Electrostatic chuck with ceramic monoblock

Abstract

An electrostatic chuck for a substrate processing system includes a body made of ceramic. A plurality of first electrodes are disposed in the body proximate a top surface of the body and configured to selectively receive a clamping signal. A gas passage is formed in the body and configured to supply a backside gas to the top surface. A coolant passage is formed in the body and configured to receive a fluid to control a temperature of the body.

Description

[0001] This application is a divisional application of patent application No. 202080014009.1, filed on January 27, 2020, by Rum Research Corporation, entitled "Electrostatic Chuck with Ceramic Monomer".

[0002] Cross-reference to related applications This disclosure is based on the U.S. national phase application, International Application No. PCT / US2020 / 015148, filed January 27, 2020, 35 USC 371, which claims the benefit of U.S. Provisional Application No. 62 / 804,465, filed February 12, 2019. The entire disclosure of the above-cited applications is incorporated herein by reference. Technical Field

[0003] This disclosure relates to substrate processing systems, and more specifically, to electrostatic chucks with ceramic monomers for use in substrate processing systems. Background Technology

[0004] The background description provided herein is for the purpose of presenting the general context of this disclosure. The work of the currently designated inventors, within the scope described in this background section and in the various aspects of the specification that could not be identified as prior art at the time of filing, neither expressly nor impliedly acknowledges that it is prior art to this disclosure.

[0005] Substrate processing systems are used to process substrates (e.g., semiconductor wafers). Exemplary processes performed on the substrate include (but are not limited to) deposition, etching, cleaning, and other types of processing. The substrate is placed on a substrate support (e.g., an electrostatic chuck (ESC)) within a processing chamber. During processing, a gas mixture is introduced into the processing chamber, and plasma may be used to initiate chemical reactions. Summary of the Invention

[0006] An electrostatic chuck for a substrate processing system comprises a monomer made of ceramic. A plurality of first electrodes are disposed within the monomer adjacent to its top surface and configured to selectively receive clamping signals. Gas channels are formed within the monomer and configured to supply back-side gas to the top surface. A plurality of coolant channels are formed within the monomer and configured to receive fluid to control the temperature of the monomer.

[0007] Among other features, the monomer comprises a plurality of ceramic green sheets. The monomer includes a first portion disposed adjacent to a substrate, and a second portion located adjacent to the first portion. The first portion is made of a first plurality of ceramic green sheets having a first mass, and the second portion is made of a second plurality of ceramic green sheets having a second mass, wherein the second mass is less than the first mass.

[0008] Among other features, the second plurality of ceramic green sheets, relative to the first ceramic green sheet, have at least one of the following: increased porosity, decreased purity, increased dielectric constant, or increased loss tangent. The plurality of first electrodes are disposed between the plurality of coolant channels and the top surface. A plurality of second electrodes are disposed in the monomer and configured to receive an RF bias signal. The plurality of second electrodes are disposed between the plurality of coolant channels and the plurality of first electrodes. A porous insert is disposed in at least one of the inlet and outlet of the gas channel.

[0009] Among other features, the monomer includes a first portion disposed adjacent to a substrate and a second portion disposed adjacent to the first portion. The second portion is made of a plurality of ceramic green sheets. The first portion is deposited on the second portion, and the first portion includes a plurality of ceramic layers and a conductive layer defining the plurality of first electrodes.

[0010] Among other features, the first portion is deposited using a process selected from the group consisting of atomic layer deposition and chemical vapor deposition. The monomer defines a lift pin cavity and further includes a lift pin assembly disposed within the lift pin cavity.

[0011] A method for manufacturing a monolithic electrostatic chuck includes: selecting a plurality of ceramic green sheets for the monolithic electrostatic chuck; cutting a plurality of features from a first selected of the plurality of ceramic green sheets, wherein the plurality of features are selected from a group consisting of a gas channel, a coolant channel, and a lifting pin cavity; forming a plurality of electrodes on a second selected of the plurality of ceramic green sheets; aligning and stacking the plurality of ceramic green sheets; and heating the stack to a predetermined temperature to form the monolithic electrostatic chuck.

[0012] Among other features, the predetermined temperature is in the range of 1000°C to 2000°C. The plurality of features includes a coolant channel that extends through adjacent ceramic green sheets. The plurality of features includes a gas channel that extends through adjacent ceramic green sheets. The method further includes distributing a porous insert material in at least one of the inlet and outlet of the gas channel before heating the stack.

[0013] Among other features, the method further includes processing at least one surface of the monolithic electrostatic chuck after heating the stack. The method also includes forming a plurality of electrodes on a selected of the plurality of ceramic green sheets prior to heating.

