Vacuum seal for electrostatic chuck

Abstract

An exemplary substrate support assembly may include an electrostatic chuck body. The body may include a support plate defining a substrate support surface. The body may include a base plate coupled with a support plate. The bottom surface of the base plate may define an annular groove. The body may include a cooling plate coupled with the base plate. The assembly may include a support handle coupled with the body. The assembly may include a heater embedded within the body. The assembly may include one or more electrodes embedded within the body. The assembly may include an annular plate disposed within the annular groove. The thermal conductivity of the annular plate may be less than about 20 W / mK. The assembly may include a vacuum sealing element disposed between the annular plate and the cooling plate. The assembly may include a thermal gasket disposed radially inward within the vacuum sealing element.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit and priority of U.S. patent application No. 17 / 885,367, filed on August 10, 2022, entitled “VACUUM SEAL FOR ELECTROSTATIC CHUCK,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present technology relates to components and devices used in semiconductor manufacturing. More specifically, the present technology relates to substrate support assemblies and other semiconductor processing equipment. Background Art

[0003] Integrated circuits are made possible by processes that produce complex patterned layers of material on the surface of a substrate. The production of patterned materials on a substrate requires controlled methods to form and remove materials. The temperatures at which these processes occur can directly affect the final product. During processing, the substrate temperature is typically controlled and maintained by components that support the substrate. Internally located heating devices can generate heat within the support, and the heat can be conductively transferred to the substrate. In some technologies, substrate supports can also be used to generate substrate-level plasma and electrostatically clamp the substrate to the support. Plasma generated near the substrate may cause component bombardment and the formation of parasitic plasma in unfavorable areas of the chamber. These conditions may also cause discharges between substrate support electrodes. In addition, the use of a pedestal to generate heat and generate plasma may cause interference effects.

[0004] Because various processing operations may utilize elevated temperatures and the formation of a substrate-level plasma, the materials of which the substrate support is composed may be exposed to temperatures that affect the electrical operation of the component. Therefore, there is a need for improved systems and methods that can be used to produce high-quality devices and structures. The present technology addresses these and other needs. Summary of the invention

[0005] An exemplary substrate support assembly may include an electrostatic chuck body. The chuck body may include a support plate defining a substrate support surface. The chuck body may include a base plate coupled to the support plate opposite the substrate support surface. The bottom surface of the base plate may define an annular recess. The chuck body may include a cooling plate coupled to the bottom surface of the base plate opposite the support plate. The assembly may include a support stem coupled to the electrostatic chuck body. The assembly may include a heater embedded in the electrostatic chuck body. The assembly may include one or more electrodes embedded in the electrostatic chuck body and spaced apart from the heater. The assembly may include an annular plate disposed in the annular recess. The annular plate may have a thermal conductivity of less than about 20 W / mK. The assembly may include a vacuum sealing element disposed between the annular plate and the cooling plate. The assembly may include a thermal gasket disposed radially inward of the vacuum sealing element.

[0006] In some embodiments, the annular recess may extend through the peripheral edge of the substrate plate. The annular plate may have a thickness of less than about 2 mm. The annular plate may have a width between about 2 mm and 20 mm. The top surface of the cooling plate may define an annular groove. A vacuum sealing element may be disposed in the annular groove. The electrostatic chuck body may define a plurality of lifting rod holes. The bottom surface of the substrate plate may define an additional annular recess surrounding each of the plurality of lifting rod holes. The assembly may include an additional annular plate. Each of the additional annular plates may be disposed in a corresponding one of the additional annular recesses. The assembly may include an additional vacuum sealing element. Each of the additional vacuum sealing elements may be disposed between the cooling plate and a corresponding one of the additional annular plates. The annular plate may include a fluorine-resistant material. The thermal expansion coefficient of the annular plate may be within about 10% of the thermal expansion coefficient of the substrate plate. One or more electrodes may be disposed in the support plate. The heater may be disposed in the substrate plate.

[0007] Some embodiments of the present technology may encompass a substrate support assembly that may include an electrostatic chuck body. The chuck body may include a support plate defining a substrate support surface. The chuck body may include a base plate coupled to the support plate opposite the substrate support surface. The bottom surface of the base plate may define an annular recess. The chuck body may include a cooling plate coupled to the bottom surface of the base plate opposite the support plate. The assembly may include a heater embedded in the electrostatic chuck body. The assembly may include one or more electrodes embedded in the electrostatic chuck body and spaced apart from the heater. The assembly may include an annular plate disposed in the annular recess. The annular plate may have a thermal conductivity of less than about 20 W / mK. The assembly may include a vacuum sealing element disposed between the annular plate and the cooling plate.

[0008] In some embodiments, the annular plate may have a thermal conductivity of less than about 5 W / mK. The assembly may include a thermal gasket disposed radially inwardly of the vacuum sealing element. The thickness of the thermal gasket may be less than about 2 mm. The vacuum sealing element may include a perfluoropolymer. The electrostatic chuck body may define a back gas channel extending through the thickness of the electrostatic chuck body and through the substrate support surface. The bottom surface of the base plate may define an additional annular recess surrounding the back gas channel. The assembly may include an additional annular plate disposed in the additional annular recess. The assembly may include an additional vacuum sealing element disposed between the cooling plate and the back gas channel. The annular channel may be disposed radially inwardly of the peripheral edge of the base plate. The thermal expansion coefficient of the annular plate may be between about 4.7 and 5.

[0009] Some embodiments of the present technology may encompass a substrate support assembly that may include one or more upper plates. The uppermost plate of the one or more plates may define a substrate support surface. The bottom surface of the lowermost plate of the one or more plates may define an annular recess. The assembly may include a cooling plate coupled to the bottom surface of the lowermost plate. The assembly may include a heater embedded in one of the one or more plates. The assembly may include an electrode embedded in one of the one or more plates and spaced apart from the heater. The assembly may include an annular plate disposed in the annular recess. The annular plate may have a thermal conductivity of less than about 20 W / mK. The assembly may include a vacuum sealing element disposed between the annular plate and the cooling plate. In some embodiments, the lowermost plate and the uppermost plate may be the same plate.

