Removable heat leveler

Abstract

An apparatus suitable for supporting a substrate in a processing chamber or other application and providing a desired thermal leveling profile is shown and described herein. The apparatus is configured to provide a thermal leveler that is removable from the apparatus.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 713,169, filed on August 1, 2018, entitled “Detachable Thermal Leveler,” the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a device comprising a thermal leveler. In particular, the present invention relates to a device having a thermal leveler which is detachable and removable from the device. Background Art

[0004] Thermal levelers or heat sinks based on pyrolytic graphite (TPG) are used in conjunction with heaters or coolers for various heat dissipation, leveling, diffusion and focusing applications. The purpose of using these levelers is to take advantage of the enhanced thermal conductivity of the TPG material to obtain the desired temperature distribution. These levelers can be in the form of bare TPG or packaged TPG structures, which are TPGs encapsulated by metals, semi-metals, ceramics or alloys such as, for example, aluminum, copper, stainless steel, silicon, aluminum nitride, aluminum oxide or tungsten copper. TPG-based heat sinks are commonly used to cool high-end electronic devices to improve system reliability. In such applications, the heat sink provides undegraded performance throughout the service life of the system, so the heat sink is part of the capital expenditure.

[0005] TPG-based thermal levelers are used to produce semiconductor equipment. Many semiconductor processes are usually carried out in a vacuum environment (i.e., a sealed chamber containing components for supporting a wafer substrate disposed therein). In semiconductor processes, a heating device usually includes a ceramic support, in which an electrode may be provided to heat the support, and in addition, an electrode may be provided to electrostatically hold the wafer or substrate against the ceramic support, i.e., an electrostatic chuck or ESC (sometimes also referred to as a pedestal). Semiconductor device manufacturing processes can be carried out in a chamber, including deposition, etching, injection, oxidation, etc. An example of a deposition process is a physical vapor deposition (PVD) process, known as sputtering deposition, in which a target usually consisting of a material to be deposited on a wafer substrate is supported above a substrate, usually fixed to the top of a chamber. Plasma is formed by a gas such as argon supplied between the substrate and the target. The target is biased, causing ions in the plasma to accelerate toward the target. The ions of the plasma interact with the target material, causing atoms of the material to be sputtered off, travel through the chamber toward the wafer, and redeposit on the surface of the semiconductor wafer being processed into an integrated circuit (IC). Other deposition processes may include, but are not limited to, plasma enhanced chemical vapor deposition (PECVD), high density plasma chemical vapor deposition (HDP-CVD), low pressure chemical vapor deposition (LPCVD), negative pressure chemical vapor deposition (SACVD), metal organic chemical vapor deposition (MOCVD), molecular beam evaporation (MBE), etc.

[0006] In some of the processes described above, it is desirable to heat the wafer by heating the support. In some other cases, heat generated on the wafer for process reasons needs to be removed. The chemical reaction rates of the materials being deposited, etched, implanted, etc. are controlled to some extent by the temperature of the wafer. If the temperature of the wafer varies too much across its entire area, undesirable non-uniformities in deposition, etching, implantation, etc. can easily be generated across the entire face of the wafer. In most cases, it is highly desirable that the deposition, etching, implantation be uniform to a near-perfect degree, because otherwise integrated circuits manufactured at different locations on the wafer will have electronic properties that deviate from the standard more than desired.

[0007] In these applications, thermal levelers help to dissipate heat in the lateral direction, improving the temperature distribution across the wafer. However, thermal levelers are exposed to corrosive chemical processes. This corrosive environment wears out the thermal leveler or the part containing the leveler, so the leveler or the part containing the leveler becomes "consumable", that is, as the performance degrades, the leveler needs to be replaced with a newly manufactured part. Replacement can be caused by degradation of the thermal leveler's performance or failure of some other sub-component of the component, such as corrosion of the heater or the leveler that encapsulates the thermal leveler, resulting in contamination or particle generation. Corrosion of the encapsulation layer of the leveler can also cause pitting and / or make the flatness out of specification. These mechanisms reduce the thermal performance of the leveler by causing poor contact with the wafer / substrate. Although it is technically feasible to replace the old and worn leveler with a newly manufactured leveler or with a newly manufactured part of the leveler, it is not an economically feasible solution because the cost of manufacturing the leveler is very high. The cost of the leveler is high because of the large number of batch processes involved in the manufacturing process. The manufacturing involves multiple steps of bonding, machining, grinding and polishing. In addition to these processes, the cost of TPG materials is high because of batch processes such as CVD and high temperature processing. Summary of the invention

[0008] The following summary of the present disclosure is provided to provide a basic understanding of some aspects. This summary is neither intended to identify key or important elements, nor to define any limitations of the embodiments or claims. Further, this summary can provide a simplified overview of some aspects that can be described in more detail in other parts of the present disclosure.