[0014] A method for manufacturing a monolithic electrostatic chuck includes: providing U ceramic green sheets having a first mass, where U is an integer greater than one; cutting a plurality of features from a selection of the U ceramic green sheets; aligning and arranging the U ceramic green sheets into a first stack; providing L ceramic green sheets having a second mass less than the first mass, where L is an integer greater than one; cutting a plurality of features from a selection of the L ceramic green sheets; aligning and arranging the L ceramic green sheets into a second stack; arranging and aligning the first stack and the second stack adjacent to each other; and heating the first stack and the second stack.

[0015] Among other features, the first stack and the second stack are heated to a temperature in the range of 1000°C to 2000°C. The method includes forming a plurality of first electrodes on a selected of the U ceramic green sheets prior to heating the first stack and the second stack, the plurality of first electrodes being configured to receive a clamping bias.

[0016] Among other features, the method includes forming a plurality of second electrodes on selected of the U ceramic green sheets before heating the first and second stacks, the plurality of second electrodes being configured to receive an RF bias. The L ceramic green sheets have, relative to the U ceramic green sheets, at least one of the following: increased porosity, decreased purity, increased dielectric constant, or increased loss tangent. The step of slicing the plurality of features includes forming a plurality of coolant channels in at least one of the U and L ceramic green sheets before heating the first and second stacks. The step of slicing the plurality of features includes forming a plurality of gas channels in at least one of the U and L ceramic green sheets before heating the first and second stacks.

[0017] Among other features, the method includes distributing a porous insert material in at least one of the inlets and outlets of the plurality of gas channels before heating the first stack and the second stack. The method also includes processing at least one surface of the first stack after heating the first stack and the second stack.

[0018] A method for manufacturing a monolithic electrostatic chuck includes: selecting a plurality of ceramic green sheets for the lower portion of an electrostatic chuck body; cutting a plurality of features from selected ones of the plurality of ceramic green sheets; aligning and stacking the plurality of ceramic green sheets; heating the stack to a predetermined temperature; and forming the upper portion of the electrostatic chuck body by depositing a plurality of layers on the upper surface of the stack. The plurality of layers comprise ceramic and define a plurality of electrodes.

[0019] Among other features, the predetermined temperature is in the range of 1000°C to 2000°C. The first mass of the ceramic material in the upper part of the electrostatic chuck body is higher than the second mass of the ceramic material in the lower part of the electrostatic chuck body. The plurality of ceramic green sheets in the lower part have, relative to the plurality of ceramic green sheets in the upper part, at least one of the following: increased porosity, decreased purity, increased dielectric constant, or increased loss tangent. The plurality of features includes coolant channels formed in adjacent portions of the plurality of ceramic green sheets. The plurality of features includes gas channels formed in adjacent portions of the plurality of ceramic green sheets.

[0020] Among other features, the method includes distributing a porous insert material in at least one of the inlets and outlets of the plurality of gas channels before heating the stack. The method includes processing at least one surface of the lower portion after heating the stack and before depositing the upper portion. The operation of depositing the plurality of films on the upper surface of the stack includes processes selected from the group consisting of atomic layer deposition and chemical vapor deposition. The method includes forming a plurality of electrodes on selected of the plurality of ceramic green sheets before heating.

[0021] The further scope of the applicability of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0022] This disclosure will be more fully understood from the detailed description and accompanying drawings, in which: Figure 1 The present disclosure shows a functional block diagram of an example substrate processing system comprising an ESC having ceramic monomers; Figure 2 A partial side cross-sectional view of an example of an ESC including a coolant passage, a back gas passage, electrodes, and RF terminals according to this disclosure; Figure 3 Another partial side cross-sectional view of an example of an ESC including a gas channel with a porous insert, a sensor, and an electrostatic terminal according to this disclosure; Figure 4 Another partial side cross-sectional view of an example of an ESC with a lifting pin assembly according to this disclosure; Figure 5 A plan view of an example ESC having a gas channel for distributing back-side gas according to this disclosure; Figure 6 A plan view of an example ESC having dual coolant channels formed in a ceramic monomer, according to this disclosure; Figure 7A plan view of an example ESC having a single coolant channel formed in a ceramic monomer, according to this disclosure; Figure 8A A side cross-sectional view of an example of a body stack containing ceramic green sheets prior to heating according to this disclosure; Figure 8B This disclosure shows the process after heating. Figure 8A The main body stacked components; Figure 9 A flowchart illustrating an example of a method for manufacturing an ESC having a monomer, according to this disclosure; Figure 10A The present disclosure shows an example of a body stack comprising a first stack of ceramic green sheets having a first mass and a second stack of ceramic green sheets having a second mass prior to heating; Figure 10B This disclosure shows the process after heating. Figure 10A The main body stacked components; Figure 11A This disclosure shows an example of the body stack of the first stack of ceramic green sheets corresponding to the lower part of the ESC before heating; Figure 11B This disclosure shows the process after heating. Figure 11A The main body stacked components; Figure 11C This disclosure shows the upper part after the deposition of the ESC. Figure 11B The main body stacked components; Figure 12 A flowchart illustrating a method for manufacturing an ESC having ceramic monomers according to this disclosure; and Figure 13 A flowchart of another method for manufacturing an ESC with ceramic monomers according to this disclosure; In the accompanying drawings, reference numerals may be used repeatedly to identify similar and / or identical elements. Detailed Implementation

