WO2022046830A1 - Graphite based thermal leveler with high thermal conductivity material encapsulated therein - Google Patents

Graphite based thermal leveler with high thermal conductivity material encapsulated therein Download PDF

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Publication number
WO2022046830A1
WO2022046830A1 PCT/US2021/047436 US2021047436W WO2022046830A1 WO 2022046830 A1 WO2022046830 A1 WO 2022046830A1 US 2021047436 W US2021047436 W US 2021047436W WO 2022046830 A1 WO2022046830 A1 WO 2022046830A1
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WO
WIPO (PCT)
Prior art keywords
graphite
leveler
thermal conductivity
high thermal
metal
Prior art date
Application number
PCT/US2021/047436
Other languages
French (fr)
Inventor
David Michael SABENS
Sudarshan NATARAJAN
Xiang Liu
Hao QU
Original Assignee
Momentive Performance Materials Quartz, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Momentive Performance Materials Quartz, Inc. filed Critical Momentive Performance Materials Quartz, Inc.
Publication of WO2022046830A1 publication Critical patent/WO2022046830A1/en

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67098—Apparatus for thermal treatment
    • H01L21/67103—Apparatus for thermal treatment mainly by conduction
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/458—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for supporting substrates in the reaction chamber
    • C23C16/4581—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for supporting substrates in the reaction chamber characterised by material of construction or surface finish of the means for supporting the substrate
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/458—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for supporting substrates in the reaction chamber
    • C23C16/4582—Rigid and flat substrates, e.g. plates or discs
    • C23C16/4583—Rigid and flat substrates, e.g. plates or discs the substrate being supported substantially horizontally
    • C23C16/4586—Elements in the interior of the support, e.g. electrodes, heating or cooling devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H01L21/687—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches
    • H01L21/68714—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support
    • H01L21/68757—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support characterised by a coating or a hardness or a material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H01L21/687—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches
    • H01L21/68714—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support
    • H01L21/68785—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support characterised by the mechanical construction of the susceptor, stage or support

Definitions

  • the disclosure relates generally to a thermal leveler for controlling thermal conductivity across interfaces.
  • the present disclosure relates to a thermal leveler to allow for greater control of the temperature distribution of a surface by reducing temperature variations, either selectively or in whole.
  • a heating apparatus typically includes a ceramic support that may have electrodes disposed therein to heat the support, and additionally may have electrodes that electrostatically hold the wafer or substrate against the ceramic support, i.e., electrostatic chuck or ESC (also sometimes called susceptors).
  • a semiconductor device fabrication process can take place in the chamber, including deposition, etching, implantation, oxidation, etc.
  • PVD physical vapor deposition
  • sputter deposition a physical vapor deposition process, known as sputter deposition, in which a target generally comprised of a material to be deposited on the wafer substrate is supported above the substrate, typically fastened to a top of the chamber.
  • Plasma is formed from a gas such as argon supplied between the substrate and the target.
  • the target is biased causing ions within the plasma to be accelerated toward the target.
  • the ions of the plasma interact with the target material, and cause atoms of the material to be sputtered off, travel through the chamber toward the wafer, and redeposit on the surface of a semiconductor wafer that is being processed into integrated circuits (IC's).
  • IC's integrated circuits
  • PECVD plasma enhanced chemical vapor deposition
  • HDP-CVD high density plasma chemical vapor deposition
  • LPCVD low pressure chemical vapor deposition
  • SACVD sub-atmospheric pressure chemical vapor deposition
  • MOCVD metal organic chemical vapor deposition
  • MBE molecular beam evaporation
  • Thermal levelers or spreaders employing a thermally conductive material are used in various heat dissipating, leveling, spreading, and focusing applications along with a heater or cooler. The goal of using these levelers is to achieve a desired temperature profile utilizing the enhanced thermal conductivity of the thermally conductive material.
  • Some levelers are metal or ceramic based structures with a thermally conductive core material such as thermal pyrolytic graphite (TPG) or diamond.
  • TPG thermal pyrolytic graphite
  • the levelers can be in the form of naked TPG or can be in an encapsulated form, i.e., TPG encapsulated by a metal, semimetal, ceramic material, or an alloy. Examples of an encapsulating material include aluminum, copper, stainless steel, silicon, aluminum nitride, aluminum oxide, or tungsten-copper.
  • Graphite based levelers are used as thermal levelers in high temperature silicon carbide epitaxy.
  • the graphite levelers are typically coated with a carbide coating such as tantalum carbide (TaC) or silicon carbide (SiC).
  • Graphite has a relatively low thermal conductivity. This can have a significant impact on temperature uniformity, which will ultimately impact process performance. Attempts to overcome these issues have included the development of sophisticated designs to actively move and rotate wafers in a double planetary motion within a given deposition system. The requirement for such designs can significantly increase the complexity and cost of the systems and, subsequently, the products produced within those systems.
  • a graphite based thermal leveler comprising a high thermal conductivity insert encapsulated in the graphite.
  • the present technology provides a leveler suitable for use in processes that require high processing temperatures such as, for example, on the order of 1400 °C or higher.
  • the graphite based leveler with the high thermal conductivity material encapsulated therein may exhibit better temperature uniformity compared to a graphite based leveler without the high thermal conductivity material insert.
  • the graphite based levelers with the high thermal conductivity insert may also allow for providing a leveler with larger dimensions than conventional levelers.
  • the present leveler constructions may allow for wafers on the order of 150 mm in diameter, 200 mm in diameter, even up to 300 mm in diameter.
  • a thermal leveler comprising a graphite body and a high thermal conductivity insert disposed within the graphite body, the high thermal conductivity insert comprising (i) a thermally conductive material having an in plane thermal conductivity higher than that of the graphite body, and (ii) a metal layer disposed on a surface of the thermally conductive material and in contact with the graphite body, the metal layer comprising a carbide forming metal.
  • the graphite body comprises a first graphite piece defining a cavity sized to receive the high thermal conductivity insert, and a second graphite piece shaped to mate with the first graphite piece and encapsulate the high thermal conductivity insert.
  • the high thermal conductivity insert is sized such that it recessed relative to an upper of the first graphite piece, and the second graphite piece comprises a ridge sized to mate within the cavity of the first graphite piece and has a depth sufficient for a surface of the ridge to contact a metal layer of the high thermal conductivity insert.
  • the high thermal conductivity insert is sized such that a portion of the insert extends above an upper surface of the first graphite piece, and the second graphite piece defines a cavity sized to mate with and surround the portion of the insert extending above the upper surface of the first graphite piece.
  • the high thermal conductivity insert is sized such that an upper surface of the insert is substantially planar with an upper surface of the first graphite piece.
  • a lower surface of the second graphite piece contacts the upper surface of the high thermal conductivity insert.
  • the first graphite piece defines a ledge adjacent an upper surface of the first graphite piece, and the second graphite piece defines a cavity size to mate with the first graphite piece.
  • the thermal leveler comprises one or more slots defined along a periphery of the graphite body and between an upper surface of the first graphite piece and a lower surface of the second graphite piece.
  • the one or more slots is a single slot extending around the entire periphery of the graphite body.
  • the thermal leveler comprises a carbide forming metal disposed with the one or more slots.
  • the carbide forming metal is a metal selected from Group IVb, Group Vb, Group VIb, and Group Vllb of the periodic table, or an alloy of two or more.
  • the carbide forming metal is selected form titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, or an alloy of two or more thereof.
  • the thermally conductive material of the thermally conductive insert is thermal pyrolytic graphite.
  • the first graphite piece has a first coefficient of thermal expansion
  • the second graphite piece has a second coefficient of thermal expansion
  • the first coefficient of thermal expansion is from about 0% to about 65% lower than the second coefficient of thermal expansion.
  • the thermal leveler comprises a coating disposed on the graphite body.
  • the thermal leveler comprises a coating disposed on the graphite body, and the coating is further disposed within the one or more slots.
  • the coating is selected from pyrolytic graphite, pyrolytic boron nitride, a quartz/glass based coating, a metal carbide, a metal nitride, a metal carbonitride, or a metal oxynitride.
  • the coating is tantalum carbide (TaC) or silicon carbide (SiC).
  • the coating is selected from lanthanum aluminosilicate (LAS), magnesium aluminosilicate (MAS), calcium aluminosilicate (CAS), or yttrium aluminosilicate (YAS).
