Improvements in chemical vapor deposition systems

Abstract

A composite wafer chuck for a chemical vapor deposition system includes an inner part configured to support a wafer; an outer part including a recess dimensioned and configured to receive the inner part; a first shaft connected to the inner part and configured to lift the inner part out of the recess in the outer part; and a second shaft connected to the outer part and configured to rotate the inner part when it is received in the recess in the outer part.

Description

IMPROVEMENTS IN CHEMICAL VAPOR DEPOSITION SYSTEMSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of, and priority to, U.S. Provisional Patent Application No. 63 / 590,498 filed on October 16, 2023, the entire contents of which is hereby incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure generally relates to chemical vapor deposition (CVD) systems. More specifically, the present disclosure relates to epitaxial deposition of silicon carbide (SiC).BACKGROUND

[0003] Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted as being prior art by inclusion in this section.

[0004] Chemical vapor deposition systems are used to deposit a coating upon a substrate (e.g., a wafer). The substrate may be supported by a rotating wafer chuck. Due to the small size of conventional process chambers, handling of substrates in and out of the chamber may present technical challenges, particularly when the substrate is being positioned on a rotating chuck. Adequate grounding of the substrate while mounted in the rotating chuck may also present challenges. In addition, temperature control during the chemical vapor deposition impacts the quality of the deposited coating. To address some of these issues, multiple zone heaters have been proposed, e.g., as previously disclosed in International Patent Application Publication PCT / US22 / 50351.

[0005] There remains room for improvement in the design of chemical vapor deposition (CVD) systems, such as systems for epitaxial deposition of silicon carbide (SiC).SUMMARY

[0006] According to one aspect of the present disclosure, a composite wafer chuck for a chemical vapor deposition system is described. The composite wafer chuck includes an inner part configured to support a wafer and an outer part including a recess dimensioned and configured to receive the inner part. A first shaft is connected to the inner part and configured to lift the inner part out of the recess in the outer part. A second shaft connected to the outer part and configured to rotate the inner part when it is received in the recess in the outer part.

[0007] In aspects, the second shaft is hollow, and the first shaft is positioned within the first shaft. In aspects, the first shaft lifts the inner part to a position where a wafer can be either loaded onto the inner part or un-loaded off of the inner part. In aspects, the second shaft is coupled to a bottom plate of a CVD reactor by a vacuum connection. In aspects, the second shaft is coupled to a bottom plate of a CVD reactor by a flexible bellows.

[0008] In aspects, the recess in the outer part is a stepped recess having a first step and a second step, the first step having a greater diameter than a diameter of the second step. In aspects, the recess in the outer part is a stepped recess having a first step and a second step, the first step having a thickness that is different from a thickness of the second step. In aspects, the inner part of the composite wafer chuck is configured to support a wafer that is pre-loaded onto a graphite wafer support, the graphite wafer support being supported by both the inner part and the outer party when the inner part is received with the recess of the outer part.

[0009] According to another aspect of the present disclosure, a system for chemical vapor deposition is described. The system includes a process chamber having a top plate; a rotating chuck within the process chamber; and a wafer heating coil located above the process chamber top plate to inductively heat a wafer positioned upon the rotating chuck. The top plate of the process chamber is a composite plate including a first dielectric plate supporting a thermal insulation material and a second dielectric plate enclosing the thermal insulation material.

[0010] In aspects, the composite plate is non-coupling to an electromagnetic field produced by the wafer heating coil. In aspects, the wafer heating coil is enclosed within a vacuum chamber constructed of material non-coupling to the wafer heating coil. In aspects, the rotating check is a composite wafer chuck including an inner part configured to support a wafer and an outer part including a recess dimensioned and configured to receive the inner part.

