Cold edge low temperature electrostatic chuck

Abstract

An electrostatic chuck is provided. In one example, the electrostatic chuck includes a base plate, a bonding layer disposed above the base plate, a ceramic plate, and a heater. The ceramic plate includes a bottom surface disposed above the bonding layer and a raised top surface for supporting a substrate. The raised top surface includes an outer diameter. The heater is disposed between the bottom surface of the ceramic plate and the bonding layer. The heater element includes an inner heating element and an outer heating element. The inner heating element is disposed in a central circular region adjacent to the bottom surface of the ceramic plate, while the outer heating element is disposed in an annular region surrounding the central circular region and adjacent to the bottom surface of the ceramic plate. The outer diameter of the outer heating element is embedded from the annular heater recessed region of the ceramic plate. The annular heater recessed region is located between the outer diameter of the raised top surface and the outer diameter of the outer heating element. The base plate includes a plurality of cooling channels. The plurality of cooling channels are disposed below the inner heating element, below the outer heating element, and below the annular heater recessed region. Each of the plurality of cooling channels is configured to allow the flow of cooling fluid to generate heat conduction cooling in the recessed area of ​​the annular heater on the ceramic plate.

Description

Technical field

[0001] The present embodiments relate to semiconductor manufacturing, and more particularly to electrostatic chuck structures, and to the temperature provided to the wafer surface when the electrostatic chuck is used to support the wafer surface in a plasma processing chamber. method of control.

Prior Technology

[0002] Many modern semiconductor wafer fabrication processes (eg, plasma etch processes) are performed in plasma processing chambers in which substrates (eg, wafers) are supported on electrostatic chucks (ESCs). In plasma etch processing, the wafer is exposed to a plasma generated within the plasma processing volume. Plasma contains various types of free radicals, positive ions and negative ions. The chemical reactions of various free radicals, positive ions, and negative ions are used to etch features, surfaces, and materials of the wafer.

[0003] In some cases, wafer temperature control during plasma etch processing operations is one of the factors that may affect the results of processed wafers. For example, during etch operations, processing conditions may generate significant heat on the wafer, which can affect the etch rate and may cause non-uniform features to be formed on the wafer. In order to provide better control of wafer temperature during plasma etch processing operations, there is a need for an ESC design that can provide better temperature control to improve the quality of processed wafers and reduce the overall cost of the system and its operating costs.

[0004] It is in this context that embodiments of the present invention arise.

Content of invention

[0005] Embodiments of the present disclosure include apparatus, methods, and system. In some embodiments, an ESC includes a base plate, a bonding layer disposed over the base plate, a ceramic plate disposed over the bonding layer, and a heater disposed between the ceramic plate and the bonding layer. In one embodiment, the base plate includes a plurality of cooling channels configured to flow a cooling fluid to generate heat conduction cooling in the ceramic plate, and in the ring heater setback region of the ceramic plate.

[0006] In another embodiment, the bonding layer is configured to be thin or have a reduced thickness, which can help facilitate conductive cooling in the ring heater setback region of the ceramic plate. Therefore, a base plate with deep and wide cooling channels with a bonded layer of reduced thickness can lead to a high heat transfer coefficient, which consequently increases the heat conduction cooling in the ring heater setback of the ceramic plate. In one embodiment, reference to "cold edge" means that the temperature in the ring heater retraction is programmed to be lower than the temperature in other parts of the ceramic chuck below the inner and outer heaters. lower or colder.

[0007] Through the configuration of the ring heater setback, the temperature along the edge of the wafer can be maintained at a lower temperature than other regions of the wafer extending towards the center of the wafer. As an example, at the beginning of the ring heater setback, this lower temperature can be controlled to be about 2-3 degrees Celsius lower than the area above the heater, while this temperature can be outside the ring heater setback. The diameter is further reduced up to about 10 degrees Celsius above (relative to the area above the heater).

[0008] In one embodiment, the heater may include an inner heating element and an outer heating element, wherein the inner heating element and the outer heating element are configured to provide the ESC with two temperature zones (e.g., an annular zone temperature zone and a central circle shaped region temperature zone). Thus, during wafer processing, the cold edge temperature region helps to control the cooling of the wafer temperature along the edge of the wafer and maintains the wafer at a desired temperature, thereby helping to improve the features formed on the wafer. The etch rate and profile. As will be described below, the amount of cooling provided by the cold edge is variable and controllably adjustable by programming the chiller set point of the chiller.

[0009] In one embodiment, an etch process may be performed, which requires rapid alternating processes for silicon etch, which is highly exothermic in nature. The processing conditions generate a large amount of heat on the wafer, which affects the etch rate and profile. It has been observed that maintaining the edge of the wafer at a reduced temperature relative to the rest of the wafer surface helps to improve the etch rate and uniformity across the wafer. In some cases, this improvement in etch rate and uniformity is necessary to meet stringent requirements for the bottom critical dimension (CD) profile of etched features. In this context, bottom CD refers to the etch profile formed near the bottom region of an etched feature during etching. By reducing the temperature at the edge of the wafer, it has been observed that the bottom CDs of features formed near or around the edge of the wafer remain at the same level as those formed in other parts of the wafer (i.e., away from the edge region). The features are similar to the profile. Therefore, an improvement in etching uniformity is achieved.

[0010] As noted above, lower temperatures in the cold edge of the wafer are facilitated by a combination of structural developments in ESC design. Broadly speaking, one structural feature is to prevent the external heater from extending over the ring heater setback, one structural feature is to reduce the thickness of the joint layer between the base plate and the ceramic plate, and another structural feature is to reduce the joint layer and cooling. Material thickness in the base plate between channels. Collectively, these structural features help divert additional cooling to the annular heater setback, while still providing heating to the central circular zone temperature zone and the annular zone temperature zone.

[0011] Advantageously, the configuration of the ESC provides temperature control over the retracted zone of the ring heater (i.e., keeps it at a lower temperature than other zones) by using the cooler to flow cooling fluid controlled by the cooler set point. colder). To further control the temperature of the ring heater retraction zone, the temperature of the cooler set point can be adjusted. For example, if it is desired to make the ring heater retreat cooler, the cooler set point can be set to flow a lower temperature. In some embodiments, since the cooler set point flows the cooling fluid in the cooling channel under most of the wafer, if the cooling system is boosted by the cooling fluid, the heater temperature can be increased. This allows the cold edge to cool while still keeping the rest of the wafer surface constant.

[0012] As a further advantage, an ESC structure with only two heaters reduces the complexity of other designs that require more heaters to achieve three or more temperature zones. Reducing the number of heaters further helps reduce the costs associated with adding an alternating current (AC) box, control system, and heater RF filter.

[0013] In one embodiment, an ESC is disclosed. The ESC includes a base plate, a bonding layer disposed over the base plate, a ceramic plate, and a heater. The ceramic plate includes a bottom surface disposed above the bonding layer, and a raised top surface for supporting a substrate. The raised top surface includes an outer diameter. A heater is disposed between the bottom surface of the ceramic plate and the bonding layer. The heater element includes an inner heating element and an outer heating element. The inner heating element is disposed in a central circular area adjacent to the bottom surface of the ceramic plate, and the outer heating element is disposed around the central circular area and adjacent to the bottom surface of the ceramic plate in the ring area. The outer diameter of the outer heating element is recessed from the ring heater setback of the ceramic plate. The annular heater setback region is between the outer diameter of the raised top surface and the outer diameter of the outer heating element. The base plate includes a plurality of cooling channels. The plurality of cooling passages are disposed under the inner heating element, under the outer heating element, and under the ring heater retraction area. Each of the plurality of cooling channels is configured to flow a cooling fluid to generate heat conduction cooling in the annular heater setback region of the ceramic plate.