  • a method of forming a thermal leveler having a graphite body encapsulating a high thermal conductivity insert comprising: (i) providing a first graphite piece defining a cavity defining a lower surface and a wall; (ii) disposing a high thermal conductivity insert into the cavity of the first graphite piece, the high thermal conductivity insert comprising a high thermal conductivity material having an upper surface and a lower surface, a first metal coating disposed on the lower surface of the high thermal conductivity material, and a second metal coating disposed on the upper surface of the high thermal conductivity material, the first and second metal coatings independently selected from a carbide forming metal; (iii) providing a second graphite piece configured with a shape configured to encapsulate the high thermal conductivity insert and disposing the second graphite piece about the first graphite piece to provide a graphite body; and (iv) subjecting the graphite body to a temperature and/or pressure sufficient for
  • the graphite body comprises one or more slots defined along the outer periphery of the graphite body between the first graphite piece and the second graphite piece.
  • the method comprises providing a carbide forming metal within the one or more slots. In one embodiment, providing the carbide forming metal within the one or more slots is carried out prior to step (iv).
  • the method comprises applying a coating to the outer surface of the graphite body.
  • the coating is applied subsequent to step (iv).
  • the coating is applied prior to step (iv), and step (iv) occurs in conjunction with the formation of the coating.
  • FIG. 1 is a perspective view of a cylindrical thermal leveler in accordance with an embodiment of the technology
  • FIG. 2. is a cross-sectional side view of a thermal leveler in accordance with an embodiment of the technology
  • FIG. 2A is a side view of an embodiment of a graphite body of a thermal leveler in accordance with an aspect of the technology
  • FIG. 2B is a side view of an embodiment of a graphite body of a thermal leveler in accordance with an aspect of the technology
  • FIG. 3 is a cross-sectional side view of a thermal leveler in accordance with a second embodiment of the technology
  • FIG. 4 is a cross-sectional side view of a thermal leveler in accordance with a third embodiment of the technology
  • FIG. 5 is a cross-sectional side view of a thermal leveler in accordance with a fourth embodiment of the technology
  • FIG. 6 is a cross-sectional side view of a thermal leveler in accordance with a fifth embodiment of the technology.
  • FIG. 7 is a representation of the relationship of the respective graphite pieces in the leveler to aspects of the leveler for considering potential deformation of the leveler during processing.
  • the words “example” and “exemplary” means an instance, or illustration.
  • the words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment.
  • the word “or” is intended to be inclusive rather than exclusive, unless context suggests otherwise.
  • the phrase “A employs B or C,” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C).
  • the articles “a” and “an” are generally intended to mean “one or more” unless context suggest otherwise.
  • the “heating apparatus,” may be used interchangeably with “treating apparatus,” “heater,” “electrostatic chuck,” “chuck,” or “processing apparatus,” referring to an apparatus containing at least one heating and/or cooling element to regulate the temperature of the substrate supported thereon, specifically, by heating or cooling the substrate.
  • substrate refers to the semiconductor wafer or the glass mold being supported/heated by the processing apparatus of the invention.
  • sheet may be used interchangeably with “layer.”
  • 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 either the single or plural form, denoting that at least one unit is present.
  • the term “heating apparatus,” may be used interchangeably with “treating apparatus,” “heater,” “electrostatic chuck,” “chuck,” “processing apparatus,” “pedestal,” upper or bottom electrode, referring to an apparatus containing at least one heating and/or cooling element to regulate the temperature of the substrate supported thereon, specifically, by heating or cooling the substrate.
  • the present technology provides a heat spreader or thermal leveler comprising a thermally conductive material having a relatively high thermal conductivity disposed within an encapsulating material.
  • the thermal leveler is a graphite based leveler with a high thermal conductivity insert disposed within (or encapsulated by) a graphite body.
  • the leveler is configured such that the high thermal conductivity insert is sufficiently bonded to the graphite body and able to withstand or survive high temperature processing conditions.
  • the thermal leveler can be used in a variety of applications to provide thermal leveling functions in a process or system.
  • the thermal leveler comprising the high thermal conductivity insert can be provided as an uncoated or bare graphite leveler.
  • the thermal leveler can provided such that the graphite body is coated with a material of interest and as desired for an intended application or end use.
  • FIG. 1 shows a pedestal heater 10 comprising a thermal leveler 20 positioned on the heater, and a carrier 30 for supporting a substrate to be treated or processed such as in a chamber 50 suitable for processing semiconductor devices.
  • the thermal leveler is a graphite based leveler comprising a graphite body and a high thermal conductivity insert disposed within the graphite body. Aspects and embodiments of the graphite based leveler in accordance with the present technology are described further herein.
  • the leveler 100 includes a graphite body 110 with a high thermal conductivity material 150 disposed in or encapsulated by the graphite body.
  • the graphite body 110 is formed of a first graphite piece 120 and a second graphite piece 130.
  • the first graphite piece and the second graphite piece collectively define a cavity in which the high thermal conductivity insert is encapsulated.
  • the first graphite piece 120 defines a cavity 122 into which the high thermal conductivity material can be inserted.
  • the second graphite piece 130 is disposed over the high thermal conductivity insert 150 to encapsulate the insert within the graphite body.
  • the high thermal conductivity insert is bonded to the graphite via a metal layer that forms a carbide with the graphite material.
  • the lower surface 152 of the high thermal conductivity insert 150 is coated with a first coating layer 160
  • an upper surface 154 of the high thermal conductivity insert 150 is coated with a second coating layer 170, where the coating layers 160 and 170 comprise a metal capable of forming a carbide bond with the graphite.
  • the metal capable of forming a carbide bond with the graphite may also be referred to herein as a carbide forming metal.
  • the layers 160 and 170 may represent either (i) a coating of the carbide forming metal prior to formation of a carbide with the graphite (i.e. , a pre-bonded state), or (ii) a metal carbide bond layer with the graphite. It will be appreciated that the final configuration of the leveler for use in processing will have the insert 150 bonded to the graphite body through a metal carbide bond layer.
  • the first graphite piece 120 and the second graphite piece 130 are joined together such that they are bonded to one another. While the first and second graphite pieces could be joined via mechanical means. In one embodiment, the first and second graphite pieces are chemically bonded to one another. As shown in FIG. 2, the first graphite piece 120 and the second graphite piece 130 are configured to provide a gap 140 or space between an upper surface 124 of the first graphite piece 120 and a lower surface 132 of the second graphite piece 130. A bonding material 180 is provided within the gap to join the upper and lower pieces.
  • the gap 140 can be continuous and extend substantially around the entire perimeter of the graphite body as shown in FIG. 2A.
  • the graphite body can comprise a plurality of gaps, which may be defined as a plurality of slots.
  • FIG 2B shows an embodiment of a graphite body having slots 140a, 140b, 140c, 140d, 140e, etc. disposed along the perimeter of the graphite body. The lengthy, height, depth, and number of slots can be selected as desired to provide an area to sufficiently bond and form a seal between the graphite pieces forming the graphite body.
  • the bonding material 180 can be selected as desired to form a sufficient bond between the upper and lower graphite pieces.
  • the bonding material can be selected from a carbide forming metal.
  • the carbide forming layer used as the bonding material 180 can be the same or different from the carbide forming metal employed to coat the high thermal conductivity insert 150.
  • the thermal leveler 100 is shown as a bare or uncoated structure.
  • a coated leveler is shown.
  • the leveler includes the same components as in FIG. 2 with respect to the graphite body 110, the high thermal conductivity insert 150, the metal carbide forming/metal carbide layers 160 and 170, and the bonding material 180.
  • the coated leveler 200 is shown with a coating layer 210 disposed on the graphite body 110.
  • the coating material surrounding the graphite body can be selected as desired for a particular purpose or intended application.
  • FIG. 4 illustrates another embodiment of a coated leveler.
  • the coated leveler 300 includes a coating layer 310 disposed on the graphite leveler body 110.
  • the leveler includes 300 the same components as in FIG. 2 with respect to the graphite body 110, the high thermal conductivity insert 150, and the metal carbide forming/metal carbide layers 160 and 170.
  • the leveler does not include the bonding material 180 in the gap between the surfaces of the lower graphite piece and the upper graphite piece.
  • the gap 140 between the lower and upper graphite pieces is filled with the coating material forming the coating 310, and the coating
  • the first and second graphite pieces utilized to form the graphite body and the high thermal conductivity insert can be shaped and sized as desired to provide the structure.
  • the high thermal conductivity insert could be sized such that the upper coating layer is substantially flush with the upper surface of the lower graphite piece, and the upper graphite piece can sit atop the metal coating layer of the high thermal conductivity insert.
  • the high thermal conductivity insert is sized to be recessed relative to the upper surface of the lower graphite piece, and the upper graphite piece is shaped to include a section 134 configured to mate with or fit within the cavity of the of the lower graphite piece.
  • FIGs. 5 and 6 show additional, non-limiting, configurations for the graphite body with the high thermal conductivity insert.
  • a thermal leveler 400 is provided with a graphite body 410 comprising a first graphite piece 420 and a second graphite piece 430.
