CN116783692A - Workpiece support for a thermal processing system - Google Patents

Abstract

A workpiece support for a thermal processing system is provided. The workpiece support includes a rotor configured to support a workpiece. The workpiece support also includes a gas supply. The gas supply may comprise a plurality of carrier pads. Each of the bearing pads may be positioned closer to the periphery of the rotor than to the center of the rotor. Each of the bearing pads defines one or more channels configured to direct gas onto the rotor to control a position of the rotor along a first axis and along a second axis that is substantially perpendicular to the first axis. Further, one or more of the bearing pads define at least one additional channel configured to direct gas onto the rotor to control rotation of the rotor about the first axis.

Description

Workpiece support for a thermal processing system

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application No. 63/130,982, entitled "Centerless Rotational Support for Thermal Processing," filed on 12/28/2020, the entire contents of which are incorporated herein by reference. The present application claims priority from U.S. provisional application No. 63/175,204, entitled "Centerless Rotational Support for Thermal Processing," filed 4/15 at 2021, the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure relates generally to heat treatment systems, and more particularly to workpiece supports for heat treatment systems.

Background

The thermal processing system includes a processing chamber in which one or more workpieces, such as semiconductor workpieces (e.g., semiconductor wafers), may be heated. Such a system may include a support for one or more workpieces. Additionally, such systems may include an energy source (e.g., a heating lamp, a laser, etc.) for heating one or more workpieces. During the heat treatment, one or more workpieces may be heated according to the treatment regime.

Disclosure of Invention

Aspects and advantages of embodiments of the disclosure will be set forth in part in the description which follows, or may be learned by practice of the embodiments.

In one aspect, a workpiece support for a thermal processing system is provided. The workpiece support includes a rotor configured to support a workpiece. The workpiece support further includes a gas supply. The gas supply device comprises a plurality of bearing pads. Each of the bearing pads is positioned closer to the periphery of the rotor than to the center of the rotor. Each of the bearing pads defines one or more channels configured to direct gas flowing therethrough onto the rotor to control the position of the rotor along a first axis and a second axis that is substantially perpendicular to the first axis. Further, one or more of the bearing pads define at least one additional channel configured to direct gas flowing therethrough onto the rotor to control rotation of the rotor about the first axis.

In another aspect, a heat treatment system is provided. The thermal processing system includes a processing chamber. The heat treatment system further includes a workpiece support. The workpiece support includes a rotor disposed within the processing chamber. The rotor is configured to support a workpiece. The workpiece support also includes a gas supply. The gas supply includes a plurality of load locks disposed within the process chamber. Each of the bearing pads is positioned closer to the periphery of the rotor than to the center of the rotor. Each of the bearing pads defines one or more channels configured to direct gas flowing therethrough onto the rotor to control the position of the rotor along a first axis and a second axis that is substantially perpendicular to the first axis. Further, one or more of the bearing pads define at least one additional channel configured to direct gas flowing therethrough onto the rotor to control rotation of the rotor about the first axis.

These and other features, aspects, and advantages of the various embodiments will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of interest.

Drawings

The detailed discussion of the embodiments is set forth in the specification with reference to the accompanying drawings, to those of ordinary skill in the art, wherein:

FIG. 1 depicts a heat treatment system according to an example aspect of the present disclosure.

Fig. 2 depicts a block diagram of components of a workpiece support according to an example embodiment of the present disclosure.

Fig. 3 depicts a perspective view of a workpiece support according to an example embodiment of the present disclosure.

Fig. 4 depicts a gas supply of a workpiece support according to an example embodiment of the present disclosure.

Fig. 5 depicts a gas supply of a workpiece support according to an example embodiment of the present disclosure.

Fig. 6 depicts a gas supply of a workpiece support according to another example embodiment of the present disclosure.

Fig. 7 depicts a cross-sectional view of a workpiece support assembly according to an example embodiment of the present disclosure.