[0023] ESCs typically consist of a ceramic plate bonded to a substrate via a bonding layer. The substrate is typically made of a metal (e.g., aluminum (Al), titanium (Ti), or other metals). The substrate is usually coated with a thin layer of ceramic (e.g., alumina) or other coatings. The ceramic coating is typically applied using electrochemical anodizing, thermal spraying, or other methods. The ceramic plate and substrate are bonded together via the bonding layer. For example, the bonding layer may contain silicone polymers, organic polymer adhesives, inorganic fillers, and / or soft metallic materials. The bonding layer typically needs to be protected from the effects of the plasma processing environment.

[0024] This design has several drawbacks. For example, the ceramic coating tends to disintegrate when exposed to high voltage, which can induce arcing in the processing chamber. The substrate and ceramic plate also have different coefficients of thermal expansion (CTE). These mismatched materials expand and contract at different rates with temperature changes. This expansion and contraction leads to misalignment and thermal stress. The ceramic coating may also crack due to the difference in CTE between the substrate and the ceramic coating.

[0025] The substrate also serves as a single RF electrode. This makes it difficult to apply different RF electrodes to different areas of the substrate.

[0026] The bonding layer acts as a thermal barrier, restricting heat transfer and resulting in higher substrate temperatures, particularly for high-power applications. Because the ceramic substrate and the base plate have different thermal conductivity (CTE) during processing, the bonding layer undergoes deformation cycling. Ultimately, this deformation cycling leads to bonding layer delamination and ESC (Electrostatic Discharge) failure.

[0027] In some examples, the ESC according to the invention is manufactured monolithically (without using a bonding layer). The ESC includes embedded electrodes for electrostatic clamping, temperature control, RF power delivery, RF shielding, etc. The ESC also includes other integrated components such as temperature sensors, current and / or voltage sensors, porous dielectric gas buffers, embedded gas channels, and / or embedded coolant channels.

[0028] The ESC according to the present invention solves many problems encountered when using previous ESC designs. Since the ESC body is monolithic and made of ceramic, the ceramic coating is omitted or has a similar CTE. Because CTE mismatch is rare or nonexistent, the possibility of ceramic coating cracking is eliminated. Therefore, the operating temperature range of the ESC can be extended.

[0029] Since the substrate is no longer made of metal, one or more electrodes are embedded in the body of the ESC. One or more RF potentials can be used to control the electrodes to allow for variations in RF bias at different locations on the substrate.

[0030] Since the bonding layer is eliminated, the failures caused by the erosion and delamination of the bonding layer are eliminated, which improves the life and reliability of the ESC.

[0031] Because the ESC is a monolithic structure made of ceramic, differences in thermal expansion and contraction throughout the entire ESC are minimized. This significantly reduces thermal mismatch and thermal stress. The elimination of the bonding layer increases thermal conductivity of the cooling fluid (e.g., gas or liquid) from the substrate to the ESC. The improved thermal conductivity, utilizing coolant channels for more efficient heat transfer, enables higher power applications.

[0032] In some examples, the body of the ESC is made of a material selected from the group consisting of alumina (Al2O3), aluminum nitride (AlN), silicon carbide (SiC), or other ceramic materials. In some examples, the body of the ESC is coated. In some examples, the coating material is selected from the group consisting of alumina (Al2O3), yttrium oxide (Y2O3), or zirconium dioxide (ZrO2).

[0033] In some examples, the body of the ESC is made of different grades or qualities of ceramic material at different vertical sections to reduce cost and / or optimize performance. For example, a higher grade of ceramic material may be used in the upper part of the ESC closer to the substrate to obtain improved purity, dielectric, electrical, or mechanical properties, while a different (e.g., lower) grade of ceramic material may be used for the lower part of the ESC.

[0034] In some examples, the ESC includes embedded electrodes made of a material selected from the group consisting of tungsten (W), lead (Pt), silver (Ag), palladium (Pd), or other conductive materials. The body of the ESC may contain one or more electrodes, which may be connected together or controlled individually. The electrodes may also be positioned in different locations within the body.

[0035] Now refer to Figure 1 This illustrates a substrate processing system 100 including an electrostatic chuck (ESC) 101. Although Figure 1 A capacitively coupled plasma (CCP) system has been shown, but the invention is also applicable to other processes, such as transformer-coupled plasma (TCP) systems, electron cyclotron resonance (ECR) plasma systems, ion beam etchers (IBE), inductively coupled plasma (ICP) systems, and / or other systems that include substrate supports.