  • the lower graphite piece includes a cavity 422 for receiving a high thermal conductivity insert 150.
  • the walls defining the cavity are sized such that a portion of the insert 150 extends above the upper surface of the first graphite piece.
  • the second graphite piece 430 defines a cavity 432 configured to fit around the portion of the insert 150 that extends beyond the upper surface of lower graphite piece 420.
  • the second graphite piece can be configured such that the lower surface 434 contacts the upper surface 424 of the first graphite piece.
  • the perimeter of the first or second graphite piece can be configured with a gap or groove to accommodate a bonding material to bond the upper lower and graphite piece or to receive a coating material to bond the graphite pieces if the leveler is coated.
  • the upper surface includes a groove to define a gap 440 between the first and second graphite pieces.
  • the leveler 400 is shown as coated with a coating 450, and the gap 440 is filled with the coating material 450. It will be appreciated that the embodiment in FIG. 5 could be provided with a bonding material in the gap 440 that is different from the coating 450 and could also be provided in an uncoated form.
  • the leveler 500 includes a graphite body 510 formed from a first graphite piece 520 and a second graphite piece 530.
  • the first graphite piece 520 defines a cavity 540 for housing a high thermal conductivity insert 550.
  • the insert is configured such that it is substantially planar with the upper surface of the first graphite piece 520.
  • the first graphite piece is configured with a ledge 522 recessed from the upper surface of the first graphite piece to define a wall portion 524.
  • the second graphite piece 530 is configured with a cavity 532 and side walls 534. The cavity is configured such that side walls 534 fit around and mate with side walls 524.
  • the second graphite piece is sized such that the lower surface 536 of the side walls 534 does not contact the surface of the ledge 522 of the first graphite piece so as to create or define a gap or slot 560 between the first and second graphite piece.
  • the second graphite piece may also define a ledge so as to create or define the slot 560 between the first and second graphite pieces to accommodate a bonding material.
  • the leveler includes a coating layer 570 surrounding the graphite body and filling the gap 560.
  • the graphite body is formed from two or more pieces of graphite configured to house and encapsulate the high thermal conductivity insert.
  • the graphite employed in the graphite body is not particularly limited and can be selected as desired.
  • the form of the graphite used for the respective pieces employed to form the graphite body is selected to provide the pieces with different properties.
  • the pieces forming the graphite body have different coefficients of thermal expansion (CTE).
  • the CTE of graphite can, in embodiments, be from about 3 to about 8.5 ppm/°C.
  • the graphite piece of the graphite body that will be positioned closest to the heat source in the intended application has a lower CTE than the graphite piece that will be disposed away from the heater.
  • the leveler where the graphite piece that will be positioned nearest to the heat source (the high temperature surface graphite piece) with a lower CTE than the graphite piece positioned distal to the heat source (the “colder” temperature surface) can prevent or reduce the degree to which the leveler may bow during processing operations where it is employed.
  • the difference in the CTE between the graphite pieces does not have to be substantial and can be fractional to prevent or reduce the degree of bowing of the leveler.
  • the graphite piece that will be disposed adjacent or nearest to the heat source is provided such that it has a CTE that is 0% to about 65% lower than the CTE of the graphite piece positioned further away from the heat source; from about 0.0001% to about 65% lower; from about 0.5% to about 60% lower; from about 1% to about 55% lower; from about 5% to about 50% lower; from about 10% to about 40% lower; from about 15% to about 35% lower; or from about 20% to about 30% lower than the graphite piece positioned further away from the heat source.
  • the difference in the CTE can be large, it will be appreciated that the difference in the CTE of the high temperature surface graphite piece and the CTE of the lower temperature or colder temperature surface graphite piece can be rather minimal to produce the desired effect.
  • the high temperature surface graphite piece can have a CTE that is from about 0.0001% to about 5% lower than the CTE of the lower temperature surface graphite; from about 0.001% to about 4% lower; from about 0.01% to about 3% lower; from about 0.1% to about 2.5% lower; from about 0.5% to about 2% lower; or from about 1% to about 1.5% lower.
  • the high temperature surface graphite piece can have a CTE that is from about 0.0001% to about 1% lower than the CTE of the lower temperature surface graphite.
  • coefficient of thermal expansion of a piece of graphite is typically evaluated by and reported by the graphite manufacturer/provider.
  • coefficient of thermal expansion can be measured by dilatometry using any suitable testing standard such as, for example ASTM E228.
  • the use of graphite pieces with different coefficients of thermal expansion allows for controlling or tuning the degree to which the leveler may or may not flex or bow when exposed to certain processing conditions.
  • the CTE of the graphite pieces are selected such that the leveler remains substantially flat and does not experience any substantial amount of bowing.
  • the CTE of the graphite pieces can be selected such that they will exhibit a targeted degree of deformation (e.g., bowing in a desired direction).
  • the CTE of the respective graphite pieces can be selected such that they will deform in a similar manner or to a substantially similar degree as the wafer support such that the leveler substantially maintains physical and thermal contact with the wafer support.
  • the CTE of the respective graphite pieces used to form the thermal leveler are selected such that:
  • CTE C oid is the CTE of the leveler on the surface opposite of the heat source during operation
  • T C oid is the temperature of the leveler on the surface opposite the heat source during operation
  • Tref is the temperature at which a desired shape is verified;
  • CTEhot is the CTE of the leveler on the surface adjacent to the heat source during operation;
  • FIG. 7 illustrates the above described parameters with respect to the location of the graphite pieces in the leveler.
  • X is about 1
  • the leveler should remain substantially flat under the processing conditions.
  • the ratio is such that X is greater than or less than 1, the leveler may exhibit deformation.
  • the value of X can be controlled to achieve a certain level of deformation as desired.
  • the high thermal conductivity insert comprises a high thermal conductivity material coated with a metal suitable for forming a metal carbide.
  • the high thermal conductivity material comprises a thermal conductivity that is greater than the thermal conductivity of the graphite forming the encapsulating body.
  • the high thermal conductivity insert comprises thermal pyrolytic graphite.
  • Thermal pyrolytic graphite (TPG) is a unique graphite material having crystallites of considerable size, the crystallites being highly aligned or oriented with respect to each other and having well ordered carbon layers or a high degree of preferred crystallite orientation.
  • TPG may be may be used interchangeably with “highly oriented pyrolytic graphite” (“HOPG”), or compression annealed pyrolytic graphite (“CAPG”).
  • HOPG highly oriented pyrolytic graphite
  • CAG compression annealed pyrolytic graphite
  • TPG is extremely thermally conductive with an inplane (a-b direction) thermal conductivity greater than 1000 W/m-K, while the thermal conductivity in the out-of-plane (z-direction) is in the range of 20 to 30 W/m-K.
  • the high thermal conductivity insert can have an in-plane thermal conductivity greater than 1000
  • the high thermal conductivity insert has an in-plane thermal conductivity of from about 1000 W/m-K to about 1500 W/m-K.
  • Thermal pyrolytic graphite is available, for example, from Momentive Performance Materials Quartz, Inc.
  • TPG is formed as described in U.S. Pat. No. 5,863,467 which is hereby incorporated herein by reference in its entirety.
  • the configuration of the thermal leveler is not particularly limited and can be selected as desired for a particular application or end use. In particular, the configuration of the thermal leveler will be chosen to provide a desired thermal profile.
  • the TPG layer may be embedded in the heater of the invention as a single layer by itself, or in one embodiment for a heater with a metal substrate, the TPG layer can be in an encapsulated form, e.g., a TPG core encapsulated within a structural metallic shell.
  • Encapsulated TPG is commercially available from Momentive Performance Materials Inc. as TCI 050® encapsulated TPG.
  • TPG can be incorporated into the heater as a contiguous single sheet, or, in one embodiment, a plurality of smaller TPG pieces in an overlapping/mosaic configuration.
  • the orientation and number of TPG sheets in the thermal leveler is not particularly limited. The number, orientation, and position of the sheets can be selected as desired to provide a particular thermal profile.
  • the carbide-forming metal can be selected from a metal which easily combines with carbon to form a carbide.
  • the carbide forming metals can be selected from a metal from Group IVb, Group Vb, Group VIb, or Group Vllb of the periodic table, or an alloy of two or more such metals.
  • suitable carbide forming metals include, but are not Imited to, titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, or alloys of two or more thereof.
  • the carbide forming metal can be deposited on the surfaces of the high thermal conductivity material in any suitable manner including, but not limited to, chemical vapor deposition (CVD), physical vapor deposition (PVD), sputtering, etc.
  • the graphite body of the thermal leveler can be uncoated or coated depending on the intended environment in which the leveler will be utilized.
  • the thermal leveler comprises a coating
  • the particular coating can be selected as desired and as is suitable for the environment and processing conditions to which the leveler will be exposed.