[0010] This technology can provide many benefits over conventional systems and techniques. For example, embodiments of the present technology can provide an electrostatic chuck mechanism that can operate at high temperatures without degrading the sealing mechanism that seals the interior of the chuck mechanism from the vacuum conditions of the processing chamber. Such a chuck mechanism can enable standard sealing elements to be used under high temperature processing conditions, which can reduce the cost and complexity of the chuck mechanism. These and other embodiments, along with their many advantages and features, are described in more detail in conjunction with the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A further understanding of the nature and advantages of the disclosed technology may be realized by reference to the remainder of the specification and the accompanying drawings.

[0012] Figure 1 A top view of an exemplary processing system in accordance with some embodiments of the present technology is shown.

[0013] Figure 2 A schematic cross-sectional view of an exemplary processing system in accordance with some embodiments of the present technology is shown.

[0014] Figure 3 A schematic partial cross-sectional view of an exemplary processing chamber according to some embodiments of the present technology is shown.

[0015] Figure 4 A schematic partial cross-sectional view of an exemplary substrate support assembly in accordance with some embodiments of the present technology is shown.

[0016] Figure 4A Some embodiments of the present technology are shown Figure 4 A top view of a substrate support assembly.

[0017] Figure 4B FIG. 1 shows a cooling plate above a substrate support assembly according to some embodiments of the present technology. Figure 4 A bottom plan view of a portion of a substrate support assembly.

[0018] Several of the drawings are included as schematic diagrams. It should be understood that the drawings are for illustration purposes only and should not be considered to be drawn to scale unless specifically noted as being drawn to scale. Furthermore, as schematic diagrams, these drawings are provided to aid understanding and may not include all aspects or information compared to realistic representations and may include exaggerated material for illustration purposes.

[0019] In the drawings, similar components and / or features may have the same reference numeral. In addition, various components of the same type may be distinguished by adding a letter after the reference numeral that distinguishes the similar components. If only the first reference numeral is used in the specification, the description applies to any similar component having the same first reference numeral, regardless of the letter. DETAILED DESCRIPTION

[0020] Plasma enhanced deposition processes can excite one or more component precursors to promote the formation of a film on a substrate. Typically, these processes are performed using a pedestal that includes a heater that can heat and control the substrate temperature at a desired process temperature. Plasma is generated by an exothermic reaction, which can generate a large amount of heat. Although many operations can be performed at temperatures high enough to overcome the thermal effects from the plasma, the heat from the plasma may affect the process when the operation occurs in a mid-range temperature (such as above or about 100° C. but below or about 500° C. or less). The heat, as well as the heat generated due to ion bombardment during plasma formation, may exceed the heat that a conventional pedestal can dissipate to maintain a set point temperature. Such high temperatures may cause failure of sealing elements, such as O-rings and gaskets used to seal the interior of the chuck mechanism from the vacuum conditions of the processing chamber.

[0021] The present technology may be incorporated into a substrate support assembly that may include components that isolate the sealing element from the highest temperatures within the chamber. For example, one or more annular plates may be disposed within a groove in a base plate of a suction cup body. These annular plates may be formed from a material having a lower thermal conductivity than the base plate and may be positioned above and / or otherwise aligned with the sealing element. This may enable the annular plates to thermally isolate or otherwise protect the sealing element from the higher temperatures of the base plate during processing operations. Such thermal isolation may provide a temperature reduction sufficient to enable conventional sealing elements (such as perfluoropolymer O-rings and gaskets) to be used in high temperature processing operations (e.g., temperatures in excess of 350°C) without the risk of thermal degradation of the sealing element.

[0022] Although the remainder of the disclosure will routinely identify specific deposition processes utilizing the disclosed techniques, it will be readily appreciated that these systems and methods are equally applicable to other deposition, etching, and cleaning chambers, and processes that may occur therein. Therefore, the techniques should not be considered limited to use with only these specific deposition processes or chambers. Prior to describing additional variations and adjustments to the systems in accordance with embodiments of the present technology, the present disclosure will discuss one possible system and chamber that may include a susceptor in accordance with embodiments of the present technology.

[0023] Figure 1 A top view of an embodiment of a processing system 100 of deposition, etching, baking and curing chambers according to an embodiment is shown. In the figure, a pair of front opening unified pods 102 supply substrates of various sizes, which are received by a robot 104 and placed in a low pressure holding area 106 before being placed in a substrate processing chamber 108a-108f (positioned in a series portion 109a-109c). A second robot 110 can be used to transfer substrate chips from the holding area 106 to the substrate processing chamber 108a-108f and back. Each substrate processing chamber 108a-108f can be equipped to perform a variety of substrate processing operations, including the formation of semiconductor material stacks described herein in addition to plasma enhanced chemical vapor deposition, atomic layer deposition, physical vapor deposition, etching, pre-cleaning, degassing, orientation and other substrate processing (including annealing, ashing, etc.).

[0024] The substrate processing chambers 108a-108f may include one or more system components for depositing, annealing, curing and / or etching dielectric or other films on a substrate. In one configuration, two pairs of processing chambers (e.g., 108c-108d and 108e-108f) may be used to deposit dielectric materials on a substrate, and a third pair of processing chambers (e.g., 108a-108b) may be used to etch the deposited dielectric. In another configuration, all three pairs of chambers (e.g., 108a-108f) may be configured to deposit a stack of alternating dielectric films on a substrate. Any one or more of the processes described may be performed in a chamber separate from the manufacturing system shown in the different embodiments. It should be understood that the system 100 contemplates additional configurations of deposition, etching, annealing and curing chambers for dielectric films.

[0025] Figure 2 A schematic cross-sectional view of an exemplary plasma system 200 according to some embodiments of the present technology is shown. The plasma system 200 can show a pair of processing chambers 108 that can be assembled in one or more tandem sections 109 described above and can include a substrate support assembly according to embodiments of the present technology. The plasma system 200 can generally include a chamber body 202 having a sidewall 212, a bottom wall 216, and an inner sidewall 201 defining a pair of processing regions 220A and 220B. Each of the processing regions 220A-220B can be similarly configured and can include the same components.