Fig. 8 depicts a cross-sectional view of a workpiece support assembly according to another example embodiment of the present disclosure.

Fig. 9 depicts a cross-sectional view of a workpiece support assembly according to yet another example embodiment of the disclosure.

Fig. 10 depicts a cross-sectional view of a workpiece support assembly according to yet another example embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to embodiments, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the embodiments, not limitation of the present disclosure. Indeed, it will be apparent to those of ordinary skill in the art that various modifications and variations can be made to the embodiments without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Accordingly, aspects of the present disclosure are intended to cover such modifications and variations.

Example aspects of the present disclosure relate to a thermal processing system, such as a Rapid Thermal Processing (RTP) system, for a workpiece (e.g., a semiconductor wafer). The thermal processing system may include a processing chamber in which the workpiece may be subjected to a thermal treatment process (e.g., a spike annealing process). The thermal processing system may further include a workpiece support configured to support a workpiece being processed. The workpiece support may include a rotor configured to support a workpiece. The rotor may also be configured to rotate the workpiece while the heat treatment process is being performed. In this way, asymmetric heating and/or cooling of the workpiece may be reduced.

The workpiece support may also include a plurality of load bearing pads. The carrier pad may define a channel configured to direct gas onto the rotor to lift the rotor off the carrier pad. In this way, the rotor may be suspended over the carrier pads via a plurality of gas pads (i.e., gas exiting channels defined in each of the carrier pads). Further, one or more of the load-bearing pads may define one or more additional channels configured to direct gas toward the rotor to control rotation of the rotor. For example, one or more additional channels may be configured to direct gas toward the rotor as needed to accelerate (i.e., accelerate) rotation of the rotor or to slow (i.e., decelerate) rotation of the rotor.

The workpiece support may also include a shaft and ball bearings to provide centering forces to the rotor. However, mechanical friction between the shaft and the ball bearings can create particles that can contaminate the workpiece. In addition, the shaft may cast shadows on the workpiece. During the heat treatment process, this shadow may cause uneven heating of the workpiece.

Example aspects of the present disclosure relate to a workpiece support for a thermal processing system. The workpiece support may include a rotor and a plurality of load bearing pads. Each of the plurality of bearing pads may be positioned closer to the periphery of the rotor than the center of the rotor. Further, one or more channels may be defined in each of the load bearing pads. The one or more channels may be configured to direct gas flowing therethrough onto the rotor to control the position of the rotor along a first axis (e.g., vertical) and along a second axis (e.g., transverse, radial) that is substantially perpendicular (e.g., less than 15 degrees, less than 10 degrees, less than 5 degrees, less than 1 degree, etc.) to the first axis. In this way, a workpiece support according to example embodiments of the present disclosure may provide centering forces to the rotor without the ball bearings and shaft discussed above.

In some embodiments, the rotor may define a bore. Further, the rotor may be configured to support the workpiece such that the workpiece floats over the aperture defined by the rotor. In this manner, one or more heating sources configured to heat the workpiece may have an unobstructed view of the workpiece.

In some embodiments, the one or more channels defined in each of the load-bearing pads may include a first channel extending along a first axis. In this way, the first channel may be configured to direct gas flowing therethrough onto the rotor to control the position of the rotor along the first axis. For example, the rotor may be spaced apart from the plurality of carrier pads along the first axis via the plurality of gas pads (i.e., gas exiting the first channels defined in each of the carrier pads). In some embodiments, the gap defined between the rotor and the plurality of carrier pads along the first axis may be in a range of about 10 microns to about 50 microns.

In some embodiments, the one or more channels defined in each of the load-bearing pads may further include a second channel extending along the second axis. In this way, the second channel may be configured to direct gas flowing therethrough onto the rotor to control the position of the rotor along the second axis. For example, the rotor may be spaced apart from the plurality of carrier pads along the second axis via the plurality of gas pads (i.e., gas exiting the second channels defined in each of the carrier pads). In some embodiments, the gap defined between the rotor and the plurality of carrier pads along the second axis may be in a range of about 10 microns to about 50 microns.