[0014] In another embodiment, a method of thermally cooling a region of an electrostatic chuck is disclosed. The electrostatic chuck includes a ceramic plate and a base plate. The method includes providing an inner heating element and an outer heating element between the base plate and the ceramic plate. The external heating element is located away from the ring heater setback of the ceramic plate. The method includes flowing a cooling fluid along a plurality of cooling passages disposed in the base plate, wherein at least one of the plurality of cooling passages is disposed below the annular heater setback, the cooling fluid being configured to pass through the ceramic Thermal cooling is induced in the annular setback region of the plate to provide a cold edge region for the substrate when it is positioned over the electrostatic chuck. The method includes activating a plurality of alternating current (AC) heaters connected to the outer heating element and the inner heating element. The method includes activating the chiller to operate at a set point temperature. The activated cooler is configured to control the flow of the cooling fluid to thermally cool the ceramic plate and the ring heater retraction, wherein the outer heating element does not extend into the ring heater retraction.

[0015] Other aspects and advantages of the present disclosure will become apparent from the following embodiments in conjunction with the accompanying drawings, wherein the accompanying drawings illustrate the principles of the present disclosure.

Implementation

[0028] The following implementations of the present disclosure provide apparatus, methods, systems for controlling temperature differentials in a wafer while the wafer is supported on an electrostatic chuck (ESC) in a plasma processing chamber during plasma etch processing . The ESC includes various structural features configured to help facilitate conductive thermal cooling to reduce and control heat along various regions of the ceramic plate of the ESC. By reducing and controlling heat along the ceramic plate (eg, the ring heater setback area of ​​the ceramic plate), a cool edge temperature zone can be provided to the wafer during the plasma etch process. Thus, the cold edge temperature region helps control the temperature of the wafer along its edge and maintains it at a desired temperature to help improve the etch rate and profile of etched features.

[0029] Some current ESCs may not be optimized to have highly conductive cooling along the peripheral region of the ceramic plate. This can lead to undesirably high temperatures along the edge of the wafer during the etch process, which can negatively impact the etch performance and profile of the processed wafer. In addition, some ESCs may be designed to have three or more temperature zones, where the three or more temperature zones require larger heaters and components (e.g., AC box, control system, heater RF filter, etc.) quantity to achieve the temperature zone. This may result in higher system and operating costs due to the larger number of components required to operate the ESC and achieve the temperature region.

[0030] In view of these issues, one of the disclosed embodiments includes an ESC having various structural features optimized to facilitate the height of the ceramic plate, and the ring heater setback region of the ceramic plate Heat conduction cooling. In one embodiment, the ESC includes a base plate having a plurality of cooling channels configured to flow a cooling fluid that creates a ceramic plate, and an annular heater retraction of the ceramic plate of the ESC. Area conduction cooling. In some embodiments, the plurality of cooling channels can be rectangular and have a specific width and height configured to have an optimized contact surface area for cooling fluid flow, which can help facilitate the flow of various areas of the ceramic plate. Heat conduction cooling in .

[0031] According to another embodiment, an ESC includes a bonding layer disposed over a base plate. In some embodiments, the bonding layer is optimized to be thin or have a reduced thickness, which results in a high heat transfer coefficient which thus facilitates heat conduction cooling from the base plate to various regions of the ceramic plate.

[0032] According to another embodiment, an ESC includes a heater having an inner heating element and an outer heating element. As used herein, the inner and outer heating elements are conductive wires embedded in the ESC, and power is supplied to the heating elements from an alternating current (AC) heater. The inner and outer heating elements can be of any shape and configured to form any path to suit the desired heating zone requirements. A heating element is disposed between the bottom surface of the ceramic plate and the bonding layer, and is configured to create two temperature zones in the ESC (eg, a central circular zone temperature zone, an annular zone temperature zone). In one embodiment, the outer heating element of the heater element does not extend below the annular heater setback of the ceramic plate such that the outer heating element does not interfere with conductive cooling by the flow of cooling fluid in the base plate . In one embodiment, the annular heater retreat region of the ceramic plate relies on conduction cooling caused by the flow of cooling fluid to form a cold edge temperature region of the wafer.

[0033] With the above in mind, the following provides a plurality of exemplary embodiments based on the drawings, wherein the drawings are provided to facilitate understanding of the present disclosure.

[0034] The ESC 102 disclosed herein may be used in any number of plasma processing chambers. These processing chambers include inductively coupled plasma (ICP) processing systems and capacitively coupled plasma (CCP) processing systems.

[0035] FIG. 1A illustrates an embodiment of a capacitively coupled plasma (CCP) processing system for etching operations. The CCP processing system includes a plasma processing chamber 118 , a control system 122 , a radio frequency (RF) source 124 , a pump 126 , and one or more gas sources 128 coupled to the plasma processing chamber 118 . The plasma processing chamber 118 includes an ESC 102 for supporting a wafer 104 , and an edge ring 114 . In some embodiments, the plasma processing chamber 118 may include a confinement ring 130 for confining the plasma 120 , and a chamber wall covering 132 .

[0036] As shown in FIG. 1A, the ESC 102 is located in a plasma processing chamber 118. In some embodiments, the ESC 102 includes a ceramic plate 106, a bonding layer 108, a base plate 110, and a heater (not shown). Ceramic plate 106 may include a raised top surface configured to support wafer 104 during processing. Bonding layer 108 is configured to secure ceramic plate 106 to base plate 110 . The bonding layer 108 may also serve as a thermal break between the ceramic plate 106 and the base plate 110 . In some embodiments, the base plate 110 can be made of aluminum material, or any other material or combination of materials that can provide sufficient electrical conduction, thermal conduction, and mechanical strength to support the operation of the ESC 102 . In some embodiments, the base plate 110 includes a plurality of cooling channels 112 configured to flow a cooling fluid to generate thermal conduction cooling in the ceramic plate, and in the annular heater retraction region of the ceramic plate. In one embodiment, the heater is disposed between the ceramic plate 106 and the bonding layer 108 . In some embodiments, the heater includes an inner heating element and an outer heating element configured to form two temperature zones in the ceramic plate. Broadly speaking, the structural features of the components of the ESC 102 are configured to work together to generate thermal conduction cooling in the ceramic plate, and in the ring heater retraction region of the ceramic plate, which in turn controls the wafer 104 temperature during processing. The structural features of the ESC 102 and its components are described in more detail below.

[0037] In some embodiments, the control system 122 is used to control the various components of the CCP processing system. In one example, as shown in FIG. 1A , control system 122 may be connected to ESC 102 , RF source 124 , pump 126 , and gas source 128 . Control system 122 includes a processor, memory, software logic, hardware logic, and input and output subsystems that communicate to, monitor, and control the CCP processing system. In some embodiments, control system 122 includes one or more recipes that include a plurality of set points and various operating parameters (e.g., voltage, current, frequency, pressure, flow rate, , power, temperature, etc.).

[0038] As further illustrated in FIG. 1A, the system may include a single RF source 124, or a plurality of RF sources capable of generating frequencies that may be used to achieve various tuning characteristics. As shown, the single RF source 124 is connected to the ESC 102 and is configured to provide an RF signal to the ESC 102 . In one example, the RF source can generate a frequency in the range of about 27 MHz to about 60 MHz and have an RF power of between about 50W to about 10kW. In another embodiment, a gas source 128 is coupled to the plasma processing chamber 118 and is configured to inject a desired processing gas into the plasma processing chamber 118 . After the RF signal is provided to the ESC 102 and process gases are injected into the chamber 118 , a plasma 120 is then formed between the upper electrode 116 and the ESC 102 . The plasma 120 can be used to etch the surface of the wafer 104 .