[0026] For example, the processing region 220B (components of which may also be included in the processing region 220A) may include a pedestal 228 disposed in the processing region through a passage 222 formed in the bottom wall 216 of the plasma system 200. The pedestal 228 may provide a heater adapted to support a substrate 229 on an exposed surface of the pedestal, such as a body portion. The pedestal 228 may include a heating element 232 (e.g., a resistive heating element) that may heat and control the substrate temperature at a desired processing temperature. The pedestal 228 may also be heated by a remote heating element, such as a lamp assembly or any other heating device.

[0027] The body of the base 228 can be coupled to the handle 226 by a flange 233. The handle 226 can electrically connect the base 228 to an electrical outlet or power box 203. The power box 203 can include a drive system that controls the height and movement of the base 228 within the processing area 220B. The handle 226 can also include an electrical interface to provide electrical power to the base 228. The power box 203 can also include an interface for electrical power and a temperature indicator, such as a thermocouple interface. The handle 226 can include a base assembly 238 suitable for removably connecting to the power box 203. The circumferential ring 235 is shown as being above the power box 203. In some embodiments, the circumferential ring 235 can be a shoulder that is suitable as a mechanical stop or platform that is configured to provide a mechanical interface between the base assembly 238 and the upper surface of the power box 203.

[0028] Rods 230 may be included that pass through passages 224 formed in the bottom wall 216 of the processing region 220B and may be used to position substrate lift pins 261 disposed through the body of the pedestal 228. The substrate lift pins 261 may selectively space the substrate 229 from the pedestal to facilitate exchange of the substrate 229 with a robot used to transfer the substrate 229 into and out of the processing region 220B through the substrate transfer port 260.

[0029] The chamber lid 204 can be coupled to the top of the chamber body 202. The lid 204 can house one or more precursor distribution systems 208 coupled thereto. The precursor distribution system 208 can include a precursor inlet passage 240, which can deliver reactants and cleaning precursors to the processing region 220B through the dual channel showerhead 218. The dual channel showerhead 218 can include an annular base plate 248 having a blocking plate 244 disposed in the middle of a face plate 246. A radio frequency ("RF") source 265 can be coupled to the dual channel showerhead 218, which can power the dual channel showerhead 218 to facilitate the generation of a plasma region between the face plate 246 and the pedestal 228 of the dual channel showerhead 218. In some embodiments, the RF source can be coupled to other portions of the chamber body 202 (such as the pedestal 228) to facilitate the generation of a plasma. A dielectric isolator 258 can be disposed between the lid 204 and the dual channel showerhead 218 to prevent the conduction of RF power to the lid 204. The shadow ring 206 may be disposed on a periphery of the base 228 that engages with the base 228 .

[0030] An optional cooling channel 247 may be formed in the annular base plate 248 of the gas distribution system 208 to cool the annular base plate 248 during operation. A heat transfer fluid (such as water, glycol, gas, etc.) may be circulated through the cooling channel 247 so that the base plate 248 may be maintained at a predetermined temperature. The liner assembly 227 may be disposed within the processing region 220B, adjacent to the sidewalls 201, 212 of the chamber body 202, to prevent the sidewalls 201, 212 from being exposed to the processing environment within the processing region 220B. The liner assembly 227 may include a circumferential pumping chamber 225, which may be coupled to a pumping system 264, which is configured to exhaust gases and byproducts from the processing region 220B and control the pressure within the processing region 220B. A plurality of exhaust ports 231 may be formed on the liner assembly 227. The exhaust port 231 may be configured to allow gas to flow from the processing region 220B to the circumferential pumping chamber 225 in a manner that facilitates processing within the system 200 .

[0031] Figure 3 A schematic partial cross-sectional view of an exemplary semiconductor processing chamber 300 is shown in accordance with some embodiments of the present technology. Figure 3 This may include the above Figure 2 One or more components discussed above may be illustrated, and further details related to the chamber may be illustrated. Chamber 300 may be used to perform semiconductor processing operations, including deposition of dielectric material stacks as previously described. Chamber 300 may illustrate a partial view of a processing region of a semiconductor processing system, and may not include all components (such as the additional cover stack components previously described), which are understood to be incorporated in some embodiments of chamber 300.

[0032] As mentioned above, Figure 3 A portion of a processing chamber 300 may be illustrated. The chamber 300 may include a showerhead 305 and a substrate support assembly 310. Together with a chamber sidewall 315, the showerhead 305 and the substrate support 310 may define a substrate processing region 320 in which a plasma may be generated. The substrate support assembly may include an electrostatic chuck body 325, which may include one or more components embedded or disposed within the body. In some embodiments, the components incorporated within the top disk may not be exposed to the processing material and may be completely retained within the chuck body 325. The electrostatic chuck body 325 may define a substrate support surface 327 and may be characterized by a thickness and a length or diameter depending on the particular geometry of the chuck body. In some embodiments, the chuck body may be elliptical and may be characterized by one or more radial dimensions passing through the chuck body from a central axis. It should be understood that the top disk may be of any geometry and when radial dimensions are discussed, they may define any length from a central location of the chuck body.

[0033] The electrostatic chuck body 325 can be coupled to a handle 330, which can support the chuck body and can include channels for delivering and receiving electrical and / or fluid lines that can be coupled to the internal components of the chuck body 325. The chuck body 325 can include associated channels or components to function as an electrostatic chuck, but in some embodiments, the assembly can function as or include components for a vacuum chuck or any other type of chuck system. The handle 330 can be coupled to the chuck body on a second surface of the chuck body opposite the substrate support surface. In some embodiments, the electrostatic chuck body 325 can be formed of a conductive material (such as a metal like aluminum or any other material that can conduct heat and / or electricity) and can be coupled to a power source (such as a DC power source, a pulsed DC power source, an RF bias power source, a pulsed RF source or bias power source, or a combination of these or other power sources) through a filter, which can be an impedance matching circuit to enable the electrostatic chuck body 325 to operate as an electrode. In other embodiments, the top of the electrostatic chuck body 325 can be formed of a dielectric material. In such embodiments, the electrostatic chuck body 325 can include a separate electrode. For example, the electrostatic chuck body 325 may include a first bipolar electrode 335a, which may be embedded in the chuck body near the substrate support surface. The electrode 335a may be electrically coupled to a DC power supply 340a. The power supply 340a may be configured to provide energy or voltage to the conductive chuck electrode 335a. This may be operated to form a plasma of a precursor within the processing region 320 of the semiconductor processing chamber 300, although other plasma operations may be similarly maintained. For example, the electrode 335a may also be a clamping mesh that serves as an electrical ground for a capacitive plasma system, including an RF source 307 electrically coupled to the showerhead 305. For example, the electrode 335a may serve as a ground path for the RF power from the RF source 307, while also serving as an electrical bias to the substrate to electrostatically clamp the substrate to the substrate support surface. The power supply 340a may include a filter, a power supply, and a plurality of other electrical components configured to provide a chuck voltage.

