Preventing deposition on pedestals in semiconductor substrate processing.

Abstract

To provide a substrate support and a heat shield structure for a substrate support that relate to substrate processing, and more particularly to preventing deposition on a pedestal used in semiconductor substrate deposition processes.SOLUTION: A heat shield structure 404 for a substrate support 400 in a substrate processing system includes an outer shield 424 configured to surround a stem 432 of the substrate support. The outer shield is further configured to define an interior space 428 between the outer shield and the upper portion of the stem and the lower surface of the substrate support, and a vertical flow path 440 between the outer shield and the lower portion of the stem of the substrate support. The outer support comprises a cylindrical portion, a first lateral portion extending radially outward from the cylindrical portion, an inclined portion extending radially outward and upward from the first lateral portion, and a second lateral portion extending radially outward from the inclined portion.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 62 / 712,436, filed July 31, 2018, and U.S. Provisional Application No. 62 / 832,952, filed April 12, 2019, the entire disclosures of which are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE This disclosure relates to substrate processing, and more particularly to preventing deposition on pedestals used in semiconductor substrate deposition processing. [Background technology]

[0003] The background art provided herein is intended to provide a general background to the present disclosure, and the work of the inventors named herein, to the extent described in this background art, along with aspects of the description that would not normally be considered prior art at the time of filing, are not admitted expressly or impliedly as prior art to the present disclosure.

[0004] Substrate processing systems are used to perform processes such as film deposition and etching on substrates, such as semiconductor wafers. Deposition may be performed, for example, using chemical vapor deposition (CVD), atomic layer deposition (ALD), and / or other deposition processes to deposit conductive films, dielectric films, or other types of films. During deposition, the substrate is placed on a substrate support, and one or more precursor gases may be supplied to the processing chamber during one or more processing steps. A plasma may be used to drive the chemical reaction. After deposition is performed, the processing gases are evacuated, and the substrate is removed from the processing chamber. [Brief explanation of the drawings]

[0005] The present disclosure will become more fully understood from the detailed description and accompanying drawings set forth below.

[0006] [Figure 1]1 is a functional block diagram illustrating an example substrate processing system according to the present disclosure.

[0007] [Figure 2A] 1 illustrates an example of a pedestal for supporting a substrate during a deposition process according to the present disclosure.

[0008] [Figure 2B] 2 illustrates an example of a heat shield structure for a pedestal according to the present disclosure.

[0009] [Figure 3A] 1A-1C illustrate example arrangements of heat shield plates according to the present disclosure.

[0010] [Figure 3B] 10A-10C illustrate an example of an insulating pin for supporting a heat shield plate according to the present disclosure.

[0011] [Figure 3C] 1 illustrates an example of a heat shield plate according to the present disclosure.

[0012] [Figure 3D] 1 illustrates an example of a radially inner shield according to the present disclosure.

[0013] [Figure 4A] 10 illustrates a pedestal with another example of a heat shield structure in accordance with the present disclosure.

[0014] [Figure 4B] 4B illustrates another example of the heat shield structure of FIG. 4A in accordance with the present disclosure.

[0015] [Figure 5A] 10 illustrates a pedestal with another example of a heat shield structure in accordance with the present disclosure.

[0016] [Figure 5B] 5B illustrates another example of the heat shield structure of FIG. 5A in accordance with the present disclosure.

[0017] In the drawings, the same numbers may be used to identify similar and / or identical elements. Summary of the Invention

[0018] A thermal shield structure for a substrate support in a substrate processing system includes an outer shield configured to surround a stem of the substrate support. The outer shield is further configured to define an interior space between the outer shield and the stem of the substrate support and between the outer shield and a lower surface of the substrate support. At least one thermal shield plate is configured to be positioned below the substrate support within the interior space between the outer shield and the lower surface of the substrate support. An edge guard extends upward from the outer shield and is configured to surround an outer periphery of the substrate support and define a gap between the edge guard and the substrate support.

[0019] The at least one thermal shield plate includes a plurality of thermal shield plates spaced apart within an interior space between the outer shield and the underside of the substrate support. The thermal shield structure further includes a plurality of insulating pins disposed between adjacent ones of the thermal shield plates. The thermal shield structure further includes an inner shield disposed between the outer shield and the stem. The inner shield extends downward from the at least one thermal shield plate and defines a second interior space between the inner shield and the stem.

