Heated substrate support for minimizing heat loss and improving uniformity

Abstract

[0009] Embodiments of a substrate support for use in a process chamber are provided herein. In some embodiments, the substrate support for use in a process chamber includes: a heater plate having an upper surface for supporting a substrate and a lower surface opposite the upper surface, the heater plate including a first material having a first thermal conductivity, and a sidewall of the heater plate and the lower surface of the heater plate being covered with a cover plate including a second material having a second thermal conductivity less than the first thermal conductivity; a hollow shaft coupled to the heater plate, the hollow shaft including a third material having a third thermal conductivity less than the first thermal conductivity; and one or more heating elements disposed on the heater plate.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to substrate processing apparatuses.

Background Art

[0002] Substrate processing apparatuses generally include a process chamber configured to perform a specific process on a substrate, such as chemical vapor deposition, atomic layer deposition, annealing, etc. A substrate support for use in a process chamber typically includes a pedestal for supporting a substrate, coupled to a hollow shaft that provides conduits for fluids, electricity, gases, etc. to the pedestal. The pedestal may also include an embedded heater for supplying heat to the substrate for a particular substrate process. In conventional pedestals, the inventors have observed that heat from the heater is transferred away from the substrate and results in heat loss to the bottom surface and shaft of the pedestal. Also, in conventional pedestals, the inventors have observed that the temperature varies across the top surface of the pedestal.

[0003] Therefore, the inventors have provided embodiments of an improved substrate support.

Summary of the Invention

[0004] Embodiments of a substrate support for use in a process chamber are provided herein. In some embodiments, a substrate support for use in a process chamber is a heater plate having an upper surface for supporting a substrate and a lower surface opposite the upper surface, including a first material having a first thermal conductivity, wherein the sidewalls and the lower surface of the heater plate are covered with a cover plate including a second material having a second thermal conductivity smaller than the first thermal conductivity, a heater plate, a hollow shaft coupled to the heater plate, including a third material having a third thermal conductivity smaller than the first thermal conductivity, and one or more heating elements disposed on the heater plate.

[0005] In some embodiments, a substrate support for use in a process chamber includes a heater plate having an upper surface and a lower surface opposite the upper surface for supporting a substrate, comprising a first material having a first thermal conductivity greater than 100 watts / meter·Kelvin (W / (m·K)), and the side walls and lower surface of the heater plate being covered by a cover plate comprising a second material having a second thermal conductivity less than the first thermal conductivity; a hollow shaft coupled to the heater plate, comprising the second material; and one or more heating elements disposed on the heater plate.

[0006] In some embodiments, the process chamber includes a chamber body defining an internal volume and a substrate support at least partially disposed within the internal volume, wherein the substrate support includes one or more heating elements disposed inside, and comprises a heater plate having an upper surface for supporting a substrate, comprising a first material having a first thermal conductivity, and the side walls and lower surface of the heater plate are covered with a cover plate comprising a second material having a second thermal conductivity less than the first thermal conductivity; and a hollow shaft coupled to the heater plate, comprising a third material having a third thermal conductivity less than the first thermal conductivity.

[0007] Other and further embodiments of this disclosure are described below.

[0008] The embodiments of this disclosure, which are briefly summarized above and discussed in more detail below, can be understood by referring to the exemplary embodiments of this disclosure shown in the accompanying drawings. However, the accompanying drawings show only typical embodiments of this disclosure and should not be considered limiting in scope, as this disclosure may allow for other equally valid embodiments. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic side view of a process chamber according to at least some embodiments of the present disclosure. [Figure 2] This is a schematic cross-sectional side view of a substrate support according to at least some embodiments of the present disclosure. [Figure 3] This is a schematic cross-sectional side view of a substrate support according to at least some embodiments of the present disclosure. [Figure 4] This is a schematic cross-sectional side view of a substrate support according to at least some embodiments of the present disclosure. [Figure 5] This is a schematic cross-sectional side view of a substrate support according to at least some embodiments of the present disclosure. [Figure 6] This is a partial schematic cross-sectional side view of a heater plate according to at least some embodiments of the present disclosure. [Modes for carrying out the invention]

[0010] For ease of understanding, the same reference numerals are used to indicate identical elements common to multiple drawings, where possible. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be incorporated into other embodiments for the benefit of the present invention without further detail.

[0011] Embodiments of substrate supports are provided herein. Substrate supports generally include a heater plate coupled to a hollow shaft. The inventors have observed that radiative and conductive heat losses from the heater plate adversely affect substrate processing uniformity and power consumption. Embodiments of substrate supports provided herein include a heater plate made of a material having a first thermal conductivity. The heater plate's sidewalls and bottom surface are covered with a second material having a second thermal conductivity lower than the first thermal conductivity to advantageously reduce heat loss from the heater plate. The reduction in heat loss from the heater plate advantageously improves the thermal uniformity provided to a substrate placed on the substrate support.