In some embodiments, at least one of the first channel or the second channel may be tapered. For example, the first channel may taper along the first axis such that the first channel does not have a constant diameter. More specifically, the diameter of the first channel may be narrowed to resemble a nozzle, thereby increasing the pressure of the gas exiting the first channel. Alternatively or additionally, the second channel may taper along the second axis such that the second channel does not have a constant diameter. More specifically, the diameter of the second channel may be narrowed to resemble a nozzle, thereby increasing the pressure of the gas exiting the second channel.

In addition to one or more channels configured to direct gas flowing therethrough onto the rotor to control the position of the rotor along the first axis and the second axis, one or more of the bearing pads may also define at least one additional channel configured to direct gas flowing therethrough onto the rotor to control the rotation of the rotor about the first axis. For example, the at least one additional channel may be configured to direct gas flowing therethrough onto the rotor to accelerate (i.e., accelerate) rotation of the rotor about the first axis. Alternatively, the at least one additional channel may be configured to direct gas flowing therethrough onto the rotor to slow (i.e., slow) rotation of the rotor about the first axis.

In some embodiments, the at least one additional channel may include a third channel and a fourth channel. The third passage may be configured to direct gas flowing therethrough onto the rotor to accelerate (i.e., accelerate) rotation of the rotor about the first axis. Conversely, the fourth passage may be configured to direct gas flowing therethrough onto the rotor to slow (i.e., slow) rotation of the rotor about the first axis.

A workpiece support assembly according to example embodiments of the disclosure may provide a number of technical effects and benefits. For example, at least one channel may eliminate the need for ball bearings and shafts for providing centering forces to the rotor, the at least one channel being disposed in each of the bearing pads and configured to direct gas flowing therethrough onto the rotor to control the position of the rotor along the first and second axes. In this way, uneven heating of the workpiece due in part to the shadow cast by the shaft on the workpiece is eliminated. In addition, particles that may contaminate the workpiece due in part to friction between the shaft and the ball bearings are eliminated.

For purposes of illustration and discussion, aspects of the disclosure will be discussed with reference to a "workpiece," "wafer," or semiconductor wafer. Those of ordinary skill in the art, with the disclosure provided herein, will appreciate that the example aspects of the present disclosure may be used in association with any semiconductor substrate or other suitable substrate. Furthermore, the term "about" as used in connection with a numerical value is intended to refer to a range of values within ten percent (10%) of the specified value.

Referring now to the drawings, FIG. 1 depicts a thermal processing system 100 according to an example embodiment of the present disclosure. As shown, the thermal processing system 100 may include a processing chamber 105. In some embodiments, the process chamber 105 may be at least partially defined by a quartz window 107 of the thermal processing system 100. For example, one of the quartz windows 107 may at least partially define a ceiling of the process chamber 105, and another one of the quartz windows 107 may at least partially define a floor or bottom surface of the process chamber 105. In some embodiments, the quartz window 107 may be doped with hydroxide OH. It should be appreciated that one or more surfaces defining the processing chamber 105 may be formed of any suitable material. For example, in some embodiments, one or more surfaces defining the processing chamber 105 may be formed of quartz.

As shown, the thermal processing system 100 may include a door 110, the door 110 being movable between an open position (e.g., as shown in fig. 1) and a closed position (not shown) to allow selective access to the processing chamber 105. For example, the door 110 may be moved to an open position to allow the workpiece 120 to be positioned within the process chamber 105. In some embodiments, the workpiece 120 may be at least partially supported by a workpiece support 130 positioned within the processing chamber 105. In this manner, heat associated with emitting light onto the lower quartz window 170 may be transferred at least partially to the workpiece 120 via the workpiece support 130. Further, once the workpiece 120 is disposed on the workpiece support 130, the door 110 may be moved to the closed position. In some embodiments, the process chamber 105 may enclose an external environment when the door 110 is in the closed position.