[0036] Although the ESC101 is shown as being mounted at the bottom of the processing chamber, it can also be mounted at the top. If mounted at the top of the processing chamber, the ESC101 can be upside down and may include peripheral substrate holding, clamping, and / or fastening hardware.

[0037] The substrate processing system 100 includes a processing chamber 104. The processing chamber 104 encapsulates the ESC 101 and other components. The processing chamber 104 also contains radio frequency (RF) plasma. During operation, the substrate 107 is placed on the ESC 101 and is electrostatically held on the ESC 101.

[0038] For example only, nozzle 109 dispenses gas and can be used as upper electrode 105. Nozzle 109 may include a rod 111 having one end connected to the top surface of processing chamber 104. Nozzle 109 is generally cylindrical and extends radially outward from the other end of rod 111 (located at a position spaced from the top surface of processing chamber 104). The substrate-facing surface of nozzle 109 includes gas through-holes through which processing gas flows. Alternatively, upper electrode 105 may include a conductive plate, and processing gas may be introduced in another manner. An electrode embedded in ESC 101 serves as lower electrode.

[0039] ESC101 may include one or more gas channels 115 and / or one or more coolant channels 116. Gas channels 115 supply back-side gas (such as helium (He) or other gases) to the back side of substrate 107. Fluid flows through coolant channels 116 in ESC101 to control the temperature of ESC101.

[0040] The RF generation system 120 outputs an RF voltage to the upper electrode 105 and / or the lower electrode in ESC 101. One of the upper electrode 105 and the lower electrode can be DC ground, AC ground, or at a floating potential. By way of example only, the RF generation system 120 may include one or more RF generators 122 that generate the RF voltage. The output of the RF generator 122 is fed to the upper electrode 105 and / or the lower electrode via one or more matching and distribution networks 124. For example, an RF plasma generator 123, an RF bias generator 125, an RF plasma matching network 127, and an RF bias matching network 129 are shown.

[0041] The gas delivery system 130 includes one or more gas sources 132-1, 132-2, ..., and 132-N (collectively referred to as gas sources 132), where N is a positive integer. Gas sources 132 supply one or more precursors, etching gases, inert gases, carrier gases, purge gases, and mixtures thereof. Vaporized precursors may also be used.

[0042] Gas source 132 is connected to manifold 140 via valves 134-1, 134-2, ..., and 134-N (collectively referred to as valves 134) and mass flow controllers 136-1, 136-2, ..., and 136-N (collectively referred to as mass flow controllers 136). The output of manifold 140 is fed to treatment chamber 104. By way of example only, the output of manifold 140 may be fed to nozzle 109.

[0043] The substrate processing system 100 also includes a temperature control system 141, which includes a temperature controller 142. Although shown separately from the system controller 160, the temperature controller 142 may be implemented as part of the system controller 160. The temperature controller 142 controls the temperature and flow rate of the coolant flowing through the coolant passage 116 via the coolant assembly 146. The coolant assembly 146 includes a coolant pump that pumps coolant from a reservoir to the coolant passage 116. The coolant assembly 146 may also include a heat exchanger that transfers heat away from the coolant. The coolant may be, for example, a liquid coolant.

[0044] Valve 156 and pump 158 are used to evacuate reactants from processing chamber 104. Robotic arm 170 transfers the substrate onto and removes the substrate from ESC 101. For example, robotic arm 170 can transfer the substrate between ESC 101 and loading lock 172. System controller 160 can control the operation of robotic arm 170 and / or loading lock 172. ESC power supply 180 selectively supplies clamping signals to cause electrodes to clamp the substrate 107.

[0045] Now refer to Figure 2 The image shows a portion 200 of ESC101. ESC101 has a monomer 210. In the example shown, monomer 210 includes an electrostatic clamping electrode 214, which may be disposed near the top surface 212 of ESC101. The electrostatic clamping electrode 214 receives a clamping signal from ESC power supply 180 to clamp the substrate 107. The electrostatic clamping electrode 214 may be connected to a terminal (shown below) that may be connected to ESC power supply 180. For example, a conductor may pass through an insulating cavity to provide connection to the electrostatic clamping electrode 214.