[0020] In another feature, the outer shield is not in direct contact with the stem or the underside of the substrate support. The thermal shield plate is not in direct contact with the underside of the substrate support, the stem of the substrate support, or the outer shield. The substrate support comprises the thermal shield structure described above. The substrate support corresponds to a pedestal configured to support a substrate during at least one of chemical vapor deposition and atomic layer deposition. A system comprises the thermal shield structure described above and a gas source configured to flow a purge gas into the interior space.

[0021] A thermal shield structure for a substrate support in a substrate processing system includes an outer shield configured to surround a stem of the substrate support. The outer shield is further configured to define an interior space between the outer shield and an upper portion of the stem and a lower surface of the substrate support, and a vertical flow path between the outer shield and the lower portion of the stem of the substrate support. The outer support includes a cylindrical portion, a first lateral portion extending radially outward from the cylindrical portion, an angled portion extending radially outward and upward from the first lateral portion, and a second lateral portion extending radially outward from the angled portion.

[0022] In another feature, the thermal shield structure further includes an edge guard extending upward from the second side portion of the outer shield. The edge guard is configured to surround the outer periphery of the substrate support and define a gap between the edge guard and the substrate support. The vertical flow path is annular. The length of the first side portion is 50% to 70% of the distance between the stem of the substrate support and the outer periphery of the substrate support. The length of the second side portion is 10% to less than 25% of the distance between the stem of the substrate support and the outer periphery of the substrate support. The angle of the inclined portion relative to the first side portion is 95 to 135 degrees.

[0023] In another feature, the second lateral portion defines a lateral flow path between the second lateral portion and the lower surface of the substrate support. The width of the lateral flow path is 1 to 10 mm. The width of the gap is 1 to 10 mm. The outer shield is not in direct contact with the stem or the lower surface of the substrate support. The substrate support comprises the thermal shield structure described above. The substrate support corresponds to a pedestal configured to support a substrate during at least one of chemical vapor deposition and atomic layer deposition. A system comprises the thermal shield structure described above and a gas source configured to flow a purge gas into the interior space through the vertical flow path.

[0024] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0025] During deposition using chemical vapor deposition (CVD), atomic layer deposition (ALD), and / or other deposition processes, a conductive film, a dielectric film, or other type of film is deposited on a substrate. While a film is being deposited on the substrate, material may also be deposited on other components disposed within the processing chamber, such as a pedestal configured to support the substrate. Over time, residual films accumulate on these components and must be removed to prevent particle contamination, mechanical deformation, and / or substrate defects. Chamber cleaning processes are periodically performed to remove residual films from components within the processing chamber. For example, periodic cleaning processes may be used.

[0026] In some instances (e.g., including, but not limited to, substrate processing systems with an active pedestal configured to be moved up and down relative to the processing chamber to adjust deposition performance), surfaces of various structures within the substrate processing system may be relatively susceptible to deposition. For example, increased temperature may be associated with increased deposition rates of tungsten. Thus, in instances where the pedestal is heated, greater amounts of tungsten may be deposited on the surface of the pedestal during the deposition process. In these instances, periodic cleaning processes may not be sufficient to completely remove the deposited tungsten or other materials from the surface of the pedestal. Furthermore, increased deposition may cause deformation of the pedestal stem, which may lead to pedestal failure.

[0027] In some deposition systems, the deposition rate of material below the pedestal (e.g., onto the underside of the pedestal, the surface of the stem, etc.) can be greater than the deposition rate of material above the pedestal (e.g., onto the upper surface of the pedestal, the substrate, etc.). For example, in a low-fluorine tungsten (LFW) ALD system, CVD occurs in the region of the processing chamber below the pedestal during LFW ALD processing. The deposition rate of CVD below the pedestal is significantly greater (e.g., by more than 10 times) than the deposition rate of ALD above the pedestal. Thus, CVD deposits a large amount of tungsten on the underside of the pedestal during LFW ALD processing.

[0028] Systems and methods according to the principles of the present disclosure reduce deposition of tungsten and other materials on the surface of the pedestal, thereby shortening cleaning time. For example, a pedestal according to the present disclosure includes a thermal shield structure disposed around the pedestal. In one example, the thermal shield structure includes an outer shield, a radially inner shield, and one or more thermal shield plates disposed between the outer shield and the underside of the pedestal. In another example, the thermal shield structure includes only a one-piece outer shield. The interior space between the outer shield and the stem may be purged with an inert gas (e.g., argon). The thermal shield structure reduces the temperature of the outer surface of the pedestal. The reduced temperature and purging of the interior space reduce deposition of tungsten and other materials on the pedestal, as described in more detail below. The corresponding reduction in deposition can result in a reduction in cleaning time (e.g., 65% relative to the cleaning time of a processing chamber without a thermal shield structure according to the present disclosure), thereby increasing substrate throughput (e.g., 10%). Additionally, pedestal life can be increased (e.g., up to two years). Power consumption associated with maintaining the pedestal at a desired temperature can also be reduced (e.g., up to 42%).