In some embodiments, one or more surfaces defining the process chamber 105 may define the gas inlet 140. In this manner, process gases provided from a gas source may flow into the process chamber 105 via the gas inlet 140. In some embodiments, the process gas may include an inert gas that does not react with the workpiece 120. Alternatively, the process gas may include a reactive gas that reacts with the workpiece 120 to deposit a layer of material on the surface of the workpiece 120. For example, in some embodiments, the process gas may include ammonium NH ₃ And (3) gas. However, it should be appreciated that the process gas may include any suitable reactive gas. For example, in alternative embodiments, the reactive gas may include H ₂ And (3) gas.

The thermal processing system 100 may include one or more heat sources 150, the one or more heat sources 150 configured to heat the workpiece 120. The heat source 150 may be disposed outside of the process chamber 105. For example, the heat source 150 may be positioned above the process chamber 105, below the process chamber 105, or both above and below the process chamber 105. During a heat treatment process, such as a rapid heat treatment or spike annealing process, one or more heat sources 150 may be configured to emit light toward the workpiece 120. More specifically, during the thermal treatment process, the heat source 150 positioned above the process chamber 105 may be configured to emit light toward an upper surface or side of the workpiece 120, and the heat source 150 positioned below the process chamber 105 may be configured to emit light toward a lower surface or side of the workpiece 120. Light emitted from one or more heat sources 150 may raise the temperature of the workpiece 120. In some embodiments, the one or more heat sources 150 may raise the temperature of the workpiece 120 by greater than about 500 ℃ for a predetermined amount of time (e.g., less than 2 seconds).

It should be appreciated that the one or more heat sources 150 may include any suitable type of heat source configured to emit light. For example, in some embodiments, the one or more heat sources 150 may include one or more heating lamps (e.g., linear lamps). In alternative embodiments, the one or more heat sources 150 may include one or more lasers configured to emit laser beams onto the workpiece 120. It should also be appreciated that the heat source 150 positioned above the process chamber 105 and the heat source 150 positioned below the process chamber 105 may be controlled separately or may be controlled together to perform a thermal treatment process.

In some embodiments, the thermal processing system 100 may include one or more reflectors 152, the one or more reflectors 152 positioned such that light emitted from the one or more heat sources 150 is directed to or toward the process chamber 105. More specifically, the reflectors 152 may direct light emitted from the one or more heat sources 150 to or toward the respective quartz windows 107 such that the light may pass through the respective quartz windows 107 and into the process chamber 105. It should be appreciated that at least a portion of the light entering the process chamber 105 via the quartz window 107 may be emitted onto the workpiece 120. In this manner, as discussed above, light emitted from the one or more heat sources 150 may raise the temperature of the workpiece 120 during a heat treatment process, such as a rapid heat treatment process (e.g., a spike annealing process).

In one embodiment, the thermal processing system 100 may include a temperature measurement system 178, the temperature measurement system 178 configured to generate and transmit data indicative of the temperature of the workpiece 120. The temperature measurement system 178 may include one or more temperature sensors 180. The temperature sensor 180 may include a pyrometer, thermocouple, thermistor, or any other suitable temperature sensor or combination of temperature sensors. Depending on the type of sensor, the temperature sensor 180 may be positioned within the process chamber 105 or may be positioned outside of the process chamber 105. For example, if the temperature sensor 180 is a pyrometer, the pyrometer need not contact the workpiece 120 and, thus, may be positioned outside of the process chamber 105. However, if the temperature sensor 180 is a thermocouple, the thermocouple must be in contact with the workpiece 120 and thus may be positioned inside the process chamber 105. Further, the temperature sensor 180 may be communicatively coupled to the controller 190 via a wired connection, a wireless connection, or both a wired and wireless connection such that data generated by the temperature sensor 180 indicative of the temperature of the workpiece 120 may be provided to the controller 190.