[0039] In some embodiments, pump 126 is connected to plasma processing chamber 118 and is configured to enable vacuum control of plasma processing 118 removes gaseous by-products. In some embodiments, the plasma processing chamber 118 includes an upper electrode 116 disposed above the ESC 102 . In some embodiments, the upper electrode 116 is electrically connected to a reference ground potential, or may be biased, or coupled to a second RF source (not shown).

[0040] FIG. 1B depicts an example of an inductively coupled plasma (ICP) processing system. In one configuration, the ICP system is also referred to as a Transformer Coupled Plasma (TCP) processing system. The system includes a plasma processing chamber 118 that includes an ESC 102, a dielectric window 134, and a TCP coil 136 (inner coil 138 and outer coil 140). The ESC 102 is configured to support a wafer 104 (when present).

[0041] In one embodiment, the ESC 102 includes a ceramic plate 106, a bonding layer 108, a base plate 110, and a heater (not shown). Bonding layer 108 is configured to secure ceramic plate 106 to base plate 110 . In some embodiments, the base plate 110 includes a plurality of cooling channels 112 configured to flow a cooling fluid to generate thermal conduction cooling in the ceramic plate, and in the annular heater retraction region of the ceramic plate. In some embodiments, the heater includes an inner heating element and an outer heating element configured to form two temperature zones in the ceramic plate.

[0042] Further shown are bias RF generator 141, and RF generator 142 coupled to TCP coil 136. In an exemplary chamber, the RF generator 142 operates at a frequency of about 13.56 MHz, and the bias RF generator 141 for bias operates at a frequency of about 400 kHz. Also, in this example, up to about 6 kW of power may be supplied, and in some embodiments up to 10 kW of power may be supplied. As shown, bias matching circuitry 144 is coupled between RF generator 141 and ESC 102 . TCP coil 136 is coupled to RF generator 142 via matching circuitry 146 including connections to inner coil (IC) 138 and outer coil (OC) 140 . Although not shown, in some embodiments, a pump is connected to the plasma processing chamber 118 to enable vacuum control of the chamber and removal of gaseous by-products from the chamber during operating plasma processing.

[0043] FIG. 2A illustrates an embodiment of an ESC 102 for supporting a wafer 104 within a chamber of a plasma processing system. As shown, the ESC 102 includes a base plate 110, a bonding layer 108 (not shown) disposed over the base plate 110, and a ceramic plate 106 disposed over the bonding layer 108, wherein the ceramic plate 106 has a The raised top surface 216 of the circle 104 . In one embodiment, the raised top surface 216 of the ceramic plate 106 includes a region configured to support the wafer 104 during processing. In some embodiments, the raised top surface 216 of the ceramic plate 106 is formed by the coplanar top surfaces of the plurality of raised structures referred to as the minimum contact area points, said The minimum contact area points are configured to support the wafer 104 during processing. According to some embodiments, where the wafer 104 is supported by the points of minimum contact area during processing, the area between the sides of the points of minimum contact area provides fluid (e.g., helium) to the backside of the wafer 104. flow to enhance temperature control of the wafer 104 . In other embodiments, a control system for lifting the wafer 104 from the ESC 102 may also be provided.

[0044] FIG. 2B illustrates a cross-section A-A of the ESC 102 shown in FIG. 2A. As shown, ESC 102 includes ceramic plate 106 , bonding layer 108 , base plate 110 , clamping electrode 202 , inner heating element 204 , and outer heating element 206 . In some embodiments, ceramic plate 106 includes a raised top surface 216 configured to support wafer 104 during processing. The ceramic plate 106 includes an annular heater setback 203 bounded by a distance D1. As shown, the distance D1 extends from the outer diameter of the raised top surface 216 of the ceramic plate 106 to the outer diameter of the outer heater 206 . In one embodiment, the distance D1 is between about 1 mm and about 20 mm, or between about 2 mm and about 20 mm. In another embodiment, distance D1 is between about 3 mm and 7 mm, and in yet another embodiment is about 5 mm. In some embodiments, the ring heater setback region 203 is configured to provide a cool edge temperature region for the wafer 104 when the wafer 104 is positioned above the raised top surface 216 during processing.

[0045] In some embodiments, ceramic plate 106 includes one or more clamping electrodes 202 for creating a raised top surface 216 that holds wafer 104 to ceramic plate 106. of electrostatic force. In some embodiments, the clamping electrode 202 may include two separate clamping electrodes 202 configured for bipolar operation in which a differential voltage is applied between the two separate clamping electrodes to generate the The wafer 104 is held to the electrostatic force of the raised top surface 216 of the ceramic plate 106 . In other embodiments, mechanical clamps may be used to hold the wafer 104 to the raised top surface 216 of the ceramic plate 106 .

[0046] In some embodiments, bonding layer 108 is disposed between ceramic plate 106 and base plate 110 and is configured to secure the ceramic plate to the base plate. The bonding layer 108 also acts as a thermal break joint between the ceramic plate 106 and the base plate 110 . Bonding layer 108 may be made of a silicon material, or any other material type that has a high heat transfer coefficient to facilitate thermal conduction cooling of the ceramic plate and ring heater setback 203 . In some embodiments, the bonding layer 108 is configured to have a thin or reduced thickness to facilitate the flow of heat conduction cooling from the base plate.

[0047] As further shown in FIG. 2B , inner heating element 204 and outer heating element 206 are disposed between the bottom surface of ceramic plate 106 and bonding layer 108 . In one embodiment, an alternating current (AC) heater 212 is connected to the outer heater element 206 and an alternating current (AC) heater 214 is connected to the inner heating element 204 . The AC heater is configured to deliver power to the inner heating element 204 and the outer heating element 206 . When the AC heater is activated, the inner heating element 204 and the outer heating element 206 generate heat, which thus provides the ESC with a central circular zone and an annular zone of temperature, respectively. For example, in one embodiment, the inner heating element 204 is disposed within a central circular region in a concentric manner extending circularly outward from a point adjacent to the centerline 210 and away from the centerline. 210 to form an inner heating element with an outer diameter of about 230 mm. Thus, when the AC heater 214 is activated, the inner heating element 204 generates heat, thereby giving the ESC a central circular area temperature band. In another embodiment, the outer heating element 206 is disposed in an annular region surrounding the central circular region. In some embodiments, the outer heating element 206 is circularly extending and has an inner diameter of about 236 mm and an outer diameter of about 285 mm. Depending on the selected dimension D1 of the annular heater setback 203, the outer diameter of the outer heater element 206 can be adjusted. Thus, when the AC heater 212 is activated, the outer heater element 206 generates heat, thereby causing the ESC to have an annular zone of temperature bands.

