Thermal conditioner for heating a substrate in a processing tool

Abstract

An example provides a thermal conditioner for delivering heat to a substrate in a processing tool. The thermal conditioner includes a body including a substrate side and a substrate holder side. The substrate side is configured to support a substrate. The substrate holder side is configured to receive heat from a heater of a substrate holder. The thermal conditioner also includes one or more contact features configured to support the body above the substrate holder to form a gap between the body and the substrate holder. The body includes a thermally conductive material configured to at least partially distribute heat received at the substrate holder side to the substrate side.

Description

Background Technology

[0001] Semiconductor device processes involve numerous material deposition, patterning, and removal steps to form integrated circuits on a substrate. Exemplary deposition processes include chemical vapor deposition (CVD) and atomic layer deposition (ALD). CVD forms a film on a substrate by exposing the substrate to a continuous flow of one or more reactants in a processing chamber under conditions that allow reactants to form a desired film on the substrate. ALD forms films layer by layer. Each film layer is formed in an ALD cycle. Each ALD cycle includes adsorbing a film precursor onto the surface of the substrate in a processing chamber, removing excess film precursor from the processing chamber, and then exposing the adsorbed precursor to reactants to form a film layer.

[0002] Thermal energy can be used to help drive the reactions that form films in CVD and ALD processes. Thermal energy can be supplied to the substrate via a substrate heater integrated with the substrate holder of the processing tool. Summary of the Invention

[0003] This invention is provided to introduce the chosen concepts in a simplified form, which will be further described in the following detailed description. This invention is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that address any or all the shortcomings mentioned in any part of this disclosure.

[0004] An example provides a thermal regulator for transferring heat to a substrate in a processing tool. The thermal regulator includes a body comprising a substrate side and a substrate holder side. The substrate side is configured to support the substrate. The substrate holder side is configured to receive heat from a heater of the substrate holder. The thermal regulator also includes one or more contact features configured to support the body above the substrate holder to form a gap between the body and the substrate holder. The body also includes a thermally conductive material configured to at least partially distribute the heat received at the substrate holder side on the substrate side.

[0005] In some such examples, each of the one or more contact features is located, or additionally, at a radial distance closer to the outer edge of the substrate holder side than to the center of the substrate holder side.

[0006] In some such examples, each of one or more contact features is located at a radial position that is greater than the radius of the substrate contact area on the substrate side, instead of or additionally.

[0007] In some such examples, the substrate holder side may instead contain a flat surface.

[0008] In some such examples, the substrate holder side alternatively or additionally includes a non-flat surface configured to make the distance of the gap vary depending on the location.

[0009] In some such examples, the thermal regulator alternatively or additionally includes an optical layer located on at least a portion of the substrate holder side. The optical layer has one or more optical properties related to infrared (IR) radiation, which differ from the optical properties of the thermally conductive material. One or more optical properties include one or more of absorptivity, reflectivity, or transmittance.

[0010] In some of these examples, thermally conductive materials are used instead of or additionally contain aluminum.

[0011] Another example provides a processing tool comprising a processing chamber and a substrate holder located within the processing chamber. The substrate holder includes a heater. The processing tool also includes a thermal regulator comprising a body. The body of the thermal regulator includes a substrate side and a substrate holder side. The substrate holder side is configured to receive heat from the heater. The body also includes a thermally conductive material configured to at least partially distribute the heat received at the substrate holder side on the substrate side.

[0012] In some such examples, the thermal regulator alternatively or additionally includes one or more contact features that support the body above the substrate holder to form a gap between the body and the substrate holder.

[0013] In some such examples, each contact feature is located, or additionally, at a radial position greater than the radius of the substrate contact area on the substrate side.

[0014] In some such examples, the substrate holder side alternatively or additionally includes a non-flat surface configured to make the distance of the gap vary depending on the location.

[0015] In some such examples, the substrate holder side may instead contain a flat surface.

[0016] In some such examples, the thermal regulator alternatively or additionally includes an optical layer located on at least a portion of the substrate holder side. The optical layer has one or more optical properties related to infrared (IR) radiation, which differ from the optical properties of the thermally conductive material. One or more optical properties include one or more of absorptivity, reflectivity, or transmittance.

[0017] In some of these examples, thermally conductive materials are used instead of or additionally contain aluminum.

[0018] In some such examples, the processing equipment includes, instead of additionally, a gas delivery system configured to control the pressure in the processing chamber within the range of 30 to 120 tors.