In some embodiments, the heat treatment system 100 may include a cooling system 200, the cooling system 200 configured to flow a cooling gas from a gas source 214 through the workpiece 120 during heat treatment. The controller 190 may control the operation of the heat source 150 and the cooling system 200 (e.g., vary the rate of supply of cooling gas through the workpiece 120) during the heat treatment to reduce the peak width associated with the heat treatment process. For example, the controller 190 may control the operation of the cooling system 200 such that the heat treatment process has a t50 peak width of about 1.8 seconds or less, such as about 1.5 seconds or less. Additionally, the controller 190 may control the operation of the workpiece support 130 to rotate the workpiece 120. For example, during a heat treatment process, such as at least during operation of the cooling system 200, the controller 190 may control operation of the workpiece support 130 to rotate the workpiece 120.

In some implementations, the controller 190 (e.g., a computer, microcontroller, other control device, etc.) may include one or more processors and one or more memory devices. The one or more storage devices may store computer readable instructions that, when executed by the one or more processors, cause the one or more processors to perform operations such as turning on or off the heat source 150 during a heat treatment, controlling the operation of the cooling system 200, or other suitable operations.

Referring now to fig. 2 and 3, components of a workpiece support 300 are provided according to an example embodiment of the present disclosure. As shown, the workpiece support 300 may include a rotor 310. The rotor 310 may be configured to support a workpiece, such as the workpiece 120 discussed above with reference to fig. 1. The workpiece support 300 may also include a gas supply 320. The gas supply 320 may include a plurality of carrier pads 330. Each of the plurality of carrier pads 330 may define at least one channel configured to direct gas flowing therethrough onto the rotor 310 to control a position of the rotor 310 along a first axis (e.g., vertical) and a position along a second axis (e.g., radial or transverse) that is substantially perpendicular to the first axis. Further, one or more of the bearing pads 330 may define at least one additional channel configured to direct gas flowing therethrough onto the rotor 310 to control rotation of the rotor 310 about the first axis.

In some embodiments, the workpiece support 300 may include a support 340 and the plurality of carrier pads 330 of the gas supply 320 may be positioned on the support 340. For example, in some embodiments, the support 340 may include one of the quartz windows 107 discussed above with reference to fig. 1. In alternative embodiments, the support 340 may be spaced apart from the quartz window 107 and positioned within the processing chamber 105 (fig. 1). In such an embodiment, the support 340 may comprise a quartz plate.

Referring now to fig. 4 and 5, a configuration of a gas supply 320 is provided according to an example embodiment of the present disclosure. As shown, the gas supply 320 may include a first carrier pad 332, a second carrier pad 334, and a third carrier pad 336. In alternative embodiments, the gas supply 320 may include more or fewer carrier pads. Details of the first, second, and third carrier pads 332, 334, 336 will now be discussed in more detail.

In some implementations, the gas supply 320 can include a first conduit 350, the first conduit 350 being fluidly coupled to each of the first carrier pad 332, the second carrier pad 334, and the third carrier pad 336. In this manner, gas may be provided to each of the carrier pads (e.g., first carrier pad 332, second carrier pad 334, third carrier pad 336) via first conduit 350. As shown, the first, second, and third carrier pads 332, 334, 336 may be positioned at different locations along the first conduit 350. For example, the first conduit 350 and the carrier pads (e.g., the first carrier pad 332, the second carrier pad 334, and the third carrier pad 336) may form a closed loop to increase the mechanical stability and rigidity of the gas supply 320.

In some embodiments, first carrier pad 332, second carrier pad 334, and third carrier pad 326 may each define at least one channel that is fluidly coupled to first conduit 350. Further, at least one channel may be configured to direct gas flowing therethrough onto rotor 310 (fig. 3) to control the position of rotor 310 along the first and second axes. In this manner, the position of rotor 310 along the first and second axes may be controlled via a plurality of gas pads (i.e., gas exiting at least one channel defined by each of first carrier pad 332, second carrier pad 334, and third carrier pad 336).