[0048] As further shown in FIG. 2B , a base plate 110 is disposed below the ceramic plate 106 and bonding layer 108 . In one embodiment, the base plate 110 may be made of a conductive material such as aluminum. In some embodiments, the base plate 110 may be used as a heat exchanger to cool the ceramic plate and the annular heater setback 203 of the ceramic plate when a cooling fluid is pressurized through the cooling channel 112 . In some embodiments, the cooling channels 112 are concentrically and circularly configured within the base plate 110 . For example, the cooling channels 112 may extend concentrically and circularly outwardly towards the periphery of the base plate starting at a point adjacent the center of the base plate. Accordingly, the configuration of the cooling channels 112 may extend from a central point of the base plate towards a point adjacent the periphery of the base plate. Thus, as the cooling fluid flows through the cooling channels 112, it passes through various areas of the base plate to provide thermally conductive cooling in the ceramic plate and in the ring heater setback area of ​​the ceramic plate. In some embodiments, each of the cooling channels 112 may have the same or different size, shape, geometry, volume, surface area, or any configuration that meets the heat conduction cooling needs of the ceramic plate. For example, the cooling channel 112 may be configured to have a specific contact surface area and volume to facilitate a specific flow rate and amount of cooling fluid flowing through the cooling channel 112 .

[0049] In some embodiments, the ESC 102 includes a peripheral seal 208 disposed between the bottom surface of the ceramic plate 106 and the top surface of the base plate 110. The perimeter seal 208 is further disposed along the radial perimeter of the bonding layer 108 and the radial perimeter of the raised top surface of the base plate 110 . In one embodiment, perimeter seal 208 is configured to prevent plasma 120 components and process by-product materials from entering the interior region where ceramic plate 106 and base plate 110 are joined to bonding layer 108 .

[0050] In some embodiments, filter circuit 211 is connected to AC heater 212, AC heater 214, and RF source 124. The filter circuit 211 is configured to prevent the AC heater from burning out when the RF source 124 is operating. For example, when the RF source 124 is operating and delivering power to the ESC 102, the filter circuit 211 is configured to block RF return current from going back to the AC heater.

[0051] FIG. 3A shows an enlarged partial view of a portion of the ESC 102 shown in FIG. 2B during conduction cooling by cooler 302. FIG. As shown, the control system 122 is connected to the chiller 302 and is configured to activate the chiller 302 to operate at the set point temperature. In some embodiments, the control system 122 continuously monitors the operation of the chiller 302 and ensures that the chiller 302 remains within the set point temperature range. When the cooler 302 is activated, the cooler 302 is configured to flow a cooling fluid through the cooling channels 112 of the base plate 110 , resulting in conductive cooling of the ceramic plate 106 and the annular heater retraction 203 of the ceramic plate 106 . In various embodiments, various types of cooling fluids may be used, such as water, or coolant liquids such as fluorinated liquids. The heat conduction cooling of the annular heater setback 203 of the ceramic plate 106 creates a cold edge temperature region 308 along the peripheral region of the ceramic plate that maintains the wafer temperature along the edge of the wafer at a lower temperature than the wafer. lower temperatures in other regions.

[0052] In one example, when the cooler 302 is activated, the cooling fluid exits the cooler 302 at a set point temperature and is pressurized through the cooling channels 112 of the base plate 110. As the cooling fluid passes through the cooling channels 112, the cooling fluid reduces the temperature at various regions of the base plate 110 and the ceramic plate by thermal conduction cooling. The heater raises the temperature in its vicinity, which counteracts the cooling due to the cooling fluid. Therefore, the temperature along the annular heater setback 203 of the ceramic plate is lower than the temperature of the area of ​​the ceramic plate where the heater is located. After the cooling fluid exits the base plate 110 , the cooling fluid returns to the cooler 302 at a temperature greater than the set point temperature, where it is cooled by the cooler 302 .

[0053] In another embodiment, to further control the temperature at the annular heater setback 203, the temperature of the cooler set point can be adjusted. For example, if cooler temperatures along the ring heater setback 203 are desired, the set point temperature of the cooler 302 may be set to flow at a cooler temperature. In some embodiments, since the cooler set point flows the cooling fluid in the cooling channels 112 below the majority of the wafer 104, the heaters (e.g., inner heating elements 204 and The temperature of the external heating element 206). This allows cooling of the ring heater setback 203 while still keeping the temperature of the rest of the wafer 104 constant. In some embodiments, temperature data associated with the annular heater setback region 203 of the ceramic plate 106 may be continuously measured to determine whether the temperature data falls within a programmed temperature value based on the setpoint temperature. This helps control wafer temperature and maintain desired processing conditions.

[0054] FIG. 3A provides a conceptual illustration of the conduction cooling caused by cooler 302, as shown in a partially enlarged view of a portion of ESC 102. As shown in FIG. For example, as shown in FIG. 3A , when the cooler 302 is activated, cooling fluid flows into the cooling channels 112 of the base plate 110 . Conductive cooling occurs, which allows heat to flow from the ceramic plate 106 and ring heater setback 203 towards the base plate 110 . As further shown in FIG. 3A , this figure provides a conceptual illustration of the flow of heat from the external heating element 206 towards the base plate 110 and the ceramic plate 106 . The portion of the ESC shown in FIG. 3A depicts the base plate 110 , the bonding layer 108 disposed over the base plate 110 , and the ceramic plate 106 disposed over the bonding layer 108 .

[0055] In the example shown, outer diameter cooling channel 112a of the plurality of cooling channels is disposed under a portion of bonding layer 108, a portion of ceramic plate 106, and annular heater setback 203. In one embodiment, the outer diameter cooling channel 112a may be partially located below the ring heater setback 203 . In some embodiments, at least a portion of the outer diameter cooling channel 112a is located in a region of the base plate opposite the annular heater setback region 203 of the ceramic plate. In one embodiment, the outer diameter cooling channel 112 a has a rectangular shape with a top portion of the rectangular shape aligned horizontally below the ring heater setback 203 .

[0056] In some embodiments, the location of the cooling channel 112 within the base plate 110 forms an interface wall 314 adjacent to the bonding layer 108. The interface wall 314 extends vertically from the top portion of the cooling channel 112 to the bottom surface of the bonding layer 108 and is defined by a distance D3. In some embodiments, distance D3 may be approximately 3.6 mm. In other embodiments, the distance D3 of the interface wall 314 is no less than about 1 mm and no more than about 6 mm. By keeping the interface wall 314 at a reduced thickness, conductive cooling using cooling fluid flow in the ceramic plate 106 can be better effected.

[0057] As further shown in FIG. 3A, in one embodiment, an external heating element 206 is disposed between the bottom surface of the ceramic plate 106 and the bonding layer 108. In some embodiments, the outer heating element 206 is recessed from the annular heater setback 203 of the ceramic plate 106 so that it does not interfere with the heat conduction cooling of the cooling channel. For example, the outer heating element 206 is configured not to extend under the ring heater setback 203 of the ceramic plate 106 . This structural feature facilitates heat conduction cooling of the ring heater retreat 203 by the flow of cooling fluid because the outer heating element 206 is not directly below the ring heater retreat 203 and does not interfere with the heat flowing towards the cooling channel 112. .

[0058] In some embodiments, bonding layer 108 may be made of a silicon material, or any other material type that has a high heat transfer coefficient to facilitate thermally conductive cooling of the ceramic plate and ring heater setback 203 . The bonding layer 108 may be defined by a thickness D2. The thickness D2 of the bonding layer 108 extends from the bottom surface of the bonding layer to the top surface of the bonding layer. In one embodiment, the thickness D2 of the bonding layer 108 may be about 0.75 mm. In other embodiments, thickness D2 may range from about 0.1 mm and less than about 2 mm. In other embodiments, the thickness D2 is set to be not less than about 1 mm. By keeping D2 at a reduced thickness, conduction cooling caused by cooling fluid flow in the base plate 110 can be improved.

