Differential substrate backside cooling

Abstract

An electrostatic chuck (ESC) has a ceramic body including an embedded electrode and having a first diameter. Three or more regions are defined on and concentrically arranged on a surface, each region comprising a retaining ring arranged on the surface and defining an outer edge of the region, and a support structure arranged on the surface and within the region. The support structure is configured to support a surface of a substrate when the substrate is held by the ESC. The ESC includes conduits formed in the ceramic body and configured to independently introduce gas through the ceramic body into each region and into the first surface. Each region is configured to maintain a corresponding positive air pressure within the region and the surface of the substrate, and the one or more embedded electrodes are configured to generate a retention force on the surface of the substrate.

Description

Technical Field

[0001] This specification relates to semiconductor systems, processes, and equipment. Background Art

[0002] Plasma etching can be used in semiconductor processing to manufacture integrated circuits. Integrated circuits can be formed from layer structures comprising multiple (e.g., two or more) layer compositions. Different etching gas chemistries (e.g., different gas mixtures) can be used to form a plasma in a processing environment, allowing a given etching gas chemistry to have increased precision and higher selectivity for the layer composition to be etched. As the scale of integrated circuits continues to trend towards smaller features and increased aspect ratios, the need to accurately etch layer structures has increased. Summary of the Invention

[0003] This specification describes techniques for differential substrate backside cooling.

[0004] These techniques generally involve implementing an electrostatic chuck design comprising multiple design parameters to produce an electrostatic chuck configured for differential substrate backside cooling to produce improved substrate temperature uniformity and tunability during a manufacturing process (eg, during plasma etching).

[0005] As used herein, a substrate refers to a wafer or another carrier structure, such as a glass plate. The wafer may include a semiconductor material, such as silicon, GaAs, InP, or another semiconductor-based wafer material. The wafer may include an insulator material, such as silicon-on-insulator (SOI), diamond, or the like. Sometimes, a substrate includes a film formed on the surface of the wafer / carrier structure. The film may be, for example, a dielectric film, a conductive film, or an insulating film. The film may be formed on the surface of the wafer using various deposition techniques, such as spin coating, atomic layer deposition (ALD), chemical vapor deposition (CVD), metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other similar techniques for forming thin film layers on a wafer or another carrier structure. In some embodiments, the manufacturing tool described herein is a plasma-based etching tool, wherein the etching process may be performed on the surface of the wafer / carrier structure and / or on a formed layer on the wafer.

[0006] In general, an innovative aspect of the subject matter described herein can be embodied in an electrostatic chuck (ESC). The ESC includes a ceramic body comprising one or more embedded electrodes and a first surface having a first diameter. Three or more regions are defined on the first surface, wherein the three or more regions are concentrically arranged on the first surface. Each region includes a retaining ring disposed on the first surface and defining an outer edge of the region, and a support structure disposed on the first surface and within the region, wherein the support structures are configured to support the surface of a substrate when the substrate is held by the electrostatic chuck. The ESC includes a conduit formed in the ceramic body and configured to independently introduce a gas through the ceramic body into each of the three or more regions and into the first surface, wherein each of the three or more regions is configured to maintain a corresponding positive gas pressure within the region and the surface of the substrate when the substrate is held by the electrostatic chuck, and wherein the one or more embedded electrodes are configured to generate a holding force on the surface of the substrate when the substrate is held by the electrostatic chuck. Other embodiments of this aspect include corresponding methods, computer systems, apparatus, and computer programs recorded on one or more computer storage devices.

[0007] In general, another innovative aspect of the subject matter described herein can be embodied in methods for cooling an electrostatic chuck during plasma processing. These methods include providing a gas through a conduit within a ceramic body of the electrostatic chuck to three or more regions defined on a first surface of the ceramic body and configured to maintain a positive gas pressure within the regions and a surface of a substrate held by the electrostatic chuck, wherein the three or more regions are concentrically arranged on the first surface, and wherein an outer edge of each of the three or more regions is defined by a respective retaining ring disposed on the first surface. These methods include providing a retaining force on the surface of the substrate by one or more electrodes disposed within the ceramic body and relative to the first surface. Other embodiments of this aspect include corresponding systems, computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0008] In general, another innovative aspect of the subject matter described herein can be embodied in a system comprising: a plasma processing chamber enclosing a processing region; a gas source configured to introduce one or more etching gases into the processing region; a plasma source configured to generate a plasma within the processing region using the one or more etching gases introduced into the processing region; and an electrostatic chuck within the plasma processing chamber and configured to hold a substrate within the processing region of the plasma processing chamber during plasma processing. The electrostatic chuck comprises: a ceramic body including one or more embedded electrodes configured to generate a holding force on a surface of the substrate when the substrate is held by the electrostatic chuck; three or more regions defined on a first surface of the ceramic body, wherein the three or more regions are concentrically arranged on the first surface, each region including a holding ring disposed on the first surface and defining an outer edge of the region; and conduits formed in the ceramic body and configured to independently introduce gas into each of the three or more regions through the ceramic body and into the first surface.

[0009] The subject matter described herein can be implemented in these and other embodiments to achieve one or more of the following advantages. The electrostatic chuck design system can utilize a model (e.g., a machine learning model) to combine different available design parameters to design custom electrostatic chuck solutions that can address chamber-specific temperature non-uniformities across a substrate. An electrostatic chuck that provides improved temperature uniformity across a substrate can result in improved uniformity of etch rates across the substrate and can result in higher fidelity and / or higher yield results for fabricated devices on the substrate. The electrostatic chuck design system can be used to design an electrostatic chuck specific to a manufacturing process (e.g., specific to a conductor film etch process or specific to a dielectric film etch process) that can address specific non-uniformities caused by the respective processes. The electrostatic chuck design model can be used to design an electrostatic chuck having a threshold density of mesa structures in one or more of the cooling zones, such that one or more of the cooling zones utilizes gas-dominated cooling, where the cooling can be dynamically tuned based on the pressure of the gas introduced into the cooling zone, e.g., in response to (or adjustment of) real-time process parameters. For example, design considerations can be used to adjust the substrate temperature (and the resulting etch rate) in real time. Although the remaining disclosure will indicate specific implementations of apparatus, systems, and methods for etching-based manufacturing tools using the disclosed technology, it will be readily understood that these systems and methods are equally applicable to a variety of other manufacturing tools and chambers. Therefore, the technology should not be considered limited to use with only the described etching manufacturing tools. Before describing the systems and methods or operations of exemplary process sequences according to some embodiments of the present technology, the present disclosure will discuss one possible system and chamber that can be used with the technology. It should be understood that the technology is not limited to the equipment described, and the processes discussed can be used in any number of processing chambers and system axes. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic cross-sectional view of an example plasma processing chamber is shown.

[0011] Figure 2 An example operating environment for an electrostatic chuck design system is shown.

[0012] Figure 3A and Figure 3B Various schematic diagrams of example electrostatic chucks are shown.

[0013] Figure 4A and Figure 4B Various schematic diagrams of another example electrostatic chuck are shown.

[0014] Figure 5A and Figure 5B Various schematic diagrams of example electrostatic chucks are shown.

[0015] Figure 6 An example graph depicting the theory of substrate backside cooling.

[0016] Figure 7 A flow chart illustrating an example process for an electrostatic chuck is shown.

[0017] Figure 8 A flow chart illustrating an example process for designing an electrostatic chuck system.

[0018] Figure 9 is a block diagram of an example general-purpose computing system.