[0009] An apparatus suitable for supporting a substrate in a processing chamber or other application and providing a desired thermal leveling profile is provided. The apparatus is configured to provide a thermal leveler that is removable from the apparatus. Thus, the thermal leveler can be removed from the apparatus when a portion of the apparatus (e.g., an outer surface of the apparatus) has deteriorated (e.g., corroded, worn, etc.) to the extent that the performance of the apparatus makes it no longer suitable for use. The thermal leveler can be removed from the apparatus and reused by being transferred to another apparatus to provide a desired thermal leveling profile.

[0010] In one aspect, an apparatus for supporting a substrate is provided, comprising a cover plate having an upper surface for supporting the substrate and a lower surface opposite to the upper surface, and a thermal leveler comprising pyrolytic graphite, the thermal leveler being disposed adjacent to the lower surface of the cover plate and being detachable from the cover plate.

[0011] In one aspect, an apparatus is provided that includes a thermal leveler releasably associated with a cover sheet.

[0012] In one embodiment, the thermal leveler is releasably associated with the cover plate via a clamp, bolts, threads, cam locks, retaining grooves, retaining rings, springs, vacuum, electrostatic force, electromagnetic force, magnetic force, adhesive, solder, or paste.

[0013] In one embodiment, a thermal leveler is disposed between the cover plate and the base plate.

[0014] In one embodiment, the thermal leveler is removably associated with the base plate.

[0015] In one embodiment, the base plate includes a lower surface, one or more side walls extending around the periphery of the base plate, and an opening defined between the one or more side walls, the thermal leveler is disposed within the opening, and the one or more side walls have a threaded surface adjacent to an upper end of the one or more side walls; wherein the cover plate is sized to be mounted within the opening of the base plate and includes a threaded side surface to engage the threaded surface of the base plate.

[0016] In one embodiment, the base plate includes an upper surface, a lower surface, and a threaded side surface, wherein the upper surface supports the thermal leveler; the cover plate includes an upper surface, one or more side walls extending downward from the upper surface of the cover plate and extending around the periphery of the cover plate, and an opening defined between the one or more side walls, the opening being sized to surround the thermal leveler and the base plate, wherein the one or more walls of the cover plate include a threaded surface to engage the threaded surface of the base plate.

[0017] In one embodiment, the cover plate includes one or more holes; the thermal leveler includes one or more holes aligned with the one or more holes of the cover plate; and the base plate includes one or more grooves aligned with the one or more holes of the thermal leveler, wherein the cover plate, the thermal leveler and the base plate are releasably connected to each other via fasteners disposed through the one or more holes of the cover plate and the thermal leveler and the grooves of the base plate.

[0018] In one embodiment, at least one of the fasteners is a pin that locks into one of one or more grooves of the base plate.

[0019] In one embodiment, at least one of the one or more recesses in the base plate has a threaded surface, and at least one of the fasteners is a threaded fastener adapted to threadably engage the at least one or more recesses with the threaded surface.

[0020] In one embodiment, the upper surface of the thermal leveler includes a groove, and the lower surface of the cover plate includes a protrusion that is aligned with and sized to fit with the groove in the upper surface of the thermal leveler.

[0021] In one embodiment, the thermal leveler comprises pyrolytic graphite.

[0022] In one embodiment, the thermal leveler comprises a pyrolytic graphite sheet disposed between an upper sheet and a lower sheet.

[0023] In one embodiment, the thermal leveler is encapsulated by a cover layer.

[0024] In one embodiment, the upper sheet, the lower sheet or the cover layer is independently selected from metal or ceramic materials.