[0019] Another example provides a method for using a thermal regulator in a processing chamber of a processing tool. The thermal regulator includes a body having a substrate side and a substrate holder side, and contact features formed between the substrate holder and the body by supporting the body above a heater of the substrate holder. The method includes placing a substrate on the thermal regulator in the processing chamber; providing power to the heater of the substrate holder to heat the substrate holder; and heating the substrate by transferring at least a portion of the heat from the heater to the substrate holder side of the thermal regulator using one or more of radiation or conduction through an air gap.

[0020] In some such examples, the heating substrate alternatively or additionally includes at least a portion of the heat from the substrate holder side of the thermal regulator being distributed at least partially on the substrate side by conducting heat through the body of the thermal regulator.

[0021] In some such examples, the method alternatively or additionally includes reflecting a portion of the radiation using an optical layer located on at least a portion of the substrate holder side of the thermal regulator.

[0022] In some such examples, at least a portion of the heat from the heater is transferred to the substrate holder side of the thermal regulator using air gap conduction instead of or additionally includes heat transfer using gas in the gap.

[0023] In some such examples, the method alternatively or additionally includes replacing the thermal regulator when it reaches a replacement threshold condition. Attached Figure Description

[0024] Figure 1 An exemplary processing tool in the form of a thermal CVD processing tool is schematically shown.

[0025] Figure 2 An exemplary thermal regulator inside the processing room is schematically depicted.

[0026] Figure 3 The temperature change measured on the substrate is shown as a function of the heater power ratio, with or without an exemplary thermal regulator, for a dual-zone substrate heater.

[0027] Figure 4 An exemplary thermal regulator including an optical layer is schematically depicted.

[0028] Figure 5 An exemplary thermal regulator that utilizes a non-flat surface to vary the gap is schematically depicted.

[0029] Figure 6 An exemplary thermal regulator is schematically depicted, the body of which comprises a variety of materials with different thermal conductivity.

[0030] Figure 7 An exemplary method for transferring heat to a substrate using a thermal regulator in a processing tool is shown. Detailed Implementation

[0031] The term "atomic layer deposition (ALD)" generally refers to a process in which a film (e.g., an oxide film) is formed on a substrate as one or more separate layers by sequentially conformally adsorbing a precursor onto the substrate and reacting the adsorbed precursor to form a film layer. Thermal ALD (TALD) utilizes heat to promote the chemical transformation of the precursor adsorbed onto the substrate. The terms "growth" and "deposition," and their variations, can also be used to refer to film formation.

[0032] The term "body" usually refers to the physical mass of a thermal regulator.

[0033] The term "chemical vapor deposition (CVD)" generally refers to a process in which a film is formed on a substrate by exposing the substrate to a continuous flow of one or more vapor precursors under conditions configured to transform one or more precursors into a film on the substrate.

[0034] The term "contact feature" typically refers to a solid structure configured to support the body of a thermal regulator above a substrate holder.

[0035] The term "etching" and its variations generally refer to the removal of material from a substrate.

[0036] The term "gap" typically refers to the spatial volume formed between the body of the thermal regulator and the substrate holder. Gas particles within the gap perform heat transfer. More specifically, in addition to colliding with each other, the gas particles also collide with the top and bottom surfaces of the spatial volume to transfer heat.

[0037] The term "heat" usually refers to thermal energy.

[0038] The term "thermal regulator" generally refers to a device that supports a substrate above a substrate holder and transfers heat generated by the heater of the substrate holder to the substrate to achieve a different substrate temperature profile than a substrate placed directly on the substrate holder.

[0039] The term "substrate holder side" typically refers to the surface of a thermal regulator configured to face the substrate holder.

[0040] The term "optical layer" typically refers to a coating on a thermal regulator that has optical properties related to infrared (IR) radiation that differ from the bulk material of the thermal regulator. Exemplary optical properties include absorptivity, reflectivity, and transmittance.

[0041] The term "processing chamber" typically refers to an enclosed enclosure in which substrate processing is performed. During substrate processing, the pressure, temperature, atmospheric composition, and other conditions within the processing chamber are controllable.

[0042] The term "processing equipment" generally refers to a machine that includes a processing chamber and other hardware configured to enable a process to be carried out within the processing chamber.

[0043] The term "substrate" generally refers to any object that can be processed in a processing tool.

[0044] The term "substrate contact area" typically refers to the area on the substrate side of a thermal regulator that is configured to be positioned below the substrate during processing.