[0019] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION

[0020] The present specification provides improved methods, systems, and assemblies for an electrostatic chuck configured for differential substrate backside cooling. Embodiments of the present disclosure include an electrostatic chuck design that includes implementing multiple design parameters to produce an electrostatic chuck configured for differential substrate backside cooling to produce improved substrate temperature uniformity and tunability during a manufacturing process (e.g., during plasma etching).

[0021] Figure 1 A schematic cross-sectional view of an example processing chamber 100 is illustrated, which is suitable for etching one or more material layers on a substrate 103 (e.g., also referred to as a "wafer") disposed in the processing chamber 100 (e.g., a plasma processing chamber). The processing chamber 100 includes a chamber body 105 that defines a chamber volume 101 in which a substrate can be processed. The chamber body 105 has sidewalls 112 and a bottom 118 that are coupled to a ground 126. The sidewalls 112 may include a liner 115 to protect the sidewalls 112 and extend the time between maintenance cycles of the plasma processing chamber 100. The chamber body 105 supports a chamber lid assembly 110 to enclose the chamber volume 101. The chamber body 105 may be made of, for example, aluminum or other suitable materials. A substrate access port 113 is formed through the sidewalls 112 of the chamber body 105, which facilitates the movement of the substrate 103 into and out of the plasma processing chamber 100. The access port 113 can be coupled to a transfer chamber and / or other chambers (not shown) of a substrate processing system, for example, to perform other processes on the substrate. A pumping port 145 is formed through the bottom 118 of the chamber body 105 and is connected to the chamber volume 101. A pumping device can be connected to the chamber volume 101 through the pumping port 145 to evacuate and control the pressure within the processing volume. The pumping device can include one or more pumps and a throttle valve.

[0022] The chamber volume 101 includes a processing region 107, such as a station for processing substrates. A substrate support 135 may be disposed within the processing region 107 of the chamber volume 101 to support a substrate 103 during processing. The substrate support 135 may include an electrostatic chuck 122 for holding the substrate 103 during processing. The electrostatic chuck (ESC) 122 may utilize electrostatic attraction to hold the substrate 103 on the substrate support 135. The ESC 122 may be powered by an RF power supply 125 integrated with a matching circuit 124. The ESC 122 may include an electrode 121 embedded within a dielectric body. The electrode 121 may be coupled to the RF power supply 125 and may provide a bias voltage that attracts plasma ions formed from process gas in the chamber volume 101 toward the ESC 122 and substrate 103 located on a susceptor. The RF power supply 125 may be cycled on and off, or pulsed, during processing of the substrate 103. In order to reduce the attraction of the sidewalls of the ESC 122 to the plasma and extend the maintenance life cycle of the ESC 122, the ESC 122 may have an isolator 128. In addition, the substrate support 135 may have a cathode liner 136 to protect the sidewalls of the substrate support 135 from the plasma gas and extend the time between maintenance of the plasma processing chamber 100. Figure 3A 、 Figure 3B 、 Figure 4A 、 Figure 4B Further details related to ESCs are discussed in conjunction with FIG5 .

[0023] The electrode 121 may be coupled to a DC power supply 150. The power supply 150 may provide a clamping voltage of approximately 200 volts to approximately 2000 volts to the electrode 121, for example, to provide a holding force. The power supply 150 may also include a system controller for controlling the operation of the electrode 121 by directing a DC current to the electrode 121 to clamp and unclamp the substrate 103. The ESC 122 may include a heater disposed within the ESC 122 and connected to a power supply for heating the substrate, while the cooling base 129 supporting the ESC 122 may include conduits for circulating a heat transfer fluid to maintain the temperature of the ESC 122 and substrate 103 disposed thereon. The ESC 122 may be configured to perform within a temperature range required by the thermal budget of the component being fabricated on the substrate 103. For example, the ESC 122 may be configured to maintain the substrate 103 at a temperature of approximately -150°C or lower to approximately 500°C or higher, depending on the process being performed. A cover ring 130 may be disposed on the ESC 122 and along a perimeter of the substrate support 135. The cover ring 130 may be configured to confine the etching gas to a desired portion of the exposed top surface of the substrate 103 while shielding the top surface of the substrate support 135 from the plasma environment within the plasma processing chamber 100.

[0024] A gas panel 160 (also referred to herein as a“gas distribution manifold”) can be coupled by gas lines 167 through the chamber lid assembly 110 with the chamber body 105 to supply process gases into the chamber volume 101. The gas panel 160 can include one or more process gas sources 161, 162, 163, 164, and can additionally include inert, non-reactive, and reactive gases as can be used for any number of suitable processes. Examples of process gases that can be provided by the gas panel 160 include, but are not limited to, hydrocarbon-containing gases including methane, sulfur hexafluoride, silicon chloride, silicon tetrachloride, carbon tetrafluoride, hydrogen bromide. Process gases that can be provided by the gas panel can include, but are not limited to, argon, chlorine, nitrogen, helium, or oxygen, sulfur dioxide, and any number of additional materials. Further, process gases can include nitrogen, chlorine, fluorine, oxygen, or hydrogen-containing gases including, for example, BCl3, C2F4, C4F8, C4F6, CHF3, CH2F2, CH3F, NF3, NH3, CO2, SO2, CO, N2, NO2, N2O, and H2, as well as any number of additional suitable precursors. Process gases from the process gas sources (e.g., sources 161, 162, 163, 164) can be combined to form one or more etching gas mixtures. For example, the gas panel 160 includes one or more process gas sources specific to oxide-based etch chemistries. In another example, the gas panel 160 includes one or more process gas sources specific to nitride-based etch chemistries.

[0025] The gas panel 160 includes various valves, pressure regulators (not shown), and mass flow controllers (not shown) arranged relative to the gas sources 161, 162, 163, and 164 to control the flow of process gases from the gas sources. Valve 166 can control the flow of process gases from the gas sources 161, 162, 163, and 164 of the gas panel 160. The operation of the valves, pressure regulators, and / or mass flow controllers can be controlled by a controller 165. The controller 165 can be operably coupled to an electro-valve (EV) manifold (not shown) to control the actuation of one or more of the valves, pressure regulators, and / or mass flow controllers. The lid assembly 110 can include a gas delivery nozzle 114. The gas delivery nozzle 114 can include one or more openings for introducing process gases from the gas sources 161, 162, 163, and 164 of the gas panel 160 into the chamber volume 101. After the process gases are introduced into the plasma processing chamber 100, the gases can be energized to form a plasma. An antenna 148, such as one or more inductor coils, may be provided near the plasma processing chamber 100. An antenna power supply 142 may power the antenna 148 via a matching circuit 141 to inductively couple energy, such as RF energy, to the process gas to maintain a plasma formed from the process gas within the chamber volume 101 of the plasma processing chamber 100. Alternatively or in addition to the antenna power supply 142, process electrodes below and / or above the substrate 103 may be used to capacitively or inductively couple RF power to the process gas to maintain the plasma within the chamber volume 101. Operation of the power supply 142 may be controlled by a controller, such as the controller 165, which also controls operation of other components within the plasma processing chamber 100.

[0026] The controller 165 can be used to control the process sequence, regulate the gas flow from the gas panel 160 into the plasma processing chamber 100, and other process parameters. When the software routine is executed by a computing device having one or more processors (e.g., a central processing unit (CPU)) in data communication with one or more memory storage devices, it converts the computing device into a special-purpose computer, such as a controller, that can control the plasma processing chamber 100 to perform processes according to the present disclosure. The software routine can also be stored and / or executed by one or more other controllers that can be associated with the plasma processing chamber 100.