[0012] Figure 1 is a schematic side view of a process chamber 100 according to at least some embodiments of the present disclosure. The configuration and arrangement of the components of the process chamber 100 shown in Figure 1 are illustrative and not intended to limit. In addition, conventional components or other details not necessary to understand the present disclosure have been omitted from the figures so as not to obscure the present disclosure. In addition, as used in the present disclosure, the terms upper, lower, top, and bottom refer to the orientation in the drawings and are not intended to limit. As shown in Figure 1, the process chamber 100 includes a chamber body 138 having an internal volume 132. A substrate support 150 is located in the internal volume 132. The substrate support 150 may generally include a heater plate 140 or pedestal and a hollow shaft 134 for supporting the heater plate 140. In some embodiments, the heater plate 140 is circular in shape. In some embodiments, the heater plate 140 includes a ceramic material. The hollow shaft 134 provides a conduit for supplying, for example, backside gas, process gas, vacuum chucking, fluid, coolant, power, etc., to the heater plate 140.

[0013] The substrate 102 is shown positioned on the heater plate 140. In some embodiments, a substrate support 150 is coupled to a gas element 110. In some embodiments, the substrate support 150 is a vacuum chuck, and the gas element 110 is a vacuum pump or other suitable vacuum source. In such embodiments, a vacuum region 104 is formed between the upper surface of the heater plate 140 and the substrate 102. In some embodiments, a pressure sensor, such as a pressure gauge 130, is operably coupled to the vacuum region 104 to measure the backside pressure of the vacuum region 104. In some embodiments, the gas element 110 is a gas source configured to supply backside gas to the upper surface of the heater plate 140. In some embodiments, the heater plate 140 includes a first gas channel 108 for supplying at least one of vacuum pressure or backside gas to the upper surface of the heater plate 140. The heater plate 140 includes one or more heating elements 112, such as a resistance heating element, coupled to a heater power supply 114.

[0014] The chamber body 138 includes openings such as slit valves 106 that selectively open the chamber body 138 to facilitate loading and unloading substrates into and out of the internal volume 132 of the chamber body 138, for example, via a substrate transfer robot 142. In some embodiments, control of the substrate transfer robot 142 is performed from the substrate transfer robot 142 to the substrate support 15 0 This facilitates the control of the position of the substrate 102 above the substrate support 150 during transport, and ultimately, the control of the position of the substrate 102 on the substrate support 150. Multiple lift pins 128 may be provided to assist in the transport of the substrate 102 between the substrate transport robot 142 and the substrate support 150.

[0015] The process chamber 100 is configured to perform one or more of various deposition processes, such as chemical vapor deposition (CVD) or plasma chemical vapor deposition (PECVD). A gas source 116 is coupled to the internal volume 132 of the chamber body 138 and supplies process gas for substrate processing (e.g., deposition). In some embodiments, the gas source 116 supplies at least one inert gas, such as nitrogen gas or a noble gas (such as argon). A pump 126 is coupled to the internal volume 132 to maintain a desired pressure within the chamber body 138 and to remove process gas and processing by-products during processing.

[0016] In some embodiments, to facilitate control of the process chamber 100, a controller 118 is coupled to components of the process chamber 100, including a pressure gauge 130 and a substrate transfer robot 142. The controller 118 may be any form of general-purpose computer processor that can be used in an industrial environment to control various chambers and subprocessors. The controller includes a central processing unit (CPU) 120, memory 122, and support circuitry 124. The memory or computer-readable medium 122 of the CPU 120 may be one or more readily available memories, such as random access memory (RAM), read-only memory (ROM), floppy disks, hard disks, or any other form of local or remote digital storage. The support circuitry 124 is coupled to the CPU 120 to support the processor.

[0017] Figure 2 is a schematic cross-sectional side view of a substrate support 150 according to at least some embodiments of the present disclosure. The substrate support 150 includes a heater plate 140 having an upper surface 210 and a lower surface 212 opposite the upper surface 210 for supporting a substrate 102. The heater plate 140 includes a first material having a first thermal conductivity. In some embodiments, the first thermal conductivity is greater than 130 watts / meter-kelvin (W / (m·K)). In some embodiments, the first thermal conductivity is about 130 to about 190 watts / meter-kelvin (W / (m·K)).

