between the film protection layer and the substrate coated by the film protection layer will cause stress on the film protection layer. The above-mentioned stresses will be concentrated at the vertical fracture. This will cause the thin-film protective layer to finally peel off from the substrate coated by the thin-film protective layer. Conversely, if there is no vertical fracture, the stress will be approximately evenly distributed throughout the film.

Therefore, in one embodiment, the first layer 408 in the thin-film protective layer stack 406 is an amorphous ceramic (such as YAG or EAG), and the second layer 410 in the thin-film protective layer stack 406 is a crystalline or nanocrystalline ceramic (Such as ceramic compound or Er ₂ O ₃ ). In the above embodiment, the second layer 410 can provide greater plasma tolerance than 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 the lattice mismatch of subsequent layers. Therefore, the lifetime of the second layer 410 can be increased.

In another example, the main body, Y ₃ Al ₅ O ₁₂ (YAG), 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 , and The solid-solution ceramic compounds including Y ₄ Al ₂ O ₉ and Y ₂ O ₃ -ZrO ₂ may each have a different thermal expansion coefficient. The greater the mismatch in the coefficient of thermal expansion between two adjacent materials, the greater the possibility that one of these materials will eventually break, peel off, or otherwise lose the bond with the other material. The protective layer stacks 406 and 506 can be formed in the above-mentioned manner to minimize the mismatch of thermal expansion coefficients between adjacent layers (or between the layers and the main body 405 and 505). For example, the main body 505 may be graphite, and the EAG may have a thermal expansion coefficient closest to the thermal expansion coefficient of graphite, followed by the thermal expansion coefficient of YAG, and then the thermal expansion coefficient of the compound ceramic. Therefore, in one embodiment, the first layer 508 may be EAG, the second layer 510 may be YAG, and the third layer 515 may be a compound ceramic.

In another example, the layers in the protective layer stack 506 may be alternating layers of two different ceramics. For example, the first layer 508 and the third layer 515 may be YAG, and the second layer 510 and the fourth layer 518 may be EAG or YF ₃ . The alternating layers described above can provide advantages similar to those mentioned above. In the example, one material used in the alternating layer is amorphous and the other material used in the alternating layer is crystalline or nanocrystalline.

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

In certain embodiments, one or more of the thin-film protective layer stacks 406, 506 are transition layers formed by heat treatment. If the main bodies 405 and 505 are ceramic main bodies, high-temperature heat treatment can be performed to promote the mutual diffusion between the thin film protective layer and the main 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 can be used as a diffusion bond between two ceramics and can provide improved adhesion between adjacent ceramics. This can help avoid cracking, peeling, or peeling of the protective layer during plasma processing.

The heat treatment may be a heat treatment at up to about 1400-1600°C for a period of up to about 24 hours (for example, in one embodiment, 3-6 hours). This can create an interdiffusion layer between the first thin-film protective layer and one or more of the adjacent ceramic body, thick protective layer, or second thin-film protective layer.

Figure 6 depicts an embodiment of a process 600 for forming one or more protective layers on an object. The text block 605 of the process 600 provides a base. The base can be used in an ALD process chamber. In one embodiment, the base has a thermally conductive semi-metal body (a semi-metal body with good thermal conductivity). In one embodiment, the thermally conductive semi-metal body is a graphite body. Alternatively, a non-thermally conductive base can be provided. The non-thermally conductive base may have a body composed of carbon-glass. In other embodiments, objects other than the base may be provided. For example, an aluminum shower head for an ALD process chamber can be provided.

In one embodiment, at the text block 608, insert the plasma resistant ceramic socket into the hole in the base. The plasma resistant ceramic socket can be pressed into the hole. In an alternative embodiment, the plasma resistant ceramic socket is inserted into the hole in the base after the text block 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 susceptor. In one embodiment, the first protective layer only covers the surface of the base facing the plasma. In another embodiment, the first protective layer covers the front and back 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 may be SiN or another suitable material. The first protective layer may have a thickness up to about 200 microns. The surface features of the base can be processed into graphite. In one embodiment, the first protective layer is ground after deposition.

At block 615, heat the base to a temperature higher than 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 the text block 620, when the susceptor is heated, an IAD is performed to deposit the second protective layer on one or more surfaces of the first protective layer. In one embodiment, the second protective layer only covers 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 of the base. In another embodiment, the second protective layer covers each surface of the first protective layer. In one embodiment, the oxygen and/or argon ions are guided to the susceptor by an ion gun before the deposition of the IAD. Oxygen and argon ions can burn off any surface organic contaminants on the first protective layer and disperse any residual particles.