[0059] As further shown in FIG. 3A, a ceramic plate 106 is disposed over bonding layer 108. Referring to FIG. The ceramic plate 106 includes an annular heater setback 203 bounded by a distance D1. A cold edge temperature zone 308 is formed along the ring heater setback 203 of the ceramic plate when the ring heater setback 203 is thermally cooled by the flow of cooling fluid in the base plate. As shown, distance D1 extends from the outer diameter of raised top surface 216 to the outer diameter of outer heating element 206 . In one embodiment, the distance D1 may range from about 2 mm to about 10 mm, or any distance required to cool the edge of the wafer 104 . In some embodiments, the annular heater setback 203 is disposed over a portion of the bonding layer 108 and at least a portion of the plurality of cooling channels 112 disposed along the outer diameter of the base plate 110 . The thickness of the ceramic plate 106 is defined by D5. The thickness D5 extends from the bottom surface of the ceramic plate 106 to the raised top surface 216 of the ceramic plate 106 . In one embodiment, the thickness D5 of the ceramic plate 106 may be about 4.5 mm.

[0060] As further shown in FIG. 3A, the wafer 104 is supported by the raised top surface 216 of the ceramic plate 106 during processing. In some embodiments, the wafer overhang portion 312 of the wafer 104 extends outward beyond the outer diameter of the raised top surface 216 by a distance D4 when the wafer 104 is on the top surface of the ceramic plate. Distance D4 extends from the outer diameter of raised top surface 216 to wafer edge 304 . In one embodiment, the distance D4 may be about 2 mm.

[0061] In some embodiments, at the boundary interface between the cold edge temperature region 308 of the ceramic plate 106 and the annular region temperature zone 316 (e.g., the boundary interface between the outer diameter of the outer heating element and the annular heater setback region) ) exists a temperature transition region 310. As shown in Figure 3A, when the cooler 302 is activated, cooling fluid flows through the cooling channels 112, which cools the ceramic plate and annular heater setback 203 to a programmed temperature value based on the cooler set point temperature. The heat conduction cooling of the ring heater retraction region 203 due to the activation of the cooler 302 creates a cold edge temperature region 308, which in turn keeps the portion of the wafer 104 along the edge of the wafer 104 at a lower temperature relative to the rest of the wafer. low temperature. As noted above, the external heating element 206 is disposed in the annular region of the ESC 102 .

[0062] The outer heating element 206 heats the annular region of the ESC 102 as it generates heat, which thus forms the annular region temperature zone 316. Thus, there is a temperature transition region 310 at the boundary of the cold edge temperature region 308 of the ceramic plate 106 and the annular region temperature band 316 . In some embodiments, the temperature gradient from the cold edge temperature zone 308 to the annular zone temperature zone 316 is uniform and gradually changes from one zone to the other.

[0063] FIG. 3A-1 depicts a temperature graph of ceramic plate 106 temperature regions (eg, cold edge temperature region 308, annular region temperature region 316, central circular region temperature region 320) and corresponding temperature transition region 310. As shown, temperature is plotted along the Y-axis and ceramic plate distance is plotted along the X-axis. The graph shows that the temperature of the cold edge temperature zone 308, the annular zone temperature zone 316, and the central circular zone temperature zone 320 is from about 12°C to about 20°C. In particular, the cold edge temperature region 308 is located at the ring heater setback 203 extending from the outer diameter of the raised top surface 216 of the ceramic plate 106 to the boundary interface 318 (e.g., outer outer diameter of the heating element 206). In one example, as shown, the temperature along cold edge temperature zone 308 (eg, D1 ) is from about 12°C to about 18°C. In another embodiment, the annular region temperature zone 316 extends from the boundary interface 318 to the inner diameter of the outer heating element 206 and the temperature is from about 18°C ​​to about 20°C. A central circular area temperature band 320 extends from the outer diameter of the inner heating element 204 to approximately the center point of the ceramic plate. It should be understood that the actual temperatures depicted in FIG. 3A-1 are examples only, and that these ranges will vary depending on the process being performed. The temperature transition region 310 is advantageously enabled by the structural design features described herein.

[0064] As further shown in FIG. 3A-1, the temperature transition region 310 includes a boundary interface 318 that separates the cold edge temperature region 308 from the annular region temperature zone 316. In one embodiment, due to the difference in cooling and heating characteristics of the two regions, the temperature of the ceramic plate gradually rises from a lower temperature to a higher temperature along the temperature transition region 310 . For example, cold edge temperature zone 308 has no heating elements, while annular zone temperature zone 316 includes external heating elements. The temperature transition region 310 depicts a gradual and steady rise in temperature from the cold edge temperature region 308 to the annular region temperature band 316 rather than a gradual or dramatic temperature transition from one region to the other. The temperature transition region 310 includes a distance D6 and a distance D7, wherein the distance D6 is a portion within the cold edge temperature region 308 and the distance D7 is a portion within the annular region temperature band 316 . In one embodiment, the distance D6 and the distance D7 are about 2 mm.

[0065] FIG. 4 depicts an enlarged partial view of a portion of the ESC 102 shown in FIG. 2B. In the depicted embodiment, the ESC 102 includes a base plate 110, a bonding layer 108 disposed over the base plate 110, and a ceramic plate 106 disposed over the bonding layer 108, wherein the base plate 110 has a structure formed on the bonding layer 108. A plurality of cooling channels 112 in the base plate. Each of the plurality of cooling channels 112 may have the same or different size, shape, geometry, volume, and surface area to facilitate the flow of cooling fluid. For example, as shown in FIG. 4, the cooling channel located near the centerline 210 of the base plate has a rectangular cross-section with a width D8 and a height D9. The width D8 and height D9 of each cooling channel may be the same or different, depending on the heat conduction cooling requirements of the ESC 102 . In one example, width D8 may be approximately 9.0 mm, and height D9 may be approximately 21 mm. In another embodiment, distance D3 is not less than about 1 mm and not greater than about 6 mm, and extends from the top portion of cooling channel 112 to the bottom surface of bonding layer 108 , as described above.

[0066] FIG. 5A depicts an embodiment of a top view of inner heating element 204 and outer heating element 206. As shown in FIG. As mentioned above, the inner heating element 204 and the outer heating element 206 are disposed between the bottom surface of the ceramic plate 106 and the bonding layer 108 . The inner heating element 204 is disposed in a central circular area adjacent the bottom surface of the ceramic plate 106 . In the example depicted, the inner heating element 204 extends circularly outward from a point adjacent the center point of the ESC 102, forming the inner heating element 204 with an outer diameter of approximately 230 mm. The outer heating element 206 is disposed in an annular region surrounding the central circular region and adjacent to the bottom surface of the ceramic plate 106 . In some embodiments, the outer heating element 206 extends circularly outward toward the periphery of the ESC 102 and has an inner diameter of about 236 mm and an outer diameter of about 285 mm.

[0067] As further shown in FIG. 5A, the AC heater 212 is connected to the input and output connections of the outer heating element 206, while the AC heater 214 is connected to the input and output connections of the inner heating element 204. pieces. AC heater 212 and AC heater 214 are configured to deliver power to respective heating elements. When the AC heater is activated, the inner heating element 204 and the outer heating element 206 generate heat thereby forming a central circular zone temperature zone 320 and an annular zone temperature zone 316 within the ceramic plate 106, respectively. As noted above, the presence of only two heaters reduces design complexity and helps reduce costs associated with added components (eg, alternating current (AC) boxes, control systems, heater RF filters, etc.).