[0046] The unit 210 also includes inner and outer radio frequency (RF) electrodes 218-I and 218-O (collectively referred to as RF electrodes 218). RF electrodes 218 receive power from terminals 220-I and 220-O (collectively referred to as terminals 220), which can be connected to a bias RF matching network 129. Terminals 220 are disposed in insulating cavities 222-I and 222-O, which extend from the bottom of ESC101 to the RF electrodes 218. RF electrodes 218 can be disposed within a predetermined distance of the top surface of the unit 210. RF electrodes 218 can be disposed across the top surface of the unit 210 according to different patterns. One or more of the RF electrodes 218-I can be disposed in the upper portion 221 of the unit 210, which protrudes upward and defines an annular groove. One or more of the RF electrodes 218-O can be disposed near the outer periphery of the unit 210. In some examples, the RF electrode 218-O may be positioned below an edge ring (not shown) located in an annular groove and centered on portion 221.

[0047] The monomer 210 also includes a gas channel 234 that receives a back-side gas (e.g., helium) delivered to the back side of the substrate 107. A coolant channel 228 is disposed in one or more planes parallel to the substrate 107. The coolant channel 228 may be dual-stranded or single-stranded.

[0048] Now refer to Figure 3 The image shows portion 300 of ESC101. One or more vertical inlets (or outlets) 310 supply fluid to coolant passages 228. Monomer 210 includes a vertical gas passage 320 that supplies backside gas to gas passage 234. A porous insert 324 is disposed in one end of the vertical gas passage 320 near the bottom surface of monomer 210. A porous insert 325 is disposed between gas passage 234 and the top surface of ESC101. Porous inserts 324 and 325 are made of porous ceramic and can be fired during the firing of the ceramic green sheet forming the monomer. In some examples, the porous insert is omitted, or it is installed after the monomer is fired. The porous insert contains small pores to prevent plasma formation in the gas passage and to prevent line of sight propagation of plasma.

[0049] Unit 210 includes a vertical cavity 330 that houses a terminal 332 connected to one end of an electrostatic clamping electrode 214. Unit 210 also includes one or more vertical cavities for temperature sensors. Exemplary temperature sensors 342-1, 342-2, and 342-3 (collectively referred to as temperature sensors 342) are respectively disposed in vertical cavities 340-1, 340-2, and 340-3 and connected to conductors 344-1, 344-2, and 344-3. Temperature sensors 342 provide temperature output signals to controllers 142 and 160.

[0050] Now refer to Figure 4 The image shows part 400 of the ESC101. Unit 210 includes a lifting pin assembly 420, which includes a lifting pin 410, a lifting pin channel 414, and a gas channel 434. In some examples, the ESC101 includes three or more lifting pin assemblies.

[0051] Now refer to Figure 5 The ESC101 includes a gas channel 234 for supplying back-side gas to the top surface of the monomer. Gas is supplied to the gas channel 234 below the substrate 107. Gas flows from the gas channel 234 through a porous insert 325 (not shown in the figure). Figure 5 (In the middle) flows at various locations to supply back-side gas below the substrate.

[0052] Now refer to Figure 6This image shows a coolant channel layer 600 formed in the monomer of ESC101. The coolant channel layer 600 contains coolant channels 602, which are double-stranded. The coolant channels 602 include an inlet 604 and an outlet 608 located at the center of the coolant channel layer 600. One end of the coolant channel 602 begins near the center and winds along a circular coil pattern until it reaches the periphery. The coolant channel 602 continues along the coil pattern from the periphery back to the center.

[0053] Now refer to Figure 7 This shows a coolant channel layer 700 formed in the single unit of ESC101. The coolant channel layer 700 includes a single-strand coolant channel 702. The coolant channel 702 includes a central inlet 704 and outlets 708 located near the periphery of the coolant channel layer 700 (and vice versa). Although in Figure 6-7 An exemplary coolant passage configuration is shown, but other configurations can be used.

[0054] Now refer to Figure 8A and 8B The ESC body stack 800 can be made from ceramic green sheets. Figure 8A The image shows an ESC body stack 800 before heating, comprising a stack 802 containing ceramic green sheets 806. Features such as holes, cavities (e.g., for gas channels, coolant channels, terminals, lifting pins), and electrodes are formed in the ceramic green sheets as needed. More porous ceramic green sheets can be used to define porous inserts within the gas channels. Figure 8B The image shows the ESC body stack after heating. Among other advantages, the ESC body stack 800 forms a single unit (features not shown) after heating. The single unit has improved electrical and thermal properties and does not contain or require bonding layers that could lead to early failure.

[0055] Now refer to Figure 9 The diagram illustrates a method 900 for manufacturing a single element of an ESC. In 910, openings are cut into one or more ceramic green sheets to define features of the ESC. In some examples, features are laser-cut into the ceramic green sheets. For example, openings are cut into the green sheets corresponding to cavities for gas channels, terminals, porous inserts, sensors, and / or gas flow. In some examples, a laser is used to scribble or ablate the top surface of the ceramic green sheet, thereby creating gas channels parallel to the plane containing the substrate. In other examples, a laser is used to cut through one or more ceramic green sheets, thereby creating gas channels, cavities, or other features oriented perpendicular to the plane containing the substrate. In some examples, each of the green sheets has a thickness ranging from 0.5 mm to 2 mm, but other thicknesses may also be used.