[0018] At least one of the side walls 214 of the heater plate 140 and the lower surface 212 of the heater plate 140 are covered with a cover plate 220 comprising a second material having a second thermal conductivity less than a first thermal conductivity. In some embodiments, the upper surface of the cover plate 220 is coplanar with the upper surface 210 of the heater plate 140. In some embodiments, the second thermal conductivity is less than 100 watts / meter·Kelvin (W / (m·K)). In some embodiments, the second thermal conductivity is about 20% to about 70% of the first thermal conductivity.

[0019] In some embodiments, the hollow shaft 206 is coupled to the heater plate 140. In some embodiments, the hollow shaft 206 may be the hollow shaft 134. The hollow shaft 206 comprises a third material having a third thermal conductivity less than a first thermal conductivity. In some embodiments, the third thermal conductivity is less than 100 watts / meter·Kelvin (W / (m·K)). In some embodiments, the third material of the hollow shaft 206 comprises a second material. In some embodiments, the hollow shaft 206 is coupled to the heater plate 140 vertically below the heater plate 140. The substrate support may include one or more lift pin openings 230 that extend through the heater plate 140 and the cover plate 220 to accommodate lift pins such as lift pins 128. In some embodiments, one or more lift pin openings 230 are located radially outward from the hollow shaft 206.

[0020] In some embodiments, the heater plate 140 is made of aluminum nitride (AlN), aluminum oxide (Al2O3), beryllium oxide (BeO), boron nitride (BN), silicon nitride (Si3N4), or silicon carbide (SiC). In some embodiments, the second material of the cover plate 220 includes aluminum nitride (AlN), aluminum oxide (Al2O3), beryllium oxide (BeO), boron nitride (BN), silicon nitride (Si3N4), or silicon carbide (SiC). In some embodiments, the heater plate 140 and the cover plate 220 are made of the same material but have different thermal conductivity (i.e., the material of the heater plate 140 has a first thermal conductivity, and the material of the cover plate 220 has a second thermal conductivity). For example, in some embodiments, the heater plate 140 is made of aluminum nitride having a first thermal conductivity, and the cover plate 220 is made of aluminum nitride having a second thermal conductivity.

[0021] Figure 3 is a schematic cross-sectional side view of a substrate support 150 according to at least some embodiments of the present disclosure. In some embodiments, the substrate support 150 includes a hollow shaft 306. In some embodiments, the hollow shaft 306 is a hollow shaft 134. In some embodiments, the hollow shaft 306 is made of the same material as the hollow shaft 206. The hollow shaft 306 has a lower portion 308 and an upper portion 310 coupled to a heater plate 140. In some embodiments, the upper portion 310 extends radially outward from the lower portion 308 and then vertically upward to the heater plate 140. In some embodiments, the hollow shaft 306 is coupled to the heater plate 140 along its outer peripheral edge 316. In some embodiments, the upper portion 310 is coupled to a cover plate 220 at a position radially outward from the heater plate 140 to advantageously reduce heat transfer from the heater plate 140 to the hollow shaft 206. In some embodiments, one or more lift pin openings 230 extend through the heater plate 140, the hollow shaft 306, and the cover plate 220 to accommodate lift pins such as lift pins 128.

[0022] FIG. 4 is a schematic cross-sectional side view of a substrate support 150 according to at least some embodiments of the present disclosure. In some embodiments, the substrate support 150 includes a hollow shaft 406. In some embodiments, the hollow shaft 406 is the hollow shaft 134. In some embodiments, the hollow shaft 406 includes the same material as the hollow shaft 206. In some embodiments, the hollow shaft 406 has a lower portion 408 and an upper portion 410 coupled to a heater plate 140. In some embodiments, the upper portion 410 extends substantially linearly radially outwardly and upwardly from the lower portion 408 to the heater plate 140. In some embodiments, the upper portion 410 has a conical shape. In some embodiments, the upper portion 410 is coupled to a cover plate 220 at a radially outer position of the heater plate 140 to advantageously reduce heat transfer from the heater plate 140 to the hollow shaft 406. In some embodiments, one or more lift pin openings 230 extend through the heater plate 140, the hollow shaft 406, and the cover plate 220 to accommodate lift pins such as lift pin 128.

[0023] Figure 5 is a schematic cross-sectional side view of a substrate support 150 according to at least some embodiments of the present disclosure. In some embodiments, the substrate support 150 includes a hollow shaft 506. In some embodiments, the hollow shaft 506 is a hollow shaft 134. In some embodiments, the hollow shaft 506 contains the same material as the hollow shaft 206. In some embodiments, the hollow shaft 506 has a lower portion 508 and an upper portion 510 coupled to a heater plate 140. In some embodiments, the upper portion 510 extends radially outward and upward from the lower portion 508 to the heater plate 140. In some embodiments, the upper portion 510 extends radially outward and upward in a non-linear or curved manner. In some embodiments, the upper portion 510 is coupled to a cover plate 220 at a position radially outward of the heater plate 140 to advantageously reduce heat transfer from the heater plate 140 to the hollow shaft 506. In some embodiments, one or more lift pin openings 230 extend through the heater plate 140, the hollow shaft 506, and the cover plate 220 to accommodate lift pins such as lift pins 128.