  • suitable coatings include, but are not limited to, pyrolytic graphite, pyrolytic boron nitride, quartz/glass based coatings, metal carbides, metal nitrides, metal carbonitrides, metal oxynitrides, etc.
  • the coating is selected from a nitride, carbide, carbonitride or oxynitride of an elements selected from B, Al, Si, Ga, Y, a refractory hard metal, a transition metal, or a combination of two or more thereof.
  • the coating is a metal carbide coating.
  • suitable metal carbide coatings include, but are not limited to, tantalum carbide (TaC) and silicon carbide (SiC).
  • the coating used to coat the graphite body is a glassceramic composition comprising at least one element selected from the group consisting of elements of the group 2a, group 3a and group 4a of the periodic table of element.
  • suitable glass-ceramic compositions include lanthanum aluminosilicate (LAS), magnesium aluminosilicate (MAS), calcium aluminosilicate (CAS), and yttrium aluminosilicate (YAS).
  • the thickness of the protective coating layer varies depending upon the application and the process used, e.g., CVD, ion plating, ETP, etc.
  • the coating disposed on the graphite body may be from about 1 pm to about 500 pm.
  • the size of the thermal levelers can be selected as desired for a particular purpose or intended application. Applicants have found that the present technology allows for the use of levelers in a wafer form on the order of 100 mm, 200 mm, 300 mm, or greater.
  • the thermal levelers can be formed by providing a graphite piece defining a cavity as a first graphite piece and disposing a high thermal conductivity insert within the cavity.
  • the high thermal conductivity insert comprises the high thermal conductivity material coated with a layer of a carbide forming metal.
  • Another graphite piece is provided as the second graphite piece to cover the high thermal conductivity insert.
  • the shape and configuration of the pieces can be provided as desired to provide a graphite body.
  • the respective graphite pieces and insert can be shaped in accordance with one or more of the previous embodiments described herein.
  • one or both of the respective pieces can be coated with the bonding material.
  • a weight, clamp, or other mechanism may be employed to hold the respective pieces together while the metal carbide layer is formed to bond the high thermal conductivity insert to the graphite.
  • the metal carbide layer can be formed by exposing the unit to heat at a temperature sufficient to form the metal carbide. This may also be sufficient to form a bond between the graphite pieces with the bonding material.
  • the formation of the metal carbide bond with the graphite and the high thermal conductivity insert can be formed prior to coating the graphite body, or it can be formed in situ during the coating process.
  • the graphite body can be formed as described above including subjecting the body to conditions sufficient to form the metal carbide bond.
  • the graphite body can be subjected to a coating process to apply a coating to the external surfaces of the graphite body.
  • the graphite body is provided such that the metal coating of the high thermal conductivity insert is not yet bonded with the graphite.
  • the graphite body is subjected to a coating process under sufficient heat and pressure to cause the metal coating disposed on the high thermal conductivity material forms a metal carbide with the graphite.
  • the type of external coating being employed to coat the graphite body will dictate whether the in situ method can be used to bond the insert and the graphite. That is, the temperature conditions/tolerances for depositing the coating must be sufficient to facilitate formation of the internal metal carbide bond.
  • the graphite pieces forming the graphite body should be configured such that the pieces can be held in compression without external means. This may be accomplished by a threaded hole disposed through the graphite pieces.
  • the leveler of the invention can be used in a number of different processes, including in a plasma-etching chamber for processing glass molds, or in semiconductor processing chambers including but not limited to atomic layer epitaxy (ALD), low pressure CVD (LPCVD), and plasma-enhanced CVD (PECVD).
  • ALD atomic layer epitaxy
  • LPCVD low pressure CVD
  • PECVD plasma-enhanced CVD

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Abstract

A graphite based thermal leveler is provided with a high thermal conductivity insert. The graphite based thermal leveler comprises graphite pieces encapsulating a high thermal conductivity insert such as, for example, thermal pyrolytic graphite. The high thermal conductivity insert includes a coating of a carbide forming metal to bond with the graphite body. The thermal leveler can be coated or uncoated. The graphite pieces can be configured to define slots for receiving a bonding material to separately bond and seal the graphite pieces forming the graphite body. The leveler provides a graphite based leveler with improved temperature uniformity compared to conventional graphite based levelers.

Description

GRAPHITE BASED THERMAL LEVELER WITH
HIGH THERMAL CONDUCTIVITY MATERIAL ENCAPSULATED THEREIN
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application 63/069,814 filed on August 25, 2020, entitled “GRAPHITE BASED LEVELER WITH HIGH THERMAL CONDUCTIVITY MATERIAL ENCAPSULATED THEREIN,” the disclosure of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The disclosure relates generally to a thermal leveler for controlling thermal conductivity across interfaces. In particular, the present disclosure relates to a thermal leveler to allow for greater control of the temperature distribution of a surface by reducing temperature variations, either selectively or in whole.
BACKGROUND
[0003] Many semiconductor processes are typically performed in a vacuum environment, i.e., a sealed chamber containing an assembly for supporting the wafer substrate(s) disposed therein. In a semiconductor process, a heating apparatus typically includes a ceramic support that may have electrodes disposed therein to heat the support, and additionally may have electrodes that electrostatically hold the wafer or substrate against the ceramic support, i.e., electrostatic chuck or ESC (also sometimes called susceptors). A semiconductor device fabrication process can take place in the chamber, including deposition, etching, implantation, oxidation, etc. As an example of a deposition process one can conceive of a physical vapor deposition (PVD) process, known as sputter deposition, in which a target generally comprised of a material to be deposited on the wafer substrate is supported above the substrate, typically fastened to a top of the chamber. Plasma is formed from a gas such as argon supplied between the substrate and the target. The target is biased causing ions within the plasma to be accelerated toward the target. The ions of the plasma interact with the target material, and cause atoms of the material to be sputtered off, travel through the chamber toward the wafer, and redeposit on the surface of a semiconductor wafer that is being processed into integrated circuits (IC's). 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), sub-atmospheric pressure chemical vapor deposition (SACVD), metal organic chemical vapor deposition (MOCVD), molecular beam evaporation (MBE), etc.
[0004] In some of the above processes it is desirable to heat the wafer by heating the support. The chemical reaction rate of the materials being deposited, etched, implanted, etc, is controlled to some degree by the temperature of the wafer. Undesirable unevenness in deposition, etching, implantation, etc., over a face of the wafer can easily result if the temperature of the wafer across its area varies too much.
[0005] Thermal levelers or spreaders employing a thermally conductive material are used in various heat dissipating, leveling, spreading, and focusing applications along with a heater or cooler. The goal of using these levelers is to achieve a desired temperature profile utilizing the enhanced thermal conductivity of the thermally conductive material. Some levelers are metal or ceramic based structures with a thermally conductive core material such as thermal pyrolytic graphite (TPG) or diamond. For structures using TPG as the core material, for example, the levelers can be in the form of naked TPG or can be in an encapsulated form, i.e., TPG encapsulated by a metal, semimetal, ceramic material, or an alloy. Examples of an encapsulating material include aluminum, copper, stainless steel, silicon, aluminum nitride, aluminum oxide, or tungsten-copper.
[0006] Graphite based levelers are used as thermal levelers in high temperature silicon carbide epitaxy. The graphite levelers are typically coated with a carbide coating such as tantalum carbide (TaC) or silicon carbide (SiC). Graphite, however, has a relatively low thermal conductivity. This can have a significant impact on temperature uniformity, which will ultimately impact process performance. Attempts to overcome these issues have included the development of sophisticated designs to actively move and rotate wafers in a double planetary motion within a given deposition system. The requirement for such designs can significantly increase the complexity and cost of the systems and, subsequently, the products produced within those systems.
SUMMARY
[0007] The following presents a summary of this disclosure to provide a basic understanding of some aspects and embodiments of the technology. This summary is intended to neither identify key or critical elements nor define any limitations of embodiments or claims. Furthermore, this summary may provide a simplified overview of some aspects that may be described in greater detail in other portions of this disclosure.
[0008] Provided is a graphite based thermal leveler comprising a high thermal conductivity insert encapsulated in the graphite. The present technology provides a leveler suitable for use in processes that require high processing temperatures such as, for example, on the order of 1400 °C or higher. The graphite based leveler with the high thermal conductivity material encapsulated therein may exhibit better temperature uniformity compared to a graphite based leveler without the high thermal conductivity material insert.
[0009] The graphite based levelers with the high thermal conductivity insert may also allow for providing a leveler with larger dimensions than conventional levelers. The present leveler constructions may allow for wafers on the order of 150 mm in diameter, 200 mm in diameter, even up to 300 mm in diameter.