[0056] At 914, electrodes, such as RF electrodes or electrostatic clamping electrodes, are formed on selected features of the ceramic green sheet. In some examples, the electrodes are formed by printing metal powder onto the ceramic green sheet. At 918, porous insert material is selectively arranged in one or more features (e.g., gas channels) of the ceramic green sheet. In some examples, the porous insert material comprises a ceramic green sheet material that is different from the green sheet material used for the ESC body (e.g., more porous). At 922, the ceramic green sheet is rotated to align (to align features) and contact-set to form a stack.

[0057] In step 924, the stacked components are heated or fired to form a monolithic ESC body. In some examples, the ESC stacked components are heated to a temperature ranging from 1000°C to 2000°C. In step 926, sensors and terminals are selectively mounted. In step 928, one or more surfaces of the ESC body are machined as needed. Machining operations can be used to flatten the surfaces of the ESC body. As will be understood, the order of one or more steps can be changed from the foregoing examples.

[0058] Now refer to Figure 10A and 10B The ESC body stack 1000 can be made of ceramic green sheets. In some examples, the ceramic green sheets have different qualities depending on their location within the ESC101. Higher quality ceramic green sheets are used near the substrate, while lower quality ceramic green sheets are used on the underside of the ESC101 or in less critical areas. Figure 10A The image shows an ESC body stack 1000 before heating, comprising a first stack 1002 containing ceramic green sheets 1006, having a first mass. The ESC body stack 1000 also includes a second stack 1004 containing ceramic green sheets 1008, having a second mass. Figure 10B The image shows the ESC body stack 1000 after heating. Among other advantages, the ESC body stack 1000 forms a monomer 1010 after heating. The monomer 1010 has improved electrical and thermal properties and does not contain or require bonding layers that could lead to early failure.

[0059] Now refer to Figures 11A to 11C The ESC body 1100 can be formed from an assembly of fired and selectively processed ceramic green sheets. Next, the top of the body is formed by depositing additional materials such as ceramic and / or conductive materials (forming electrodes). Through-holes or apertures can be defined to allow placement of sensors (such as temperature sensors), lifting pin assemblies, terminals of RF electrodes, gas channels, etc.

[0060] exist Figure 11A In the ESC body stack 1100, there is a stack of ceramic green sheets 1106. Figure 11BThe image shows the ESC body stack 1100 after the ceramic green sheet has been heated into monomer 1104. Figure 11C The image shows the deposition of one or more ceramic materials and one or more conductive materials (e.g., for defining electrodes) in the upper part of ESC101 (both layers are jointly identified as 1120). Figure 11B The ESC body stack 1100. In some examples, the upper surface of ESC101 is machined to provide a flat surface prior to deposition.

[0061] Now refer to Figure 12 The diagram illustrates a method 1200 for manufacturing a single unit of an ESC. At 1210, L ceramic green sheets with a first mass are selected for the lower portion of the ESC body, where L is an integer greater than one. At 1214, openings are cut into one or more of the L ceramic green sheets to define features of the lower portion of the ESC. In some examples, features are laser-cut into the ceramic green sheets. For example, openings corresponding to cavities for gas channels, terminals, porous inserts, sensors, and / or gas flow are cut into the green sheets. In some examples, a laser is used to scribble or ablate the top surface of the ceramic green sheet to create gas channels parallel to the plane containing the substrate. In other examples, a laser is used to cut through one or more ceramic green sheets, thereby creating gas channels, cavities, or other features oriented perpendicular to the plane containing the substrate. In some examples, each of the green sheets has a thickness ranging from 0.5 mm to 2 mm, but other thicknesses may also be used.

[0062] In step 1218, U ceramic green sheets with a second mass are selected for the upper part of the ESC body, where U is an integer greater than one. In some examples, the second mass is higher than the first mass. For example, the second mass may differ from the first mass in terms of porosity, purity, dielectric constant, loss tangent, or other properties.

[0063] At 1222, features are cut out from one or more of the U ceramic green sheets to define the upper portion of the ESC. At 1224, electrodes, such as RF electrodes or electrostatic clamping electrodes, are formed on selected of the U ceramic green sheets and / or the L ceramic green sheets. In some examples, electrodes are formed by printing metal powder onto the ceramic green sheets.

[0064] At 1228, the L ceramic green sheets are rotated and aligned (to align features) and placed in contact to form a first stack. At 1230, porous insert material is selectively arranged in one or more features of the L ceramic green sheets. In some examples, the porous insert material comprises a green sheet material different from the green sheet material used for the upper and lower parts of the ESC body. At 1232, the U ceramic green sheets are rotated and aligned (to align features) and placed in contact to form a second stack. At 1232, porous insert material is selectively arranged in the features of the U ceramic green sheets.