[0027] In some embodiments, the controller 165 is in data communication with a characterization device 172. The characterization device 172 may include one or more sensors (e.g., image sensors) operable to collect process data related to the processing chamber 100. For example, the characterization device 172 may include an optical emission spectroscopy device configured to monitor a signal within the processing region of the processing chamber 100, such as emitted light from the plasma. For example, the signal may be the dominant wavelength or the wavelength of highest intensity of the emitted light. The characteristics (e.g., wavelength and intensity) of the emitted light from the plasma within the processing region may depend in part on the etching gas mixture used to generate the plasma and the layer composition of the layer being etched. For example, each etching gas mixture and the corresponding layer composition being etched may have a corresponding signal signature. Emission wavelengths unique or distinct for each etching gas mixture and corresponding layer composition may be monitored to determine etching conditions of the layer being etched, such as the remaining thickness of the layer being etched. The characteristics of the light emitted from the plasma may vary, for example, based on the etching process. For example, the intensity of the monitored signal may change as material is removed from the layer being processed. The characterization device 172 may be configured to collect process data including respective signals corresponding to the etching gas mixture used in wafer processing and the corresponding layer composition of the structure being processed in the processing chamber 100. The controller 165 may receive the process data from the characterization device 172 and determine one or more actions to perform based on the process data.

[0028] In some embodiments, at the end point of the etching process for the wafer, an automatic or semi-automatic robotic manipulator (not shown) may be used to transfer the wafer from the substrate support out of the process chamber, for example, through the substrate access port 113. For example, the robotic manipulator may transfer the wafer to another chamber (or another location) to perform another step in the manufacturing process.

[0029] In some embodiments, portions of the substrate support 135, such as the electrostatic chuck 122, can be adapted to compensate for non-uniformities in the etch rate across a substrate held by the substrate support 135. Non-uniformities in the etch rate can arise due to non-uniformities in the temperature across the substrate, such as due to varying plasma loading in a manufacturing tool. Non-uniformities in the etch rate across the substrate can be process dependent, such as differences in non-uniformity between a dielectric etch process and a conductor etch process. Non-uniformities in the etch rate across the substrate can be manufacturing tool dependent, such as differences in non-uniformity between manufacturing tools due to tolerances, aging, calibration, etc. of each manufacturing tool. Generating an ESC design to compensate for specific non-uniformities in a manufacturing tool, process, etc. can result in higher fidelity of the manufacturing process across the substrate, such as a higher yield of manufactured parts.

[0030] In some embodiments, designing an ESC to improve process uniformity across a substrate includes tuning various design parameters of the ESC. Relationships between the various design parameters in an ESC design can be complex, where a design parameter can affect one or more other design parameters. Tuning the various design parameters into an ESC design can yield a unique solution for the ESC to improve process uniformity (e.g., temperature uniformity) across a substrate during a manufacturing process.

[0031] Figure 2 An example operating environment 200 is shown for an electrostatic chuck (ESC) design system 202. The ESC design system 202 includes an ESC model 204. The ESC model 204 can include, for example, a machine learning model, where the machine learning model can be trained using supervised or unsupervised learning. The ESC design system 202 can use one or more ESC models 204 to produce simulations of process behavior for an ESC design to model the effects of a set of variables on performance results for the ESC design. For example, one or more models 204 can be used to produce simulations of cooling behavior (e.g., temperature uniformity) for an ESC design based on a set of variables (e.g., design parameters and / or process variables). The ESC model 204 can be configured to receive as input (i) design parameters 206, (ii) process uniformity data 208, (iii) process variables 210, or (iv) any combination thereof. The ESC model 204 can produce as output a prediction (e.g., an ESC design 212). The prediction produced by the ESC model 204 can be an ESC design that is likely (e.g., has an increased likelihood) to have improved performance, temperature uniformity, ease of manufacturing, etc. For example, the ESC model 204 can produce ESC design predictions that are optimized for thermal management on a substrate surface during a manufacturing process.

[0032] The design parameters 206 include features or components of the ESC that can be configurable (e.g., adjustable) in response to process non-uniformities during a manufacturing process (e.g., temperature non-uniformities of a substrate held by the ESC). The design parameters 206 can include a material composition of one or more components of the ESC, for example, a material composition of a body of the ESC. At times, the body of the ESC is composed of a ceramic material, for example, AI2O3 and / or AIN.

[0033] The design parameters 206 can include a number of cooling regions on a surface of the ESC, for example, on a surface of a ceramic body of the ESC, for example, as referenced with respect to FIGS. 1-2. Figure 3A and Figure 3B and Figure 5BFor example, the plurality of cooling zones may be three or more (e.g., three, four, five, six, seven, or more) cooling zones. The design parameters 206 may include a distance between the surface of the ceramic body of the ESC and the back side of the substrate when the substrate is held (e.g., held, clamped, fixed, etc.) by the ESC, for example, as described in reference to FIG. Figure 4A and Figure 4B For example, in the cooling region, the distance between the surface of the ceramic body of the ESC and the back side of the substrate in the cooling region can adjust the heat transfer coefficient in the cooling region. The design parameters 206 may include the distribution and density of support structures (e.g., mesas) arranged on the surface of the ceramic body of the ESC and within each of the plurality of cooling regions on the surface of the ESC, for example, as described in reference Figure 5A For example, different densities of the mesas can result in contact-dominated cooling or gas-dominated cooling.

[0034] The process uniformity data 208 may include direct and / or indirect measurements of process uniformity of a manufacturing process on a manufacturing tool. The process uniformity data 208 may be generated for a manufacturing process that includes corresponding process variables 210. The process uniformity data may include, for example, etch rate data corresponding to an etch rate on a substrate for a manufacturing process that uses a set of process variables 210. The etch rate data may be generated using metrology tools, such as ellipsometry, interferometry, etc., to characterize etching performed on a substrate. The etch rate data may include an etch rate map of the substrate, the etch rate map including a plurality of sample points, wherein an etch rate is determined at each of the plurality of sample points. The process uniformity data may include, for example, temperature data at one or more points along the substrate during the manufacturing process. The temperature data may be generated using, for example, an optical probe to measure non-contact backside substrate temperature. In another example, the temperature data may be generated using interferometry (e.g., etalon interferometry) to measure the center point temperature of the substrate surface.

[0035] Process variables 210 include, for example, etch material compositions and recipes for performing a manufacturing process (e.g., an etching process). A recipe may include instructions for controlling the operation of a manufacturing tool during a manufacturing process using the recipe, such as controlling plasma power, substrate temperature, etching time, etc.

[0036] The recipe can also include instructions for temperature control of one or more temperature-regulated components of the ESC. In particular, the recipe can include instructions for controlling operation of one or more electrodes within the ceramic body to generate localized heating. The one or more electrodes can include, for example, a plurality of zone heaters, where each of the plurality of zone heaters is operable to heat a portion of the ESC. For example, the multi-zone heater can include two, three, or four zone heaters. In another example, the plurality of zone heaters can be micro-zone (e.g., pixel) heaters, where the ESC can include about 20, 40, 50, 100, 150, 200, or more micro-zone heaters, each operable to heat a portion of the ESC. The recipe can include instructions for controlling operation of cooling channels (e.g., flow of coolant, temperature of coolant, etc.) located in a cooling base (e.g., cooling base 139 of substrate support 135) of the substrate support. In some implementations, the recipe includes instructions for controlling operation of a gas flow through a plurality of conduits within the ceramic body of the ESC and to a cooling region of a surface of the ESC, for example, as described in reference to Figure 3A and Figure 3B are described in further detail.