In some embodiments, at least one channel defined in each of the first, second, and third load bearing pads 332, 334, and 336 may include a first channel 360 and a second channel 362. The first channel 360 may extend along a first axis. In this manner, gas exiting first channel 360 may lift rotor 310 off of the carrier pads (e.g., first carrier pad 332, second carrier pad 334, third carrier pad 336) such that rotor 310 is spaced apart from the carrier pads along the first axis. The second channel 362 may extend along a second axis. In this way, second channel 362 may be configured to control the position of rotor 310 along the second axis. More specifically, the gas exiting the second channel 362 may resist forces acting on the rotor 310 such that movement of the rotor 310 along the second axis is restricted.

In some embodiments, one or more of the carrier pads (e.g., first carrier pad 332, second carrier pad 334, third carrier pad 336) may define at least one additional channel that is separated from one or more channels (e.g., first channel 360, second channel 362) configured to direct gas flowing therethrough onto rotor 310 to control the position of the rotor along the first and second axes. As shown, the second and third load-bearing pads 334, 336 may each define a third channel 364, the third channel 364 being separated from the first and second channels 360, 362.

In some embodiments, the third channel 364 defined by the second carrier pad 334 and the third carrier pad 336 may be fluidly coupled to a separate conduit of the gas supply 320. For example, a third channel 364 defined by the second carrier pad 334 may be fluidly coupled to a second conduit 370 of the gas supply 320. Conversely, a third channel 364 defined by the third carrier pad 336 may be fluidly coupled to a third conduit 380 of the gas supply 320.

Third passage 364 may be configured to direct gas flowing therethrough onto rotor 310 to control rotation of rotor 310 about the first axis. For example, a third channel 364 defined by the second carrier pad 334 may be configured to direct gas flowing therethrough onto the rotor 310 to accelerate (i.e., accelerate) rotation of the rotor 310 about the first axis. Conversely, a third channel 364 defined by the third carrier pad 336 may be configured to direct gas flowing therethrough onto the rotor 310 to slow (i.e., slow) rotation of the rotor 310 about the first axis.

Referring now to fig. 6, another embodiment of a gas supply 320 is provided in accordance with an example embodiment of the present disclosure. As shown, the second and third carrier pads 334, 336 may each define a fourth channel 366. Further, third and fourth channels 364, 366 defined in second and third load-bearing pads 334, 336 may be fluidly coupled to second and third conduits 370, 380, respectively. In such an embodiment, third channel 364 may be configured to direct gas flowing therethrough onto rotor 310 to accelerate (i.e., accelerate) the rotation of the gas about the first axis. Conversely, fourth channel 366 may be configured to direct gas flowing therethrough onto rotor 310 to slow (i.e., slow) the rotation of the gas about the first axis.

Referring now to fig. 7, a cross-sectional view of a workpiece support 300 is provided in accordance with an example embodiment of the present disclosure. As shown, each of the plurality of carrier pads 330 may define a first channel 360 and a second channel 362. The first channel 360 may extend along the first axis 410. In this manner, first channel 360 may direct gas flowing therethrough onto rotor 310 to lift rotor 310 off of plurality of carrier pads 330. Conversely, the second channel 362 may extend along the second axis 412 that is substantially perpendicular to the first axis 410. In this manner, second channel 362 may direct gas flowing therethrough onto rotor 310 to resist forces acting on rotor 310, thereby restricting movement of rotor 310 along second axis 412.

As shown, when first channel 360 directs gas flowing therethrough onto rotor 310, a first gas gap 430 may be defined between rotor 310 and plurality of carrier pads 330 along first axis 410. Further, when second channel 362 directs gas flowing therethrough onto rotor 310, a second air gap 440 may be defined between rotor 310 and plurality of carrier pads 330 along second axis 412. In some embodiments, the first air gap 430 and the second air gap 440 may each be in the range of about 10 microns to about 50 microns.