[0024] FIG. 6 is a partial schematic cross-sectional side view of a heater plate 140 according to at least some embodiments of the present disclosure. In some embodiments, the heater plate 140 includes an electrode 644 disposed or embedded in the heater plate 140 to generate plasma within the internal volume 132. The electrode 644 may comprise an RF mesh and may be coupled to an RF power source 650. In some embodiments, the heater plate 140 comprises a plurality of plates 602 joined, fixed, or otherwise coupled to each other. For example, in some embodiments, one or more heating elements 112 may be sandwiched between two of the plurality of plates 602. In some embodiments, the electrode 644 may be sandwiched between two of the plurality of plates 602. In some embodiments, one or more heating elements 112 are disposed between a first plate 610 and a second plate 620 of the plurality of plates 602. In some embodiments, the electrode 644 is disposed between a second plate 620 and a third plate 630 of the plurality of plates 602.

[0025] The foregoing is directed to embodiments of the present disclosure, but other and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure.

Claims

1. A heater plate having an upper surface for supporting a substrate and a lower surface opposite to the upper surface, comprising a first material having a first thermal conductivity, wherein the side walls of the heater plate and the lower surface of the heater plate are covered by a cover plate comprising a second material having a second thermal conductivity less than the first thermal conductivity, A hollow shaft coupled to the cover plate, comprising a third material having a third thermal conductivity smaller than the first thermal conductivity, The hollow shaft has a lower portion and an upper portion that are coupled to the heater plate. The upper portion comprises a hollow shaft, which is coupled to the cover plate at a position radially outward from the heater plate, One or more heating elements arranged on the heater plate, A substrate support for use in a processing chamber, comprising the above features.

2. The substrate support according to claim 1, wherein the upper portion extends radially outward from the lower portion and extends vertically upward to the heater plate.

3. The substrate support according to claim 1, wherein the upper portion extends radially outward and upward from the lower portion to the heater plate.

4. The substrate support according to any one of claims 1 to 3, wherein the first thermal conductivity is greater than 130 watts / meter-kelvin (W / (m·K)).

5. The substrate support according to any one of claims 1 to 3, wherein the heater plate includes one or more lift pin openings.

6. The heater plate is made of aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ), beryllium oxide (BeO), boron nitride (BN), silicon nitride (Si 3 N 4 A substrate support according to any one of claims 1 to 3, made of ), or silicon carbide (SiC).

7. The second material is aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ), beryllium oxide (BeO), boron nitride (BN), silicon nitride (Si 3 N 4 A substrate support according to any one of claims 1 to 3, comprising ), or silicon carbide (SiC).

8. A substrate support according to any one of claims 1 to 3, wherein the first material and the second material are the same material.

9. The substrate support according to any one of claims 1 to 3, wherein the first thermal conductivity is greater than 100 watts / meter Kelvin (W / (m·K)).

10. A substrate support according to any one of claims 1 to 3, wherein the second thermal conductivity and the third thermal conductivity are less than 100 watts / meter Kelvin (W / (m·K)).

11. The substrate support according to any one of claims 1 to 3, wherein the second material is the same material as the third material.

12. The heater plate is made of aluminum nitride having the first thermal conductivity, The cover plate is made of aluminum nitride having the second thermal conductivity, The upper surface of the cover plate is on the same plane as the upper surface of the heater plate. A substrate support according to any one of claims 1 to 3.

13. A chamber body that defines the internal volume, A substrate support according to any one of claims 1 to 3, arranged in the internal volume, A process chamber equipped with a process chamber.

14. The process chamber according to claim 13, wherein the first thermal conductivity is greater than 100 watts / meter-kelvin (W / (m·K)).

15. The process chamber according to claim 13, wherein the second and third thermal conductivity are less than 100 watts / meter Kelvin (W / (m·K)).

16. At least one of the first material and the second material is aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ), beryllium oxide (BeO), boron nitride (BN), silicon nitride (Si 3 N 4 ), or silicon carbide (SiC), the process chamber according to claim 13.

17. The process chamber according to claim 13, further comprising one or more lift pins arranged in the internal volume and configured to extend through one or more lift pin openings of the heater plate.

18. The process chamber according to claim 13, wherein the substrate support is a vacuum chuck.

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