[0034] The electrostatic chuck body may also include a second bipolar electrode 335b, which may also be embedded within the chuck body proximate the substrate support surface. The electrode 335b may be electrically coupled to a DC power supply 340b. The power supply 340b may be configured to provide energy or voltage to the conductive chuck electrode 335b. Additionally, electrical components and details regarding bipolar chucks according to some embodiments are further described below, and any design may be implemented with the processing chamber 300. For example, additional plasma-related power supplies or components may be incorporated.

[0035] In operation, a substrate can be at least partially brought into contact with a substrate support surface of an electrostatic chuck body, which can create a contact gap, and which can substantially create a capacitive effect between the surface of the pedestal and the substrate. A voltage can be applied to the contact gap, which can create an electrostatic force for chucking. Power supplies 340a and 340b can provide charge that migrates from the electrodes to the substrate support surface where it can accumulate, and can create a charge layer at the substrate that has a Coulomb attraction to opposite charges, and can electrostatically hold the substrate against the substrate support surface of the chuck body. This charge migration can occur by a current flowing through the dielectric material of the chuck body, which is based on a finite resistance within the dielectric for Johnsen-Rahbek type chucking, which can be used in some embodiments of the present technology.

[0036] The chuck body 325 may also define a recessed area 345 within the substrate support surface, which may provide a recessed pocket in which a substrate may be disposed. The recessed area 345 may be formed at an interior region of the top disk and may be configured to receive a substrate for processing. As shown, the recessed area 345 may encompass a central region of the electrostatic chuck body and may be sized to accommodate any variety of substrate sizes. The substrate may be disposed within the recessed area and is contained by an outer region 347 that may surround the substrate. In some embodiments, the height of the outer region 347 may be such that the substrate is flush with or recessed below the surface height of the substrate support surface at the outer region 347. In some embodiments, the recessed surface may control edge effects during processing, which may improve uniformity of deposition on the substrate. In some embodiments, an edge ring may be disposed around the periphery of the top disk and may at least partially define a recess in which a substrate may be disposed. In some embodiments, the surface of the chuck body may be substantially flat and the edge ring may fully define a recess in which a substrate may be disposed.

[0037] In some embodiments, the electrostatic chuck body 325 and / or handle 330 can be an insulating or dielectric material. For example, oxides, nitrides, carbides, and other materials can be used to form the components. Exemplary materials may include ceramics (including aluminum oxide, aluminum nitride, silicon carbide, tungsten carbide, and any other metal or transition metal oxide, nitride, carbide, boride, or titanate, as well as combinations of these materials and other insulating or dielectric materials). Different grades of ceramic materials can be used to provide composite materials configured to operate within a specific temperature range, so in some embodiments, different ceramic grades of similar materials can be used for the top disc and handle. Dopants can also be added in some embodiments to adjust electrical properties. Exemplary dopant materials can include yttrium, magnesium, silicon, iron, calcium, chromium, sodium, nickel, copper, zinc, or any number of other elements known to be incorporated into ceramic or dielectric materials.

[0038] The electrostatic chuck body 325 may also include an embedded heater 350 contained within the chuck body. In embodiments, the heater 350 may include a resistive heater or a fluid heater. In some embodiments, the electrode 335 may operate as a heater, but by separating these operations, more individual control may be provided and an extended heater coverage may be provided while limiting the area where the plasma is formed. The heater 350 may include a polymer heater bonded or coupled to the chuck body material to heat the top disk, although the conductive element may be embedded within the electrostatic chuck body and configured to receive an electrical current (such as an AC current). The electrical current may be delivered through the handle 330 through a channel similar to the DC power supply discussed above. The heater 350 may be coupled to a power supply 365, which may provide electrical current to the resistive heating element to facilitate heating of the associated chuck body and / or substrate. In embodiments, the heater 350 may include a plurality of heaters, and each heater may be associated with a region of the chuck body, so an exemplary chuck body may include a similar number of regions as heaters or a greater number of regions. In some embodiments, the chucking grid electrode 335, if present, may be positioned between the heater 350 and the substrate supporting surface 327, and in some embodiments as will be further described below may maintain a distance between the electrode within the chuck body and the substrate supporting surface.

[0039] The heater 350 can regulate the temperature across the entire electrostatic chuck body 325 and the substrate residing on the substrate support surface 327. The heater can have an operating temperature range to heat the chuck body and / or substrate to above or about 100°C, and the heater can be configured to heat to above or about 125°C, above or about 150°C, above or about 175°C, above or about 200°C, above or about 250°C, above or about 300°C, above or about 350°C, above or about 400°C, above or about 450°C, above or about 500°C, above or about 550°C, above or about 600°C, above or about 650°C, above or about 700°C, above or about 750°C, above or about 800°C, above or about 850°C, above or about 900°C, above or about 950°C, above or about 1000°C, or more. The heater may also be configured to operate within any range encompassed between any two of these specified numbers, or within a smaller range included in any of these ranges, as well as below any specified temperature.