[0029] Referring now to FIG. 1 , an example of a substrate processing system 100 including a substrate support (e.g., a pedestal configured for CVD and / or ALD deposition) according to the present disclosure is shown. A substrate support 104 is disposed within a processing chamber 108. A substrate 112 is placed on the substrate support 104 during processing. For example, deposition is performed on the substrate 112. The substrate 112 is removed, and one or more additional substrates are processed. Over time, residual films or other materials (e.g., tungsten) accumulate on components (e.g., sidewalls of the processing chamber 108, surfaces of the substrate support 104, etc.). Cleaning is periodically performed to remove residual films or other materials deposited on surfaces within the processing chamber 108.

[0030] Gas supply system 120 includes gas sources 122-1, 122-2, ..., and 122-N (collectively, gas sources 122) connected to valves 124-1, 124-2, ..., and 124-N (collectively, valves 124) and mass flow controllers 126-1, 126-2, ..., and 126-N (collectively, MFCs 126). MFCs 126 control the flow of gas from gas sources 122 to manifold 128, where the gases combine. The output of manifold 128 is fed through optional pressure regulator 132 to manifold 136. The output of manifold 136 is input to a gas distribution device, such as a multi-injector showerhead 140. Although manifolds 128 and 136 are shown, a single manifold may be used.

[0031] In some examples, the temperature of the substrate support 104 may be controlled using a resistive heater 160. The substrate support 104 may include a coolant channel 164. A cooling fluid is supplied to the coolant channel 164 from a fluid reservoir 168 and a pump 170. Pressure sensors 172, 174 may be disposed in the manifold 128 or the manifold 136, respectively, to measure pressure. A valve 178 and a pump 180 may be used to evacuate reactants from the processing chamber 108 and / or to control the pressure within the processing chamber 108.

[0032] The controller 182 includes a dose controller 184 that controls the dose amount delivered by the multi-injector showerhead 140. The controller 182 also controls the gas supply from the gas supply system 120. The controller 182 controls the pressure in the processing chamber and / or the evacuation of the reactants using valves 178 and pumps 180. The controller 182 controls the temperature of the substrate support 104 and the substrate 112 based on temperature feedback (e.g., from a sensor in the substrate support (not shown) and / or a sensor measuring the coolant temperature (not shown)).

[0033] In some examples, the substrate processing system 100 may be configured to perform etching on a substrate 112 within the same processing chamber 108. Accordingly, the substrate processing system 100 may include an RF generation system 188 configured to generate and supply RF power (e.g., as a voltage source, a current source, etc.) to one of a lower electrode (e.g., a base plate of the substrate support 104 as shown) and an upper electrode (e.g., the showerhead 140). By way of example only, the output of the RF generation system 188 is described herein as an RF voltage. The other of the lower and upper electrodes may be DC grounded, AC grounded, or floating. By way of example only, the RF generation system 188 may include an RF generator 192 configured to generate an RF voltage supplied by a matching / power distribution network 196 to generate a plasma within the processing chamber 108 for etching the substrate 112. In other examples, the plasma may be generated inductively or remotely. As shown for illustrative purposes, RF generation system 188 corresponds to a capacitively coupled plasma (CCP) system, although the principles of the present disclosure may be implemented in other suitable systems, such as, by way of example only, a transformer coupled plasma (TCP) system, a CCP cathode system, or a remote microwave plasma generation / delivery system.

[0034] The substrate support 104 according to the present disclosure includes a thermal shield structure 198. The thermal shield structure 198 reduces deposition of tungsten and other materials on the surface of the substrate support 104, as described in more detail below. In some examples of the substrate processing system 100, the substrate support 104 may be configured to move up and down within the processing chamber 108 to adjust deposition parameters during processing. In these examples, the thermal shield structure 198 may be configured to move up and down as well to maintain the position of the thermal shield structure 198 relative to the substrate support 104.