[0037] The output of the ESC model 204 can include an ESC design 212 that specifies an implementation of one or more features / components of the design parameters 206. For example, the ESC design 212 can include a plurality of cooling regions, a density / distribution of support structures within each of the plurality of cooling regions, and a size of the support structures within each of the plurality of cooling regions. In some embodiments, the ESC design 212 can include operating parameters, for example, a gas pressure provided to each of the plurality of cooling regions during a manufacturing process.

[0038] In some embodiments, the generated ESC design 212 can be provided to a manufacturer 214 to manufacture the ESC based on the ESC design 212. At times, the ESC manufacturing can be performed using one or more manufacturing techniques, for example, using wet casting, subtractive manufacturing, additive manufacturing, sintering, diffusion bonding, etc.

[0039] Figure 3A and Figure 3B Various schematic diagrams of example portions of an electrostatic chuck are shown. Figure 3B A schematic plan view 350 of a top surface of a ceramic body of an example electrostatic chuck 302 is shown, where the top surface 301, having a diameter 313, faces a backside of a substrate when the substrate is held by the ESC 302. As described in this specification, the backside of the substrate is a surface opposite a processing surface, for example, a surface that undergoes an etching process within a manufacturing tool. At times, the backside of the substrate is a surface opposite a surface on which one or more films are formed on a wafer / carrier structure of the substrate.

[0040] The ESC 302 may include one or more cooling zones defined between the back side of the substrate and the top surface of the ESC. The one or more cooling zones each have an outer edge defined by a corresponding retaining ring formed on the top surface of the ESC. The retaining ring may be formed on the top surface composed of the same ceramic material as the ceramic body of the ESC. For example, the retaining ring may be formed using subtractive manufacturing and / or additive manufacturing of the ceramic body such that the retaining ring and the ceramic body are a unitary structure. A gas (e.g., helium) may be introduced into the cooling zone through the body of the ESC and introduced into the cooling zone to provide cooling to a portion of the substrate corresponding to the cooling zone. As shown, the ESC 302 includes three cooling zones 304, 306, and 308 arranged on the top surface of the ceramic body of the ESC, wherein each cooling zone has an outer edge defined by a corresponding retaining ring 310, 312, and 314. Although reference is made to Figure 3A and Figure 3B While discussed as including three cooling zones, more or fewer cooling zones are possible. For example, four, five, six, seven, or more cooling zones may each be defined at an outer edge by a respective retaining ring. Positive pressure gas may be introduced into each of the plurality of cooling zones, wherein the flow of the introduced gas may be individually (e.g., independently) controlled. Independently controlling the gas flow to each of the plurality of cooling zones may include using a flow meter and valves to control the gas flow to provide the same or different gas flows to each of the plurality of cooling zones. In some embodiments, controlling the gas flow to a given cooling zone controls the degree of cooling applied to a portion of the substrate corresponding to the cooling zone. In some cases, by manipulating the gas flow to each cooling zone through a controller, different amounts of cooling may be applied to different portions of the substrate corresponding to different cooling zones.

[0041] exist Figure 3A and Figure 3B In the example ESC 302 shown in FIG, the top surface 301 of the ceramic body 303 includes an edge region 316 that is located outside of the retaining ring 314 and is not included in the cooling regions 304, 306, or 308. The retaining rings 310, 312, and 314 are concentrically arranged relative to a center point 318 of the top surface 301 of the ESC 302. Although Figure 3A and Figure 3B 302. The retaining rings 310, 312, 314 are depicted as being evenly spaced, but the retaining rings may be non-evenly spaced. The height 309 of each retaining ring 310, 312, 314 is substantially equal so that an airtight seal is formed in each cooling zone 304, 306, 308 when the substrate is retained by the ESC 302. In other embodiments, the ESC may not include an edge region.

[0042] The interior cooling region 304 defined by the retaining ring 310 encloses a circular volume. Specifically, when a substrate is held by the ESC 302, the volume is defined by the inner surface of the retaining ring 310, the top surface 301 of the ESC 302, and the backside of the substrate aligned on the plane 315, for example, as shown in the partial cross-sectional view of the ESC 300 in Figure 3A

[0043] The cooling regions are coupled to one or more gas conduits, for example, gas conduits 320, 322, 324, within the ceramic body 303 of the ESC 302 and are configured to introduce a gas, for example, a gas flow 305, into each cooling region. The gas conduits can fluidically couple a gas source, for example, from a subassembly of the ESC, through a portion of the ceramic body 303 to the top surface 301 of the ESC 302. The gas conduits, for example, gas conduits 320, 322, and 324, can each include a porous plug. The porous plug can be composed of a different material composition and / or have a different internal structure, for example, porosity, than the ceramic body of the ESC. The porous plug can be configured to allow a gas flow through the porous plug to the top surface of the ceramic body and limit, for example, prevent, backflow of contaminants from the top surface of the ceramic body into the gas conduit. The gas conduits can include gas outlet holes, for example, laser-drilled or AM-defined holes, in the gas flow path between the porous plug and the top surface of the ceramic body. The gas outlet holes can be arranged in an outlet hole array relative to the porous plug. The gas outlet holes can be configured to allow a gas flow through the gas outlet holes to the surface of the ceramic body but limit, for example, prevent, backflow of contaminants from the top surface of the ceramic body into the gas conduit.

[0044] Although depicted in Figure 3A as a respective gas conduit in each cooling region, the cooling regions can have two or more gas conduits that introduce a gas into the cooling region. The gas conduits can introduce helium, argon, nitrogen, or another inert gas into each cooling region. The gas pressure within the cooling region can be low to negligible turbulent flow introduced by the gas into the cooling region, for example, when operating in steady-state conditions. The gas pressure of the cooling region can be selected based in part on the thermal conductivity requirements of the cooling region. For example, for a given gas, a higher gas pressure introduced into the cooling region can result in a greater thermal conductivity than a lower gas pressure.

[0045] The volume defined in each cooling region is substantially gas-tight and can be maintained at a positive pressure for a duration of time. The positive pressure can include between about 1 Torr and about 50 Torr. For example, the positive pressure can include at least about 2 Torr, 5 Torr, 10 Torr, 15 Torr, 20 Torr, 25 Torr, or more. The positive pressure can be based on an amount of clamping force exerted by the electrodes 121 on the backside of the substrate. For example, during a manufacturing process, the positive pressure can be selected to exert a smaller force on the backside of the substrate than the clamping force exerted between the electrodes and the backside of the wafer. ​

[0046] In some embodiments, cooling zones 304, 306, and 308 include one or more support structures, such as support structure 328. The support structure, such as a mesa, is disposed on top surface 301 of ceramic body 303 and extends to plane 315, such as height 309. Height 309 of the support structure can be (e.g., substantially) the same height and can also be (e.g., substantially) the same height as retaining rings 310, 312, and 314, such that each support structure contacts the backside surface of the substrate when the substrate is held by the ESC.

[0047] Despite Figure 3A and Figure 3B 304, 306, and 308 and relative to the retaining rings 310, 312, and 314 are evenly or unevenly distributed, as shown in FIG. Figure 5A In some embodiments, support structure 328 comprises a cylindrical shape having a circular cross-section parallel to the top surface of the ceramic body of the ESC, e.g., Figure 3B As shown. Other cross-sectional shapes are also possible, such as rectangular, polygonal, etc. In some embodiments, a combination of two or more different shape types can be used, for example, each cooling zone having a corresponding type of shape, or a mixture of two or more shape types in the cooling zones. The minimum density of support structures in the cooling zones can be set based on the number of support structures required to maintain at least a threshold flatness of the substrate when held by the ESC. For example, the minimum density of support structures in the cooling zones can be set to prevent bending or flexing of the substrate when, for example, the substrate is clamped / unclamped by the electrode 121.