[0011] In aspects, the wafer heating coil includes first and second wafer heating coils, the first wafer heating coil inductively coupled to a first half of the inner part of the composite wafer chuck and the second wafer heating coil inductively coupled to a second half of the inner part of the composite wafer chuck. In aspects, the first wafer heating coil is connected to a first power supply and the second wafer heating coil is connected to a second power supply, wherein the first power supply operates at a first frequency and the second power supply operates at a second frequency different from the first frequency to allow for independent temperature control of the first and second halves of the inner part of the composite wafer chuck. In aspects, the first and second wafer heating coils are independently movable from a first position that is a first distance from the top plate of the process chamber to a second position that is a second distance from the top plate of the process chamber, the second distance greater than the first distance.

[0012] In aspects, the process chamber includes first and second vertical walls fabricated of a conducting material that can be inductively heated by additional zone control heating coils located outside the process chamber, the system further comprising first and second insulating material on each of the first and second vertical walls. In aspects, the system further includes a first resistive heater positioned between the first vertical wall and the first insulating material; and a second resistive heater positioned between the second vertical wall and the second insulating material.

[0013] In aspects, the system further includes a gas inlet port extending through the first vertical wall and the first insulating material, the gas inlet port directing precursor species across a top of the rotating chuck; and an exhaust port extending through the second vertical wall and the second insulating material, the exhaust port removing byproduct gases from the process chamber. In aspects, the system further includes a preheater to heat precursor species prior to the precursor species entering the gas inlet port. In aspects, the gas inlet port includes first, second and third injectors. In aspects, each of the first, second and third injectors directs a separate precursor across the top of the rotating chuck. In aspects, at least one of the first, second or third injector has a tapered geometry.

[0014] In aspects, the gas inlet port includes an upper injector and a lower injector. In aspects, each of the upper and lower injectors directs a different precursor across the top of the rotating chuck. In yet other aspects, the process chamber has a round geometry.BRIEF DESCRIPTION OF THE FIGURES

[0015] Features of the present disclosure will become more fully apparent from the following description, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which:

[0016] Fig. 1 shows an illustrative system for chemical vapor deposition that may incorporate various aspects of the presently disclosed features;

[0017] Fig. 2 shows the process chamber of the system of Fig. 1 with the cover removed to show internal structures thereof;

[0018] Fig. 3a - 3d show various views of a prior art wafer handling system for use in a CVD system as disclosed, for example, in International Patent Application Publication PCT / US22 / 50351;

[0019] Fig. 4 shows a cross section view of a prior art horizontal cross-flow epitaxial reactor geometry where a wafer is resting on a chuck, or susceptor, that is inductively heated from below;

[0020] Fig. 5a - 5c schematically illustrate top cross sectional views of various prior art CVD reactors with various configurations of gas injector and exhaust lines;

[0021] Fig. 6a schematically illustrates a side cross sectional view of a composite rotating wafer chuck having a wafer loaded thereon according to another embodiment of the present disclosure;

[0022] Fig. 6b schematically illustrates a side cross sectional view of the composite rotating wafer chuck of Fig. 6a with the wafer in the unload position, supported by the inner support part of the composite rotating wafer chuck;

[0023] Figs. 7a-d schematically illustrate various configurations of a composite chuck according to exemplary embodiments of the present disclosure;

[0024] Fig. 8 schematically illustrates a side cross sectional view of a CVD reactor with a single wafer heating coil located above the process chamber top plate and incorporating a composite rotating wafer chuck according to another embodiment of the present disclosure;

[0025] Fig. 9 schematically illustrates a side cross sectional view of a CVD reactor with a single wafer heating coil located above the process chamber top plate and additional resistive heaters located outside the process chamber walls but inside of the thermal insulation according to another embodiment of the present disclosure;

[0026] Fig. 10 schematically illustrates a side cross sectional view of a CVD reactor with two independent heating coils located above the process chamber top plate and incorporating a composite rotating wafer chuck according to another embodiment of the present disclosure;

[0027] Figs. 1 la-c schematically illustrate top cross sectional views of example CVD reactors with various configurations of gas injector and exhaust lines according to additional embodiments of the present disclosure;