[0045] The term "substrate temperature profile" typically refers to the substrate temperature as a function of location on the substrate. The uniformity of the substrate temperature profile can be measured as the temperature range within the profile.

[0046] The term "substrate holder" generally refers to any structure configured to support a substrate in a processing chamber during processing.

[0047] The term "substrate side" typically refers to the surface of the thermal regulator facing the substrate during substrate processing.

[0048] As described above, chemical vapor deposition (CVD) forms a film by exposing a substrate to a continuous flow of one or more film precursors, configured to chemically react one or more precursors and form a film on the substrate. Various energy types can drive the film-forming reaction. For example, plasma-enhanced CVD (PECVD) uses plasma to provide energy to drive the film-forming reaction. Thermal CVD, on the other hand, uses thermal energy to drive the film-forming reaction in the absence of plasma.

[0049] The film formation rate in a CVD process can depend on the substrate temperature. For example, the substrate temperature can affect the adsorption of reactants onto the substrate surface during film formation. In this respect, films may have different deposition rates at different temperatures.

[0050] Thermal CVD processing tools use heaters integrated into a substrate holder to heat the substrate. However, such heaters can exhibit non-uniform heat output depending on their location, potentially leading to a non-uniform substrate temperature profile at the substrate surface. This non-uniformity may arise from factors such as the heater geometry (e.g., heater coil spacing) and / or the substrate holder (e.g., heater connection hardware). A non-uniform substrate temperature profile can result in non-uniform film growth on the substrate. This can potentially impact manufacturing yield. Furthermore, developing, manufacturing, and installing new substrate holders for adjusting substrate temperature profiles can be time-consuming and expensive.

[0051] Therefore, this document discloses examples of thermal regulators for transferring and redistributing heat from a substrate holder heater to a substrate within a processing chamber. In short, the thermal regulator comprises a body and contact features. The contact features are configured to support the body above a substrate holder to form a gap between the body and the substrate holder. The gap helps to at least partially separate the thermal regulator from the heater geometry integrated within the substrate holder. Heat is transferred from the substrate heater to the thermal regulator body primarily via infrared (IR) radiation and air gap conduction. The body of the thermal regulator includes a substrate side configured to support the substrate. The body also includes a substrate holder side configured to receive heat from the heater of the substrate holder. The body further includes a thermally conductive material configured to at least partially distribute the heat received at the substrate holder side across the substrate side. As discussed in more detail below, the thermal regulator can help provide a more uniform substrate temperature profile than a substrate disposed on a substrate holder without a thermal regulator. Furthermore, in some examples, the thermal regulator can also be designed to achieve a desired non-uniform temperature profile. Compared to substrate holders with integrated heaters, the disclosed thermal regulator has lower design and manufacturing costs. This allows for the replacement of different thermal regulators to achieve different substrate temperature profiles within the same processing tool.

[0052] Before discussing the exemplary thermal regulator in more detail, Figure 1 An exemplary processing tool 100 in the form of a thermal CVD processing tool is schematically shown. The processing tool 100 includes a heat regulator 102 disposed on a substrate holder 104 within a processing chamber 106. The heat regulator 102 is configured to support and heat a substrate 108 disposed within the processing chamber 106. Therefore, the heat regulator 102 includes a body and contact features configured to support the body above the substrate holder 104 to form a gap 110. The heat regulator 102 receives at least some heat from a heater 112 integrated in the substrate holder 104 using radiation and / or conduction through the air gap 110. Furthermore, the heat regulator 102 heats the substrate 108 by distributing the received heat through thermal conduction via the body. The exemplary heat regulator and corresponding heat transfer are related to…Figure 2 This will be discussed in more detail. In this way, the thermal regulator 102 can help provide a specified substrate temperature profile at the substrate 108. As an example, the thermal regulator 102 can help provide a more uniform substrate temperature profile than that of a substrate on a substrate holder 104 without the thermal regulator 102. This can help at least partially mitigate the inappropriate non-uniform heat distribution of the heater 112. As another example, the thermal regulator 102 can help provide a temperature at the substrate 108 that is lower than the lowest controllable temperature that the heater 112 can provide. In such examples, the thermal regulator 102 can act as a thermal resistor.

[0053] The treatment tool 100 also includes flow control hardware 114 for connecting one or more treatment chemical sources 116 to the treatment chamber 106. For example, the flow control hardware 114 may include any suitable components, such as a mass flow controller, valve, and / or conduit. Furthermore, the treatment tool 100 includes a treatment chemical inlet 118 configured to introduce treatment chemicals into the treatment chamber 106. In other examples, although the treatment chemical inlet 118 is depicted as a nozzle, the treatment tool may include a nozzle or other suitable inlet hardware different from or other than the treatment chemical inlet 118.