[0065] At 1236, the first stack and the second stack are brought into contact. At 1238, the first and second stacks are heated or fired to form a monolithic ESC body. In some examples, the ESC stack is heated to a temperature in the range of 1000°C to 2000°C. At 1242, sensors and terminals are selectively mounted. At 1246, one or more surfaces of the ESC body are machined as needed. The machining operation can be used to flatten the surface of the ESC body. As will be understood, the order of one or more steps can be changed from the foregoing examples.

[0066] Now refer to Figure 13 This illustrates another method 1300 for manufacturing an ESC with a monomer. In 1310, L ceramic green sheets are selected for the lower portion of the ESC body. In 1314, features are cut out from one or more of the L ceramic green sheets to define the features of the lower portion of the ESC body. In 1324, electrodes are selectively formed on the selected of the L ceramic green sheets.

[0067] At 1332, the L ceramic green sheets are brought into contact to form a stack. At 1334, porous insert material is selectively disposed in one or more features of the L ceramic green sheets. At 1338, the stack is heated to form the lower part of the ESC body. At 1340, the upper surface of the lower part of the ESC body is selectively machined.

[0068] At 1342, dielectric and / or conductive materials are deposited. In some examples, deposition processes (e.g., atomic layer deposition (ALD), chemical vapor deposition (CVD), spraying, or other processes) are used to deposit the dielectric and / or conductive materials. At 1346, the sensor is selectively mounted in one or more features of the ESC body. In some examples, multiple processing steps (including photolithography, deposition of dielectric, conductive, and / or mask materials, and / or etching) are performed to define the RF or electrostatic clamping terminals with the surrounding dielectric material. As will be understood, the quality of the dielectric material in the upper part of the ESC body may be higher than that of the ceramic green sheet used in the lower part of the ESC body.

[0069] In some examples, single-unit ESCs can be used in higher power applications. Previous designs, which included separate ceramic plates, metal bodies, and bonding layers, were limited to 10kW to 20kW, while single-unit ESCs can be used at power levels of 10kW to 50kW and higher. As can be understood, using higher power facilitates higher etching rates.

[0070] The foregoing description is merely illustrative in nature and is in no way intended to limit this disclosure, its application, or its use. The broad teachings of this disclosure can be implemented in various forms. Therefore, while this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon examination of the drawings, specification, and appended claims. It should be understood that one or more steps in the method may be performed in different orders (or simultaneously) without altering the principles of this disclosure. Furthermore, while each embodiment is described above as having certain features, any one or more of those features described relative to any embodiment of this disclosure may be implemented in and / or combined with features of any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitution of one or more embodiments for each other remains within the scope of this disclosure.

[0071] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.), including “connection,” “joint,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “set.” Unless the relationship between the first and second elements is explicitly described as “direct,” the relationship described in the above disclosure can be a direct relationship, where no other intermediate element exists between the first and second elements, but it can also be an indirect relationship, where one or more intermediate elements exist between the first and second elements (spatially or functionally). As used herein, the phrase “at least one of A, B, and C” should be interpreted as meaning the use of a non-exclusive logical OR (A or B or C) logic and should not be interpreted as meaning “at least one of A, at least one of B, and at least one of C.”

[0072] In some implementations, the controller is part of a system, which may be part of the examples described above. Such a system may include semiconductor processing apparatus, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after the processing of semiconductor wafers or substrates. The electronics may be referred to as a “controller”, which can control various components or sub-components of one or more systems. Depending on the processing requirements and / or system type, the controller may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer tools and other transfer tools, and / or loading locks connected to or interfaced with a specific system.

[0073] In general, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software for receiving instructions, issuing instructions, controlling operations, enabling cleaning operations, enabling endpoint measurements, etc. Integrated circuits can include chips in the form of firmware storing program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions can be instructions sent to the controller in the form of various individual settings (or program files), which define operating parameters for performing specific processes on or for a semiconductor wafer or system. In some embodiments, operating parameters can be part of a recipe defined by a process engineer to complete one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silica, surfaces, circuits, and / or wafer dies.

[0074] In some implementations, the controller may be part of or coupled to a computer integrated with, coupled to, or otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or be all or part of a fab host system, allowing remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of manufacturing operations, examine the history of past manufacturing operations, examine trends or performance criteria of multiple manufacturing operations, change parameters of the current process, set processing steps to follow the current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide processing recipes to the system via a network (which may include a local network or the Internet). The remote computer may include a user interface that enables input or programming of parameters and / or settings, which are then sent from the remote computer to the system. In some examples, the controller receives instructions in the form of data specifying parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of processing to be performed and the type of tool to which the controller is configured to interface with or control the tool. Therefore, as described above, a controller can be distributed, for example, by comprising one or more discrete controllers networked together and operating toward a common purpose (such as the processing and control described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a room that communicate with one or more integrated circuits remotely (e.g., at the platform level or as part of a remote computer), which together control processing on the room.