[0068] FIG. 5B illustrates an example of a top view of the ESC 102 showing various temperature zones within the ESC 102. In one embodiment, the ESC 102 may have a cold edge temperature zone 308 , an annular zone temperature zone 316 , and a central circular zone temperature zone 320 . The cold edge temperature region 308 is located along the perimeter of the ceramic plate 106 . The cold edge temperature zone 308 is controlled by the cooler setting, forming an indirect temperature regulation zone without heaters. In one embodiment, the cold edge temperature region 308 has an inner diameter of about 285 mm and an outer diameter of about 295 mm. As mentioned above, the cold edge temperature region 308 is located within the ring heater setback region 203 of the ceramic plate 106 . In one embodiment, the cold edge temperature region 308 is created when the cooler 302 is activated to operate at the set point temperature. Next, the cooling fluid flows through the cooling channels 112 and causes thermally conductive cooling in the annular heater setback 203 of the ceramic plate 106 .

[0069] In one embodiment, the shape and contact surface area of ​​the cooling channel 112 can help facilitate conduction cooling of the ring heater setback region 203 to create a cold edge temperature region 308. For example, the cooling channel 112 having a rectangular cross-section and having a greater width and height than conventional designs increases the contact surface area for fluid contact. This improves the heat transfer coefficient and increases the conduction cooling of the annular heater setback 203 and other areas of the ceramic plate.

[0070] In another embodiment, the reduced thickness bonding layer 108 can help facilitate thermally conductive cooling of the ring heater setback region 203. For example, a bond layer of half thickness doubles the heat transfer coefficient, which in turn facilitates heat conduction cooling of the ring heater retreat region 203 and other regions of the ceramic plate. Thus, during processing of the wafer 104, the cold edge temperature region 308 is controlled by the cooler setpoint temperature that controls the temperature of the portion of the wafer along the cold edge temperature region. Controlling the temperature of the wafer 104 and maintaining it at a desired temperature can help improve the etch rate and uniformity across the wafer to meet the bottom critical dimension (CD) profile of etched features.

[0071] In some embodiments, annular zone temperature zone 316 has an inner diameter of about 236 mm and an outer diameter of about 285 mm. In one embodiment, the annular zone temperature band 316 is formed when the AC heater 212 delivers power to the outer heating element 206 and thereby generates heat. In another embodiment, the central circular area temperature zone 320 begins at a point adjacent to the center point of the ESC 102 and has an outer diameter of approximately 231 mm. In one embodiment, the central circular area temperature band 320 is formed when the AC heater 214 delivers power to the inner heating element 204 and thereby generates heat.

[0072] Accordingly, the ESC 102 may have three temperature zones, such as a cold edge temperature zone 308 , an annular zone temperature zone 316 , and a central circular zone temperature zone 320 . Since the ring heater setback region 203 does not have any heating elements extending below its region, the cold edge temperature region 308 is passively dependent on the cooler set point temperature, and the cooling fluid circulating through the cooling channels of the base plate. The heat conduction cooling caused by the flow. The annular zone temperature zone 316 and the central circular zone temperature zone are affected by conduction cooling by the respective outer heating element 206 and inner heating element 204, and coolers. This three temperature zone configuration can reduce system and operating costs by reducing the number of components required to operate the ESC 102 .

[0073] FIG. 5C illustrates an example of a top view of the ESC 102 showing the results of a thermal transfer simulation of the ESC 102. In one example, thermal transfer simulations show that the temperature of the ESC 102 ranges from about 13.7°C to about 22.8°C. In one embodiment, the cold edge temperature region 308 (which has an inner diameter of about 285 mm and an outer diameter of about 295 mm) has a temperature of about 13.7°C. In another embodiment, the temperature range of the annular region temperature zone 316 (having an inner diameter of about 236 mm and an outer diameter of about 285 mm) is between about 21.0°C and about 14.0°C. In another embodiment, the central circular area temperature zone 320 (which begins at a point adjacent to the center point of the ESC 102 and has an outer diameter of about 231 mm) has a temperature of about 20.0°C.

[0074] Generally speaking, since the central circular region temperature zone 320 and the annular region temperature zone 316 are affected by the combination of cooler and heating element, the cold edge temperature region 308 is mainly caused by the cooling effect caused by the cooler Therefore, the cold edge temperature zone 308 will be approximately at a lower or equal temperature relative to the central circular zone temperature zone 320 and the annular zone temperature zone 316 . The temperatures shown in FIG. 5C are examples only, and it should be understood that actual temperatures will vary depending on the process being performed (including power settings, cooler settings, etc.). However, the temperature graph is useful to illustrate how the cold edge is controlled relative to the rest of the ESC.

[0075] FIG. 6 shows a schematic diagram of the control system 122 of FIG. 1A, according to some embodiments. Although not shown, a similar control system 122 is used in the TCP system of FIG. 1B. In some embodiments, control system 122 is configured as a process controller to control semiconductor fabrication processes performed in a plasma processing system. In various embodiments, the control system 122 includes a processor 601, a storage hardware unit (HU) 603 (eg, memory), an input HU 605, an output HU 607, an input / output (I / O) interface 609, I / O interface 611 , network interface controller (NIC) 613 , and data communication bus 615 . The processor 601 , storage HU 603 , input HU 605 , output HU 607 , I / O interface 609 , I / O interface 611 , and NIC 613 are in data communication with each other through a data communication bus 615 . Input HU 605 is configured to receive data communications from a plurality of external devices. Examples of inputs to HU 605 include data acquisition systems, data acquisition cards, and the like. Output HU 607 is configured to transmit data to a plurality of external devices.

[0076] An example of an output HU 607 is a device controller. Examples of NIC 613 include network interface cards, network adapters, and the like. I / O interface 609 and I / O interface 611 are each defined to provide compatibility between different hardware units coupled to the I / O interface. For example, I / O interface 609 may be defined to convert signals received from input HU 605 into data communication bus 615 compatible form, amplitude, and / or speed. Likewise, I / O interface 611 may be defined to convert signals received from data communication bus 615 into a form, amplitude, and / or speed compatible with output HU 607 . Although various operations are described herein as being performed by processor 601 of control system 122, it should be understood that in some embodiments, various operations may be controlled by multiple processors of control system 122 and / or by and System 122 is executed by the complex processors of the complex computing system of the data communication.

[0077] In some embodiments, control system 122 is used to control various devices in the wafer fabrication system based in part on sensed values. For example, control system 122 may control one or more of valve 617, filter heater 619, wafer support structure heater 621, pump 623, and other devices 625 based on sensed values ​​and other control parameters By. Valves 617 may include valves associated with controlling the backside gas supply system, the process gas supply system, and the temperature control fluid circulation system. The control system 122 receives values ​​sensed from, for example, pressure gauges 627 , flow meters 629 , temperature sensors 631 , and / or other sensors 633 (eg, voltage sensors, current sensors, etc.). The control system 122 may also be used to control processing conditions within the plasma processing system during performing plasma processing operations on the wafer 104 . For example, the control system 122 may control the type and amount of process gas supplied to the plasma processing chamber from the process gas supply system. Additionally, the control system 122 may control the operation of the DC supply to the clamping electrodes 202 . The control system 122 may also control the operation of the lifting devices for the lift pins. The control system 122 also controls the operation of the backside gas supply system and the temperature control fluid circulation system. The control system 122 also controls the operation of the pump 126 , which controls the removal of gaseous by-products from the chamber 118 . It should be appreciated that the control system 122 is equipped to provide programmed and / or manual control of any function within the plasma processing system.