[0054] The processing tool 100 also includes an exhaust system 120. The exhaust system 120 is configured to exhaust gas from the processing chamber 106. The exhaust system 120 may include any suitable hardware, including one or more low-vacuum pumps, one or more high-vacuum pumps, and one or more valves for controlling the exhaust flow rate. The flow control hardware 114 and the exhaust system 120 cooperate to function as a gas delivery system configured to control the pressure of the processing chamber 106 during substrate processing 108. Exemplary pressures are in the range of 10 Torr to 120 Torr.

[0055] The processing tool 100 also includes a controller 122 configured to control various operations of the processing tool 100. Here, the controller 122 is operatively coupled to the heater 112, the flow control hardware 114, and the exhaust system 120. For example, the controller 122 is configured to control the processing tool 100 to operate the heater 112 to generate heat for the process. The controller 122 is also configured to operate the flow control hardware 114 to deliver selected processing chemicals or mixtures of processing chemicals into the processing chamber 106 at a selected rate. The controller 122 is also configured to operate the exhaust system 120 to remove gases from the processing chamber 106. The controller 122 may include any suitable computing system. Although this discussion relates to thermal CVD processing tools, the thermal regulator 102 can be used in any other suitable non-plasma processing tool. Examples include ALD tools and etching tools.

[0056] Figure 2 An exemplary thermal regulator 200 in a processing chamber 202 is schematically depicted. For example, the processing chamber 202 can be used in any suitable processing tool (e.g., processing tool 100). As shown, the thermal regulator 200 is disposed on a substrate holder 204 located within the processing chamber 202. The substrate holder 204 includes a heater 206.

[0057] The thermal regulator 200 includes a body 208 comprising a substrate side 208a. The substrate side 208a is configured to support a substrate 212 in a substrate contact region 214. The body 208 also includes a substrate holder side 208b configured to receive heat from a heater 206. The body 208 is at least partially formed of a thermally conductive material configured to distribute heat received at the substrate holder side 208b at least partially across the substrate side 208a by thermal conduction. The thermally conductive material may be selected based on process requirements, such as tolerance to processing chemicals (including materials used in plasma cleaning processes, such as fluorinated materials) and the expected process temperature range. In some examples, the thermally conductive material may comprise aluminum, anodic aluminum, aluminum alloys, aluminum oxides, aluminum nitrides, yttrium oxides, combinations thereof, and / or one or more other suitable ceramic or metallic materials. In some examples, the thermal regulator may be coated with a protective coating. For example, an aluminum thermal regulator may be coated with one or more layers of aluminum oxide and / or yttrium oxide. In many examples, the thermally conductive material can be either electrically conductive or dielectric.

[0058] The thermal regulator 200 also includes a plurality of contact features 218 configured to support the body 208 over the substrate holder 204 to form a gap 220 between the body 208 and the substrate holder 204. The gap 220 helps to at least partially separate the geometry of the thermal regulator 200 from that of the heater 206. In various examples, one or more sides of the gap 220 are closed, partially closed, open, or any suitable combination thereof.

[0059] Some heat from heater 206 is transferred to substrate holder side 208b via air gap conduction through gap 220. Other heat is radiated across gap 220. The heat transferred to thermal regulator 200 via air gap conduction is at least partially based on the distance of gap 220, one or more gas types within gap 220, and the gas density within gap 220. For example, air gap conduction is proportional to the collision rate of gas molecules with each other and the collision rate of gas molecules with surrounding walls (e.g., upper wall, lower wall, and / or sidewalls) (e.g., the collision rate with substrate holder 204 and thermal regulator 200). In some examples, the gas within gap 220 is a process gas from processing chamber 202. In other examples, the substrate holder may include a gas outlet configured to introduce conditioning gas into gap 220. Exemplary conditioning gases include helium, hydrogen, argon, and mixtures thereof. A more specific example includes a mixture of 10% helium and 90% nitrogen. In this way, the distance across gap 220 and the gas within gap 220 can help provide the specified heat transferred via air gap conduction between substrate holder 204 and substrate holder side 208b. Furthermore, depending on the gas in gap 220, some heat can be transferred to substrate holder side 208b via convective heat transfer. More specifically, a gas with sufficient temperature, flow rate, and thermal properties can flow between thermal regulator 200 and substrate holder 204. In some examples, convective heat transfer may be greater at higher pressures than at lower pressures (e.g., more heat can be transferred at 50 Torr compared to 2 Torr).