[0035] 2A and 2B, an example substrate support 200 is shown with a thermal shield structure 204 according to the present disclosure. In Figure 2A, the thermal shield structure 204 is shown disposed on the substrate support 200. In Figure 2B, the thermal shield structure 204 is shown without the substrate support 200 for simplicity.

[0036] The substrate support 200 includes a base plate 208 (e.g., a conductive base plate such as aluminum, which may include the coolant channels 164 described above in FIG. 1 ) and a ceramic layer 212. In some examples, the ceramic layer 212 may be selectively heated (e.g., using the resistive heater 160 described above in FIG. 1 ). During processes such as CVD and ALD deposition, the temperature within the processing chamber 108, and therefore the temperature of surfaces within the processing chamber 108 (e.g., the surface of the substrate support 200), may increase significantly. For example, various surfaces within the processing chamber 108 and on the substrate support 200 may increase to temperatures between 300 and 500°C. The thermal shield structure 204 is positioned such that the temperature on the outer surface 216 of the thermal shield structure 204 is significantly reduced. For example, the temperature on the outer surface 216 of the thermal shield structure 204 may be less than 300°C (e.g., between 200 and 285°C) during deposition processes. The deposition rate of tungsten decreases exponentially below 300° C. In some examples, the thermal shield structure 204 reduces temperature non-uniformities on the top surface 220 of the ceramic layer 212.

[0037] The thermal shield structure 204 comprises an outer shield 224 (including an outer surface 216), a radially inner shield 228, and one or more thermal shield plates 232 disposed between the outer shield 224 and a lower surface 236 of the substrate support 200. An interior space 240 is defined between the outer shield 224, a portion of a stem 244 of the substrate support 200, the inner shield 228, and the lower surface 236 of the substrate support 200. The thermal shield plates 232 surround the stem 244 and are disposed between the lower surface 236 of the substrate support 200 and the outer shield 224. Thus, the thermal shield plates 232 function as a thermal radiation barrier between the lower surface 236 of the substrate support 200 and the outer shield 224, reducing the temperature of the outer surface 216 of the outer shield 224. In other words, the heat shield plate 232 reduces the transfer of heat from the underside 236 of the substrate support 200 to the outer shield 224. The inner shield 228 prevents the transfer of heat from the outer shield 224 to the stem 244. The outer shield 224, the inner shield 228, and the heat shield plate 232 may be constructed of aluminum.

[0038] An inert gas (e.g., argon) may be supplied to the interior space 240. For example, the inert gas may be flowed from the gas supply system 120 into the interior space 240 via one or more inlets 248. The inert gas flows upward between the outer shield 224 and the stem 244 and the inner shield 228, and flows outward between the outer shield 224 and the heat shield plate 232. The inert gas may also flow upward in an interior space 252 defined between the inner shield 228 and the stem 244. The inert gas flows through the interior 252 and between adjacent ones of the heat shield plates 232.

[0039] The outer shield 224 includes an annular edge guard 256 extending upward from the outer shield 224 around the outer periphery 260 of the substrate support 200. For example, the edge guard 256 at least partially overlaps the base plate 208 and the ceramic layer 212 to protect the outer periphery 260 of the substrate support 200 corresponding to the base plate 208 and the ceramic layer 212. The edge guard 256 defines a gap (e.g., a vertical gap) 264 between the outer shield 224 and the outer periphery 260 of the substrate support 200 to prevent direct contact between the outer shield 224 and the substrate support 200. Therefore, heat transfer from the outer shield 224 to the substrate support 200 is further minimized. Furthermore, the inert gas flowing into the interior space 240 exits through the gap 264, providing a purge flow of gas to prevent process materials from entering the interior space 240. The flow of inert gas is indicated by arrows in FIG. 2A . In this way, deposition of material (eg, tungsten) onto surfaces of the substrate support 200, stem 244, etc. within the interior space 240 is prevented.

[0040] The inner shield 228 includes an annular outer lip 268 that extends radially outward from the inner shield 228. The annular outer lip 268 overlaps the bottommost one of the heat shield plates 232, and the inner shield 228 extends downwardly within the outer shield 224. Thus, the heat shield plate 232 supports the inner shield 228, and the inner shield 228 is not in direct thermal (i.e., physical) contact with the stem 244.