[0028] Fig. 12 schematically illustrates a side cross sectional view of a CVD reactor with a gas inlet split into an upper injector and a lower injector according to another embodiment of the present disclosure; and

[0029] Fig. 13 schematically illustrates a side cross sectional view of a CVD reactor with a split gas inlet and independently movable heating coils according to another embodiment of the present disclosure.DETAILED DESCRIPTION

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well as the singular forms, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one having ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0032] In describing the present disclosure, it will be understood that a number of systems, methodologies, techniques and steps are disclosed. Each of these has individual benefit and each can also be used in conjunction with one or more, or in some cases all, of the other disclosed techniques. Accordingly, for the sake of clarity, this description will refrain from repeating every possible combination of the individual steps in an unnecessary fashion.

[0033] Nevertheless, the specification should be read with the understanding that such combinations are entirely within the scope of the disclosure.

[0034] Turning now to Fig. 1, an illustrative system 100 for chemical vapor deposition includes a wafer transport unit 10, a cassette housing 20, a process chamber 30 and a process module 60. Wafer transport unit 10 includes a robotic arm (not shown) and suitable motors (not shown) and controls (not shown) for movement of the robotic arm to allow wafer transport unit 10 to retrieve a wafer 50 from cassette 22 in cassette housing 20, and deliver wafer 50 to process chamber 30. Process module 60 includes heating and cooling systems, gasses for CVD deposition process, one or more plasma generators, a vacuum system, exhaust structures, etc. typically found in CVD systems. The one or more plasma generators may generate one or more of: DC plasma, pulsed DC plasma, RF plasma, pulsed RF plasma, intermediate frequency (IF) plasma, pulsed IF plasma, mixed DC and RF plasma, mixed DC and IF plasma, mixed IF and RF plasma, mixed DC and RF and IF plasma, microwave plasma, or microwave plasma mixed with one or more of DC, RF, or IF plasma. In embodiments, a “pulsed DC” source may be employed to create plasma with constant electric field orientation with optional on / off cycling (unlike RF plasma, where polarity is switching during one oscillation period). Process module 60 also includes controller(s) to control the various functions of the CVD system.

[0035] As seen in Fig. 2, process chamber 30 includes a flange 32 including an opening 33 through which wafer 50 is introduced by wafer transport unit 10 into process chamber 30. A valve (not shown) seals process chamber 30 after introduction of wafer 50 as is known to those skilled in the art. A showerhead 300 is mounted to process chamber 30. Sensors 35a, 35b and 35c are mounted through showerhead 300 to detect the temperature of the wafer 50. In embodiments, sensors 35a-c are optical pyrometers that can sense a temperature of wafer 50 as it rotates, without requiring direct contact with wafer 50. A gas inlet port 37 is also provided to permit introduction of process gas (e.g., premixed gases required for CVD deposition of a film onto a substrate) intoprocess chamber 30. Process chamber 30 also includes a view port 39 and a port (not shown) to remove exhaust gases from process chamber 30.

[0036] Fig 3a shows a a prior art wafer handling system including a wafer chuck 10 with a rotating shaft 11 and wafer lifter pins 12 as disclosed, for example, in International Patent Application Publication PCT / US22 / 50351. Fig. 3b also shows a wafer 13 in the unload position supported by the lifter pins. As an example, a wafer can be a SiC wafer with a diameter of more than 100 mm, for example, 150 mm or, for example, 200 mm, or larger. Fig. 3c shows a cross section view of a chuck and a shaft with lifter pins supporting a wafer in the unload position. Fig. 3d depicts a wafer in a process position showing lifter pins retracted below bottom surface of a rotating chuck.