[0060] The heat transferred by radiation is a function of the reciprocal of the square of the distance 220. Radiative heat transfer is also based on the optical properties of the thermal regulator 200 at the substrate holder side 208b, such as IR absorptivity, reflectivity, and transmittance. In some examples, the thermal regulator may include an optical layer located on the substrate holder side to help achieve desired IR absorptivity, reflectivity, and / or transmittance properties, such as those related to… Figure 4 The subject of discussion.

[0061] Depending on the configuration of the thermal regulator, some heat from the heater can be transferred to the body of the thermal regulator via thermal conduction through the contact area between the contact features and the substrate holder. At the substrate, this thermal conduction can result in thermal hotspots in the substrate temperature profile. In this regard, in the depicted example, each of the plurality of contact features 218 is located radially at a radius greater than the substrate contact area 214 of the substrate side 208a. This helps to reduce the amount of heat transferred to the substrate via undesirable thermal conduction through the contact features. Furthermore, the thermal regulator can be configured to have a smaller total contact area with the substrate holder compared to the total area of ​​the thermal regulator. This helps to support the thermal regulator above the substrate holder while minimizing thermal conduction. In some examples, the plurality of contact features 218 may comprise three pins arranged in a triangular pattern. In other examples, the plurality of contact features may have another configuration to modulate heat transfer in a different manner. In some such examples, the plurality of contact features may comprise more than three contact points and / or non-planar contact surfaces that partially contact the substrate holder. In a further example, multiple contact features 218 may be omitted, and thus the substrate holder side 208b may be in substantially continuous contact with the substrate holder 204 over the total surface area of ​​the substrate holder side 208b.

[0062] In the depicted example, the substrate holder side 208b includes a flat surface to form a substantially uniform distance across the gap 220. The term "substantially" refers to the variation in the distance of the gap 220 due to surface roughness deviating from the average plane of the substrate holder side 208b. This configuration facilitates uniform air gap conduction across the substrate holder side 208b. In other examples, the substrate holder side 208b may include a non-flat surface, as related to... Figure 5 The subject of discussion.

[0063] As described above, the thermal regulator 200 can be easily removed from the processing chamber and replaced with a different thermal regulator. This allows the thermal regulator 200 to be easily replaced with a thermal regulator of the same design at the end of its life, and / or exchanged with a thermal regulator of a different design. The substrate holder 204 can be lowered to accommodate the thermal regulator 200. This allows the substrate 212 to maintain the desired spacing from the nozzle. This also positions the substrate side 208a at the transfer plane of the existing processing chamber. Although not depicted, the thermal regulator 200 may include an opening to accommodate the lifting pin of the substrate holder 204.

[0064] The heat regulator 200 can be manufactured using any suitable method. For example, a metal heat regulator 200 (e.g., aluminum) can be machined or cast. A ceramic heat regulator 200 (e.g., aluminum nitride) can be formed using additive manufacturing, molding / sintering / annealing, or other ceramic manufacturing methods. In various examples, the body 208 and the plurality of contact features 218 can be formed as a single component or as separate components and then fixed together.

[0065] Figure 3 This diagram shows the measured temperature change of the substrate in the processing chamber as a function of heater ratios, with and without the use of an exemplary thermal regulator. Here, the thermal regulator comprises an aluminum structure with three contact features. Each of the three contact features is located radially outside the radius of the substrate contact area. The heater ratios are used to control the power of the outer heating zone of the dual-zone heater relative to the power of the inner heating zone. The power of the inner heating zone is controlled by a set point (SP), and the power of the outer heating zone is set based on the power of the inner heating zone. In the test bench processing chamber, the dual-zone heater is integrated into a ceramic substrate holder. The temperature change is measured over a temperature range between a maximum and a minimum temperature. This temperature range is used to indicate the uniformity of the corresponding substrate temperature profile.

[0066] The measured temperature changes are obtained using a substrate containing an integrated thermocouple (“thermocouple substrate”). The thermocouple substrate is placed on a ceramic substrate holder without a thermal regulator to obtain data for a first temperature change graph 300. The setpoint for the dual-zone heater is 405°C for a specified temperature at the thermocouple substrate. Next, a thermal regulator is placed on the substrate holder, and the thermocouple substrate is placed on the thermal regulator to obtain data for a second temperature change graph 302. For the second temperature change graph 302, the setpoint is 455°C to bring the thermocouple substrate to a specified temperature. The higher setpoint is used to compensate for heat loss due to the gap between the substrate holder and the thermal regulator. As shown, in the second temperature change graph 302, the uniformity provided by the thermal regulator is 33% to 50% higher than in the first temperature change graph 300 (e.g., without a thermal regulator).