[0040] Figure 4A schematic partial cross-sectional view of a substrate support assembly 400 according to some embodiments of the present technology is shown. As described above, the present technology can be used in some embodiments for film deposition and curing in a single chamber. The substrate support assembly 400 can be similar to the substrate support assembly 310 and can include any features, components or characteristics of the above-mentioned supports, including any associated components or power supplies. The substrate support assembly 400 can include a support handle 405, which can be a conductive material. An electrostatic chuck body 425, which can include one or more components embedded or disposed within the body, can be positioned on top of the support handle 405. In some embodiments, the components contained within the top disk can not be exposed to the processing material and can be completely retained within the chuck body 425. The electrostatic chuck body 425 can define a substrate support surface 427 and can be characterized by a thickness and a length or diameter depending on the specific geometry of the chuck body. In some embodiments, the chuck body 425 can be elliptical and can be characterized by one or more radial dimensions passing through the chuck body from a central axis. It should be understood that the top disk can be of any geometry and when radial dimensions are discussed, they can define any length starting from the center of the chuck body 425.

[0041] The electrostatic chuck body 425 may include a plurality of plates coupled together. For example, the electrostatic chuck body 425 may include one or more upper plates 430, which may be made of an insulating material (e.g., having a thickness greater than 10 14 ohm-meter resistivity) or dielectric materials. For example, oxides, nitrides, carbides and other materials can be used to form components. Exemplary materials may include ceramics, including aluminum oxide, aluminum nitride, silicon carbide, tungsten carbide and any other metal or transition metal oxide, nitride, carbide, boride or titanate, and combinations of these materials and other insulating or dielectric materials. As shown, the upper plate 430 may include a support plate 430a and a base plate 430b bonded to each other and / or otherwise coupled. For example, the support plate 430a and the base plate 430b may be combined using metal bonding techniques, such as diffusion bonding, welding and / or other bonding techniques that can be used to couple the upper plates 430 together. In some embodiments, the bonding technique may include forming a metal interlayer 442 such as aluminum or other metals between adjacent upper plates 430 to bond the upper plates 430 together.

[0042] The electrostatic chuck body 425 may include a heater 450, such as an AC heating coil. In some embodiments, the heater 450 may be formed of a conductive wire, such as a wire formed of nickel chromium. An insulating shell may be provided around the heater 450 to prevent short circuits. The heater 450 may be formed of one or more heating elements. As just one example, the conductive wire may be provided in a radially extending spiral or other tortuous shape within the electrostatic chuck body 425 to provide relatively uniform heating on the substrate support surface 427. Each heating element of the heater 450 may be coupled to a power source (such as an AC power source that delivers AC current to the heater 450) to heat the top disk. The current may be delivered to the heater 450 by one or more rods or wires (not shown) disposed within the channel formed within the handle 405 and the electrostatic chuck body 425. In some embodiments, a temperature sensor may extend along the rod or wire. The heater 450 may have a range of operating temperatures to heat the chuck body 425 and / or the substrate to above or about 100°C, and the heater 450 may be configured to heat to above or about 125°C, above or about 150°C. , above or about 175° C., above or about 200° C., above or about 250° C., above or about 300° C., or higher. Heater 450 can also be configured to operate within any range included between any two of these specified numbers, or within a smaller range included in any of these ranges.

[0043] The electrostatic chuck body 425 can include one or more electrodes 435 that can function as clamping electrodes to clamp a substrate to the substrate support surface 427. Each electrode 435 can be electrically coupled to a DC power source that can provide energy or voltage to the electrode 435. The electrode 435 can be a clamping grid that operates as an electrical ground for a capacitive plasma system that includes an RF source electrically coupled to a showerhead. For example, the electrode 435 can function as a ground path for RF power from the RF source while also functioning as an electrical bias to the substrate to provide electrostatic clamping of the substrate to the substrate support surface.

[0044] The heater 450 and each electrode 435 may be disposed to be embedded in the electrostatic chuck body 425. For example, the electrode 435 may be embedded in the electrostatic chuck body 425 near the substrate support surface 427, and the heater 450 may be spaced apart from the electrode 435, such as being disposed further away from the substrate support surface 427. In some embodiments, the heater 450 and the electrode 435 may be embedded in the same upper plate 430 (e.g., the support plate 430a), while in other embodiments, the heater 450 and the electrode 435 may be disposed in a separate upper plate 430. For example, the electrode 435 may be disposed in the support plate 430a, and the heater 450 may be set in the base plate 430b.

[0045] The uppermost plate (e.g., support plate 430a) of the upper plates 430 may define a substrate support surface 427, wherein one or more upper plates 430 (e.g., base plate 430b) are coupled to the uppermost plate opposite the substrate support surface 427. In some embodiments, the uppermost plate and the lowermost plate may be the same plate, such as when one or more upper plates 430 include only support plate 430a. The bottom surface 432 of the lowermost plate (e.g., support plate 430a in a single upper plate embodiment or base plate 430b in a double upper plate embodiment) may define an annular recess 434. The annular recess 434 may extend through the peripheral edge of the lowermost plate (e.g., base plate 430b), as shown here, such that the annular recess 434 includes or is defined by only an upper wall and an inner wall. In other embodiments, the annular recess 434 may be inserted radially inward relative to the peripheral edge of the lowermost plate, such that the annular recess 434 includes or is defined by an inner wall, an upper wall, and an outer wall.

[0046] The annular recess 434 may have a depth of less than about 2 mm. For example, the depth of the annular recess 434 may be between 0.1 mm and 2 mm (or about the value), between 0.15 mm and 1.75 mm (or about the value), between 0.2 mm and 1.5 mm (or about the value), between 0.25 mm and 1.25 mm (or about the value), between 0.3 mm and 1 mm (or about the value), between 0.35 mm and 0.75 mm (or about the value), or between 0.4 mm and 0.5 mm (or about the value). The width of the annular recess 434 may be between 2 mm and 20 mm (or about the value), between 3 mm and 18 mm (or about the value), between 4 mm and 16 mm (or about the value), between 5 mm and 14 mm (or about the value), between 6 mm and 12 mm (or about the value), or between 7 mm and 10 mm (or about the value).