The two types of IAD that can be performed include EB-IAD and IBS-IAD. EB-IAD can be implemented by vapor deposition. IBS-IAD can be performed by sputtering solid target material. The second protective layer can 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 can resist cracking at 450°C. In one embodiment, the protective layer may not experience any cracking after repeated thermal cycles up to 550°C. In a further embodiment, the second protective layer resists cracking at temperatures up to 650°C. The second protective layer can resist cracking. Although the second protective layer is deposited on the first protective layer and the base, both the first protective layer and the base have different thermal expansion coefficients from the second protective layer.

The deposition rate of the second protective layer can be about 1-8 angstroms per second, and can be changed 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 changed 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 is used to achieve a thicker coating in a shorter and more cost-effective coating process.

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

At block 625, a decision is made whether to deposit any additional protective layer (for example, any additional thin-film protective layer). If an additional protective layer is about to be deposited, the process continues to block 630. At the text block 630, another protective layer is formed on the second protective layer by using IAD.

In one embodiment, the other protective layer is composed of a ceramic that is 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 the solid-solution ceramic compounds of Y ₄ Al ₂ O ₉ and Y ₂ O ₃ -ZrO ₂ .

In another embodiment, the other protective layer is composed of the same ceramic as the ceramic of the second protective layer. For example, the mask can be disposed on the base after the second protective layer is formed. This mask may have openings where features (such as bumps and seals) will be formed on the base (e.g., in recesses in the base). An additional protective layer can then be deposited to form these features. In one embodiment, the height of the feature (e.g., bump) is 10-20 microns.

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

Figure 7A depicts the deposition mechanism applicable to a variety of energy particle deposition techniques (for example, ion assisted deposition (IAD)). Exemplary IAD methods include deposition processes that incorporate 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 the plasma resistant coating described herein. Any of the IAD methods can be performed in the presence of reactive gas species (such as O ₂ , N ₂ , halogen, etc.).

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

In one embodiment, the thin film protective layer 715 is formed using IAD as previously described throughout this document. Figure 7B depicts a schematic diagram of the IAD deposition equipment. As shown in the figure, the material source 752 (also referred to as the target body) provides the flow rate of the deposition material 702, while the energy particle source 755 provides the flow rate of the energy particles 703, and the two collide with the object 750 during the entire process of the IAD process. The energy particle source 755 may be oxygen or other ion sources. The energy particle source 755 can also provide other types of energy particles, such as inert radicals, neutron atoms, and nano-sized particles from particle generating sources (such as from plasma, reactive gas or from a material source that provides deposition materials) . The material source (for example, the target body) 752 for providing the deposition material 702 may be a ceramic sintered block, which corresponds to the same ceramic that will form the thin-film protective layer 715. For example, the material source may be a ceramic compound sintered block, 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 sintered block. The IAD can use one or more plasmas or beams to provide a source of material and a source of energy ions. Alternatively, the material source may be metal.

It is also possible to provide reactive species during the deposition process of the plasma resistant coating. In one embodiment, the energy particles 703 include at least one of a non-reactive species (for example, Ar) or a reactive species (for example, O). In a further embodiment, during the formation of the plasma resistant coating, reactive species, such as CO and halogens (Cl, F, Br, etc.) can also be introduced to further increase the selective removal of most weakly bonded to The tendency of the deposition material of the thin film protective layer 715.

With the IAD process, the energy particles 703 can be controlled by the energy ion (or other particles) source 755 independently of other deposition parameters. The energy (for example, rate), density, and incident angle of the energy ion flux can be adjusted to control the composition, structure, crystal orientation, and grain size of the thin film protective layer. The additional parameters that can be adjusted are the temperature of the object during the deposition process and the deposition cycle.

Use ion-assisted energy to compact the coating and accelerate the deposition of materials on the surface of the substrate. Both the voltage and current of the ion source can be used to change the ion assist energy. The voltage and current can be adjusted to achieve high and low coating density, control the stress of the coating and the crystallinity of the coating. The range of ion assist energy is about 50-500 V and about 1-50 amperes (A). Ion assist energy can also be used to deliberately change the stoichiometry of the coating. For example, a metal target can be applied during the deposition process and converted into a metal oxide.