[0075] Example systems may include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, rotary rinsing chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfering edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, orbital chambers or modules, and any other semiconductor processing systems that may be associated with or used in the manufacture and / or preparation of semiconductor wafers.

[0076] As described above, depending on one or more processing steps to be performed by the tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the plant, a host computer, another controller, or tools used in the transport of materials to and from the tool location and / or loading port in the semiconductor manufacturing plant.

Claims

1. An electrostatic chuck for a substrate processing system, comprising: Monomer, which is made of ceramic; A plurality of first electrodes are disposed in the monomer adjacent to the top surface of the monomer and configured to selectively receive clamping signals; A gas channel, formed in the monomer, is configured to supply back-side gas to the top surface; as well as Multiple coolant channels in a circular coil pattern are formed within the monomer and configured to receive fluid to control the temperature of the monomer. The plurality of coolant passages include coolant passages with inlets and outlets, and satisfy any of the following conditions: i) Both the inlet and the outlet are located at the center of the coolant channel layer of the monomer; or ii) The inlet is located at the center of the coolant channel layer, while the outlet is located near the periphery of the coolant channel layer.

2. The electrostatic chuck according to claim 1, wherein the single unit comprises a plurality of ceramic green sheets.

3. The electrostatic chuck of claim 1, wherein the monomer comprises a first portion disposed adjacent to a substrate and a second portion located adjacent to the first portion, wherein the first portion is made of a first plurality of ceramic green sheets having a first mass, and the second portion is made of a second plurality of ceramic green sheets having a second mass, wherein the second mass is different from the first mass.

4. The electrostatic chuck according to claim 3, wherein the second plurality of ceramic green sheets have at least one of the following relative to the first plurality of ceramic green sheets: increased porosity, decreased purity, increased dielectric constant, or increased loss tangent.

5. The electrostatic chuck of claim 1, wherein the plurality of first electrodes are disposed between the plurality of coolant channels and the top surface.

6. The electrostatic chuck of claim 1, further comprising a plurality of second electrodes disposed in the unit and configured to receive an RF bias signal.

7. The electrostatic chuck of claim 6, wherein the plurality of second electrodes are disposed between the plurality of coolant channels and the plurality of first electrodes.

8. The electrostatic chuck according to claim 1, further comprising a porous insert disposed in at least one of the inlet and outlet of the gas passage.

9. The electrostatic chuck according to claim 1, wherein: The monomer comprises a first portion disposed adjacent to the substrate, and a second portion disposed adjacent to the first portion; The second part is made of multiple ceramic green sheets; and The first portion is deposited on the second portion, and the first portion includes a plurality of ceramic layers and a conductive layer defining the plurality of first electrodes.

10. The electrostatic chuck of claim 9, wherein the first portion is deposited using a process selected from the group consisting of atomic layer deposition and chemical vapor deposition.

11. The electrostatic chuck according to claim 1, wherein the single unit defines a lifting pin cavity and further comprises a lifting pin assembly disposed in the lifting pin cavity.

12. The electrostatic chuck according to claim 1, wherein: Each layer of the monomer is formed of the same type of material; and The monomer does not have a bonding layer.

13. The electrostatic chuck according to claim 1, wherein: The monomer comprises a first part and a second part; and The first portion protrudes upward from the second portion, and its outer diameter is smaller than that of the second portion; and The gas passage is at least partially located in the first part.

14. The electrostatic chuck of claim 6, wherein the plurality of second electrodes includes an internal radio frequency electrode and an external radio frequency electrode, and wherein the internal radio frequency electrode and the external radio frequency electrode are configured to receive different radio frequency bias voltages.

15. The electrostatic chuck of claim 1, wherein both the inlet and the outlet are located at the center of the coolant channel layer of the monomer.

16. The electrostatic chuck of claim 1, wherein the inlet is located at the center of the coolant channel layer, and the outlet is located near the periphery of the coolant channel layer.

17. The electrostatic chuck of claim 1, wherein the ceramic of the monomer comprises at least one of alumina and aluminum nitride.

18. An electrostatic chuck for a substrate processing system, comprising: Monomer, which is made of ceramic; A plurality of first electrodes are disposed in the monomer adjacent to the top surface of the monomer and configured to selectively receive clamping signals; A gas channel, formed in the monomer, is configured to supply back-side gas to the top surface; Multiple coolant channels in a circular coil pattern are formed within the monomer and configured to receive fluid to control the temperature of the monomer. A porous insert is disposed in at least one of the inlet and outlet of the gas passage.

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