[0041] 3A, 3B, 3C, and 3D, example components of the heat shield structure 204 will now be described in detail. In FIG. 3A, a portion 300 of the heat shield structure 204 includes an outer shield portion 304 including edge guards 308 and heat shield plates 312. The heat shield plates 312 are supported on the outer shield portion 304 and on each of the underlying plates of the heat shield plates 312 using insulating pins 316. An example of the insulating pins 316 is shown in more detail in FIG. 3B. The insulating pins 316 include a central disk portion 320 configured to maintain uniform spacing between adjacent heat shield plates 312 and pin portions 324 configured to be received within respective holes 328 in the heat shield plates 312 shown in FIG. 3C. The insulating pins 316 are constructed of an insulating material (e.g., ceramic). Therefore, the heat shield plate 312 is not in direct thermal contact with the outer shield portion 304, the substrate support 200, or each other. Furthermore, the radius of the central opening 332 of the heat shield plate 312 is larger than the radius of the stem 244. Therefore, the heat shield plate 312 is not in direct thermal contact with the stem 244.

[0042] 3D , the radially inner shield 336 includes an annular outer lip 340 that extends radially outward from the inner shield 336. The annular outer lip 340 overlaps the bottommost one of the heat shield plates 312, and a body 344 extends downwardly through the central opening 332 in the heat shield plate 312.

[0043] 4A and 4B, another example substrate support 400 is shown with a heat shield structure 404 in accordance with the present disclosure. In Figure 4A, the heat shield structure 404 is shown disposed on the substrate support 400. In Figure 4B, the heat shield structure 404 is shown without the substrate support 400 for simplicity.

[0044] The substrate support 400 includes a base plate 408 and a ceramic layer 412. In some examples, the ceramic layer 412 may be selectively heated. The thermal shield structure 404 is arranged to significantly reduce the temperature on the outer surface 416 of the thermal shield structure 404, similar to that described above in FIGS. 2A and 2B , which may reduce temperature non-uniformities on the upper surface 420 of the ceramic layer 412. In this example, in contrast to the example of FIGS. 2A and 2B , the thermal shield structure 404 includes an outer shield 424 (which may include the outer surface 416 and be constructed of aluminum) but does not include a radially inner shield 228 or a thermal shield plate 232. However, in some examples, the thermal shield structure 404 of FIGS. 4A and 4B may be combined with one or more radially inner shields and thermal shield plates.

[0045] An interior space 428 is defined between the outer shield 424 and the stem 432 and lower surface 436 of the substrate support 400. An annular channel 440 (e.g., a vertical annular channel) is defined between the outer shield 424 and a lower portion of the stem 432. The interior space 428 reduces the transfer of heat from the lower surface 436 of the substrate support 400 to the outer shield 424, reducing the temperature of the outer surface 416 of the outer shield 424.

[0046] An inert gas (e.g., argon) may be supplied to the interior space 428 through an annular passage 440 that surrounds a lower portion of the stem 432. For example, the inert gas may be flowed from the gas supply system 120 into the annular passage 440 via one or more inlets 444. The inert gas flows upward between the outer shield 424 and the stem 432 and into the interior space 428.

[0047] The outer shield 424 includes an annular edge guard 448 extending upward from the outer shield 424 around the periphery 452 of the substrate support 400. For example, the edge guard 448 at least partially overlaps the base plate 408 to protect the periphery 452 of the substrate 400. The edge guard 448 defines a gap (e.g., a vertical gap) 456 between the outer shield 424 and the periphery 452 of the substrate support 400 to prevent direct contact between the outer shield 424 and the substrate support 400. Thus, heat transfer from the outer shield 424 to the substrate support 400 is further minimized.

[0048] The inert gas supplied to the interior space 428 exits the interior space 428 through the side channel 460 and the gap 456, providing a purge flow of gas to prevent process materials from entering the interior space 428. By way of example only, the widths of the gap 456 and the side channel 460 are between 1 and 10 mm. The widths of the gap 456 and the side channel 460 may be the same or different. The upward outward flow of gas from the gap 456 also prevents the accumulation of deposition material at the outer periphery 452 of the substrate support 400. The flow of inert gas is indicated by arrows in FIG. 4A . In this way, deposition of material (e.g., tungsten) on surfaces within the interior space 428, such as the substrate support 400, the stem 432, and the base plate 408 and the ceramic layer 412 at the outer periphery 452, is prevented.