[0010] In one aspect, provided is a thermal leveler comprising a graphite body and a high thermal conductivity insert disposed within the graphite body, the high thermal conductivity insert comprising (i) a thermally conductive material having an in plane thermal conductivity higher than that of the graphite body, and (ii) a metal layer disposed on a surface of the thermally conductive material and in contact with the graphite body, the metal layer comprising a carbide forming metal.
[0011] In one embodiment, the graphite body comprises a first graphite piece defining a cavity sized to receive the high thermal conductivity insert, and a second graphite piece shaped to mate with the first graphite piece and encapsulate the high thermal conductivity insert.
[0012] In one embodiment, the high thermal conductivity insert is sized such that it recessed relative to an upper of the first graphite piece, and the second graphite piece comprises a ridge sized to mate within the cavity of the first graphite piece and has a depth sufficient for a surface of the ridge to contact a metal layer of the high thermal conductivity insert.
[0013] In one embodiment, the high thermal conductivity insert is sized such that a portion of the insert extends above an upper surface of the first graphite piece, and the second graphite piece defines a cavity sized to mate with and surround the portion of the insert extending above the upper surface of the first graphite piece. [0014] In one embodiment, the high thermal conductivity insert is sized such that an upper surface of the insert is substantially planar with an upper surface of the first graphite piece.
[0015] In one embodiment, a lower surface of the second graphite piece contacts the upper surface of the high thermal conductivity insert.
[0016] In one embodiment, the first graphite piece defines a ledge adjacent an upper surface of the first graphite piece, and the second graphite piece defines a cavity size to mate with the first graphite piece.
[0017] In one embodiment in accordance with any of the previous embodiments, the thermal leveler comprises one or more slots defined along a periphery of the graphite body and between an upper surface of the first graphite piece and a lower surface of the second graphite piece.
[0018] In one embodiment, the one or more slots is a single slot extending around the entire periphery of the graphite body.
[0019] In one embodiment, the thermal leveler comprises a carbide forming metal disposed with the one or more slots.
[0020] In one embodiment in accordance with any of the previous embodiments, the carbide forming metal is a metal selected from Group IVb, Group Vb, Group VIb, and Group Vllb of the periodic table, or an alloy of two or more.
[0021] In one embodiment in accordance with any of the previous embodiments, the carbide forming metal is selected form titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, or an alloy of two or more thereof.
[0022] In one embodiment in accordance with any of the previous embodiments, the thermally conductive material of the thermally conductive insert is thermal pyrolytic graphite. [0023] In one embodiment in accordance with any of the previous embodiments, the first graphite piece has a first coefficient of thermal expansion, the second graphite piece has a second coefficient of thermal expansion, and the first coefficient of thermal expansion is from about 0% to about 65% lower than the second coefficient of thermal expansion.
[0024] In one embodiment in accordance with any of the previous embodiments, the thermal leveler comprises a coating disposed on the graphite body.
[0025] In one embodiment, the thermal leveler comprises a coating disposed on the graphite body, and the coating is further disposed within the one or more slots.
[0026] In one embodiment in accordance with any of the previous embodiments, the coating is selected from pyrolytic graphite, pyrolytic boron nitride, a quartz/glass based coating, a metal carbide, a metal nitride, a metal carbonitride, or a metal oxynitride. In one embodiment, the coating is tantalum carbide (TaC) or silicon carbide (SiC). In one embodiment, the coating is selected from lanthanum aluminosilicate (LAS), magnesium aluminosilicate (MAS), calcium aluminosilicate (CAS), or yttrium aluminosilicate (YAS).
[0027] In another aspect, provided is a method of forming a thermal leveler having a graphite body encapsulating a high thermal conductivity insert, the method comprising: (i) providing a first graphite piece defining a cavity defining a lower surface and a wall; (ii) disposing a high thermal conductivity insert into the cavity of the first graphite piece, the high thermal conductivity insert comprising a high thermal conductivity material having an upper surface and a lower surface, a first metal coating disposed on the lower surface of the high thermal conductivity material, and a second metal coating disposed on the upper surface of the high thermal conductivity material, the first and second metal coatings independently selected from a carbide forming metal; (iii) providing a second graphite piece configured with a shape configured to encapsulate the high thermal conductivity insert and disposing the second graphite piece about the first graphite piece to provide a graphite body; and (iv) subjecting the graphite body to a temperature and/or pressure sufficient for the first and second metal layers of the high thermal conductivity insert to form a metal carbide bond with the first and second graphite pieces, respectively.
[0028] In one embodiment of the method, the graphite body comprises one or more slots defined along the outer periphery of the graphite body between the first graphite piece and the second graphite piece.
[0029] In one embodiment, the method comprises providing a carbide forming metal within the one or more slots. In one embodiment, providing the carbide forming metal within the one or more slots is carried out prior to step (iv).
[0030] In one embodiment, the method comprises applying a coating to the outer surface of the graphite body. In one embodiment, the coating is applied subsequent to step (iv). In one embodiment, the coating is applied prior to step (iv), and step (iv) occurs in conjunction with the formation of the coating.
[0031] These and other aspects and embodiments of the invention are described with reference to the detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a perspective view of a cylindrical thermal leveler in accordance with an embodiment of the technology;
[0033] FIG. 2. is a cross-sectional side view of a thermal leveler in accordance with an embodiment of the technology;
[0034] FIG. 2A is a side view of an embodiment of a graphite body of a thermal leveler in accordance with an aspect of the technology;
[0035] FIG. 2B is a side view of an embodiment of a graphite body of a thermal leveler in accordance with an aspect of the technology; [0036] FIG. 3 is a cross-sectional side view of a thermal leveler in accordance with a second embodiment of the technology;
[0037] FIG. 4 is a cross-sectional side view of a thermal leveler in accordance with a third embodiment of the technology;
[0038] FIG. 5 is a cross-sectional side view of a thermal leveler in accordance with a fourth embodiment of the technology;
[0039] FIG. 6 is a cross-sectional side view of a thermal leveler in accordance with a fifth embodiment of the technology; and
[0040] FIG. 7 is a representation of the relationship of the respective graphite pieces in the leveler to aspects of the leveler for considering potential deformation of the leveler during processing.
DETAILED DESCRIPTION
[0041] Reference will now be made to exemplary embodiments, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional changes may be made. Moreover, features of the various embodiments may be combined or altered. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments. In this disclosure, numerous specific details provide a thorough understanding of the subject disclosure. It should be understood that aspects of this disclosure may be practiced with other embodiments not necessarily including all aspects described herein, etc.
[0042] As used herein, the words “example” and “exemplary” means an instance, or illustration. The words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment. The word “or” is intended to be inclusive rather than exclusive, unless context suggests otherwise. As an example, the phrase “A employs B or C,” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles “a” and “an” are generally intended to mean “one or more” unless context suggest otherwise.
[0043] As used herein, the “heating apparatus,” may be used interchangeably with “treating apparatus,” “heater,” “electrostatic chuck,” “chuck,” or “processing apparatus,” referring to an apparatus containing at least one heating and/or cooling element to regulate the temperature of the substrate supported thereon, specifically, by heating or cooling the substrate.
[0044] As used herein, the term “substrate” refers to the semiconductor wafer or the glass mold being supported/heated by the processing apparatus of the invention. As used herein, the term “sheet” may be used interchangeably with “layer.”
[0045] 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 either the single or plural form, denoting that at least one unit is present. As used herein, the term “heating apparatus,” may be used interchangeably with “treating apparatus,” “heater,” “electrostatic chuck,” “chuck,” “processing apparatus,” “pedestal,” upper or bottom electrode, referring to an apparatus containing at least one heating and/or cooling element to regulate the temperature of the substrate supported thereon, specifically, by heating or cooling the substrate.
[0046] The present technology provides a heat spreader or thermal leveler comprising a thermally conductive material having a relatively high thermal conductivity disposed within an encapsulating material. In one aspect, the thermal leveler is a graphite based leveler with a high thermal conductivity insert disposed within (or encapsulated by) a graphite body. The leveler is configured such that the high thermal conductivity insert is sufficiently bonded to the graphite body and able to withstand or survive high temperature processing conditions.
[0047] The thermal leveler can be used in a variety of applications to provide thermal leveling functions in a process or system. In one embodiment, the thermal leveler comprising the high thermal conductivity insert can be provided as an uncoated or bare graphite leveler. In other embodiments, the thermal leveler can provided such that the graphite body is coated with a material of interest and as desired for an intended application or end use.
[0048] FIG. 1 shows a pedestal heater 10 comprising a thermal leveler 20 positioned on the heater, and a carrier 30 for supporting a substrate to be treated or processed such as in a chamber 50 suitable for processing semiconductor devices. The thermal leveler is a graphite based leveler comprising a graphite body and a high thermal conductivity insert disposed within the graphite body. Aspects and embodiments of the graphite based leveler in accordance with the present technology are described further herein.