[0047] The annular plate 440 may be disposed within the annular recess 434. For example, the annular plate 440 may be seated against one or more surfaces defining the annular recess 434. In some embodiments, the annular plate 440 may have similar dimensions to the annular recess 434, such that the annular plate 440 at least substantially fills the annular recess 434. For example, the thickness of the annular plate 440 may be between 0.1 mm and 2 mm (or approximately), between 0.15 mm and 1.75 mm (or approximately), between 0.2 mm and 1.5 mm (or approximately), between 0.25 mm and 1.25 mm (or approximately), between 0.3 mm and 1 mm (or approximately), between 0.35 mm and 0.75 mm (or approximately), or between 0.4 mm and 0.5 mm (or approximately). In some embodiments, such a thickness can enable the bottom surface of the annular plate 440 to be substantially flush with the bottom surface of the lowermost plate (e.g., base plate 430b), although in other embodiments, the annular plate 440 can have a thickness greater than or less than the depth of the annular recess 434, so that the bottom surface of the annular plate 440 is recessed or protruded relative to the bottom surface of the lowermost plate. The width of the annular plate 440 can be between 2 mm and 20 mm (or approximately the value), between 3 mm and 18 mm (or approximately the value), between 4 mm and 16 mm (or approximately the value), between 5 mm and 14 mm (or approximately the value), between 6 mm and 12 mm (or approximately the value), or between 7 mm and 10 mm (or approximately the value).

[0048] The annular plate 440 may be formed of a material having a thermal conductivity of less than or about 20 W / mK, less than or about 15 W / mK, less than or about 10 W / mK, less than or about 5 W / mK, less than or about 3 W / mK, less than or about 1 W / mK, less than or about 0.8 W / mK, less than or about 0.6 W / mK, less than or about 0.4 W / mK, less than or about 0.2 W / mK, or less, which may enable the annular plate 440 to isolate the sealing element or other components from the high temperature of the upper plate 430 caused by the heater 450. The annular plate 440 may be formed of a material having a coefficient of thermal expansion within about 10%, within about 8%, within about 6%, within about 5%, within about 3%, within about 1%, or less of the coefficient of friction of the lowermost plate. In certain embodiments, the lowermost plate and the annular plate 440 may each have a coefficient of thermal expansion between (or about) 4.5 and 5.5, between (or about) 4.6 and 5.25, or between (or about) 4.7 and 5. In some embodiments, the annular plate 440 may be formed of or otherwise include a fluorine-resistant material. Suitable materials for the annular plate 440 may include, but are not limited to, ceramic materials (such as aluminum oxide, aluminum nitride, silicon carbide, tungsten carbide, and any other metal or transition metal oxide, nitride, carbide, boride or titanate, and combinations of these materials and other insulating or dielectric materials), glass, perfluoropolymers, polyamides, and the like. The annular plate 440 may be formed of and / or coated with a fluorine-compatible material (such as a perfluoropolymer and / or an inorganic coating (e.g., aluminum oxide)).

[0049] The electrostatic chuck body 425 can define a plurality of lift pin holes 455 that can accommodate lift pins for lifting a substrate relative to the substrate support surface 427 during a substrate transfer operation. The bottom surface 432 of the lowermost plate (e.g., the support plate 430a in a single upper plate embodiment or the base plate 430b in a dual upper plate embodiment) can define an additional annular recess 434a around each lift pin hole 455, wherein, in some embodiments, each additional annular recess 434a is similar to the annular recess 434. For example, in some embodiments, each additional annular recess 434a can have a depth and / or width similar to the annular recess 434, although other dimensions are possible in various embodiments. For example, the width and / or depth of one or more additional annular recesses 434a can be less than or greater than the width and / or depth of the annular recess 434. This size can be determined based on the size of a respective vacuum sealing element that is positioned against an annular plate seated within a respective additional annular recess 434a, wherein the size of the additional annular plate 434a is selected to sufficiently thermally isolate the respective vacuum sealing element from the high temperatures exhibited by the upper plate 430. Each additional recess 434a can receive an additional annular plate 440a, which in some embodiments can be similar to the annular plate 440. For example, in some embodiments, each additional annular plate 440a can have a thickness and / or width similar to the annular recess 434a, although other sizes are possible in various embodiments.

[0050] like Figure 4BAs shown, the electrostatic chuck body 425 can define one or more backside gas channels 445 that can extend through the thickness of the electrostatic chuck body 425 and enable delivery of one or more gases, such as (but not limited to) purge gas, to the backside of the substrate located atop the substrate support surface 427. Each backside gas channel 445 can be coupled to a gas source, such as a gas panel, that delivers gas to the substrate receiving surface via the backside gas channel 445. The bottom surface 432 of the lowermost plate (e.g., the support plate 430a in the single upper plate embodiment or the base plate 430b in the dual upper plate embodiment) can define an additional annular recess 434b surrounding the backside gas channel 445, wherein the additional annular recess 434b is similar to the annular recess 434 in some embodiments. For example, in some embodiments, each additional annular recess 434b can have a depth and / or width similar to the annular recess 434, although other dimensions are possible in various embodiments. For example, the width and / or depth of one or more additional annular recesses 434b may be less than or greater than the width and / or depth of annular recess 434. This size may be determined based on the size of a corresponding vacuum sealing element that is disposed against an annular plate seated within the corresponding additional annular recess 434b, wherein the size of the additional annular plate 434b is selected to sufficiently thermally isolate the corresponding vacuum sealing element from the high temperatures exhibited by the upper plate 430. Each additional recess 434b may receive an additional annular plate 440b, which in some embodiments may be similar to annular plate 440. For example, in some embodiments, each additional annular plate 440b may have a thickness and / or width similar to annular plate 440, although other sizes are possible in various embodiments.

[0051] The upper surface 431 of the base plate 430b may define an annular recess 433 that may receive the fastening plate 460, such as Figure 4A The fastening plate 460 can be formed of a machinable material, such as a metal or a polymeric material, which can be machined to include a plurality of threaded holes that can receive fasteners for securing additional components of the electrostatic chuck body 425 to the upper plate 430, as will be discussed in more detail below. Figure 4B An annular plate 434, additional annular plate 434a, and additional annular plate 434b are shown positioned around portions of lift pin apertures 455 and backside gas passages 445 defined within base plate 430b (or other lowermost upper plate 430).