[0025] In one embodiment, the upper sheet, the lower sheet or the covering layer is independently selected from: aluminum, copper, silver, gold, nickel, beryllium, tin, lead, steel, steel alloy, copper tungsten, copper molybdenum, invar, aluminum beryllium, tin lead; oxides, nitrides, carbides, carbonitrides or oxynitrides of elements selected from the group consisting of boron, aluminum, silicon, gallium, yttrium, high temperature resistant hard metals and transition metals.

[0026] In one embodiment, the thermal leveler comprises a plurality of pyrolytic graphite sheets.

[0027] In one embodiment, the plurality of pyrolytic graphite flakes have graphene basal planes that are parallel or perpendicular to the substrate surface.

[0028] In one embodiment, the apparatus comprises a plurality of thermal levelers.

[0029] In one embodiment, the plurality of thermal levelers comprises pyrolytic graphite having a graphene basal plane parallel or perpendicular to the substrate surface.

[0030] In one embodiment, the susceptor plate includes a heater and / or a cooler.

[0031] In one embodiment, the device includes an electrode disposed therein.

[0032] In another aspect, a process for heating or cooling a substrate is provided, comprising heating or cooling a substrate disposed on an upper surface of the cover plate of any of the foregoing embodiments.

[0033] In one embodiment, the process includes heating the substrate to an endpoint, removing the substrate from the apparatus, releasing the cover sheet from the thermal leveler, providing a fresh cover sheet and releasably attaching it to the thermal leveler, and providing a second substrate to the apparatus and heating the second substrate.

[0034] The following description and the accompanying drawings disclose various illustrative aspects. Some improvements and novel aspects can be explicitly identified, while others can be obvious from the description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings illustrate various systems, devices, apparatus, and associated methods, wherein like reference numerals refer to like parts throughout, and in the drawings:

[0036] Figure 1 is a perspective view showing an embodiment of a heating device;

[0037] Figure 2 is a cross-sectional view of one embodiment of an apparatus including a removable thermal leveler;

[0038] Figure 3 is a cross-sectional view of one embodiment of an apparatus including a removable thermal leveler;

[0039] FIG4a is a cross-sectional view of one embodiment of an apparatus including a removable thermal leveler;

[0040] FIG4 b is a cross-sectional view of one embodiment of an apparatus including a removable thermal leveler;

[0041] Figure 5 is a cross-sectional view of one embodiment of an apparatus including a removable thermal leveler;

[0042] Figure 6 is a cross-sectional view of one embodiment of an apparatus including a removable thermal leveler;

[0043] Figure 7 is a cross-sectional view of one embodiment of an apparatus including a removable thermal leveler;

[0044] 8a-8d show cross-sectional views of embodiments of a thermal leveler;

[0045] 9a-9c show top views of embodiments of a thermal leveler;

[0046] Fig.10 A cross-sectional view of an embodiment of a thermal leveler is shown. DETAILED DESCRIPTION

[0047] Reference will now be made to exemplary embodiments, examples of which are shown in the accompanying drawings. It should be understood that other embodiments may be employed and that structural and functional changes may be made. In addition, the features of the various embodiments may be combined or altered. Therefore, the following description is presented only in an illustrative manner and should not limit in any way the various replacements and modifications that may be made to the illustrated embodiments. In the present disclosure, many specific details provide a thorough understanding of the subject disclosure. It should be understood that various aspects of the present disclosure may be practiced with other embodiments that do not necessarily include all aspects described herein, etc.

[0048] As used herein, the words "example" and "exemplary" mean an instance or illustration. The words "example" or "exemplary" do not indicate a key or preferred aspect or embodiment. Unless the context indicates otherwise, the word "or" is intended to be inclusive and not exclusive. As an example, the expression "A employs B or C" includes any inclusive combination (e.g., A employs B; A employs C; or A employs B and C). As another aspect, the articles "a" and "an" are generally intended to mean "one or more," unless the context indicates otherwise.

[0049] As used herein, "heating device" may be used interchangeably with "processing device", "heater", "electrostatic chuck", "chuck" or "processing device", "base", "upper electrode or lower electrode" to refer to a device comprising at least one heating and / or cooling element to adjust the temperature of a substrate supported thereon, in particular by heating or cooling the substrate.