[0049] Referring to FIG. 2, an embodiment of a general configuration of a thermal leveler in accordance with an embodiment of the present technology is shown. The leveler 100 includes a graphite body 110 with a high thermal conductivity material 150 disposed in or encapsulated by the graphite body. The graphite body 110 is formed of a first graphite piece 120 and a second graphite piece 130. The first graphite piece and the second graphite piece collectively define a cavity in which the high thermal conductivity insert is encapsulated. In FIG.2 the first graphite piece 120 defines a cavity 122 into which the high thermal conductivity material can be inserted. The second graphite piece 130 is disposed over the high thermal conductivity insert 150 to encapsulate the insert within the graphite body.
[0050] The high thermal conductivity insert is bonded to the graphite via a metal layer that forms a carbide with the graphite material. In FIG. 2, the lower surface 152 of the high thermal conductivity insert 150 is coated with a first coating layer 160, and an upper surface 154 of the high thermal conductivity insert 150 is coated with a second coating layer 170, where the coating layers 160 and 170 comprise a metal capable of forming a carbide bond with the graphite. The metal capable of forming a carbide bond with the graphite may also be referred to herein as a carbide forming metal.
[0051] It will be appreciated that the layers 160 and 170 may represent either (i) a coating of the carbide forming metal prior to formation of a carbide with the graphite (i.e. , a pre-bonded state), or (ii) a metal carbide bond layer with the graphite. It will be appreciated that the final configuration of the leveler for use in processing will have the insert 150 bonded to the graphite body through a metal carbide bond layer.
[0052] The first graphite piece 120 and the second graphite piece 130 are joined together such that they are bonded to one another. While the first and second graphite pieces could be joined via mechanical means. In one embodiment, the first and second graphite pieces are chemically bonded to one another. As shown in FIG. 2, the first graphite piece 120 and the second graphite piece 130 are configured to provide a gap 140 or space between an upper surface 124 of the first graphite piece 120 and a lower surface 132 of the second graphite piece 130. A bonding material 180 is provided within the gap to join the upper and lower pieces.
[0053] The gap 140 can be continuous and extend substantially around the entire perimeter of the graphite body as shown in FIG. 2A. In another embodiment, the graphite body can comprise a plurality of gaps, which may be defined as a plurality of slots. FIG 2B shows an embodiment of a graphite body having slots 140a, 140b, 140c, 140d, 140e, etc. disposed along the perimeter of the graphite body. The lengthy, height, depth, and number of slots can be selected as desired to provide an area to sufficiently bond and form a seal between the graphite pieces forming the graphite body. [0054] The bonding material 180 can be selected as desired to form a sufficient bond between the upper and lower graphite pieces. In one embodiment, the bonding material can be selected from a carbide forming metal. The carbide forming layer used as the bonding material 180 can be the same or different from the carbide forming metal employed to coat the high thermal conductivity insert 150.
[0055] The thermal leveler 100 is shown as a bare or uncoated structure. Referring to FIG. 3, a coated leveler is shown. In FIG. 3, the leveler includes the same components as in FIG. 2 with respect to the graphite body 110, the high thermal conductivity insert 150, the metal carbide forming/metal carbide layers 160 and 170, and the bonding material 180. For the sake of brevity the description of those layers is not repeated with respect to FIG. 3. In FIG. 3, the coated leveler 200 is shown with a coating layer 210 disposed on the graphite body 110. The coating material surrounding the graphite body can be selected as desired for a particular purpose or intended application. Examples of suitable coatings include, but are not limited to metal carbides (e.g., tantalum carbide, silicon carbide, etc.), pyrolytic graphite, pyrolytic boron nitride, quartz, metal nitrides (e.g., silicon nitride, aluminum nitride, etc.) [0056] FIG. 4 illustrates another embodiment of a coated leveler. The coated leveler 300 includes a coating layer 310 disposed on the graphite leveler body 110. In FIG. 4, the leveler includes 300 the same components as in FIG. 2 with respect to the graphite body 110, the high thermal conductivity insert 150, and the metal carbide forming/metal carbide layers 160 and 170. For the sake of brevity the description of those layers is not repeated with respect to FIG. 4. In the embodiment shown in FIG. 4, the leveler does not include the bonding material 180 in the gap between the surfaces of the lower graphite piece and the upper graphite piece. In the embodiment in FIG. 4, the gap 140 between the lower and upper graphite pieces is filled with the coating material forming the coating 310, and the coating
310 helps to bond and seal the graphite pieces of the graphite body. [0057] The first and second graphite pieces utilized to form the graphite body and the high thermal conductivity insert can be shaped and sized as desired to provide the structure. In embodiments, the high thermal conductivity insert could be sized such that the upper coating layer is substantially flush with the upper surface of the lower graphite piece, and the upper graphite piece can sit atop the metal coating layer of the high thermal conductivity insert. In FIGs. 2-4, the high thermal conductivity insert is sized to be recessed relative to the upper surface of the lower graphite piece, and the upper graphite piece is shaped to include a section 134 configured to mate with or fit within the cavity of the of the lower graphite piece. [0058] It will be appreciated that the graphite body is not limited to such configurations. FIGs. 5 and 6 show additional, non-limiting, configurations for the graphite body with the high thermal conductivity insert.
[0059] In the embodiment shown in FIG. 5, a thermal leveler 400 is provided with a graphite body 410 comprising a first graphite piece 420 and a second graphite piece 430. The lower graphite piece includes a cavity 422 for receiving a high thermal conductivity insert 150. The walls defining the cavity are sized such that a portion of the insert 150 extends above the upper surface of the first graphite piece. The second graphite piece 430 defines a cavity 432 configured to fit around the portion of the insert 150 that extends beyond the upper surface of lower graphite piece 420. The second graphite piece can be configured such that the lower surface 434 contacts the upper surface 424 of the first graphite piece. The perimeter of the first or second graphite piece can be configured with a gap or groove to accommodate a bonding material to bond the upper lower and graphite piece or to receive a coating material to bond the graphite pieces if the leveler is coated. As shown in FIG. 5, the upper surface includes a groove to define a gap 440 between the first and second graphite pieces. In FIG. 5, the leveler 400 is shown as coated with a coating 450, and the gap 440 is filled with the coating material 450. It will be appreciated that the embodiment in FIG. 5 could be provided with a bonding material in the gap 440 that is different from the coating 450 and could also be provided in an uncoated form.
[0060] In the embodiment of FIG. 6, the leveler 500 includes a graphite body 510 formed from a first graphite piece 520 and a second graphite piece 530. The first graphite piece 520 defines a cavity 540 for housing a high thermal conductivity insert 550. In this embodiment, the insert is configured such that it is substantially planar with the upper surface of the first graphite piece 520. The first graphite piece is configured with a ledge 522 recessed from the upper surface of the first graphite piece to define a wall portion 524. The second graphite piece 530 is configured with a cavity 532 and side walls 534. The cavity is configured such that side walls 534 fit around and mate with side walls 524. The second graphite piece is sized such that the lower surface 536 of the side walls 534 does not contact the surface of the ledge 522 of the first graphite piece so as to create or define a gap or slot 560 between the first and second graphite piece. The second graphite piece may also define a ledge so as to create or define the slot 560 between the first and second graphite pieces to accommodate a bonding material. In FIG. 6, the leveler includes a coating layer 570 surrounding the graphite body and filling the gap 560.
[0061] The graphite body is formed from two or more pieces of graphite configured to house and encapsulate the high thermal conductivity insert. The graphite employed in the graphite body is not particularly limited and can be selected as desired. In one embodiment, the form of the graphite used for the respective pieces employed to form the graphite body is selected to provide the pieces with different properties. In one embodiment, the pieces forming the graphite body have different coefficients of thermal expansion (CTE). The CTE of graphite can, in embodiments, be from about 3 to about 8.5 ppm/°C. In one embodiment, the graphite piece of the graphite body that will be positioned closest to the heat source in the intended application has a lower CTE than the graphite piece that will be disposed away from the heater. Without being bound to any particular theory, providing the leveler where the graphite piece that will be positioned nearest to the heat source (the high temperature surface graphite piece) with a lower CTE than the graphite piece positioned distal to the heat source (the “colder” temperature surface) can prevent or reduce the degree to which the leveler may bow during processing operations where it is employed. The difference in the CTE between the graphite pieces does not have to be substantial and can be fractional to prevent or reduce the degree of bowing of the leveler. In one embodiment, the graphite piece that will be disposed adjacent or nearest to the heat source is provided such that it has a CTE that is 0% to about 65% lower than the CTE of the graphite piece positioned further away from the heat source; from about 0.0001% to about 65% lower; from about 0.5% to about 60% lower; from about 1% to about 55% lower; from about 5% to about 50% lower; from about 10% to about 40% lower; from about 15% to about 35% lower; or from about 20% to about 30% lower than the graphite piece positioned further away from the heat source.