[0048] In some embodiments, gases of varying pressures can be introduced into the cooling region via gas conduits 320, 324, and 326, for example, by a controller operating corresponding flow regulators, valves, and the like. During the manufacturing process, the varying pressures of air can be used to offset non-uniform heating of the substrate, for example, by the plasma. For example, during the manufacturing process, the center and / or edge regions of the substrate may sometimes be hotter than the middle region of the substrate.

[0049] During operation of a manufacturing tool including an ESC, a recipe for a manufacturing process may include a higher pressure entering the inner region 304 and a lower pressure entering the outer region 308. For example, the gas pressure in the inner region 304 may be 20 Torr, while the gas pressure in the outer cooling region 308 may be 10 Torr, and wherein the intermediate cooling region 306 may be pressurized to 15 Torr.

[0050] In some embodiments, the same pressure of gas can be introduced by the respective gas conduits into the cooling zones during the manufacturing process. In some embodiments, the pressure of the gas introduced by the respective gas conduits into one or more of the cooling zones can be dynamically adjusted during the manufacturing process, e.g., including recipe instructions for the manufacturing process. Dynamic pressure adjustment in the cooling zones can be used to adjust the process temperature of the substrate held by the ESC 302, which in turn can adjust the etch rate in the respective cooling zone.

[0051] To simplify and highlight the features discussed above, Figure 3A and Figure 3B Portions of the ESC 302 are depicted, with some components not depicted, particularly embedded electrodes (e.g., multiple heating elements and / or microzone heaters) within the ceramic body of the ESC. In Figure 3A embedded electrodes 330 within the ceramic body of the ESC are shown, e.g., Figure 1 The electrodes 121 shown are used to provide a holding force (e.g., clamping force) on the substrate when the substrate is held / clamped to the ESC.

[0052] The design parameters 206 can include a distance between a surface of the ceramic body of the ESC and a backside of the substrate when the substrate is held (e.g., held, clamped, fixed, etc.) by the ESC. For example, in a cooling zone, the distance between a surface of the ceramic body of the ESC and a backside of the substrate in the cooling zone can adjust a heat transfer coefficient in the cooling zone.

[0053] Figure 4A and Figure 4B Various schematic diagrams showing portions of an example electrostatic chuck are shown. As Figure 4A shown in the cross-sectional view 400 in Figure 4B the plan view 450 in, the ceramic body 403 can have a top surface 401 having a diameter 413 and including multiple layers having respective diameters 417, 419, 421, with each layer defining a cooling zone. For example, cooling zones 404, 406, and 408, with each cooling zone having a respective holding ring 410, 412, and 414 defining an outer edge of the cooling zone. Each of the cooling zones 404, 406, and 408 has a respective distance 416, 418, and 420 from the top surface 401 of the ESC 402 to a plane 422 that is coplanar with a backside of a substrate when the substrate is held by the ESC 402. Thus, the holding rings 410, 412, and 414 have heights corresponding to the distances 416, 418, and 420 of the cooling zones 404, 406, and 408, respectively.

[0054] The cooling zones are included within the ceramic body of the ESC and are configured to direct gas (e.g., gas flow 430) into one or more gas conduits, such as gas conduits 424, 426, and 428, for each cooling zone. Figure 4A 1 and 2. Depicted in FIG. 1 are respective gas conduits in each cooling zone, but a cooling zone may have two or more gas conduits that introduce gas into the cooling zone. For example, a gas conduit may introduce helium or another gas into each cooling zone.

[0055] In some embodiments, cooling zones 404, 406, and 408 include one or more support structures, such as support structure 432. The support structure, such as a mesa, is disposed on the top surface of the ceramic body. The support structure may have a height (e.g., substantially equal to the distances 416, 418, and 420 of the corresponding zones, and may also have a height (e.g., substantially equal to the height of retaining rings 410, 412, and 414) such that when the substrate is held by the ESC, such as on plane 422, a corresponding surface of each support structure contacts the backside surface of the substrate. In one example, the magnitudes of distances 416, 418, and 420 may be associated with X, 2X, and 4X, respectively, where distance 416 is the distance X from top surface 401 to plane 422, distance 418 is the distance 2X from top surface 401 to plane 422, and distance 420 is the distance 4X from top surface 401 to plane 422.

[0056] Despite Figure 4A and Figure 4B , but the support structures may be distributed uniformly or non-uniformly within the cooling regions 404, 406, and 408 and relative to the retaining rings 410, 412, and 414, as described with respect to FIG. Figure 5A discussed in further detail.

[0057] The distances 416, 418, and 420 of the cooling regions 404, 406, and 408 between the top surface 401 of the ESC 402 and the plane 422 may be selected based in part on counteracting localized heating of the substrate held by the ESC during the manufacturing process. Figure 6 As shown, a shallower distance between the top surface 401 and the flat surface 422 results in a greater heat transfer coefficient than a greater distance between the top surface 401 and the flat surface 422. The relationship between the heat transfer coefficient and the gap between the back side of the substrate and the top surface of the ESC (e.g., also referred to as the "wafer chuck gap") is shown in FIG. Figure 6The different gas pressures introduced into the volume defined by the cooling zones and including the gap are described in terms of a heat transfer coefficient. Briefly, for a given wafer chuck gap, as the positive pressure within the cooling zone increases, the heat transfer coefficient also increases, resulting in more efficient heat removal from the zone. Further, for a given positive pressure introduced into the cooling zone, a smaller wafer chuck gap will have a greater heat transfer coefficient (and thus increased heat removal efficiency) than a larger wafer chuck gap. At times, the interaction between the wafer chuck gap and the positive pressure of the gas flow for the cooling zone can be selected for the cooling zone to achieve a threshold heat transfer coefficient and resulting heat removal efficiency.

[0058] As shown in cross-sectional view 400, the edge region can be a distance 434 from the plane 422, where the edge region 436 can or can not include a support structure. In some embodiments, the distance 434 from the top surface 401 to the plane 422 in the edge region 436 is greater than each of the distances 416, 418, and 420.

[0059] In some embodiments, to counteract non-uniform heating of the substrate held by the ESC during a manufacturing process, different distances between the top surface 401 and the plane 422 can be selected for the ESC.

[0060] Figure 4A Electrodes 438 shown in Figure 1 Electrodes 121 shown in Figure 4A A portion of the ESC 402 is shown, where some components are not shown, particularly the heater electrodes (e.g., multiple heating elements and / or microzone heaters).

[0061] In some embodiments, the design parameters can include a distribution and density of support structures (e.g., mesas) disposed on a surface of the ceramic body of the ESC and within each of the plurality of cooling zones on the surface of the ESC. For example, different densities of mesas can result in contact dominated cooling or gas dominated cooling.