[0037] Fig. 4 shows a cross section view of a prior art horizontal cross-flow epitaxial reactor geometry where a wafer is resting on a chuck, or susceptor, that is inductively heated from below by a flat “pancake” induction coil 21. A chuck with a wafer can be rotated during the deposition process for improved uniformity. A hot wall reactor enclosure can be made of graphite walls 221 and 223 and ceiling 222. For thermal insulation, the reactor enclosure may be surrounded by thermally insulating material 231, 232 and 233 made, for example, from graphite foam or, for example, graphite felt. A gas inlet port 24 provides delivery of the precursor species for reaction and an exhaust port 25 provides exhaust of any unreacted precursor and byproduct gases.

[0038] Fig. 5a schematically shows a top view of a prior art CVD reactor 31 illustrating gas flow from inlet 32 to exhaust 33 over the rotating wafer surface. Fig. 5b shows that in some prior art systems a gas inlet may consist of three separate injectors thereby allowing independent control of the molar ratio between reaction precursors in main injector 34 and supplementary injectors 35 and 36. Fig. 5c shows that a main injector may have a tapered shape 37.

[0039] Fig. 6a shows a cross section drawing of a composite wafer chuck 40 consisting of outer support part 41, inner support part 42 and rotation shafts 43 and 44 in accordance with aspects of the present disclosure. Rotation shaft 43 is connected to the outer support part 41 to enable wafer rotation and rotation shaft 44 is connected to the inner support part 42 to enable lifting the inner support part in the unload position. Rotation shaft 43 is also coupled to a bottom plate 45 of a CVD reactor by a flexible bellows 46 or other vacuum connection to allow for vertical motion. As seen in Fig. 6b, a wafer 50 is in the unload position, supported only by inner support part 42 which islifted from a recessed portion 47 of outer support part 41, thereby allowing for an automated loading and unloading of wafer 50.

[0040] Fig. 7a-d show side cross-sections of various possible configurations of a composite chuck suitable for use in the reactors of the present disclosure. Fig. 7a shows the composite chuck of Fig. 6a having a stepped recess in outer support part 41 configured to receive a correspondingly shaped inner support part 42, and where upper step 53 has a greater diameter than lower step 54. Fig. 7b shows a composite chuck 40a having a tapered recess in outer support part 51 configured to receive a correspondingly shaped inner support part 52 to provide a tapered j oint. Fig. 7c shows a composite chuck 40b having a stepped recess in outer support part 41c configured to receive a correspondingly shaped inner support part 42b where upper step 53a and lower step 54 have non equal thickness. Fig. 7d shows an intermediate graphite wafer support 55 that may be loaded and unloaded along with the wafer 50 onto composite wafer chuck 40 for more controllable cool down rate outside of the CVD process reactor.

[0041] Fig. 8 shows an embodiment of a CVD reactor in accordance with an embodiment of the disclosure with a main wafer heating coil 61 located above the process chamber top plate and additional zone control heating coils 62 located outside of process chamber. As those skilled in the art reading this disclosure will appreciate, in the horizontal gas flow epitaxial reactor geometry shown, wafer 50 is resting on composite chuck 40, or susceptor, that is inductively heated from above by main wafer heating coil 61. Gas inlet port 24 and exhaust port 25 provide delivery of the precursor species for reaction and exhaust of the byproduct gases, respectively. Vertical walls 221 and 223 of a reactor chamber may be fabricated of conducting material that can be inductively heated, i.e., graphite, and insulated with heat insulating material 231 and 233, such as, for example, a graphite foam or, for example, a graphite felt. Process chamber composite top plate has a dielectric plate 63 providing a mechanical support for a thermal insulation material 64 and a dielectric plate 65 enclosing an insulation material and providing external mechanical support. Dielectric plates 63 and 65 may be composed of ceramic material, for example, pyrolytic boron nitride or, for example, tantalum carbide, or a high temperature crystalline material, for example, silicon carbide or, for example, sapphire. Insulation material 64 may be constructed of, for example, a graphite felt, or, for example, a graphite foam. A composite top plate is essentially non coupling to electromagnetic field produced by induction heating coil 61 thereby allowing to heat a composite wafer chuck and a wafer to be processed. In another embodiment, an induction coilmay be enclosed into a separate vacuum chamber constructed of material non coupling to the induction coil, such as, for example, quartz. Such a separate vacuum chamber may be beneficial in protecting the induction coil from deposition.