[0062] While the difference in the CTE can be large, it will be appreciated that the difference in the CTE of the high temperature surface graphite piece and the CTE of the lower temperature or colder temperature surface graphite piece can be rather minimal to produce the desired effect. In one embodiment, the high temperature surface graphite piece can have a CTE that is from about 0.0001% to about 5% lower than the CTE of the lower temperature surface graphite; from about 0.001% to about 4% lower; from about 0.01% to about 3% lower; from about 0.1% to about 2.5% lower; from about 0.5% to about 2% lower; or from about 1% to about 1.5% lower. In one embodiment, the high temperature surface graphite piece can have a CTE that is from about 0.0001% to about 1% lower than the CTE of the lower temperature surface graphite.
[0063] The coefficient of thermal expansion of a piece of graphite is typically evaluated by and reported by the graphite manufacturer/provider. Alternatively, coefficient of thermal expansion can be measured by dilatometry using any suitable testing standard such as, for example ASTM E228.
[0064] The use of graphite pieces with different coefficients of thermal expansion allows for controlling or tuning the degree to which the leveler may or may not flex or bow when exposed to certain processing conditions. In one embodiment, the CTE of the graphite pieces are selected such that the leveler remains substantially flat and does not experience any substantial amount of bowing. In another embodiment, the CTE of the graphite pieces can be selected such that they will exhibit a targeted degree of deformation (e.g., bowing in a desired direction). This may be desirable in certain applications where temperature uniformity is desired with respect to a wafer support material disposed on the upper surface (i.e., the surface away from the heater pedestal) of the leveler, and the wafer support is known to deform during processing (due to the materials used to form the wafer support). The CTE of the respective graphite pieces can be selected such that they will deform in a similar manner or to a substantially similar degree as the wafer support such that the leveler substantially maintains physical and thermal contact with the wafer support.
[0065] In one embodiment, the CTE of the respective graphite pieces used to form the thermal leveler are selected such that:
[CTEcold * (Tcold - Tref)] / [CTEhot * (Thot - Tref)] = X where:
• CTECoid is is the CTE of the leveler on the surface opposite of the heat source during operation;
• TCoid is is the temperature of the leveler on the surface opposite the heat source during operation;
Tref is is the temperature at which a desired shape is verified; • CTEhot is is the CTE of the leveler on the surface adjacent to the heat source during operation;
• Thot is is the temperature of the leveler on the surface adjacent to the heat source during operation;
• X is a selected value.
FIG. 7 illustrates the above described parameters with respect to the location of the graphite pieces in the leveler. When X is about 1, the leveler should remain substantially flat under the processing conditions. When the ratio is such that X is greater than or less than 1, the leveler may exhibit deformation. As discussed above, by the selection of the CTE for the respective graphite pieces of the leveler, the value of X can be controlled to achieve a certain level of deformation as desired.
[0066] The high thermal conductivity insert comprises a high thermal conductivity material coated with a metal suitable for forming a metal carbide. The high thermal conductivity material comprises a thermal conductivity that is greater than the thermal conductivity of the graphite forming the encapsulating body. In one embodiment, the high thermal conductivity insert comprises thermal pyrolytic graphite. Thermal pyrolytic graphite (TPG) is a unique graphite material having crystallites of considerable size, the crystallites being highly aligned or oriented with respect to each other and having well ordered carbon layers or a high degree of preferred crystallite orientation. TPG may be may be used interchangeably with “highly oriented pyrolytic graphite” (“HOPG”), or compression annealed pyrolytic graphite (“CAPG”). TPG is extremely thermally conductive with an inplane (a-b direction) thermal conductivity greater than 1000 W/m-K, while the thermal conductivity in the out-of-plane (z-direction) is in the range of 20 to 30 W/m-K. The high thermal conductivity insert can have an in-plane thermal conductivity greater than 1000
W/m-K; greater than 1100 W/m-K, greater than 1200 W/m-K, greater than 1300 W/m-K, greater than 1400 W/m-K, even greater than 1500 W/m-K. In one embodiment, the high thermal conductivity insert has an in-plane thermal conductivity of from about 1000 W/m-K to about 1500 W/m-K.
[0067] Thermal pyrolytic graphite is available, for example, from Momentive Performance Materials Quartz, Inc. In one embodiment, TPG is formed as described in U.S. Pat. No. 5,863,467 which is hereby incorporated herein by reference in its entirety. The configuration of the thermal leveler is not particularly limited and can be selected as desired for a particular application or end use. In particular, the configuration of the thermal leveler will be chosen to provide a desired thermal profile. The TPG layer may be embedded in the heater of the invention as a single layer by itself, or in one embodiment for a heater with a metal substrate, the TPG layer can be in an encapsulated form, e.g., a TPG core encapsulated within a structural metallic shell. Encapsulated TPG is commercially available from Momentive Performance Materials Inc. as TCI 050® encapsulated TPG. TPG can be incorporated into the heater as a contiguous single sheet, or, in one embodiment, a plurality of smaller TPG pieces in an overlapping/mosaic configuration. The orientation and number of TPG sheets in the thermal leveler is not particularly limited. The number, orientation, and position of the sheets can be selected as desired to provide a particular thermal profile.
[0068] The carbide-forming metal can be selected from a metal which easily combines with carbon to form a carbide. The carbide forming metals can be selected from a metal from Group IVb, Group Vb, Group VIb, or Group Vllb of the periodic table, or an alloy of two or more such metals. Examples of suitable carbide forming metals include, but are not Imited to, titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, or alloys of two or more thereof. The carbide forming metal can be deposited on the surfaces of the high thermal conductivity material in any suitable manner including, but not limited to, chemical vapor deposition (CVD), physical vapor deposition (PVD), sputtering, etc.
[0069] As previously described, the graphite body of the thermal leveler can be uncoated or coated depending on the intended environment in which the leveler will be utilized. When the thermal leveler comprises a coating, the particular coating can be selected as desired and as is suitable for the environment and processing conditions to which the leveler will be exposed. Examples of suitable coatings include, but are not limited to, pyrolytic graphite, pyrolytic boron nitride, quartz/glass based coatings, metal carbides, metal nitrides, metal carbonitrides, metal oxynitrides, etc. In one embodiment, the coating is selected from a nitride, carbide, carbonitride or oxynitride of an elements selected from B, Al, Si, Ga, Y, a refractory hard metal, a transition metal, or a combination of two or more thereof.
[0070] In one embodiment, the coating is a metal carbide coating. Examples of suitable metal carbide coatings include, but are not limited to, tantalum carbide (TaC) and silicon carbide (SiC).
[0071] In one embodiment, the coating used to coat the graphite body is a glassceramic composition comprising at least one element selected from the group consisting of elements of the group 2a, group 3a and group 4a of the periodic table of element. Examples of suitable glass-ceramic compositions include lanthanum aluminosilicate (LAS), magnesium aluminosilicate (MAS), calcium aluminosilicate (CAS), and yttrium aluminosilicate (YAS).
[0072] The thickness of the protective coating layer varies depending upon the application and the process used, e.g., CVD, ion plating, ETP, etc. In one embodiment, the coating disposed on the graphite body may be from about 1 pm to about 500 pm. [0073] The size of the thermal levelers can be selected as desired for a particular purpose or intended application. Applicants have found that the present technology allows for the use of levelers in a wafer form on the order of 100 mm, 200 mm, 300 mm, or greater.
[0074] The thermal levelers can be formed by providing a graphite piece defining a cavity as a first graphite piece and disposing a high thermal conductivity insert within the cavity. The high thermal conductivity insert comprises the high thermal conductivity material coated with a layer of a carbide forming metal. Another graphite piece is provided as the second graphite piece to cover the high thermal conductivity insert. The shape and configuration of the pieces can be provided as desired to provide a graphite body. In embodiments, the respective graphite pieces and insert can be shaped in accordance with one or more of the previous embodiments described herein.
[0075] In an embodiment employing a bonding material disposed between the lower surface of the second graphite piece and the upper surface of the first graphite piece, one or both of the respective pieces can be coated with the bonding material.
[0076] If necessary, a weight, clamp, or other mechanism may be employed to hold the respective pieces together while the metal carbide layer is formed to bond the high thermal conductivity insert to the graphite. The metal carbide layer can be formed by exposing the unit to heat at a temperature sufficient to form the metal carbide. This may also be sufficient to form a bond between the graphite pieces with the bonding material.