[0067] exist Figure 2 In one example, thermal regulator 200 comprises a solid structure in which the body and the contact area are formed of the same material. In other examples, the thermal regulator may use additional components and / or materials to provide a different heat distribution on the substrate than that achieved by thermal regulator 200. For example, the thermal regulator may include an optical layer to alter the IR optical properties of the thermal regulator compared to a thermal regulator without an optical layer. Figure 4An exemplary thermal regulator 400 including an optical layer 402 is schematically shown. For example, the thermal regulator 400 can be used in any suitable processing chamber (e.g., processing chamber 202).

[0068] Similar to thermal regulator 200, thermal regulator 400 includes a body 404 and a plurality of contact features 406 configured to support the body 404 above a substrate holder 408. The body 404 includes a substrate side 404a and a substrate holder side 404b, and is made of a thermally conductive material. An optical layer 402 is located on the substrate holder side 404b. As shown, the optical layer 402 is directly coated onto the body 404. In other examples, one or more interlayers may be disposed between the optical layer and the body of the thermal regulator. The optical layer 402 has one or more optical properties related to IR radiation that differ from the optical properties of the thermally conductive material of the body 404. One or more optical properties include one or more of absorptivity, reflectivity, or transmittance. As an example, the optical layer 402 may include a multilayer dielectric mirror having a higher IR reflectivity than the thermally conductive material. In this example, less IR radiation will be received at the substrate holder side 404b compared to the case without the optical layer 402. In the illustrated example, optical layer 402 covers the entire substrate holder side 404b. In other examples, optical layer 402 may cover a portion of the substrate holder side 404b. This configuration helps to vary the IR radiation received at the substrate holder side 404b depending on the location. Figure 4 This is illustrative. In other examples, the optical layer may have a different configuration.

[0069] Alternatively or additionally, the thermal regulator may utilize a non-planar substrate holder side to help control air gap conduction and / or radiation received at the thermal regulator. The distance between the substrate holder side and the substrate side of the thermal regulator allows for varying thicknesses within the body of the thermal regulator. Figure 5An exemplary thermal regulator 500 is schematically depicted. The thermal regulator 500 can be used in any suitable processing chamber (e.g., processing chamber 202). Similar to thermal regulator 200, thermal regulator 500 includes a body 502 and a plurality of contact features 504 configured to support the body 502 against a substrate holder 506 to form a gap 508. The body 502 includes a thermally conductive material, a substrate side 502a, and a substrate holder side 502b. However, the substrate holder side 502b includes a non-planar surface configured to vary the distance of the gap 508 depending on its position. In the depicted example, the distance of the gap 508 is the distance from the substrate holder 506 to the substrate holder side 502b. This variation in the distance of the gap 508 can change the amount of heat received by air gap conduction and IR radiation depending on the position on the substrate holder side 502b.

[0070] In the depicted example, gap 508 has a relatively long distance in the outer region 514 and a relatively short distance in the inner region 516. In this respect, the substrate holder side 502b will receive less heat from the heater of substrate holder 506 in the outer region 514 than in the inner region 516. In this way, the non-flat surface of substrate holder side 502b can help reduce the heat transferred in the outer region 514. This can help offset the non-uniformity of the heater and / or substrate holder, where the temperature gradient in the outer region 514 is hotter than in the inner region 516. In this respect, the non-flat surface can help the thermal regulator 500 provide a more uniform substrate temperature profile at substrate 518 compared to a substrate holder without thermal regulator 500. In other examples, the substrate holder side may include a non-flat surface configured to provide designated first and second heating zones with different temperatures at the substrate. In a further example, the substrate holder side may include a non-flat surface having an inclined configuration and / or more than two regions. Figure 5 This is illustrative. In other examples, the substrate holder side may include a non-planar surface with another suitable configuration.

[0071] In the example above, the thermal regulator comprises a body made of a single material. In other examples, the body may have more than one material. Figure 6 An exemplary thermal regulator 600 using different materials in the body 602 is schematically depicted. For example, the thermal regulator 600 can be used in any suitable processing chamber (e.g., processing chamber 202). Similar to the thermal regulator 200, the thermal regulator 600 includes a plurality of contact features 604 configured to support the body 602 over the substrate holder 606 to form a gap 608. The body 602 includes a substrate holder side 602a and a substrate side 602b.