[0050] As used herein, the term "substrate" refers to a semiconductor wafer or glass mold supported / heated by the processing apparatus of the present invention. As used herein, the term "sheet" is used interchangeably with "layer".

[0051] As used herein, the term "circuit" may be used interchangeably with "electrode", and the term "heating element" may be used interchangeably with "heating electrode", "electrode", "resistor", "heating resistor" or "heater". The term "circuit" may be used in single or multiple forms to indicate the presence of at least one unit.

[0052] The thermal leveler can have multiple zones. Based on the construction and layout of the TPG (as exemplified in Figures 8 and 9) and the layout and location of the heaters and coolers relative to the TPG, the temperatures of different zones may be different. As used herein, thermal uniformity or relatively uniform temperature refers to the difference between the highest and lowest temperature points over a certain length within the zone. Thermal uniformity within a zone is critical and can range from 3% of the full 300mm to less than 0.5% of the full 300mm.

[0053] In a plasma chamber for processing substrates such as semiconductor wafers or glass lenses, the substrate temperature significantly affects the processing. For processing equipment to uniformly regulate the temperature of the substrate being processed, it is desirable that the equipment provide temporal and spatial control of the surface temperature of the substrate. Graphite is an anisotropic material with a unique ability to direct heat in a preferred direction. Pyrolytic graphite (TPG) is a unique graphite material that consists of crystallites of considerable size that are highly aligned or oriented relative to each other and have well-ordered carbon layers or highly preferred crystallite orientations. TPG can be used interchangeably with "highly oriented pyrolytic graphite" ("HOPG") or compression annealed pyrolytic graphite ("CAPG"). TPG has extremely high thermal conductivity, with an in-plane (ab direction) thermal conductivity greater than 1000 W / mK, while the thermal conductivity along the out-of-plane (z direction) is in the range of 5 to 30 W / mK. In one embodiment, TPG has an in-plane thermal conductivity greater than 1500 W / mK.

[0054] In one embodiment, the heating device 100 is as follows Figure 1 As shown, it includes a disk-shaped metal or ceramic substrate in which an electrode (not shown) is buried, and its top surface 112 is used as a support surface for a substrate (e.g., a wafer W). In one embodiment, the top surface 112 is made highly flat (within a surface fluctuation of 0.05 mm) to further enhance the temperature control of the substrate W. An electrical terminal 130 for supplying power to the heating resistor can be attached at the center of the bottom surface of the substrate, or in one embodiment, attached to the side of the substrate.

[0055] In one embodiment, the top surface 112 is relatively uniform in temperature, i.e., the difference between the highest and lowest temperatures on the top surface is less than 10° C. In a second embodiment, the temperature difference is less than 5° C. The temperature uniformity of the top surface 112 corresponds to a uniform temperature of the heated substrate W. In one embodiment, the substrate W has a maximum temperature variation of 5° C., and in a second embodiment, the maximum temperature variation is 2° C.

[0056] In the heater device, one or more electrodes may be employed. Depending on the application, the electrode may be used as a resistive heating element, a plasma generation electrode, an electrostatic chuck electrode, or an electron beam electrode. The electrode may be embedded in the substrate of the heater toward the top (close to the wafer substrate) or the bottom (away from the wafer substrate). The bottom position may help spread the pattern of the electrode and aid in heat distribution to the wafer substrate.

[0057] In one embodiment, the electrode is in the form of a membrane electrode and is formed by processes known in the art, including screen printing, spin coating, plasma spraying, spray pyrolysis, reactive spray deposition, sol-gel, torch, arc, ion plating, ion implantation, sputtering deposition, laser ablation, evaporation, electroplating, and laser surface alloying. In one embodiment, the membrane electrode comprises a metal with a high melting point, such as tungsten, molybdenum, rhenium, and platinum or an alloy thereof. In another embodiment, the membrane electrode comprises at least one of a carbide or oxide of hafnium, zirconium, cerium, and mixtures thereof.

[0058] In another embodiment, the electrode layer is in the form of an elongated continuous strip of pyrolytic graphite. Pyrolytic graphite ("PG") is first deposited onto a heater base (e.g., a pyrolytic boron nitride coated graphite base) via a process known in the art (e.g., chemical vapor deposition). The PG is then processed into a predetermined pattern, such as a spiral, a serpentine, etc. The formation of the electrical pattern of the heating area (i.e., the electrically isolated resistive heater path) can be accomplished by techniques known in the art, including but not limited to micromachining, microabrasion, laser cutting, chemical etching, or electron beam etching.