[0078] In some embodiments, the control system 122 is configured to execute a computer program that includes functions for controlling process time, process gas delivery system temperature, pressure differential, valve position, process gas mixing, process gas flow rate, backside cooling gas flow rate, chamber pressure, chamber temperature, wafer support structure temperature (wafer temperature), RF power level, RF frequency, RF pulse, impedance matching system settings, cantilever assembly position, A set of commands for bias power, and other parameters specific to the process. In some embodiments, other computer programs stored on memory devices associated with control system 122 may be used. In some embodiments, there is a user interface associated with the control system 122 . The user interface includes a display 635 (eg, a display screen and / or graphical software display of the device and / or process conditions), and user input devices 637 such as pointing devices, keyboards, touch screens, microphones, and the like.

[0079] The software used to direct the operation of control system 122 can be designed or configured in many different ways. The computer programs for directing the operation of the control system 122 to perform the various wafer fabrication processes in the process sequence can be written in any known computer readable programming language, such as assembly language, C, C++, Pascal, Fortran wait. The compiled object code or script is executed by the processor 601 to perform the tasks certified in the program. The control system 122 can be programmed to control various process control parameters related to process conditions, such as filter differential pressure, process gas composition and flow rate, backside cooling gas composition and flow rate, temperature, pressure, plasma conditions (e.g., , RF power level and RF frequency), bias voltage, cooling gas / fluid pressure, and chamber wall temperature. Examples of sensors that may be monitored during the wafer fabrication process include, but are not limited to, mass flow control modules, pressure sensors (eg, pressure gauge 627 ), and temperature sensor 631 . Appropriately programmed feedback and control algorithms can be used with data from these sensors to control / adjust one or more process control parameters to maintain desired process conditions.

[0080] In some implementations, the control system 122 is part of a larger manufacturing control system. Such a manufacturing control system may include semiconductor processing equipment including processing tools, chambers, and / or wafer processing platforms, and / or specific processing components (eg, wafer susceptors, gas flow systems, etc.). These manufacturing control systems can be integrated with electronic components to control their operation before, during, and after processing wafers. Control system 122 may control various components or subcomponents of the manufacturing control system. Depending on wafer processing requirements, control system 122 can be programmed to control any of the processes disclosed herein, including process gas delivery, backside cooling gas delivery, 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, Positioning and Operation Settings, Connection to Specific Systems or bonded one-tool and other transport tools and / or load lock chambers for wafer transport in and out.

[0081] In broad terms, control system 122 may be defined as an electronic component having various integrated circuits, logic, memory, and / or software to receive instructions, send instructions, control operations, enable wafer processing operations, Enable endpoint measurements and more. The integrated circuits may include chips storing program instructions in the form of firmware, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or chips that execute program instructions (e.g., software) One or more microprocessors or microcontrollers. Program instructions may be instructions transmitted to control system 122 in the form of various individual settings (or program files) defining operational parameters for performing specific steps on wafers within the system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to process one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafers One or more processing steps are performed during the fabrication of the die.

[0082] In some implementations, the control system 122 can be part of, or coupled to, a computer that is integrated with and coupled to the plasma processing system, or otherwise networked with the system connection, or a combination thereof. For example, the control system 122 may reside in the "cloud", or all or a portion of the FAB's main computer system to allow remote access for wafer processing. The computer enables remote access to the system to monitor the current progress of the machining operation, view the history of past machining operations, view trends or performance metrics from multiple machining operations, change the parameters of the current process, set the processing steps after the current process , or start a new process. In some examples, a remote computer (eg, a server) may provide processing recipes to the system via a network, which may include a local area network, or the Internet.

[0083] The remote computer may include a user interface to enable input or programming of parameters and / or settings which are then transmitted from the remote computer to the system. In some examples, control system 122 receives instructions in the form of data specifying parameters for various processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of treatment to be performed within the plasma treatment system. Thus, as noted above, the control system 122 may be distributed, for example, by including one or more discrete controllers networked with each other and directed toward a common purpose (such as the steps described herein and control) to operate. An example of a decentralized controller distributed for this purpose would be one or more integrated circuits located on the plasma processing system that are located remotely (e.g., at the platform level or as part of a remote computer) and that combine to One or more integrated circuits that control processes on the chamber are in communication.

[0084] Without limitation, exemplary systems to which the control system 122 may be connected may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module. group, cleaning chamber or module, edge etch chamber or module, physical vapor deposition (PVD) chamber or module, chemical vapor deposition (CVD) chamber or module, atomic layer deposition (ALD) chamber or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, orbital chambers or modules, and those that may be related to or used in the processing and / or manufacture of semiconductor wafers Any other semiconductor processing system. As noted above, the control system 122 may communicate to one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, depending on one or more process steps to be performed by the tool. , a tool adjacent to a tool, a tool throughout a fab, a host computer, another controller, or a tool used in material handling to bring containers of substrates into and out of a semiconductor fabrication facility's tool locations, and / or load ports .

[0085] The embodiments described herein may also be practiced in combination with various computer system configurations, including handheld hardware units, microprocessor systems, microprocessor-based or programmable consumer electronics, mini Computers, mainframes, etc. Embodiments described herein may also be practiced in combination with distributed computing environments where tasks are performed by remote processing hardware units that are linked through a network. It should be appreciated that the embodiments described herein, particularly those associated with the control system 122, may employ various computer-implemented operations involving data stored in the computer system. These operations are operations requiring physical manipulations of physical quantities. Any operations described herein which form part of the Examples are practical machine operations. The embodiments are also related to hardware units or devices for performing these operations. Equipment may be purpose-built as a special-purpose computer. When a computer is defined as a special purpose computer, the computer can perform other processing, program execution, or routines that are not part of the special purpose and still be able to operate the special purpose. In some embodiments, the operations may be performed by a general-purpose computer selectively activated by one or more computer programs stored in the computer's memory, in cache, or accessed over a network or configuration. When data is obtained over a network, the data can be processed by other computers on the network (eg, the cloud of computing resources).

[0086] Various embodiments described herein may be implemented by processing control instructions, such as computer-readable code on a non-transitory computer-readable medium. A non-transitory computer-readable medium is any data storage hardware unit that can store data, where the data can be subsequently read by a computer system. Examples of non-transitory computer-readable media include hard drives, network-attached storage (NAS), ROM, RAM, compact disc-ROMs (CD-ROMs), CD-recordables (CD-Rs), rewritable CDs (CD-RW), magnetic tape, and other optical and non-optical data storage hardware units. Non-transitory computer-readable media may include computer-readable tangible media distributed over network-coupled computer systems such that computer-readable code is stored and executed in a distributed fashion.

[0087] While the foregoing disclosure contains certain details for purposes of clarity of understanding, it will be evident that certain changes and modifications may be practiced within the scope of the appended claims. For example, it should be appreciated that one or more features from any embodiment disclosed herein may be combined with one or more features of any other embodiment disclosed herein. Accordingly, the presented embodiments are to be regarded as illustrative rather than restrictive, and the claimed patents are not limited to the details given herein, but may be practiced within the scope and equivalents of the described embodiments. Revise. [Simple description of the diagram]

[0016] The present disclosure may be better understood by referring to the following embodiments in conjunction with the accompanying drawings, wherein:

[0017] FIG. 1A illustrates an embodiment of a capacitively coupled plasma (CCP) processing system for etching operations, according to an implementation of the present disclosure.

[0018] FIG. 1B illustrates an example of an inductively coupled plasma (ICP) processing system, according to an implementation of the present disclosure.