[0052] The electrostatic chuck body 425 may include a cooling plate 465 coupled to the lowermost plate (as shown, base plate 430b) of the upper plate 430. The cooling plate 465 may be positioned below the upper plate 430 and may be directly or indirectly connected to the top end of the support handle 405. The cooling plate 465 may be formed of a material having a high thermal conductivity. The high thermal conductivity helps to dissipate excess heat from the upper plate 430 to reduce thermal displacement that may cause uneven film on the substrate. The material forming the cooling plate 465 may also have a thermal expansion coefficient similar to that of the upper plate 430 to prevent the electrostatic chuck body 425 from being damaged or deformed during temperature fluctuations. For example, the difference between the coefficients of thermal expansion of the upper plate 430 and the cooling plate 465 can be less than or about 20%, less than or about 15%, less than or about 10%, less than or about 9%, less than or about 8%, less than or about 7%, less than or about 6%, less than or about 5%, less than or about 4%, less than or about 3%, less than or about 2%, less than or about 1%, or less. The cooling plate 465 can be made of a metal such as aluminum, stainless steel, or other material. Alternatively, the cooling plate 465 can be made of a composite ceramic (such as SiC or molybdenum infiltrated with aluminum silicon alloy) to match the coefficient of thermal expansion of the upper plate 430.

[0053] The cooling plate 465 can be coupled to the lowermost plate of the upper plate 430 (e.g., coupled to the base plate 430b opposite the support plate 430a in a dual plate embodiment), such as by using one or more fasteners. For example, the bottom surface 466 of the cooling plate 465 can define a plurality of counterbores 467 that can receive the heads of corresponding fasteners 468 (such as bolts) that can be used to fasten the cooling plate 465 to the lowermost plate of the upper plate 430. The threaded portion of each fastener 468 can extend through a hole formed in the thermal gasket 485 and engage with threads formed in the fastening plate 460 to secure the cooling plate 465 to the lowermost plate of the upper plate 430.

[0054] As part of the electrostatic chuck body 425, a cooling plate 465 can define each lift pin hole 455 and a portion of each backside gas channel 445. The cooling plate 465 can define one or more cooling channels 470. In some embodiments, the top end of each cooling channel 470 can form a ring or other circuitous pattern around the interior of the cooling plate 465 and can be connected to a cooling fluid source through inlet and outlet channels through the support handle 405. A cooling fluid such as water or a coolant can be circulated through each cooling channel 470 to cool the lower portion of the electrostatic chuck body 425, thereby helping to dissipate excess heat generated during the plasma formation process, which can reduce or eliminate thermal displacement and result in more uniform film deposition on the substrate. The cooling fluid can be circulated at a temperature of less than or about 125°C, less than or about 120°C, less than or about 115°C, less than or about 110°C, less than or about 105°C, less than or about 100°C, less than or about 95°C, less than or about 90°C, less than or about 85°C, less than or about 80°C, less than or about 75°C, less than or about 70°C, less than or about 65°C, less than or about 60°C, less than or about 55°C, less than or about 50°C, or lower.

[0055] The upper surface 469 of the cooling plate 465 may define one or more annular grooves 475. Each groove 475 may be aligned with a corresponding annular plate 440. For example, the outermost groove 475a may be aligned with the annular plate 440. If the electrostatic chuck body 425 includes a lift pin hole 455 and / or a back gas channel 445, grooves 475b and 475c may be included and aligned with additional annular plates 440a and 440b, respectively. The size and shape of each groove 475 may be designed to receive a corresponding vacuum sealing element 480. Each vacuum sealing element 480 (such as an O-ring) may be seated in a corresponding groove 475 so that when the cooling plate 465 is fastened against the lowermost plate of the upper plate 430, the vacuum sealing element 480 may be compressed between the cooling plate 465 and the corresponding one of the annular plates 440. This can provide a vacuum seal to be formed, which can cause the pressure within the substrate support assembly 400 (which is typically at atmospheric pressure levels) to be different from the pressure within the chamber environment and / or the lift pin bore 455 (which is typically maintained at a vacuum). In addition, the vacuum sealing element 480 can prevent any back gas from flowing from the back gas channel 445 to the interior of the electrostatic chuck body 425. The presence of the annular plate 440 can help isolate the vacuum sealing element 480 from the high temperatures exhibited by the upper plate 430 during processing operations, which can enable the use of a more conventional vacuum sealing element 480. For example, the vacuum sealing element 480 can be an O-ring formed of a perfluoropolymer (PFP). Alternatively, other types of high temperature O-rings can be used. In one embodiment, an insulating high temperature O-ring is used. The O-ring can be a stepped O-ring having a first step of a first thickness and a second step of a second thickness. This can promote uniform tightening of the fastener by causing the amount of force used to tighten the fastener to increase significantly after a set amount of compression of the O-ring. Additional grooves and / or O-rings (not shown) may also be provided on the top side of the cooling plate 465 around the holes through which cables and / or other components of the substrate support assembly 400 pass.

[0056] The substrate support assembly 400 may include a thermal gasket 485 disposed between at least a portion of the base plate 430b (or other lowermost plate of the upper plate 430) and the cooling plate 465. For example, the thermal gasket 485 may be disposed radially inward of the vacuum sealing element 480a, which is disposed radially outward (e.g., seated within the groove 475a), and may define a plurality of holes to provide access for the fastener 468, the lift pin hole 455, the back gas channel 445, and / or other features of the electrostatic chuck body 425. In some embodiments, the thermal gasket 485 may be formed of PFP, such as DuPont TM ECCtreme TM , DuPont and DUPRATM Alternatively, the gasket may be a stack of alternating layers of graphite foil and polyimide. The thermal gasket 485 may have a thickness between 0.1 mm and 2 mm (or about the value), between 0.15 mm and 1.75 mm (or about the value), between 0.2 mm and 1.5 mm (or about the value), between 0.25 mm and 1.25 mm (or about the value), between 0.3 mm and 1 mm (or about the value), between 0.35 mm and 0.75 mm (or about the value), or between 0.4 mm and 0.5 mm (or about the value).