[0059] Back to reference Figure 1 , the device 100 includes a cover plate 110 and a base plate 120 defining an upper surface 112. According to the present invention, the device includes a thermal leveler, such as a TPG-based leveler disposed between the cover plate and the base plate. The thermal leveler is detachable from the device and can be removed from the device as needed. For example, when the surface 112 is deemed no longer suitable for use in the desired heating operation, the thermal leveler can be removed from the device. The leveler can be removed and subsequently transferred to another device configured to receive and secure the thermal leveler.

[0060] The thermal leveler may be releasably removable from the device. The thermal leveler may be associated with or secured in the device by any suitable fastener or fastening mechanism. This may include, but is not limited to, clamps, bolts, threads, cam locks, retaining grooves, retaining rings, springs, vacuum, electrostatic forces, electromagnetic forces, magnetic forces, adhesives, solders, pastes, etc. In the case of adhesive type fasteners (e.g., adhesives, solders, pastes, etc.), the adhesive fastener should be such that the adhesive fastener can "reflow" to a sufficient degree to allow the leveler to be removed from the cover plate and / or base plate.

[0061] Figure 2-7 Different embodiments of devices according to aspects of the invention are shown. Figure 2An embodiment of an apparatus 200 is shown having a cover plate 210 and a base plate 220. A heat leveler 230 is disposed between the cover plate and the base plate. The apparatus is held together by pins 240. The pins may be formed as part of the underside of the cover plate. In another embodiment, the pins may be formed as part of the base plate and extend from its upper surface. The pins are arranged to pass through holes in the heat leveler and can be locked into grooves in the base plate (or cover plate) as designed.

[0062] Figure 3 An apparatus 300 is shown having a cover plate 310, a base plate 320, and a thermal leveler 330 disposed between the cover plate 310 and the base plate 320. The cover plate is secured to the base plate via threaded fasteners 340. The cover plate and the thermal leveler are configured to have an eyelet through which a fastener can be inserted, and the base plate is configured to have a threaded slot 322 to receive a threaded portion of the fastener. The cover plate can be configured such that a portion of the eyelet is sized to allow the head of the fastener to be flush or recessed relative to an upper surface 312 of the cover plate. It should be understood that this configuration can be reversed such that the cover plate includes a threaded recessed portion configured to receive a threaded fastener inserted through the eyelets in the base plate and the thermal leveler.

[0063] FIG4a shows an apparatus 400 having a cover plate 410, a base plate 420, and a thermal leveler 430 disposed between the cover plate and the base plate. In the embodiment of FIG4a, the base plate includes an opening through which the thermal leveler can be inserted and positioned within the base plate. The base plate includes a threaded opening 424 configured to receive the cover plate having a threaded surface to mate with a threaded portion of the base plate. In this embodiment, the base plate is configured such that it has an upper surface 422 that is coextensive with the upper surface 412 of the cover plate when the cover plate is fastened to the base plate, thereby forming the entire upper surface of the apparatus.

[0064] It should be understood that this configuration can be reversed as shown in Figure 4b, and the device 400' can be configured so that the cover plate 410' is mounted on top of the heat leveler 430' resting on the base plate 420'. The base plate 420' and the cover plate 410' are configured to have threads, and the device can be secured by the threaded engagement of the cover plate 410' and the base plate 420'.

[0065] Figure 5 The device 500 is shown to include only a cover plate 510 and a heat leveler 520. The cover plate and the heat leveler are configured with threads 512 and 522 to allow the cover plate to engage with the threads of the heat leveler.

[0066] Figure 6An apparatus 600 is shown, which includes a cover plate 610, a base plate 620, and a heat leveler 630 disposed between the cover plate and the base plate. The apparatus includes a cam lock system to secure the cover plate to the base plate and to hold the heat leveler in place. The cam lock system includes a pin or dowel 640 and a cam 650 to engage and interlock with the dowel. The dowel may have threads adapted to be screwed into a groove 622 in the base plate.