Referring now to fig. 8, a cross-sectional view of a workpiece support 300 is provided according to another example embodiment of the disclosure. The workpiece support 300 may be configured in substantially the same manner as the workpiece support 300 in fig. 7. For example, each of the load-bearing pads 330 of the workpiece support 300 in fig. 8 may define a first channel 360 extending along the first axis 410 and a second channel 362 extending along the second axis 412. However, in contrast to the workpiece support 300 of fig. 7, the rotor 310 of the workpiece support 300 of fig. 8 may define the aperture 316. Further, the rotor 310 in fig. 8 may be configured to support the workpiece 120 such that the workpiece 120 is positioned over the aperture 316. In this manner, one or more heat sources 150 (fig. 1) of the thermal processing system 100 may have an unobstructed view of the workpiece 120.

Referring now to fig. 9, a cross-sectional view of a workpiece support 300 is provided according to yet another example embodiment of the disclosure. The workpiece support 300 may be configured in substantially the same manner as the workpiece support 300 in fig. 7. For example, each of the load-bearing pads 330 of the workpiece support 300 in fig. 9 may include a first channel 360 extending along the first axis 410. Further, each of the load-bearing pads 330 of the workpiece support 300 in fig. 9 may define a second channel 362. However, in contrast to the second channels 362 in fig. 7 defined by each of the carrier pads 330, the second channels 362 in fig. 9 defined by each of the carrier pads 330 do not extend along the second axis 412. Instead, the second channels 362 defined by each of the bearing pads 330 are angled relative to the second axis 412 such that the second channels 362 direct gas flowing therethrough onto the tapered surface 318 of the rotor 310. For example, in some embodiments, the second channel may be angled relative to the second axis 412 such that an acute angle 450 (e.g., less than 90 degrees) is defined between the second channel 362 and the second axis 412.

Referring now to fig. 10, a cross-sectional view of a workpiece support 300 is provided in accordance with yet another example embodiment of the present disclosure. The workpiece support 300 may be configured in substantially the same manner as in fig. 7. For example, the workpiece support 300 in fig. 10 may include a plurality of load-bearing pads 330, the plurality of load-bearing pads 330 being positioned closer to the periphery 312 of the rotor 310 than to the center 314 of the rotor 310. However, in contrast to the carrier pad 330 in fig. 7, the carrier pad 330 in fig. 10 does not define two separate channels (e.g., the first channel 360 and the second channel 362 in fig. 7) configured to direct gas flowing therethrough onto the rotor to control the position of the rotor 310 along the first axis 410 and the second axis 412. Instead, the carrier pad 330 in fig. 10 includes a single channel 500, the single channel 500 being fluidly coupled to the first conduit 350 of the gas supply 320 (fig. 2). Further, the single channel 500 may be angled with respect to the second axis 412. For example, in some embodiments, an acute angle 510 (e.g., less than 90 degrees) may be defined between the single channel 500 and the second axis 400. The single channel 500 may be configured to direct gas flowing therethrough onto the curved surface 319 of the rotor 310. In this manner, the position of rotor 310 along first axis 410 and second axis 412 may be controlled via venting gas from one channel (e.g., single channel 500) rather than venting gas from two separate channels (e.g., first channel 360 and second channel 362).

While the present subject matter has been described in detail with respect to specific example embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.

Claims (19)

1. A workpiece support for a thermal processing system, the workpiece support comprising:

a rotor configured to support a workpiece;

a gas supply comprising a plurality of load-bearing pads, each of the load-bearing pads being positioned closer to a periphery of the rotor than a center of the rotor;

one or more channels defined in each of the load-bearing pads, the one or more channels configured to direct gas onto the rotor to control the position of the rotor along a first axis and a second axis, the second axis being substantially perpendicular to the first axis; and

at least one additional channel is defined in one or more of the load-bearing pads, the at least one additional channel configured to direct gas onto the rotor to control rotation of the rotor about the first axis.