[0062] Figure 5A A plan view 500 of a portion of an example electrostatic chuck is shown. The plan view 500 of an example top surface 501 of the ESC 502 includes a plurality of cooling zones 504, 506, and 508. The cooling zones 504, 506, and 508 are defined at an outer edge by respective retaining rings 510, 512, and 514. In some embodiments, as shown, an edge region 516 is defined by the outer edge of the retaining ring 514, where the edge region 516 does not include in a cooling zone. Figure 5A

[0063] ​Cooling regions 504, 506, and 508 include support structures, such as support structure 528. The support structures, such as mesas, are disposed on the top surface of the ceramic body and extend to (e.g., substantially) the same height and are also (e.g., substantially) the same height as the retaining rings 510, 512, and 514, such that when the substrate is held by the ESC, the support structures each contact the backside surface of the substrate, e.g., as described in reference to FIG. Figure 3A and Figure 3B Descriptive.

[0064] In some embodiments, one or more cooling zones can include support structures of varying densities. The density of support structures in a cooling zone can be below a threshold density such that cooling in the cooling zone is gas-dominated in that zone. In other words, the primary contribution to cooling in the cooling zone is due to the positive gas pressure, e.g., helium pressure, introduced into the cooling zone by the gas conduit while the substrate is held by the ESC. In a gas-dominated cooling scheme, the support structures and contact points between the retaining ring and the backside of the substrate while the substrate is held by the ESC serve as a secondary cooling mechanism for the cooling zone.

[0065] In some embodiments, the density of support structures in the cooling zone can be above a threshold density, such that cooling in the cooling zone is contact-dominated in that zone. In other words, when the substrate is held by the ESC, the primary contributor to cooling in that zone is located at the contact points between the support structures and the retaining ring and the backside of the substrate. In a contact-dominated cooling scheme, the gas cooling mechanism is a secondary cooling mechanism for the cooling zone.

[0066] Despite Figure 5A 504 , may have a density of support structures equal to that of the cooling zone, but in some embodiments, the density of support structures may vary from the central cooling zone to the outer cooling zones of the ESC. For example, the central cooling zone, such as cooling zone 504 , may have a density of support structures of 0.75x, the middle cooling zone, such as cooling zone 506 , may have a density of support structures of 1x, and the outer zones, such as cooling zone 508 , may have a density of support structures of 1.25x. In another example, both cooling zones may have the same density of support structures.

[0067] In some embodiments, one or more cooling zones can include a non-uniform distribution of support structures. For example, a cooling zone can include a density gradient of support structures arranged relative to the top surface 501 of the ceramic body of the ESC. A higher density of support structures can be located adjacent to one or more retaining rings that define the cooling zone and gradually transition to a lower density of support structures in the central region of the cooling zone. The density gradient of the support structures can reduce the sharpness of the boundary between contact-dominated cooling at the retaining rings and gas-dominated cooling in the central region of the cooling zone.

[0068] In some embodiments, the multiple cooling zones included in the ESC design include four or more cooling zones arranged on the top surface 551 of the ESC 552. For example, Figure 5B As shown in the plan view 550 of ESC 552 in FIG, ESC 552 includes four cooling zones, such as 554, 556, 558, and 560. Cooling zones 554, 556, 558, and 560 are defined at their outer edges by respective retaining rings 562, 564, 566, and 568. In some embodiments, as shown in FIG5D, edge zone 570 is defined by the outer edge of retaining ring 568, wherein edge zone 570 is not included in the cooling zones.

[0069] In some embodiments, one or more of the features described with reference to Figures 3, 4, and 5 may be considered for incorporation into an ESC design. In some embodiments, all of the features described with reference to Figures 3, 4, and 5 may be considered for incorporation into an ESC design.

[0070] As described herein, during the manufacturing process, the introduction of gas into the cooling region of the ESC can produce the primary temperature control of the substrate. Figure 1 As described above, the ESC includes one or more heaters. Sometimes, the ESC may include multiple heating zones (e.g., via multiple heating elements) that can generate secondary temperature adjustments during the manufacturing process, where the heating zones can locally (and independently) adjust the temperature of the substrate within the heating zones during the manufacturing process. Multiple heating zones (e.g., four heating zones) can be located within the ceramic body and further spaced apart from the top surface of the ESC's ceramic body. Consequently, the respective effects of the multiple heating zones can (sometimes) be less than the effect of the gas pressurized cooling zones described above.

[0071] In some embodiments, the ESC may include (e.g., further include) micro-zone heaters that can produce tertiary temperature adjustments during the manufacturing process, wherein the micro-zone heaters can locally (and independently) adjust the temperature of the substrate in "pixel-like" regions of the micro-zone heaters during the manufacturing process. The micro-zone heaters can be located within the ceramic body and further spaced from the top surface of the ceramic body of the ESC from the multiple heater regions. As a result, the corresponding effect of the micro-zone heaters can (sometimes) be less than the effect of the multiple heating zones and gas pressurized cooling zones described above.

[0072] In some embodiments, a controller of a manufacturing tool (e.g., controller 165) can execute a recipe comprising instructions for a manufacturing process. The recipe can comprise temperature control instructions that can be executed by the controller 165 to control operation of various temperature-related components of the manufacturing tool. For example, the temperature-related components can comprise (A) a gas pressure introduced into each cooling zone of an ESC, (B) a temperature setting for each of a plurality of heaters having respective heating zones within a ceramic body of the ESC, (C) a temperature setting for each microzone heater within the ceramic body of the ESC, (D) a flow of coolant into cooling channels located in a base of a substrate support, or (E) any combination thereof. In addition to the ESC operating components of the manufacturing tool to control, for example, plasma power, flow of etching gas, etc., the recipe instructions can also comprise executable instructions related to other process parameters.

[0073] Figure 7 A flowchart of an example process for performing a substrate process is shown. For convenience, the process 700 will be described as being performed by a system of one or more computing devices located in one or more locations and appropriately programmed in accordance with this specification. For example, a suitably programmed controller, such as controller 172 of the system 100 Figure 1 may perform the process 700.

[0074] For each of the three or more cooling zones defined on the first surface of the ceramic body, the system receives control instructions comprising a gas pressure provided to the cooling zone (702). In some embodiments, receiving the control instructions to provide the gas pressure to each of the three or more cooling zones comprises receiving the control instructions defined in a recipe for performing a substrate process. In some embodiments, the recipe can comprise a target temperature (e.g., a substrate process temperature) for a portion of the substrate corresponding to the cooling zone, where the system can determine the gas pressure provided to the cooling zone from the target temperature, for example, using a backside substrate gas cooling profile shown in Figure 6 .

[0075] The system controls a backside substrate temperature of a substrate by providing a gas flow through a plurality of conduits within a ceramic body of an electrostatic chuck to three or more zones defined on a first surface of the ceramic body to establish a determined gas pressure to the three or more cooling zones, where the three or more cooling zones are configured to maintain a positive gas pressure within the zones and a surface of the substrate held by the electrostatic chuck (704). The three or more zones are arranged concentrically on the first surface, and where an outer edge of each of the three or more zones is defined by a respective retaining ring arranged on the first surface. The gas flow to each of the three or more zones can be independently provided to each of the three or more zones, where the gas flow can be independently controlled by the system to provide a selected gas pressure into each cooling zone.

[0076] In some implementations, providing the gas through the plurality of conduits within the ceramic body of the electrostatic chuck to the three or more regions defined on the first surface of the ceramic body includes providing a different gas pressure to each of the three or more regions. At times, providing the gas through the conduits within the ceramic body of the electrostatic chuck to the three or more regions defined between the first surface of the ceramic body and a surface of a substrate held by the electrostatic chuck includes cooling the surface of the substrate by contact primary cooling.

[0077] In some implementations, providing the gas through the conduits within the ceramic body of the electrostatic chuck to the three or more regions defined between the first surface of the ceramic body and a surface of a substrate held by the electrostatic chuck includes cooling the surface of the substrate by gas primary cooling.