[0042] Fig. 9 schematically illustrates a side cross sectional view of a CVD reactor with a single wafer heating coil 61 located above the process chamber top plate and additional resistive heaters 71, 72 located outside the process chamber walls, but inside of the thermal insulation. Heaters 71 and 72 provide a hot wall reactor configuration that may help reduce end zone thermal losses.

[0043] Fig. 10 shows a heating coil comprised of two independent coils 81 and 82 in such a way that coil 81 is essentially inductively coupled to at least half of an inner support part 42 and coil 82 is essentially inductively coupled to at least half of an outer support part 41. Induction coils 81 and 82 can be connected to separate power supplies operating at different frequencies to allow for independent temperature control of inner and outer zones. Such a heating coil configuration provides additional temperature control to improve uniformity of a deposition rate. While shown with two coils, it should be understood that 3, 4, or more coils may be included to control composite chuck temperature.

[0044] Fig. I la shows gas flow from inlet 32 to exhaust line 33 over the rotating wafer surface, and that gas injector line 32 may be optionally preheated by an induction heating coil 91 to reduce gas heating time inside of the process chamber, increase the reaction efficiency, and reduce low density deposits on process chamber walls. It may also be beneficial to provide additional heating to exhaust line 33 by means of additional induction heating coil 92 to reduce low density byproduct deposits in close proximity to a process chamber. Fig. 1 lb shows that the same concept can be applied to a gas inlet system that includes three separate injectors (e.g., a main injector 34 and supplementary injectors 35 and 36) thereby allowing control of the molar ratio between precursors. In embodiments, the main injector 34 may have a tapered injector geometry as shown in Fig. 1 lb, although other geometries are contemplated. Fig. 11c shows that round reactor chamber 93 geometry can advantageously be employed in some instances to reduce gas flow turbulence and achieve more laminar gas flow over the wafer surface.

[0045] Fig. 12 presents a cross section schematical view of a process chamber where the gas inlet is further split into upper injector 101 and lower injector 102 to further control precursor molar flow ratio and balance of a purge gas. Although shown in Fig. 12 as a single inlet, it shouldbe understood that injector 101 may be also divided into several independent gas paths along the wafer diameter. Similarly, an exhaust flow balance may be controlled by dividing exhaust gas flow between exhaust lines 103 and 104 to fine tune laminar gas flow control in the process chamber. Furthermore, volume underneath wafer chuck 40 may be purged separately and gas flow may be separately exhausted through line 105 located underneath wafer chuck 40.

[0046] Fig. 13 depicts a temperature control method to adjust the susceptor 40 (and wafer 50) inner and outer zone temperature by independently moving inner induction coil 81 from position 111 to position 112 and outer induction coil 82 from position 113 to position 114. In such a configuration coils 81, 82 can be electrically connected via a flexible wire and be a part of the same coil operating at same frequency powered by same power supply.

[0047] In other embodiments, side wall heaters and injector and / or exhaust heaters can be resistive heaters.

[0048] While parallel-plate PECVD reactor temperature control has been disclosed, it is contemplated that the novel heating / cooling system may be utilized in many different applications where there is a rotating component that needs to be heated and cooled. The system may be especially suitable to “flat” rotating surfaces found in cluster tool (and non-cluster) process chambers for metal organic chemical vapor deposition (MOCVD), atomic layer deposition (ALD), low pressure chemical vapor deposition (LPCVD), physical vapor deposition (PVD), annealing, heat treating, plasma etching and other similar processes involving elevated temperatures which require temperature uniformity and rapid cooling for high-throughput. The described rotary temperature control technique may also be applicable to larger, non-planar processed parts, when rotary motion is involved to create rotationally-symmetrical temperature control.