2. The workpiece support of claim 1, wherein the one or more channels defined in each of the load-bearing pads comprise:

a first channel extending along the first axis, the first channel configured to direct gas onto the rotor to control a position of the rotor along the first axis; and

a second channel extends along the second axis, the second channel configured to direct gas onto the rotor to control a position of the rotor along the second axis.

3. The workpiece support of claim 2, wherein:

the first channel tapers along the first axis; and

the second channel tapers along the second axis.

4. The workpiece support of claim 2, wherein:

a first air gap is defined between the rotor and the plurality of load-bearing pads along the first axis when air is directed onto the rotor via the first channel to control a position of the rotor along the first axis; and

a second air gap is defined between the rotor and the plurality of load-bearing pads along the second axis when gas is directed onto the rotor via the second channel to control a position of the rotor along the second axis.

5. The workpiece support of claim 4, wherein the first air gap and the second air gap range from about 10 microns to about 50 microns.

6. The workpiece support of claim 2, wherein the at least one additional channel comprises:

a third channel configured to direct gas onto the rotor to accelerate rotation of the rotor about the first axis; and

a fourth passage configured to direct gas onto the rotor to slow rotation of the rotor about the first axis.

7. The workpiece support of claim 6, wherein the gas supply further comprises:

a first conduit fluidly coupled to the first and second channels, the first conduit configured to deliver gas to the first and second channels;

a second conduit fluidly coupled to the third channel, the second conduit configured to deliver the gas to the third channel; and

a third conduit fluidly coupled to the fourth channel, the third conduit configured to deliver the gas to the fourth channel.

8. The workpiece support of claim 1, further comprising:

a support configured to support the plurality of load bearing pads.

9. The workpiece support of claim 1, wherein the rotor defines a bore.

10. The workpiece support of claim 9, wherein the rotor is configured to support the workpiece such that the workpiece is positioned over the aperture.

11. The workpiece support of claim 9, wherein the one or more channels defined in each of the plurality of load-bearing pads are angled with respect to the second axis.

12. A heat treatment system, comprising:

a processing chamber; and

a workpiece support disposed within the processing chamber, the workpiece support comprising:

a rotor configured to support a workpiece;

a gas supply comprising a plurality of load-bearing pads, each of the load-bearing pads being positioned closer to a periphery of the rotor than a center of the rotor;

one or more channels defined in each of the load-bearing pads, the one or more channels configured to direct gas onto the rotor to control the position of the rotor along a first axis and a second axis, the second axis being substantially perpendicular to the first axis; and

at least one additional channel is defined in one or more of the load-bearing pads, the at least one additional channel configured to direct gas onto the rotor to control rotation of the rotor about the first axis.

13. The thermal processing system of claim 12, wherein the one or more channels defined in each of the load-bearing pads comprise:

a first channel extending along the first axis, the first channel configured to direct gas onto the rotor to control a position of the rotor along the first axis; and

a second channel extends along the second axis, the second channel configured to direct gas onto the rotor to control a position of the rotor along the second axis.

14. The thermal processing system of claim 13, wherein said at least one additional channel comprises:

a third channel configured to direct gas onto the rotor to accelerate rotation of the rotor about the first axis; and

a fourth passage configured to direct gas onto the rotor to slow rotation of the rotor about the first axis.

15. The thermal processing system of claim 12, further comprising:

a support configured to support the plurality of load bearing pads.

16. The thermal processing system of claim 12, wherein the rotor defines a bore.

17. The thermal processing system of claim 16, wherein the rotor is configured to support the workpiece such that the workpiece is positioned over the aperture.

18. The thermal processing system of claim 12, wherein the one or more channels defined in each of the plurality of load bearing pads are angled with respect to the second axis.

19. The thermal processing system of claim 18, wherein the one or more channels are configured to direct gas onto a curved surface of the rotor.