[0067] The cover plate, thermal leveler, and / or base plate may be configured with additional features that may be used to provide additional support, centering, or locking capabilities. For example, the surface of the thermal leveler may be provided with slots that may receive protrusions defined in the surface of the cover plate and / or base plate. Figure 7 , the device 700 includes a cover plate 710, a base plate 720, and a thermal leveler 730 disposed between the cover plate and the base plate. A surface 732 of the thermal leveler includes a slot or recessed area 734, and a surface 712 of the cover plate that engages the surface 732 of the thermal leveler includes a protrusion 714 that is configured to fit into the slot 734 of the thermal leveler. Again, it should be understood that the opposing surface of the thermal leveler and the upper surface of the base plate can be configured to have such a profile to allow similar engagement. The shape and / or number of such features are generally not limited and can be selected as needed for a particular purpose or intended application.

[0068] The thermal leveler comprises pyrolytic graphite. The configuration of the thermal leveler is not particularly limited and may be selected as required for a particular application or end use. In particular, the configuration of the thermal leveler will be selected to provide a desired thermal profile. The TPG layer may be embedded in the heater of the present invention alone as a single layer, or in one embodiment for a heater having a metal substrate, the TPG layer may be in an encapsulated form, such as a TPG core encapsulated within a structural metal shell. Encapsulated TPG is available from Momentive Performance Materials as a Encapsulated TPG is available. TPG can be incorporated into the heater as a continuous single sheet or, in one embodiment, as multiple smaller TPG sheets in an overlapping / mosaic configuration. Figures 8a-8d show cross-sectional views of examples of thermal leveler configurations. In Figure 8a, thermal leveler 800a is a TPG sheet. In Figure 8b, thermal leveler 800b includes a TPG sheet 810b disposed between a metal or ceramic upper layer 820b and a metal or ceramic lower layer 830b. In Figure 8c, thermal leveler 800c includes a TPG sheet 810c encapsulated by a metal or ceramic layer 820c.

[0069] There is no particular limitation on the orientation and number of TPG sheets in the thermal leveler. The number, orientation and location of the sheets can be selected as needed to provide a specific thermal distribution. As shown in FIG. 8d , a thermal leveler 800d is shown in which TPG sheets 810d and 820d are disposed or encapsulated in a metal or ceramic 830d.

[0070] Figures 9a-9c show top views of embodiments of different thermal leveler configurations. In Figure 9a, thermal leveler 900a includes TPG sheets 910a. In Figure 9b, thermal leveler 900b includes a central TPG sheet 910b and a TPG sheet 920b that defines a ring around the periphery of the thermal leveler. In Figure 9c, TPG sheets 910c, 920c, and 930c are arranged in a triangle with spaces between adjacent sheets. Again, these are merely examples of possible configurations of TPG sheets in a thermal leveler. The number, shape, and orientation of the sheets can be selected as desired to provide a desired thermal distribution. In addition, the thermal distribution can be configured by the orientation of the planes of the graphene layers in the TPG sheets (e.g., the sheets are arranged so that the graphene planes are oriented parallel to the surface of the sheet or perpendicular to the surface of the sheet).

[0071] The heat leveler may also be provided with grooves. The grooves may be provided to receive gases, O-rings, fluids, heater attachments, cooler attachments, and the like. Fig.10 A heat leveler 1000 is shown having grooves 1010 disposed in the surface of the heat leveler. Fig.10 In the figures, the thermal leveler is generally shown as a block. It should be understood that if the thermal leveler is formed of TPG itself, the grooves can be in the surface of the TPG material, or if the TPG sheet is disposed between or encapsulated by a metal or ceramic material, the grooves can be disposed in the metal or ceramic layer. The grooves can also be disposed in any surface of the thermal leveler as desired.

[0072] There is no particular limitation on the TPG in the thermal leveler. TPG can be used interchangeably with "highly oriented pyrolytic graphite" ("HOPG") or compression annealed pyrolytic graphite ("CAPG"). TPG has extremely high thermal conductivity, with an in-plane (ab direction) thermal conductivity greater than 1000 W / mK, and an out-of-plane (z direction) thermal conductivity in the range of 5 to 30 W / mK. In one embodiment, TPG has an in-plane thermal conductivity greater than 1500 W / mK. In one embodiment, the TPG layer has a thickness in the range of approximately 0.5 mm to 15 mm, with a thickness fluctuation (parallelism) within 0.005 mm. In another embodiment, the TPG layer has a thickness in the range of 1 mm to 10 mm. In a third embodiment, the TPG layer has a thickness in the range of 2 to 8 mm.