A heater can be used to heat the deposition chamber and/or the substrate and the deposition rate can be adjusted to control the coating temperature. The substrate (object) temperature during the deposition process can be roughly divided into low temperature (about 120-150°C, in one embodiment, typical room temperature) and high temperature (about 270°C or higher in one embodiment). In one embodiment, a deposition temperature of about 300°C is used. Alternatively, 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 the 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 changed to achieve the highest uniformity coating. 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 changed by changing the position and/or direction of the substrate. By optimizing the deposition angle, a uniform coating with three-dimensional geometry can be achieved.

EB-IAD and IBS-IAD deposition are suitable for a wide range of surface conditions. However, it is preferable to polish the surface to achieve uniform coating coverage. A variety of fixing devices can be used to hold the substrate during the IAD deposition process.

Figure 8 depicts the corrosion rate of the thin film protective layer formed according to 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 in the figure, compared to SiC, the thin film protective layer deposited by IAD shows more improved corrosion resistance. For example, SiC shows a corrosion rate exceeding 2.5 µm (µm/RFHr) per RF hour. On the contrary, the EAG, YAG and YF ₃ thin film protective layers deposited by IAD all showed corrosion rates below 0.2 µm/RFHr.

The foregoing description proposes various specific details (such as embodiments of specific systems, components, methods, etc.) to provide a good understanding of the various embodiments of the present invention. However, a person having ordinary knowledge in the art can understand that at least some embodiments of the present invention can be carried out without these specific details. In other instances, the conventional components or methods are not described in detail or exist in a simple text block diagram format to avoid unnecessary interference with the present invention. Therefore, the specific details presented are only exemplary. Specific implementations may differ from these exemplary details and still be considered to be within the scope of the present invention.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described with reference to the embodiment is included in at least one embodiment. Therefore, the words "in one embodiment" or "in an embodiment" appearing in different places throughout this specification do not necessarily all refer to the same embodiment. In addition, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". When the word "about" or "approximately" is used in this article, it is intended to mean that the nominal value presented is accurate within ±30%.

Although the operations of the methods herein are illustrated and described in a specific order, the order of operations of each method may be changed so that certain operations can be performed in the reverse order or at least a part of certain operations can be performed together with other operations. In another embodiment, the instructions or sub-operations of the unique operation may be intermittent and/or alternating.

It is understood that the above description is intended to be descriptive and not restrictive. Those skilled in the art can learn many other embodiments after reading and understanding the above description. Therefore, the scope of the present invention should be determined with reference to the attached patent application scope and the full scope of equivalents given by the above-mentioned patent application scope.

100‧‧‧Processing chamber 105‧‧‧Chamber body 106‧‧‧Internal space 110‧‧‧Nozzle 122、123、124‧‧‧Nozzle 125‧‧‧ Chamber discharge device 130‧‧‧Heating element 132‧‧‧Base 134、200‧‧‧Base 135、330‧‧‧First protective layer 136、308‧‧‧Second protective layer 137‧‧‧Drain port 138, 140, 142, 144, 146‧‧‧Gas transmission pipeline 150‧‧‧Remote plasma source 152‧‧‧Gas panel 154‧‧‧Gate Valve 156‧‧‧Throttle valve 160‧‧‧Pump 201, 202, 203, 204, 205, 206, 215‧‧‧Concave 208‧‧‧Outer Ring 210‧‧‧Lift pin hole 220‧‧‧hole 250‧‧‧Plasma resistant socket 300, 400, 500, 750‧‧‧ objects 305、405、505‧‧‧Main body 406、506‧‧‧Thin film protection layer stack 408、508‧‧‧First floor 410, 510‧‧‧ second floor 515‧‧‧The third floor 518‧‧‧Fourth floor 600‧‧‧Process 605, 608, 610, 615, 620, 625, 630‧‧‧ text block 702‧‧‧Deposition material 703‧‧‧Energy Particle 715‧‧‧Thin film protective layer 752‧‧‧Material source 755‧‧‧Energy Particle Source

The present invention is described by way of examples (not limitation) in the accompanying drawings, and similar component symbols in the accompanying drawings refer to similar components. It should be noted that different component symbols referring to "a" or "one" embodiment in this disclosure do not necessarily refer to the same embodiment, and the above component symbols mean at least one.