[0072] The body 602 also includes a first thermally conductive material 610 and a second thermally conductive material 620 with different thermal properties. Examples of thermal properties include thermal conductivity and heat capacity. For example, in some examples, the first thermally conductive material 610 and the second thermally conductive material 620 may also have different optical properties related to IR radiation, such as reflectivity or absorptivity. As shown, the first thermally conductive material 610 is located within a first region 622 of the substrate contact region 624. Furthermore, a portion of the second thermally conductive material 620 is located within a second region 626 of the substrate contact region 624. Therefore, the second thermally conductive material 620 and the first thermally conductive material 610 can help control the distribution of heat received at the substrate holder side 602a within a corresponding region of the substrate side 602b.

[0073] As a more specific example, the first thermally conductive material 610 may comprise aluminum, and the second thermally conductive material 620 may comprise aluminum oxide. In such an example, the lower thermal conductivity of the aluminum oxide, compared to the first thermally conductive material 610, will result in less heat received at the substrate holder side 602a being distributed in the second region 626 via conduction through the second thermally conductive material 620. In this configuration, the thermal regulator 600 may help provide a lower temperature region in the substrate temperature profile corresponding to the second region 626. Accordingly, the first thermally conductive material 610 may help provide a higher temperature region in the substrate temperature profile corresponding to the first region 622. In other examples, the body of the thermal regulator may comprise more than two thermally conductive materials. In a further example, the thermally conductive materials may have another configuration.

[0074] In various examples, the thermal regulator may have any suitable combination of the structures and / or materials disclosed herein. As one example, the thermal regulator may include an optical layer and utilize a non-planar surface to vary the gap. As another example, the thermal regulator may include an optical layer and a body made of two or more materials. In some such examples, the thermal regulator may also utilize a non-planar surface to vary the gap. In further examples, other combinations of configurations are also contemplated.

[0075] Figure 7 A flowchart is shown for an exemplary method 700 for using a thermal regulator disposed on a substrate holder in a processing chamber. For example, method 700 can be implemented using any suitable processing tool (e.g., processing tool 100). The thermal regulator includes a body having a substrate side and a substrate holder side, and contact features that support the body above a heater of the substrate holder to form a gap between the substrate holder and the body.

[0076] At 702, method 700 includes placing a substrate on a thermal regulator in a processing chamber. At 704, method 700 further includes supplying power to a heater of a substrate holder to heat the substrate holder. At 706, method 700 additionally includes heating the substrate by transferring at least some of the heat from the heater to the substrate holder side of the thermal regulator via one or more of IR radiation or air gap conduction through the gap. More specifically, transferring at least some of the heat from the heater to the substrate holder side of the thermal regulator via air gap conduction includes transferring heat using gas in the gap, as indicated at 708. In other examples, 708 may be omitted.

[0077] In some examples, the thermal regulator includes an optical layer located on at least a portion of the substrate holder side. The optical layer contains one or more optical properties related to IR radiation that differ from the optical properties of the thermally conductive material of the thermal regulator body, such as different absorptivity, reflectivity, and / or transmittance. In such examples, at 710, method 700 may include reflecting some of the IR radiation using the optical layer located on at least a portion of the substrate holder side of the thermal regulator. In other examples, such an optical layer is omitted from the thermal regulator.

[0078] Next, at 712, the heated substrate includes at least some of the heat from the substrate holder side of the thermal regulator being at least partially distributed on the substrate side by conducting heat through the body of the thermal regulator. For example, method 700 may optionally include replacing the thermal regulator when it reaches a replacement threshold condition, as shown at 714. Examples of replacement threshold conditions include a specified number of process cycles, visual inspection, film growth outside of process specifications, and / or another suitable condition. Furthermore, in some examples, the thermal regulator may be replaced with another thermal regulator having a different temperature profile.

[0079] The use of thermal regulators, as disclosed herein, can help provide a more uniform substrate temperature profile to a substrate disposed on a thermal regulator than to a substrate disposed on a substrate holder without a thermal regulator. Furthermore, to achieve the desired substrate temperature profile, designing, manufacturing, and installing a thermal regulator in a processing chamber can be faster and less expensive than designing and manufacturing a new substrate holder.