[0049] While epitaxial deposition of silicon carbide (SiC) has been disclosed, it is contemplated that other material systems may benefit from the disclosed reactor geometries, for example aluminum nitride (AIN), aluminum gallium nitride (AlGaN), aluminum scandium nitride (AlScN), boron nitride (BN), boron-doped aluminum nitride (BAIN) and other material systems. Similarly, use of chlorine or HCl-based precursors to form chloride adatoms at the growth surface may benefit from the disclosed reactor geometries.

[0050] Also, while described in terms of depositing a coating on a wafer, it should be understood that the present systems may be used to provide a coating on any suitable substrate.

[0051] The systems described herein may utilize one or more controllers to receive various information and transform the received information to generate an output. The controller may include any type of computing device, computational circuit, or any type of processor or processing circuit capable of executing a series of instructions that are stored in a memory. The controller may include multiple processors and / or multicore central processing units (CPUs) and may include any type of processor, such as a microprocessor, digital signal processor, microcontroller, programmable logic controller (PLC), field programmable gate array (FPGA), or the like. The controller may also include a memory to store data and / or instructions that, when executed by the one or more processors, causes the one or more processors to perform one or more methods and / or algorithms.

[0052] Any of the herein described methods, programs, algorithms or codes may be converted to, or expressed in, a programming language or computer program. The terms “programming language” and “computer program,” as used herein, each include any language used to specify instructions to a computer, and include (but is not limited to) the following languages and their derivatives: Assembler, Basic, Batch files, BCPL, C, C+, C++, Ladder Logic, Delphi, Fortran, Java, JavaScript, machine code, operating system command languages, Pascal, Perl, PL1, scripting languages, Visual Basic, metalanguages which themselves specify programs, and all first, second, third, fourth, fifth, or further generation computer languages. Also included are database and other data schemas, and any other meta-languages. No distinction is made between languages which are interpreted, compiled, or use both compiled and interpreted approaches. No distinction is made between compiled and source versions of a program. Thus, reference to a program, where the programming language could exist in more than one state (such as source, compiled, object, or linked) is a reference to any and all such states. Reference to a program may encompass the actual instructions and / or the intent of those instructions.

[0053] The storage and / or memory device may be one or more physical apparatus used to store data or programs on a temporary or permanent basis. In some embodiments, the controller may include volatile memory and requires power to maintain stored information. In some embodiments, the controller includes non-volatile memory and retains stored information when it is not powered. In some embodiments, the non-volatile memory includes flash memory. In some embodiments, the non-volatile memory includes dynamic random-access memory (DRAM). In some embodiments, the non-volatile memory includes ferroelectric random access memory (FRAM). Insome embodiments, the nonvolatile memory includes phase-change random access memory (PRAM). In some embodiments, the controller is a storage device including, by way of nonlimiting examples, CD-ROMs, DVDs, flash memory devices, magnetic disk drives, magnetic tapes drives, optical disk drives, and cloud computing based storage. In some embodiments, the storage and / or memory device is a combination of devices such as those disclosed herein. Code or instructions contained thereon can be represented by carrier wave signals, infrared signals, digital signals, and by other like signals.

[0054] It should be understood that the foregoing description is only illustrative of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications and variances. The embodiments described with reference to the attached drawing figures are presented only to demonstrate certain examples of the disclosure. Other elements, steps, methods, and techniques that are insubstantially different from those described above are also intended to be within the scope of the disclosure.

Claims

WHAT IS CLAIMED IS1. A composite wafer chuck for a chemical vapor deposition system comprising; an inner part configured to support a wafer; an outer part including a recess dimensioned and configured to receive the inner part; a first shaft connected to the inner part and configured to lift the inner part out of the recess in the outer part; and a second shaft connected to the outer part and configured to rotate the inner part when it is received in the recess in the outer part.

2. The composite wafer chuck of claim 1, wherein the second shaft is hollow and the first shaft is positioned within the first shaft.