[0057] In the foregoing description, for the purpose of explanation, many details have been set forth in order to provide an understanding of various embodiments of the present technology. However, it will be apparent to one skilled in the art that certain embodiments may be practiced without some of these details or with other details.

[0058] Several embodiments have been disclosed, and those skilled in the art will recognize that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. In addition, in order to avoid unnecessarily obscuring the present technology, many well-known processes and elements are not described. Therefore, the above description should not be considered to limit the scope of the present technology.

[0059] Where a range of values ​​is provided, it is understood that each intermediate value (unless the context clearly dictates otherwise, the smallest fraction of the lower limit unit) also specifically discloses intermediate values ​​between the upper and lower limits of the range. Any narrower range between any specified value or unspecified intermediate value within a specified range and any other specified or intermediate value within the specified range is included. The upper and lower limits of these smaller ranges may be independently included in or excluded from the range, and each range (where one of the limits is included, neither of the limits is included, or both are included in each range in the smaller range) is also included in the technology, subject to any explicitly excluded limits in the range. If the range includes one or both of the limits, those ranges excluding one or both of the included limits are also included.

[0060] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a heater" includes a plurality of such heaters and reference to "the rod" includes reference to one or more rods and equivalents thereof known to those skilled in the art, and so forth.

[0061] Furthermore, when the words “comprise(s)”, “comprising”, “contain(s)”, “containing”, “include(s)” and “including” are used in this specification and the following claims, they are intended to specify the presence of stated features, integers, components or operations, but do not preclude the presence or addition of one or more other features, integers, components, operations, actions or groups.

Claims

1. A substrate support assembly, comprising: The electrostatic chuck body includes: a support plate defining a substrate support surface; a base plate coupled to the support plate opposite the substrate support surface, wherein a bottom surface of the base plate defines an annular recess; and a cooling plate coupled to the bottom surface of the base plate opposite the support plate; a support handle coupled to the electrostatic chuck body; a heater, the heater being embedded in the electrostatic chuck body; one or more electrodes embedded within the electrostatic chuck body and spaced apart from the heater; an annular plate disposed within the annular recess, the annular plate having a thermal conductivity of less than about 20 W / mK; a vacuum sealing element disposed between the annular plate and the cooling plate; and A thermal gasket is disposed radially inwardly of the vacuum sealing element.

2. The substrate support assembly of claim 1, wherein: The annular recess extends across a peripheral edge of the base plate.

3. The substrate support assembly of claim 1 , wherein: The thickness of the annular plate is less than about 2 mm.

4. The substrate support assembly of claim 1 , wherein: The width of the annular plate is between about 2 mm and 20 mm.

5. The substrate support assembly of claim 1 , wherein: The top surface of the cooling plate defines an annular groove; and The vacuum sealing element is disposed within the annular groove.

6. The substrate support assembly of claim 1, wherein: The electrostatic chuck body defines a plurality of lift rod holes; the bottom surface of the base plate defining an additional annular recess around each of the plurality of lift rod holes; The substrate support assembly includes an additional annular plate; each of the additional annular plates being disposed within a respective one of the additional annular recesses; The substrate support assembly includes an additional vacuum sealing element; and Each of the additional vacuum sealing elements is disposed between the cooling plate and a respective one of the additional annular plates.

7. The substrate support assembly of claim 1, wherein: The annular plate includes a fluorine-resistant material.

8. The substrate support assembly of claim 1, wherein: The annular plate has a coefficient of thermal expansion within about 10% of a coefficient of thermal expansion of the base plate.

9. The substrate support assembly of claim 1, wherein: The one or more electrodes are disposed within the support plate; and The heater is disposed within the base plate.

10. A substrate support assembly comprising: The electrostatic chuck body includes: a support plate defining a substrate support surface; a base plate coupled to the support plate opposite the substrate support surface, wherein a bottom surface of the base plate defines an annular recess; and a cooling plate coupled to the bottom surface of the base plate opposite the support plate; a heater, the heater being embedded in the electrostatic chuck body; one or more electrodes embedded within the electrostatic chuck body and spaced apart from the heater; an annular plate disposed within the annular recess, the annular plate having a thermal conductivity of less than about 20 W / mK; and A vacuum sealing element is disposed between the annular plate and the cooling plate.

11. The substrate support assembly of claim 10, wherein: The annular plate has a thermal conductivity of less than about 5 W / mK.

12. The substrate support assembly of claim 10, further comprising: A thermal gasket is disposed radially inwardly of the vacuum sealing element.

13. The substrate support assembly of claim 12, wherein: The thermal gasket has a thickness of less than about 2 mm.

14. The substrate support assembly of claim 10, wherein: The vacuum sealing element includes a perfluoropolymer.

15. The substrate support assembly of claim 10, wherein: The electrostatic chuck body defines a backside gas passage extending through a thickness of the electrostatic chuck body and through the substrate supporting surface.

16. The substrate support assembly of claim 15, wherein: the bottom surface of the base plate defining an additional annular recess around the backside gas channel; The substrate support assembly includes an additional annular plate disposed within the additional annular recess; and The substrate support assembly includes an additional vacuum sealing element disposed between the cooling plate and the backside gas channel.

17. The substrate support assembly of claim 10, wherein: The annular channel is disposed radially inwardly of a peripheral edge of the base plate.

18. The substrate support assembly of claim 10, wherein: The annular plate has a coefficient of thermal expansion of between approximately 4.7 and 5.

19. A substrate support assembly comprising: One or more upper panels, where: An uppermost plate of the one or more plates defines a substrate supporting surface; and A bottom surface of a lowermost plate of the one or more plates defines an annular recess; a cooling plate coupled to the bottom surface of the lowermost plate; a heater embedded in one of the one or more plates; an electrode embedded in one of the one or more plates and spaced apart from the heater; an annular plate disposed within the annular recess, the annular plate having a thermal conductivity of less than about 20 W / mK; and A vacuum sealing element is disposed between the annular plate and the cooling plate.

20. The substrate support assembly of claim 19, wherein: The lowermost plate and the uppermost plate are the same plate.

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