[0080] It should be understood that the configurations and / or methods described herein are presented as examples, and therefore these specific examples or illustrations should not be considered limiting, as many variations are possible. The particular subroutines or methods described herein may represent one or more of any number of processing strategies. In this regard, the various actions shown and / or described may be performed in the order shown and / or described, in a different order, in parallel, or may be omitted. Similarly, the order of the above processes may be changed.

[0081] The object of this disclosure includes all novel and non-obvious combinations and sub-combinations of various processes, systems and configurations, as well as other features, functions, actions and / or properties disclosed herein, and any and all equivalents thereof.

Claims

1. A thermal regulator for transferring heat to a substrate in a processing tool, the thermal regulator comprising: The body comprises a substrate side and a substrate holder side. The substrate side is configured to support the substrate, and The substrate holder side is configured to receive heat from the heater of the substrate holder; as well as One or more contact features configured to support the body above the substrate holder to form a gap between the body and the substrate holder. The body comprises a thermally conductive material configured to distribute at least a portion of the heat received at the substrate holder side on the substrate side.

2. The thermal regulator of claim 1, wherein each of the one or more contact features is located at a radial distance from the outer edge of the substrate holder side than from the center of the substrate holder side.

3. The thermal regulator according to claim 2, wherein each contact feature is located at a radial position greater than the radius of the substrate contact area on the substrate side.

4. The thermal regulator of claim 1, wherein the substrate holder side comprises a flat surface.

5. The thermal regulator of claim 1, wherein the substrate holder side includes a non-flat surface configured to vary the distance of the gap depending on the position.

6. The thermal regulator of claim 1, further comprising an optical layer located on at least a portion of the substrate holder side, the optical layer having one or more optical properties related to infrared (IR) radiation, the one or more optical properties being different from the optical properties of the thermally conductive material, the one or more optical properties including one or more of absorptivity, reflectivity, or transmittance.

7. The thermal regulator of claim 1, wherein the thermally conductive material comprises aluminum.

8. A processing tool, comprising: Processing room; A substrate holder, located within the processing chamber, the substrate holder comprising a heater; and A thermal regulator, comprising: The body includes a substrate side and a substrate holder side, the substrate holder side being configured to receive heat from the heater. The body comprises a thermally conductive material configured to distribute at least a portion of the heat received at the substrate holder side on the substrate side.

9. The processing tool of claim 8, wherein the thermal regulator further comprises one or more contact features that support the body above the substrate holder to form a gap between the body and the substrate holder.

10. The processing tool of claim 9, wherein each contact feature is located at a radial position greater than the radius of the substrate contact region on the substrate side.

11. The processing tool of claim 10, wherein the substrate holder side includes a non-flat surface configured to vary the distance of the gap depending on the position.

12. The processing tool of claim 8, wherein the substrate holder side comprises a flat surface.

13. The processing tool of claim 8, wherein the thermal regulator further comprises an optical layer located on at least a portion of the substrate holder side, the optical layer having one or more optical properties related to infrared (IR) radiation, the one or more optical properties being different from the optical properties of the thermally conductive material, the one or more optical properties including one or more of absorptivity, reflectivity, or transmittance.

14. The processing tool of claim 8, wherein the thermally conductive material comprises aluminum.

15. The processing apparatus of claim 8, further comprising a gas delivery system configured to control the pressure of the processing chamber within the range of 30 Torr to 120 Torr.

16. A method for using a heat regulator in a processing chamber of a processing tool, the heat regulator comprising a body having a substrate side and a substrate holder side, and contact features supporting the body above a heater of a substrate holder to form a gap between the substrate holder and the body, the method comprising: The substrate is placed on the thermal regulator in the processing chamber; Power is supplied to the heater of the substrate holder to heat the substrate holder; as well as The substrate is heated by transferring at least a portion of the heat from the heater to the substrate holder side of the thermal regulator through one or more of radiation or conduction through the air gap.

17. The method of claim 16, wherein heating the substrate comprises distributing at least a portion of the heat from the substrate holder side of the thermal regulator at least partially on the substrate side by conducting the heat through the body of the thermal regulator.

18. The method of claim 16, further comprising reflecting a portion of the radiation using an optical layer located on at least a portion of the substrate holder side of the thermal regulator.

19. The method of claim 16, wherein transferring at least a portion of the heat from the heater to the substrate holder side of the thermal regulator via the air gap includes transferring the heat via gas in the gap.

20. The method of claim 16, further comprising replacing the thermal regulator when the thermal regulator reaches a replacement threshold condition.

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