[0049] The outer shield 424 includes a generally vertical cylindrical portion 464 that defines an annular flow path 440 between the outer shield 424 and a lower portion of the stem 432. A first lateral portion 468, an angled portion 472, and a second lateral portion 476 extend radially outward from the cylindrical portion 464 to the edge guard 448. By way of example only, the outer shield 424 transitions from the first lateral portion 468 to the angled portion 472 at a point 480 that is located between 50% and 75% of the distance between the stem 432 and the outer periphery 452. In other words, the length of the first lateral portion 468 is between 50% and 75% of the distance between the stem 432 and the outer periphery 452. The angle of the angled portion 472 relative to the first lateral portion 468 is between 95 and 135 degrees.

[0050] The angled portion 472 extends from point 480 to a point 484 where the outer shield 424 transitions from the angled portion 472 to the second side portion 476. By way of example only, the distance from point 484 to the outer periphery 452 is greater than or equal to 10% and less than 25% of the total distance between the outer periphery 452 and the stem 432, so as to define a minimum length side flow path 460. The minimum length side flow path 460 increases the velocity and pressure of gases flowing out of the interior space 428.

[0051] 5A and 5B, another example substrate support 500 is shown with a heat shield structure 504 in accordance with the present disclosure. In Figure 5A, the heat shield structure 504 is shown disposed on the substrate support 500. In Figure 5B, the heat shield structure 504 is shown without the substrate support 500 for simplicity.

[0052] The substrate support 500 includes a base plate 508 and a ceramic layer 512. The ceramic layer 512 may be selectively heated. The thermal shield structure 504 is positioned to significantly reduce the temperature on an outer surface 516 of the thermal shield structure 504, similar to that described above in Figures 2A and 2B, which may reduce temperature non-uniformities on an upper surface 520 of the ceramic layer 512. In this example, the thermal shield structure 504 includes an outer shield 524 (which includes the outer surface 516 and may be constructed of aluminum).

[0053] An interior space 528 is defined between the outer shield 524 and the stem 532 and lower surface 536 of the substrate support 500. An annular flow path 540 (e.g., a vertical annular channel) is defined between the outer shield 524 and the stem 532. The interior space 528 reduces the transfer of heat from the lower surface 536 of the substrate support 500 to the outer shield 524, reducing the temperature of the outer surface 516 of the outer shield 524.

[0054] An inert gas (e.g., argon) may be supplied to the interior space 528 through an annular passage 540 that surrounds a lower portion of the stem 532. For example, the inert gas may be flowed from the gas supply system 120 into the annular passage 540 via one or more inlets 544. The inert gas flows upward between the outer shield 524 and the stem 532 and into the interior space 528.

[0055] In some examples, the outer shield 524 includes an annular edge guard 548 extending upward from the outer shield 524 around the periphery 552 of the substrate support 500. For example, the edge guard 548 at least partially overlaps the base plate 508 to protect the periphery 552 of the substrate 500. The edge guard 548 defines a gap (e.g., a vertical gap) 556 between the outer shield 524 and the periphery 552 of the substrate support 500 to prevent direct contact between the outer shield 524 and the substrate support 500. Thus, heat transfer from the outer shield 524 to the substrate support 500 is further minimized.

[0056] The inert gas supplied to the interior space 528 exits the interior space 528 through the side channel 560 and the gap 556, providing a purge flow of gas to prevent process materials from entering the interior space 528. By way of example only, the width of the gap 556 and the side channel 560 is between 1 and 10 mm. The widths of the gap 556 and the side channel 560 may be the same or different. The upward outward flow of gas from the gap 556 also prevents the accumulation of deposition material at the outer periphery 552 of the substrate support 500. The flow of inert gas is indicated by arrows in FIG. 5A . In this way, deposition of material (e.g., tungsten) on surfaces within the interior space 528, such as the substrate support 500, the stem 532, and the base plate 508 and the ceramic layer 512 at the outer periphery 552, is prevented.

[0057] As shown, outer shield 524 may be comprised of multiple (e.g., two) sections. For example, outer shield 524 may include a vertical stem portion 564 and a horizontal plate portion 568. Stem portion 564 surrounds stem 532. The upper end of stem portion 564 supports plate portion 568. For example, inner diameter 572 defining the inner opening of plate portion 568 may rest on annular ledge 576 defining the outer diameter of the upper end of stem portion 564.