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

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

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

Figures 3-5 depict a cross-sectional side view of an exemplary object with a stack of protective layers on the surface.

Figure 6 depicts an embodiment of the process of forming one or more protective layers on an object.

FIG. 7A depicts the deposition mechanism applicable to various deposition techniques that utilize energy particles (for example, ion-assisted deposition (IAD)).

Figure 7B depicts a schematic diagram of the IAD deposition equipment.

Figure 8 depicts the corrosion rate of the thin film protective layer formed according to an embodiment of the present invention.

Domestic hosting information (please note in the order of hosting organization, date and number) no

Foreign hosting information (please note in the order of hosting country, institution, date and number) no

600‧‧‧Process

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

Claims (20)

An object for a process chamber includes: a main body, the main body including a thermally conductive material, wherein the main body includes a hole; a plasma resistant socket into which the plasma resistant socket is inserted; a first protective layer, the The first protective layer is located on a surface of the main body, the first protective layer is a thermally conductive ceramic; and a second protective layer, the second protective layer is located on the first protective layer, the second protective layer includes an electric resistant Plasma ceramic film, the plasma resistant ceramic film resists rupture at temperatures up to 650°C. The article according to claim 1, wherein the thermally conductive material includes graphite. The article according to claim 1, wherein the thermally conductive material includes a thermally conductive semi-metal, and the first protective layer includes silicon carbide. The article according to claim 1, wherein the article is a base for an atomic layer deposition chamber. The article according to claim 1, wherein the second protective layer includes 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 according to claim 1, wherein the thickness of the second protective layer is 5-50 microns. The article according to claim 1, wherein the plasma resistant socket is composed of a sintered ceramic, the sintered ceramic includes 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 solid-solution ceramic compounds. The article according to claim 1, wherein a first diameter of the hole corresponds to an outer diameter of the plasma resistant socket, and wherein the plasma resistant socket includes a second hole, the second hole having a diameter smaller than the first diameter Of a second diameter. The article according to 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 article according to claim 1, wherein: a bottom of the plasma resistant socket has an outer diameter smaller than a top of the plasma resistant socket. The article according to claim 1, wherein: there is 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 Ground filling the gap between the wall of the hole and the outer wall of the plasma resistant socket. A method for forming a plasma-resistant film includes the following steps: drilling a hole in a thermally conductive 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; and performing ion-assisted deposition to deposit a second protective layer on the first protective layer, the second protective layer Including a plasma-resistant ceramic film, the plasma-resistant ceramic film resists cracking at temperatures up to 650°C. The method according to claim 12, further comprising the steps of: heating the thermally conductive body to a temperature of about 200-400° C.; and when the thermally conductive body and the first protective layer are heated, performing the ion-assisted deposition. The method according to claim 12, wherein the step of depositing the first protective layer includes the following steps: performing a chemical vapor deposition process. The method of claim 12, wherein the thermally conductive body includes a base for an atomic layer deposition chamber, the thermally conductive body includes graphite, the first protective layer includes silicon carbide, and the second protective layer includes a Ceramics selected from the group consisting of Er ₃ Al ₅ O ₁₂ , Y ₃ Al ₅ O ₁₂ and YF ₃ . The method according to claim 12, wherein the thickness of the second protective layer is 5-50 microns. The method according to claim 12, wherein after depositing the first protective layer and before performing the ion-assisted deposition step, The plasma resistant socket is inserted into the hole. The method according to claim 12, wherein the plasma resistant socket is composed of a sintered ceramic, the sintered ceramic includes 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 the solid-solution ceramic compound, and wherein the plasma resistant socket includes an additional hole having a diameter smaller than the hole inserted into the plasma resistant socket. The method of claim 12, wherein the plasma-resistant socket is inserted into the hole before 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 are There is a gap therebetween, 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 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 inserted into one of the plurality of holes; A first protective layer on a surface of the graphite body, the first protective layer including silicon carbide; and a second protective layer on the first protective layer, the The second protective layer includes a plasma-resistant ceramic film that resists cracking at temperatures up to 650°C, wherein the second protective layer includes a layer selected from Er ₃ Al ₅ O ₁₂ , Y ₃ Al ₅ O ₁₂ and YF ₃ is a group of ceramics; wherein at least one of the first protective layer or the second protective layer covers the plurality of plasma resistant sockets.

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