[0077] For thermal levelers having an external coating layer disposed on the graphite body, the formation of the metal carbide bond with the graphite and the high thermal conductivity insert can be formed prior to coating the graphite body, or it can be formed in situ during the coating process. In the former, the graphite body can be formed as described above including subjecting the body to conditions sufficient to form the metal carbide bond. Subsequent to forming the metal carbide bond with within the high thermal conduct! vity/metal/graphite system, the graphite body can be subjected to a coating process to apply a coating to the external surfaces of the graphite body.
[0078] In the in situ process, the graphite body is provided such that the metal coating of the high thermal conductivity insert is not yet bonded with the graphite. The graphite body is subjected to a coating process under sufficient heat and pressure to cause the metal coating disposed on the high thermal conductivity material forms a metal carbide with the graphite. It will be appreciated that the type of external coating being employed to coat the graphite body will dictate whether the in situ method can be used to bond the insert and the graphite. That is, the temperature conditions/tolerances for depositing the coating must be sufficient to facilitate formation of the internal metal carbide bond. Additionally, the graphite pieces forming the graphite body should be configured such that the pieces can be held in compression without external means. This may be accomplished by a threaded hole disposed through the graphite pieces.
[0079] The leveler of the invention can be used in a number of different processes, including in a plasma-etching chamber for processing glass molds, or in semiconductor processing chambers including but not limited to atomic layer epitaxy (ALD), low pressure CVD (LPCVD), and plasma-enhanced CVD (PECVD).
[0080] The foregoing description identifies various, non-limiting embodiments of a thermal leveler. Modifications may occur to those skilled in the art and to those who may make and use the invention. The disclosed embodiments are merely for illustrative purposes and not intended to limit the scope of the invention or the subject matter set forth in the claims.

Claims

CLAIMS What is claimed is:
1. A thermal leveler comprising a graphite body and a high thermal conductivity insert disposed within the graphite body, the high thermal conductivity insert comprising (i) a thermally conductive material having an in plane thermal conductivity higher than that of the graphite body, and (ii) a metal layer disposed on a surface of the thermally conductive material and in contact with the graphite body, the metal layer comprising a carbide forming metal.
2. The thermal leveler of claim 1, wherein the graphite body comprises a first graphite piece defining a cavity sized to receive the high thermal conductivity insert, and a second graphite piece shaped to mate with the first graphite piece and encapsulate the high thermal conductivity insert.
3. The thermal leveler of claim 2, wherein the high thermal conductivity insert is sized such that it recessed relative to an upper of the first graphite piece, and the second graphite piece comprises a ridge sized to mate within the cavity of the first graphite piece and has a depth sufficient for a surface of the ridge to contact a metal layer of the high thermal conductivity insert.
4. The thermal leveler of claim 2, wherein the high thermal conductivity insert is sized such that a portion of the insert extends above an upper surface of the first graphite piece, and the second graphite piece defines a cavity sized to mate with and surround the portion of the insert extending above the upper surface of the first graphite piece.
22
5. The thermal leveler of claim 2, wherein the high thermal conductivity insert is sized such that an upper surface of the insert is substantially planar with an upper surface of the first graphite piece.
6. The thermal leveler of claim 5, wherein a lower surface of the second graphite piece contacts the upper surface of the high thermal conductivity insert.
7. The thermal leveler of claim 5, wherein the first graphite piece defines a ledge adjacent an upper surface of the first graphite piece, and the second graphite piece defines a cavity size to mate with the first graphite piece.
8. The thermal leveler of any of claims 2-7 comprising one or more slots defined along a periphery of the graphite body and between an upper surface of the first graphite piece and a lower surface of the second graphite piece.
9. The thermal leveler of claim 8, wherein the one or more slots is a single slot extending around the entire periphery of the graphite body.
10. The thermal leveler of claims 8 or 9, comprising a carbide forming metal disposed with the one or more slots.
11. The thermal leveler of any of claims 1-10, wherein the carbide forming metal is a metal selected from Group IVb, Group Vb, Group VIb, and Group Vllb of the periodic table, or an alloy of two or more.
12. The thermal leveler of claim 11, wherein the carbide forming metal is selected form titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, or an alloy of two or more thereof.
13. The thermal leveler of any of claims 1-12, wherein the thermally conductive material of the thermally conductive insert is thermal pyrolytic graphite.
14. The thermal leveler of any of claims 2-13, wherein the first graphite piece has a first coefficient of thermal expansion, the second graphite piece has a second coefficient of thermal expansion, and the first coefficient of thermal expansion is from about 0% to about 65% lower than the second coefficient of thermal expansion.
15. The thermal leveler of any of claims 1-14 comprising a coating disposed on the graphite body.
16. The thermal leveler of claims 8 or 9, wherein the thermal leveler comprises a coating disposed on the graphite body, and the coating is further disposed within the one or more slots.
17. The thermal leveler of claims 15 or 16, wherein the coating is selected from pyrolytic graphite, pyrolytic boron nitride, a quartz/glass based coating, a metal carbide, a metal nitride, a metal carbonitride, or a metal oxynitride.
18. The thermal leveler of claim 17, wherein the coating is tantalum carbide
(TaC) or silicon carbide (SiC).
19. The thermal leveler of claim 17, wherein the coating is selected from lanthanum aluminosilicate (LAS), magnesium aluminosilicate (MAS), calcium aluminosilicate (CAS), or yttrium aluminosilicate (YAS).
20. A method of forming a thermal leveler having a graphite body encapsulating a high thermal conductivity insert, the method comprising:
(i) providing a first graphite piece defining a cavity defining a lower surface and a wall;
(ii) disposing a high thermal conductivity insert into the cavity of the first graphite piece, the high thermal conductivity insert comprising a high thermal conductivity material having an upper surface and a lower surface, a first metal coating disposed on the lower surface of the high thermal conductivity material, and a second metal coating disposed on the upper surface of the high thermal conductivity material, the first and second metal coatings independently selected from a carbide forming metal;
(iii) providing a second graphite piece configured with a shape configured to encapsulate the high thermal conductivity insert and disposing the second graphite piece about the first graphite piece to provide a graphite body; and
(iv) subjecting the graphite body to a temperature and/or pressure sufficient for the first and second metal layers of the high thermal conductivity insert to form a metal carbide bond with the first and second graphite pieces, respectively.
21. The method of claim 20, wherein the graphite body comprises one or more slots defined along the outer periphery of the graphite body between the first graphite piece and the second graphite piece.
25
22. The method of claim 21 comprising providing a carbide forming metal within the one or more slots.
23. The method of claim 22, wherein providing the carbide forming metal within the one or more slots is carried out prior to step (iv).
24. The method of claim 20 comprising applying a coating to the outer surface of the graphite body.
25. The method of claim 24, wherein the coating is applied subsequent to step (iv).
26. The method of claim 24, wherein the coating is applied prior to step (iv), and step (iv) occurs in conjunction with the formation of the coating.
26
PCT/US2021/047436 2020-08-25 2021-08-25 Graphite based thermal leveler with high thermal conductivity material encapsulated therein WO2022046830A1 (en)

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DE102006056812A1 (en) * 2006-09-26 2008-03-27 General Electric Co. Heater for regulating/controlling surface temperature of substrate e.g. mold for glass lens, comprises a thermal pyrolytic layer in base support for providing specific maximum temperature variation, and having specific thermal conductivity
US20100053841A1 (en) * 2008-09-04 2010-03-04 Momentive Performance Materials Inc. Wafer processing apparatus having a tunable electrical resistivity
US7901509B2 (en) * 2006-09-19 2011-03-08 Momentive Performance Materials Inc. Heating apparatus with enhanced thermal uniformity and method for making thereof
US20130327274A1 (en) * 2012-06-07 2013-12-12 Mitsubishi Electric Corporation Substrate support and semiconductor manufacturing apparatus
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US5863467A (en) 1996-05-03 1999-01-26 Advanced Ceramics Corporation High thermal conductivity composite and method
DE102006056615A1 (en) * 2006-07-06 2008-01-10 General Electric Co. Wafer processing device for use in semiconductors processing chamber for production of semiconductors, has base substrate on which wafer is located, where filler seals gap in device
US7901509B2 (en) * 2006-09-19 2011-03-08 Momentive Performance Materials Inc. Heating apparatus with enhanced thermal uniformity and method for making thereof
DE102006056812A1 (en) * 2006-09-26 2008-03-27 General Electric Co. Heater for regulating/controlling surface temperature of substrate e.g. mold for glass lens, comprises a thermal pyrolytic layer in base support for providing specific maximum temperature variation, and having specific thermal conductivity
US20100053841A1 (en) * 2008-09-04 2010-03-04 Momentive Performance Materials Inc. Wafer processing apparatus having a tunable electrical resistivity
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