[0058] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its applications, or uses. The broad teachings of the present disclosure may be embodied in a variety of forms. Accordingly, while the present disclosure includes specific examples, the true scope of the disclosure is not limited to those examples, as other variations will become apparent from a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of the present disclosure. Furthermore, although each embodiment is described as having particular features, any one or more of the features described with respect to any embodiment of the present disclosure can be implemented in any of the other embodiments and / or combined with any of the features of the other embodiments, even if the combination is not expressly described. In other words, the above-described embodiments are not mutually exclusive, and substituting one or more embodiments for one another is within the scope of the present disclosure.

[0059] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers) are described using various terms, such as "connected," "engaged," "coupled," "adjacent," "adjacent," "on top of," "above," "below," and "disposed." When describing a relationship between first and second elements in this disclosure, unless expressly stated as "direct," the relationship may be a direct relationship where no other intervening elements exist between the first and second elements, or an indirect relationship where one or more intervening elements exist (spatially or functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean the logical (A or B or C) using a non-exclusive logical OR, and not to mean "at least one of A, at least one of B, and at least one of C."

[0060] In some embodiments, the controller is part of a system, which may be part of the examples described above. Such systems may include semiconductor processing equipment, such as one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (e.g., wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of semiconductor wafers or substrates. The electronics may be referred to as a "controller" and may control various components or subcomponents of the system. Depending on the processing requirements and / or type of system, the controller may be programmed to control any of the processes disclosed herein, such as supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid supply settings, position and motion settings, and wafer movement in and out of tools and other transfer tools and / or load locks connected or coupled to the specific system.

[0061] Generally, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer, or instructions for the system. The operational parameters, in some embodiments, may be part of a recipe defined by a process engineer to accomplish one or more process steps during processing of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0062] In some embodiments, the controller may be part of or connected to a computer that is integrated with, connected to, or otherwise networked with the system, or a combination thereof. For example, the controller may be in the “cloud” or may be all or part of a fab host computer system that can enable remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, or examine trends or performance indicators from multiple manufacturing operations, to change parameters of a current process, configure processing steps according to a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network (which may include a local network or the Internet). The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, where the instructions specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed as well as the type of tool the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by having one or more separate controllers that are networked and operate toward a common purpose (such as the process and control described herein). One example of a distributed controller for such purposes is one or more integrated circuits on the chamber that communicate with one or more remotely located integrated circuits (e.g., at the platform level or located as part of a remote computer) that cooperate to control the process in the chamber.

[0063] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be associated with or utilized in the fabrication and / or manufacturing of semiconductor wafers.