[0078] The system provides a holding force on the surface of the substrate by the one or more electrodes disposed within the ceramic body and relative to the first surface (706).

[0079] In some implementations, the process 700 can further include supporting the surface of the substrate by a plurality of support structures disposed on the first surface of the ceramic body and within at least one of the three or more regions. At times, supporting the surface of the substrate by the plurality of support structures disposed on the first surface of the ceramic body includes supporting the surface of the substrate by different densities of structures in at least one of the three or more regions.

[0080] In some implementations, the process 700 can further include providing heating to the surface of the substrate by one or more heating elements disposed within the ceramic body.

[0081] As described above with reference to Figure 2 The model can be used to determine a set of design parameters for an ESC to improve temperature uniformity on a surface of a substrate of a manufacturing process in a manufacturing system, as described above with reference to Figure 8 A flowchart of an example process 800 for modeling parameters of an electrostatic chuck design is shown.

[0082] The system receives data describing a plurality of manufacturing processes performed in a manufacturing system, including (i) temperature non-uniformities on a surface of a substrate for the manufacturing processes in the manufacturing system and using different electrostatic chuck configurations each having a set of design parameters, and (ii) process parameters of the manufacturing processes in the manufacturing system, and trains a model to produce parameter values for predicting design parameters of an ESC in response to a given input (802).

[0083] The system provides the temperature non-uniformity data collected for the manufacturing processes performed in the manufacturing system and the process parameters of the manufacturing processes as inputs to the model (804).

[0084] The system receives from the model a predicted set of design parameters, the design parameters including: (A) a plurality of three or more regions defined on a first surface of a ceramic body of an electrostatic chuck, each region having an outer edge defined by a retaining ring disposed on the first surface; and (B) receiving from the model a distribution of a plurality of support structures disposed on the first surface and within each of the plurality of three or more regions (806).

[0085] In some implementations, when the substrate is held by the ESC, the first surface of the ceramic body is aligned along a plane parallel to a surface of the substrate.

[0086] In some embodiments, the three or more regions can be oriented such that respective surfaces of the three or more regions along the first surface of the ceramic body can be at different distances perpendicular to the surface of the substrate, wherein the support structure in each of the three or more regions can have a height corresponding to the respective distance of the three or more regions from the surface of the substrate.

[0087] In some embodiments, each of the three or more regions may include a different density of support structures.

[0088] In some embodiments, process 800 also includes design parameters including (C) one or more heating elements (e.g., multiple heating zones, microheaters) disposed within the ceramic body, and / or (D) one or more electrodes disposed within the ceramic body and relative to the first surface, e.g., clamping electrodes.

[0089] The system provides the predicted set of design parameters for manufacturing the electrostatic chuck to, for example, one or more manufacturing systems for manufacturing the electrostatic chuck (808).

[0090] Figure 9 9 is a block diagram of an example computer system 900 that can be used to perform the operations described above. For example, such as those performed by the electrostatic chuck model. System 900 includes a processor 910, a memory 920, a storage device 930, and an input / output device 940. Each of components 910, 920, 930, and 940 can be interconnected, for example, using a system bus 950. Processor 910 is capable of processing instructions for execution within system 900. In one implementation, processor 910 is a single-threaded processor. In another implementation, processor 910 is a multi-threaded processor. Processor 910 is capable of processing instructions stored in memory 920 or on storage device 930.

[0091] The memory 920 stores information within the system 900. In one implementation, the memory 920 is a computer-readable medium. In one implementation, the memory 920 is a volatile memory unit. In another implementation, the memory 920 is a non-volatile memory unit.

[0092] The storage device 930 can provide mass storage for the system 900. In one implementation, the storage device 930 is a computer-readable medium. In various implementations, the storage device 930 may include, for example, a hard disk device, an optical disk device, a storage device shared by multiple computing devices (e.g., a cloud storage device) over a network, or some other mass storage device.

[0093] The input / output device 940 provides input / output operations for the system 900. In one implementation, the input / output device 940 may include one or more of a network interface device (e.g., an Ethernet card), a serial communication device (e.g., an RS-232 port), and / or a wireless interface device (e.g., an 802.11 card). In another implementation, the input / output device may include a driver device configured to receive input data and send output data to a peripheral device 960, such as a keyboard, a printer, and a display device. However, other implementations may also be used, such as a mobile computing device, a mobile communication device, a set-top television client device, and the like.

[0094] Despite Figure 9 An example processing system is described in the specification, but the subject matter and implementation of the functional operations described in this specification may be implemented in other types of digital electronic circuit systems, or in computer software, firmware, or hardware (including the structures disclosed in this specification and their structural equivalents), or in a combination of one or more of them.

[0095] The subject matter, actions, and various aspects of the operations described in this specification, such as a computing device such as controller 165 and the processes performed by controller 165, can be implemented in digital electronic circuitry, in tangibly embodied computer software or firmware, in computer hardware (including the structures disclosed in this specification and their structural equivalents), or in a combination of one or more thereof. The subject matter, actions, and operations described in this specification can be implemented as or in one or more computer programs, such as one or more modules of computer program instructions encoded on a computer program carrier, for execution by a data processing device or to control the operation of the data processing device. The carrier can be a tangible, non-transitory computer storage medium. Alternatively or additionally, the carrier can be an artificially generated propagated signal, such as a machine-generated electrical, optical, or electromagnetic signal, generated to encode information for transmission to a suitable receiver device for execution by the data processing device. A computer storage medium can be a machine-readable storage device, a machine-readable storage substrate, a random or serial access storage device, or a combination of one or more of these, or a portion of the above. A computer storage medium is not a propagated signal.

[0096] The term "data processing apparatus" encompasses all types of equipment, devices, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. A data processing apparatus may include dedicated logic circuitry, such as an FPGA (field programmable gate array), an ASIC (application-specific integrated circuit), or a GPU (graphics processing unit). In addition to hardware, the apparatus may also include code that creates an execution environment for a computer program, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of these.

[0097] A computer program may be written in any form of programming language, compiled or interpreted, declarative or procedural; and it may be deployed in any form, including as a stand-alone program, such as an application, or as a module, component, engine, subroutine, or other unit suitable for execution in a computing environment that may include one or more computers at one or more locations interconnected by a data communications network.

[0098] A computer program may, but need not, correspond to a file in a file system. A computer program may be stored as part of a file that holds other programs or data, such as one or more scripts stored in a markup language document, in a single file dedicated to the program in question, or in multiple coordinated files, such as a file that holds one or more modules, subroutines, or code sections.

[0099] The processes and logic flows described in this specification can be performed by one or more computers executing one or more computer programs to perform operations by operating on input data and generating output. The processes and logic flows can also be performed by special purpose logic circuitry, e.g., an FPGA, an ASIC, or a GPU, or by a combination of special purpose logic circuitry and one or more programmed computers.

[0100] Computers suitable for the execution of a computer program can be based on general or special purpose microprocessors or both, as well as any other kind of central processing unit. Generally, a central processing unit will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a central processing unit for performing instructions and one or more memory devices for storing instructions and data. The central processing unit and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0101] Generally, a computer will also include, or be operatively coupled to, one or more mass storage devices for storing data or instructions. A mass storage device can be, for example, a magnetic disk, magnetic tape, optical disk, or solid-state drive. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few.