[0073] In one embodiment, the TPGs are held in place and embedded within the thermal leveler simply by adhesion of the underlying substrate and / or outer coating to which they contact. In another embodiment, the TPGs (in the form of pure TPG flakes, or as encapsulated TPG cores in a metal housing, as pure pyrolytic graphite in small piece sizes, e.g., rectangular, square pieces; random sizes; or in "ribbons") are bonded in place using high temperature adhesives known in the art.

[0074] The outer layer or encapsulation layer of the thermal leveler can be selected as needed to facilitate the desired heat distribution of the leveler. The outer layer or encapsulation layer of the thermal leveler can be, for example, a metal or ceramic material. Examples of suitable materials for coating, covering and / or encapsulating the TPG include, but are not limited to, aluminum, copper, silver, gold, nickel, beryllium, tin, lead and steel or alloys or composites thereof, such as Kovar, copper-tungsten, copper-molybdenum, Invar, Inconel, Hastelloy, aluminum-beryllium and tin-lead, oxides, nitrides, carbides, carbonitrides or oxynitrides of elements selected from the group consisting of boron, aluminum, silicon, gallium, yttrium, high temperature hard metals, transition metals; oxides, oxynitrides of aluminum.

[0075] The cover plate and / or base plate may be formed of any suitable material as desired for a particular purpose or intended application. The cover and / or base plate may form part of the heater construction. The cover and / or base plate may be formed of a metal or ceramic material. Examples of suitable metals include, but are not limited to, high temperature materials such as copper or aluminum alloys. Examples of suitable ceramic materials include, but are not limited to, oxides, nitrides, carbides, carbonitrides or oxynitrides of an element selected from the group consisting of boron, aluminum, silicon, gallium, yttrium, high temperature hard metals, transition metals; oxides, oxynitrides of aluminum; and combinations thereof.

[0076] The base plate or cover plate may optionally include features that help control the temperature of the device. The base plate or cover plate may include, for example, heater tubes, cooling tubes, or a combination thereof.

[0077] Assembly of the device can be achieved by setting up corresponding components (e.g., a cover plate, a heat leveler, and an optional base plate), attaching fasteners, and securing the components together, wherein the components are configured to be secured to each other by specific fasteners or fastening mechanisms. The device is similarly disassembled by separating the fasteners or fastening mechanisms. The heat leveler can be removed from the system and used in a subsequent process, or a different heat leveler can be inserted into the device. If necessary due to decomposition of the parts (e.g., wear / decomposition of the cover plate due to exposure to processing conditions), the corresponding components can be replaced as needed. Therefore, in one embodiment, it may be necessary to replace the cover plate for use in a processing operation.

[0078] The device may include other features as needed for a particular purpose or application. In one embodiment, the device includes lift pins disposed through the base plate and / or the thermal leveler. The cover plate may include grooves to receive the lift pins pushed through the base plate and / or the thermal leveler. The pins engage the cover plate through the grooves and when force is applied to the pins, the cover plate is pushed or separated from the device.

[0079] What has been described above includes examples of this specification. Of course, it is not possible to describe every conceivable combination of components or methods of operation for the purpose of describing this specification, but those skilled in the art will appreciate that many further combinations and permutations of this specification are possible. Accordingly, this specification is intended to encompass all such changes, modifications and variations that fall within the spirit and scope of the appended claims. Further, to the extent that the term "comprising" is used in the specification or claims, such term is intended to be inclusive, in a manner similar to the term "includes", as interpreted when "includes" is adopted as a transitional word in a claim.

[0080] The foregoing description identifies various non-limiting embodiments of the thermal control assembly. Modifications may occur to those skilled in the art and those who can make and use the invention. The disclosed embodiments are for illustrative purposes only and are not intended to limit the scope of the invention or the subject matter set forth in the claims.