3. The composite wafer chuck of claim 1, wherein the first shaft lifts the inner part to a position where a wafer can be one of loaded onto the inner part or un-loaded off of the inner part.

4. The composite wafer chuck of claim 1, wherein the second shaft is coupled to a bottom plate of a CVD reactor by a vacuum connection.

5. The composite wafer chuck of claim 1, wherein the second shaft is coupled to a bottom plate of a CVD reactor by a flexible bellows.

6. The composite wafer chuck of claim 1, wherein the recess in the outer part is a stepped recess having a first step and a second step, the first step having a greater diameter than a diameter of the second step.

7. The composite wafer chuck of claim 1, wherein the recess in the outer part is a stepped recess having a first step and a second step, the first step having a thickness that is different from a thickness of the second step.

8. The composite wafer chuck of claim 1 , wherein the inner part is configured to support a wafer that is pre-loaded onto a graphite wafer support, the graphite wafer support being supported by both the inner part and the outer party when the inner part is received with the recess of the outer part.

9. A system for chemical vapor deposition, the system comprising: a process chamber having a top plate; a rotating chuck within the process chamber; and a wafer heating coil located above the process chamber top plate to inductively heat a wafer positioned upon the rotating chuck, wherein the top plate of the process chamber is a composite plate including a first dielectric plate supporting a thermal insulation material and a second dielectric plate enclosing the thermal insulation material.

10. The system of claim 9, wherein the composite plate is non-coupling to an electromagnetic field produced by the wafer heating coil.

11. The system of claim 9, wherein the wafer heating coil is enclosed within a vacuum chamber constructed of material non -coupling to the wafer heating coil.

12. The system of claim 9, wherein the rotating check is a composite wafer chuck including an inner part configured to support a wafer and an outer part including a recess dimensioned and configured to receive the inner part.

13. The system of claim 12, wherein the wafer heating coil comprises first and second wafer heating coils, the first wafer heating coil inductively coupled to a first half of the inner part of the composite wafer chuck and the second wafer heating coil inductively coupled to a second half of the inner part of the composite wafer chuck.

14. The system of claim 13, wherein the first wafer heating coil is connected to a first power supply and the second wafer heating coil is connected to a second power supply, wherein the first power supply operates at a first frequency and the second power supply operates at a second frequency different from the first frequency to allow for independent temperature control of the first and second halves of the inner part of the composite wafer chuck.

15. The system of claim 13, wherein the first and second wafer heating coils are independently movable from a first position that is a first distance from the top plate of the process chamber to a second position that is a second distance from the top plate of the process chamber, the second distance greater than the first distance.

16. The system of claim 9, wherein the process chamber includes first and second vertical walls fabricated of a conducting material that can be inductively heated by additional zone control heating coils located outside the process chamber, the system further comprising first and second insulating material on each of the first and second vertical walls.

17. The system of claim 16, further comprising a first resistive heater positioned between the first vertical wall and the first insulating material; and a second resistive heater positioned between the second vertical wall and the second insulating material.

18. The system of claim 16, further comprising: a gas inlet port extending through the first vertical wall and the first insulating material, the gas inlet port directing precursor species across a top of the rotating chuck; and an exhaust port extending through the second vertical wall and the second insulating material, the exhaust port removing byproduct gases from the process chamber.

19. The system of claim 18, further comprising a preheater to heat precursor species prior to the precursor species entering the gas inlet port.

20. The system of claim 18, wherein the gas inlet port includes first, second and third injectors.

21. The system of claim 20, wherein each of the first, second and third injectors directs a separate precursor across the top of the rotating chuck.

22. The system of claim 20, wherein at least one of the first, second or third injector has a tapered geometry.

23. The system of claim 18, wherein the gas inlet port includes an upper injector and a lower injector.

24. The system of claim 23, wherein each of the upper and lower injectors directs a different precursor across the top of the rotating chuck.

25. The system of claim 20, wherein the process chamber has a round geometry.

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