[0064] As described above, depending on the processing step or steps being performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to carry containers of wafers to or from tool locations and / or load ports within a semiconductor fabrication factory. The present disclosure can also be realized in the following forms. [Form 1] 1. A thermal shield structure for a substrate support in a substrate processing system, comprising: an outer shield configured to surround a stem of the substrate support, the outer shield further configured to define an interior space between (i) the outer shield and the stem of the substrate support, and (ii) the outer shield and a lower surface of the substrate support; at least one thermal shield plate configured to be positioned below the substrate support within the interior space between the outer shield and the lower surface of the substrate support; an edge guard extending upwardly from the outer shield, the edge guard configured to (i) surround a periphery of the substrate support and (ii) define a gap between the edge guard and the substrate support; A heat shielding structure comprising: [Form 2] A thermal shielding structure as described in claim 1, wherein the at least one thermal shielding plate includes a plurality of thermal shielding plates spaced apart within the interior space between the outer shield and the lower surface of the substrate support. [Form 3] A heat shielding structure according to claim 2, further comprising a plurality of heat insulating pins disposed between adjacent plates of the heat shielding plate. [Form 4] A heat shielding structure according to claim 1, further comprising an inner shield disposed between the outer shield and the stem. [Form 5] A heat shielding structure as described in claim 4, wherein the inner shield extends downward from the at least one heat shield plate and defines a second internal space between the inner shield and the stem. [Form 6] 2. The heat shield structure according to claim 1, wherein the outer shield is not in direct contact with either the stem or the underside of the substrate support. [Form 7] A thermal shielding structure plate according to claim 1, wherein the thermal shielding plate is not in direct contact with the underside of the substrate support, the stem of the substrate support, or the outer shield. [Form 8] 10. A substrate support comprising the thermal shield structure of claim 1, wherein the substrate support corresponds to a pedestal configured to support a substrate during at least one of chemical vapor deposition and atomic layer deposition. [Form 9] A system comprising the thermal shielding structure of claim 1, further comprising a gas source configured to flow a purge gas into the interior space. [Form 10] 1. A thermal shield structure for a substrate support in a substrate processing system, comprising: an outer shield configured to surround a stem of the substrate support, the outer shield further configured to define (i) an interior space between the outer shield and an upper portion of the stem and a lower surface of the substrate support, and (ii) a vertical flow path between the outer shield and a lower portion of the stem of the substrate support; The outer shield is A cylindrical portion and a first lateral portion extending radially outward from the cylindrical portion; an angled portion extending radially outward and upward from the first lateral portion; a second lateral portion extending radially outward from the angled portion; A heat shielding structure comprising: [Form 11] A thermal shield structure as described in claim 10, further comprising an edge guard extending upward from the second side portion of the outer shield, the edge guard configured to (i) surround an outer periphery of the substrate support and (ii) define a gap between the edge guard and the substrate support. [Form 12] 11. The heat shielding structure of claim 10, wherein the vertical flow path is annular. [Form 13] 11. The heat shielding structure according to claim 10, wherein the length of the first side portion is 50% to 70% of the distance between the stem of the substrate support and the outer periphery of the substrate support. [Form 14] A thermal shielding structure as described in claim 10, wherein the length of the second side portion is greater than or equal to 10% and less than 25% of the distance between the stem of the substrate support and the outer periphery of the substrate support. [Form 15] 11. The heat shielding structure according to claim 10, wherein the angle of the inclined portion relative to the first side portion is 95 to 135 degrees. [Form 16] 11. The thermal shield structure of claim 10, wherein the second side portion defines a lateral flow path between the second side portion and the lower surface of the substrate support. [Form 17] 17. The heat shielding structure according to claim 16, wherein the width of the side flow path is 1 to 10 mm. [Form 18] 12. The heat shielding structure according to claim 11, wherein the gap has a width of 1 to 10 mm. [Form 19] 11. The thermal shield structure of claim 10, wherein the outer shield is not in direct contact with either the stem or the underside of the substrate support. [Form 20] 11. A substrate support comprising the thermal shield structure of claim 10, wherein the substrate support corresponds to a pedestal configured to support a substrate during at least one of chemical vapor deposition and atomic layer deposition. [Form 21] 11. A system comprising the thermal shield structure of claim 10, further comprising a gas source configured to flow a purge gas through the vertical flow path into the interior space.

Claims

1. 1. A thermal shield structure for a substrate support in a substrate processing system, comprising: an outer shield configured to surround a stem of the substrate support, the outer shield further configured to define (i) an interior space between the outer shield and an upper portion of the stem and a lower surface of the substrate support, and (ii) a vertical flow path between the outer shield and a lower portion of the stem of the substrate support; The outer shield is A cylindrical portion and a first lateral portion extending radially outward from the cylindrical portion; an angled portion extending radially outward and upward from the first lateral portion; a second lateral portion extending radially outward from the angled portion; A heat shielding structure comprising:

2. 10. The thermal shield structure of claim 1, further comprising an edge guard extending upwardly from the second side portion of the outer shield, the edge guard configured to (i) surround a periphery of the substrate support, and (ii) define a gap between the edge guard and the substrate support.

3. The heat shield structure of claim 1 , wherein the vertical flow path is annular.

4. 2. The heat shield structure of claim 1, wherein a length of the first lateral portion is 50% to 70% of a distance between the stem of the substrate support and an outer periphery of the substrate support.

5. 2. The heat shield structure of claim 1, wherein a length of the second side portion is greater than or equal to 10% and less than 25% of a distance between the stem of the substrate support and an outer periphery of the substrate support.

6. 2. The heat shield structure of claim 1, wherein the angle of the inclined portion relative to the first side portion is between 95 and 135 degrees.

7. The thermal shield structure of claim 1 , wherein the second side portion defines a lateral flow path between the second side portion and the lower surface of the substrate support.

8. 8. The heat shield structure according to claim 7, wherein the width of the side flow passage is 1 to 10 mm.

9. 3. The heat shield structure according to claim 2, wherein the width of the gap is 1 to 10 mm.

10. 10. The thermal shield structure of claim 9, wherein the outer shield is not in direct contact with the stem or the underside of the substrate support.

11. 10. A substrate support comprising the thermal shield structure of claim 1, wherein the substrate support corresponds to a pedestal configured to support a substrate during at least one of chemical vapor deposition and atomic layer deposition.

12. 10. A system comprising the thermal shield structure of claim 1, further comprising a gas source configured to flow a purge gas through the vertical flow passage into the interior space.

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