Claims

1. An apparatus comprising a thermal leveler disposed between a cover plate and a base plate, the thermal leveler being releasably associated with the cover plate and detachably associated with the base plate, wherein: (i) the base plate includes a lower surface, one or more side walls extending around a periphery of the base plate, and an opening defined between the one or more side walls, the thermal leveler is disposed within the opening, and the one or more side walls have a threaded surface adjacent an upper end of the one or more side walls; wherein the cover plate is sized to fit within the opening of the base plate and includes a threaded side surface to engage the threaded surface of the base plate; or (ii) the base plate includes an upper surface, a lower surface, and a threaded side surface, the upper surface supporting the thermal leveler; the cover plate includes an upper surface, one or more side walls extending downwardly from the upper surface of the cover plate and extending around the periphery of the cover plate, and an opening defined between the one or more side walls, the opening being sized to surround the thermal leveler and the base plate, wherein the one or more side walls of the cover plate include a threaded surface to engage the threaded surface of the base plate; or (iii) the cover plate includes one or more holes; the thermal leveler includes one or more holes aligned with the one or more holes of the cover plate; and the base plate includes one or more grooves aligned with the one or more holes of the thermal leveler, wherein the cover plate, the thermal leveler and the base plate are releasably connected to each other via fasteners disposed through the one or more holes of the cover plate and the thermal leveler and the grooves of the base plate.

2. The device according to claim 1, wherein: The thermal leveler is releasably associated with the cover plate via a clamp, bolts, threads, cam locks, retaining grooves, retaining rings, springs, vacuum, electrostatic force, electromagnetic force, magnetic force, adhesive, solder, or paste.

3. The device according to claim 1, wherein: In (iii), at least one of the fasteners is a pin that locks into one of one or more grooves of the base plate.

4. The device according to claim 1 or 3, wherein: In (iii), at least one of the one or more recesses in the base plate has a threaded surface, and at least one of the fasteners is a threaded fastener adapted to threadably engage the at least one or more recesses with the threaded surface.

5. The device according to any one of claims 1 to 3, wherein: The upper surface of the thermal leveler includes a groove, and the lower surface of the cover plate includes a protrusion that is aligned with and sized to fit with the groove in the upper surface of the thermal leveler.

6. The device according to any one of claims 1 to 3, wherein: The thermal leveler includes pyrolytic graphite.

7. The device according to claim 6, wherein: The thermal leveler includes a pyrolytic graphite sheet disposed between an upper sheet and a lower sheet.

8. The device according to claim 7, wherein: The thermal leveler is encapsulated by a cover layer.

9. The device according to claim 8, wherein: The upper sheet, the lower sheet or the cover layer is independently selected from metal or ceramic materials.

10. The device according to claim 9, wherein: The upper sheet, the lower sheet or the covering layer is independently selected from: aluminum, copper, silver, gold, nickel, beryllium, tin, lead, steel, steel alloy, copper tungsten, copper molybdenum, Invar, aluminum beryllium, tin-lead, oxides, nitrides, carbides, carbonitrides or oxynitrides of elements selected from the group consisting of boron, aluminum, silicon, gallium, yttrium, high-temperature resistant hard metals and transition metals.

11. The device according to any one of claims 1 to 3, wherein: The thermal leveler includes a plurality of pyrolytic graphite sheets.

12. The device according to claim 11, wherein The plurality of pyrolytic graphite flakes have graphene basal planes that are parallel or perpendicular to a surface of the substrate.

13. The apparatus according to any one of claims 1 to 3, comprising a plurality of thermal levelers.

14. The device according to claim 13, wherein: The plurality of thermal levelers include pyrolytic graphite having a graphene basal plane parallel to or perpendicular to a substrate surface.

15. The apparatus according to claim 3, wherein: The susceptor plate includes a heater and / or a cooler.

16. The device according to any one of claims 1 to 3, wherein: The device includes an electrode disposed therein.

17. A method for heating or cooling a substrate, comprising heating or cooling a substrate disposed on an upper surface of a cover plate of the apparatus of any one of claims 1 to 16.

18. The method according to claim 17, comprising: Heat the substrate to the end point, Remove the substrate from the device, Release the cover from the heat leveler, providing a fresh cover sheet and releasably attaching it to the thermal leveler, and A second substrate is provided to the apparatus and the second substrate is heated.

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