[0019] FIG. 2A illustrates an embodiment of an electrostatic chuck for supporting a wafer within a chamber of a plasma processing system, according to an implementation of the present disclosure.

[0020] FIG. 2B depicts cross-section A-A of the electrostatic chuck shown in FIG. 2A, according to an implementation of the present disclosure.

[0021] FIG. 3A shows an enlarged partial view of a portion of the electrostatic chuck shown in FIG. 2B during conduction cooling by a cooler, according to an implementation of the present disclosure.

[0022] FIG. 3A-1 shows a temperature diagram of temperature regions and corresponding temperature transition regions of a ceramic plate according to an implementation of the present disclosure.

[0023] FIG. 4 depicts an enlarged partial view of a portion of the electrostatic chuck shown in FIG. 2B, according to an implementation of the present disclosure.

[0024] FIG. 5A illustrates an embodiment of a top view of an inner heating element and an outer heating element, according to an implementation of the present disclosure.

[0025] FIG. 5B depicts an embodiment of a top view of an electrostatic chuck showing various temperature zones in the electrostatic chuck, according to an implementation of the present disclosure.

[0026] FIG. 5C depicts an embodiment of a top view of an electrostatic chuck showing thermal transfer simulation results for the electrostatic chuck, according to an implementation of the present disclosure.

[0027] FIG. 6 shows a schematic diagram of the control system of FIG. 1A, according to an implementation of the present disclosure.

Claims

1. An electrostatic chuck, comprising: Base plate; A bonding layer is disposed above the base plate; A ceramic plate having a bottom surface disposed above the bonding layer and a raised top surface for supporting a substrate; A heater is disposed between the bottom surface of the ceramic plate and the base plate. The heater includes an inner radial heating element and an outermost radial heating element. The inner radial heating element is disposed in a central circular region adjacent to the bottom surface of the ceramic plate, and the outermost radial heating element is disposed in an annular region surrounding the central circular region and adjacent to the bottom surface of the ceramic plate. The outermost radial heating element is embedded from the annular heater recessed region of the ceramic plate, and the annular heater recessed region is located between the outermost radial heating element and the upward extension of the raised top surface. The base plate includes a plurality of cooling channels disposed below the inner radial heating element, below the outermost radial heating element, and below the annular heater recessed region. Each of the plurality of cooling channels is configured to allow flow of cooling fluid to generate heat conduction cooling in the ceramic plate and in the annular heater recessed region of the ceramic plate.

2. The electrostatic chuck of claim 1, wherein the plurality of cooling channels are configured to circulate the cooling fluid in the base plate, wherein one of the plurality of cooling channels is located below the retracted area of ​​the annular heater.

3. The electrostatic chuck of claim 2, wherein one of the plurality of cooling channels has a rectangular shape and is located within the base plate, and the top inner surface of the one of the plurality of cooling channels is horizontally aligned below the retracted area of ​​the annular heater.

4. The electrostatic chuck of claim 2, wherein one of the plurality of cooling channels is partially defined by an interface wall adjacent to the bonding layer and located below the retracted region of the annular heater.

5. The electrostatic chuck of claim 4, wherein the interface wall has a dimension of not less than 1 mm and not more than 6 mm.

6. The electrostatic chuck of claim 1, wherein the heater is attached to the bottom surface of the ceramic plate.

7. The electrostatic chuck of claim 1, wherein the thickness of the bonding layer is between 0.1 mm and less than 2 mm.

8. The electrostatic chuck of claim 7, wherein the thickness of the bonding layer is 0.75 mm.

9. The electrostatic chuck of claim 1, wherein the retracted area of ​​the annular heater is between 2 mm and 10 mm.

10. The electrostatic chuck of claim 1, wherein the bonding layer is disposed between the base plate and the annular heater retraction region of the ceramic plate to provide thermal conduction cooling of the annular heater retraction region of the ceramic plate using the cooling fluid.

11. The electrostatic chuck of claim 1, wherein when the substrate is disposed above the raised top surface, the thermal conduction cooling of the annular heater retraction region of the ceramic plate provides a cold edge region for the substrate.

12. The electrostatic chuck of claim 1, wherein the temperature transition region is provided in the ceramic plate at the interface between the outermost radial edge of the outermost radial heating element and the retracted region of the annular heater.

13. The electrostatic chuck of claim 1, wherein the outermost radial heating element does not extend below the annular heater retraction region of the ceramic plate; and the annular heater retraction region of the ceramic plate is disposed above a portion of the bonding layer and above at least a portion of one of the plurality of cooling channels disposed along the outer diameter of the base plate.

14. The electrostatic chuck of claim 1, wherein the retracted region of the annular heater is located radially outward than the outermost radial heating element and radially inward than the upward extension of the raised top surface of the ceramic plate.

15. The electrostatic chuck of claim 1, wherein the outermost radial cooling channel of the plurality of cooling channels is disposed below the retracted area of ​​the annular heater and below the bonding layer.

16. The electrostatic chuck of claim 1, wherein i) the outer diameter of the outermost radial heating element is less than or equal to the inner diameter of the annular heater retraction region; and ii) the outer diameter of the annular heater retraction region is less than or equal to the outer diameter of the raised top surface.

17. The electrostatic chuck of claim 1, wherein the ceramic plate comprises: a lower portion disposed directly on the bonding layer; and an upper portion extending upward from the lower portion and having a smaller outer diameter than the lower portion, wherein the raised top surface comprises a top surface of the upper portion and a radially outer surface.

18. The electrostatic chuck of claim 17 further includes a seal, wherein: The outer diameter of the bonding layer and the outer diameter of the top of the base plate are smaller than the outer diameter of the lower part of the ceramic plate; and the sealing member is disposed radially outside the top of the bonding layer and the base plate, and is located between the base plate and the lower part of the ceramic plate.

19. The electrostatic chuck of claim 1, wherein the heater is disposed in the bonding layer.

20. A method for thermally cooling a region of an electrostatic chuck, the electrostatic chuck comprising a ceramic plate and a base plate, wherein the ceramic plate includes a raised top surface for supporting a substrate, the method comprising: A radially inner heating element and a radially outermost heating element are provided between the base plate and the ceramic plate, wherein the radially outermost heating element is embedded from an annular heater recessed region of the ceramic plate, and the annular heater recessed region is located between the radially outermost heating element and the upward extension of the raised top surface; cooling fluid flows along a plurality of cooling channels provided in the base plate, wherein one of the plurality of cooling channels is located below the annular heater recessed region, and the cooling flow system flowing in the one of the plurality of cooling channels is configured to cause thermal cooling in the annular heater recessed region of the ceramic plate to provide a cold edge region for the substrate when the substrate is placed above the electrostatic chuck; a plurality of alternating current (AC) heaters are activated, which are connected to the radially outermost heating element and the radially inner heating element; and a cooler is activated to operate at a set point temperature, the activation of the cooler being used to control the flow of the cooling fluid to thermally cool the ceramic plate and the annular heater recessed region.

21. The method for thermally cooling an area of ​​the electrostatic chuck as described in claim 20 further includes: The operation controller manages the operation of the cooler at the setpoint temperature.

22. The method for thermally cooling an area of ​​the electrostatic chuck as described in claim 20 further includes: A bonding layer is provided above the base plate, the bonding layer having a thickness between 0.1 mm and less than 2 mm.

23. The method for thermally cooling an area of ​​the electrostatic chuck as described in claim 20 further includes: Monitor temperature data related to the retracted area of ​​the annular heater on the ceramic plate, and determine whether the temperature data falls within the range of temperature values ​​planned based on the setpoint temperature.

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