[0102] To provide for user interaction, the subject matter described herein may be implemented on one or more computers having: a display device for displaying information to the user or configured to communicate with the user, such as an LCD (liquid crystal display) monitor, or a virtual reality (VR) or augmented reality (AR) display, and input devices through which the user can provide input to the computer, such as a keyboard and a pointing device, such as a mouse, trackball, or touchpad. Other types of devices may also be used to provide for user interaction; for example, feedback and responses provided to the user may be any form of sensory feedback, such as visual, audio, verbal, or tactile; and input from the user may be received in any form, including acoustic, verbal, or tactile input, including touch motions or gestures, or dynamic or directional motions or gestures. In addition, the computer may interact with the user by sending files to and receiving files from a device used by the user; for example, by sending a web page to a web browser on the user's device in response to a request received from the web browser, or by interacting with an application running on the user's device (e.g., a smartphone or tablet). Furthermore, a computer may interact with a user by sending text messages or other forms of information to a personal device (e.g., a smartphone running a messaging application) and receiving response messages from the user.

[0103] This specification uses the term "configured to" in connection with systems, devices, and computer program elements. A system of one or more computers being configured to perform a particular operation or action means that the system has installed thereon software, firmware, hardware, or a combination thereof that, in operation, causes the system to perform the operation or action. A system of one or more computer programs being configured to perform a particular operation or action means that the one or more programs include instructions that, when executed by a data processing device, cause the device to perform the operation or action. A system of special-purpose logic circuitry being configured to perform a particular operation or action means that the circuitry has electronic logic that performs the operation or action.

[0104] Although this specification contains many specific implementation details, these should not be interpreted as limitations on the scope of what is claimed, as defined by the claims themselves, but rather as descriptions of features that may be specific to a particular embodiment of a particular invention. Certain features described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable subcombination. Furthermore, although features may be described above as functioning in certain combinations, or even initially claimed as such, in some cases one or more features from a claimed combination may be deleted from that combination, and the claim may be directed to a subcombination or a variant of a subcombination.

[0105] Similarly, while operations are depicted in the drawings and recited in the claims in a particular order, this should not be understood as requiring such order nor limiting all illustrations to that particular order. Multi-tasking and parallel processing can be advantageous in certain circumstances. Furthermore, the separation of various system modules and components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program elements and systems are often integrated in a single software product or packaged into multiple software products.

[0106] Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the acts recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes described in the figures do not necessarily require the particular order or sequence shown in order to achieve the desired results. In some instances, multitasking and parallel processing can be advantageous.

Claims

1. An electrostatic chuck (ESC), comprising: a ceramic body comprising one or more embedded electrodes, the ceramic body comprising a first surface having a first diameter; three or more regions defined on the first surface, wherein the three or more regions are concentrically arranged on the first surface, each region comprising: a retaining ring disposed on the first surface and defining an outer edge of the region; and a plurality of support structures disposed on the first surface and within the region, wherein the plurality of support structures are configured to support a surface of the substrate when the substrate is held by the electrostatic chuck; and a plurality of conduits formed in the ceramic body and configured to independently introduce a gas into each of the three or more regions and into the first surface through the ceramic body, wherein each of the three or more regions is configured to maintain a corresponding positive gas pressure within the region and the surface of the substrate when the substrate is held by the electrostatic chuck, and The one or more embedded electrodes are configured to generate a holding force on the surface of the substrate when the substrate is held by the electrostatic chuck.

2. The ESC of claim 1 , further comprising one or more heating elements disposed within the ceramic body and configured to heat at least a portion of the surface of the substrate while the substrate is held by the electrostatic chuck. 3 . The ESC of claim 1 , wherein each of the three or more regions comprises a uniform density of the plurality of support structures. 4 . The ESC of claim 3 , wherein each of the three or more regions comprises a different density of the plurality of support structures arranged within the region. 5 . The ESC of claim 1 , wherein at least one of the three or more regions comprises a non-uniform density of the plurality of support structures.

6. The ESC of claim 5, wherein the non-uniform density of the plurality of support structures comprises a density gradient having a higher density adjacent the retaining ring defining an outer edge of the region and a lower density at a center point of the region.

7. The ESC of claim 1, wherein at least one of the three or more regions comprises a table having a center height trend that is different from a center height trend of one or more other regions of the three or more regions.

8. The ESC of claim 1, further comprising second and third surfaces having respective second and third diameters, wherein each of the three or more regions is defined on a respective surface.

9. The ESC of claim 1, wherein a density of the plurality of support structures in at least one of the three or more regions is a threshold density for contact-dominated cooling.

10. The ESC of claim 1, wherein a density of the plurality of support structures in at least one of the three or more regions is a threshold density for gas-dominated cooling.

11. The ESC of claim 1 , wherein the plurality of conduits are configured to independently introduce a different gas pressure into each of the three or more regions when the substrate is held by the ESC.

12. The ESC of claim 1, wherein the arrangement of the retaining ring and the plurality of support structures in each cooling zone of the three or more zones is defined by parameters generated by a machine learning model.

13. A method of cooling an electrostatic chuck during plasma processing, the method comprising: providing gas through a plurality of conduits within a ceramic body of the electrostatic chuck to three or more regions defined on a first surface of the ceramic body and configured to maintain positive gas pressure within the regions and a surface of a substrate held by the electrostatic chuck, wherein the three or more regions are concentrically arranged on the first surface, and wherein an outer edge of each of the three or more regions is defined by a corresponding retaining ring disposed on the first surface; as well as A retention force is provided on the surface of the substrate by one or more electrodes within the ceramic body and disposed relative to the first surface.

14. The method of claim 13 , wherein providing the gas to three or more regions defined on the first surface of the ceramic body through the plurality of conduits within the ceramic body of the electrostatic chuck comprises providing a different gas pressure to each of the three or more regions.

15. The method of claim 14, further comprising: The surface of the substrate is supported by a plurality of support structures arranged on the first surface of the ceramic body and in at least one of the three or more regions.

16. The method of claim 15, wherein supporting the surface of the substrate by a plurality of support structures arranged on the first surface of the ceramic body comprises supporting the surface of the substrate by structures of different densities in at least one of the three or more regions.

17. The method of claim 14, wherein providing the gas through conduits within the ceramic body of the electrostatic chuck to three or more regions defined between the first surface of the ceramic body and the surface of the substrate held by the electrostatic chuck comprises cooling the surface of the substrate by contact-directed cooling.

18. The method of claim 14, wherein providing the gas through conduits within the ceramic body of the electrostatic chuck to three or more regions defined between the first surface of the ceramic body and the surface of the substrate held by the electrostatic chuck comprises cooling the surface of the substrate by gas-directed cooling.

19. The method of claim 14, further comprising: Heating of the surface of the substrate is provided by one or more heating elements disposed within the ceramic body.

20. A system comprising: a plasma processing chamber enclosing a processing region; a gas source configured to introduce one or more etching gases into the processing region; a plasma source configured to generate a plasma within the processing region using the one or more etching gases introduced into the processing region; as well as an electrostatic chuck within the plasma processing chamber and configured to hold a substrate in the processing region of the plasma processing chamber during plasma processing, the electrostatic chuck comprising: a ceramic body comprising one or more embedded electrodes configured to generate a holding force on a surface of the substrate when the substrate is held by the electrostatic chuck; three or more regions defined on a first surface of the ceramic body, wherein the three or more regions are concentrically arranged on the first surface, each region including a retaining ring disposed on the first surface and defining an outer edge of the region; and A plurality of conduits are formed in the ceramic body and configured to independently introduce a gas into each of the three or more regions and into the first surface through the ceramic body.

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