Workpiece support system

Abstract

A workpiece support system is disclosed. This support system allows the back side of a workpiece to be exposed to an incident ion beam while the front side remains uncontacted. The workpiece support system includes a pivotable latch having an open position and a closed position. In the closed position, the pivotable latch contacts only the edge exclusion zone of the workpiece. This reduces the possibility of damage to the front side of the workpiece. Furthermore, the workpiece support system may include a universal joint allowing multiple rotational degrees of freedom.

Description

[Technical Field]

[0001] The embodiments disclosed herein relate to a workpiece support that allows processing of the back side of a workpiece without contacting the front surface of the workpiece. This application claims priority to U.S. Patent Application Serial No. 18 / 392,246, filed December 21, 2023, the entire disclosure of which is incorporated herein by reference. [Previous Technology]

[0002] The manufacturing of semiconductor devices continues to become increasingly complex. Currently, in some cases, it may be necessary to process both surfaces of a workpiece, such as silicon, silicon carbide, or gallium nitride wafers. For example, to create certain structures, it may be beneficial to perform ion implantation processes on both surfaces of the workpiece. Implantation on the back side of semiconductor device wafers has become common in power device manufacturing applications. In this case, dopants are implanted into the bottom surface of the wafer to improve electrical performance. One such application is adding field stop regions to insulated-gate bipolar transistor (IGBT) devices. A second back-side processing method uses ion implantation to alleviate or control wafer stress and physical deformation. Selective ion implantation can be used to reduce wafer bending, which makes lithography processes more difficult.

[0003] When both surfaces of a workpiece need to be processed, the front surface can be processed first.

[0004] However, in some embodiments, the processing of the front surface may include the formation of three-dimensional structures, such as fin field-effect transistors (FinFETs). Once these three-dimensional structures are created, placing the front surface on an electrostatic clamp carries the risk of damaging these structures.

[0005] Therefore, it would be advantageous if there were a system that allowed processing of the back side of a workpiece without having to contact the already processed front surface. Furthermore, it would be advantageous if this system allowed for workpiece rotation and tilting, as is conventionally performed using electrostatic clamps. [Summary of the Invention]

[0006] A workpiece support system is disclosed. This support system allows the back side of a workpiece to be exposed to an incident ion beam while the front surface of the workpiece remains uncontacted. The workpiece support system includes a pivotable latch having an open position and a closed position. In the closed position, the pivotable latch contacts only the edge exclusion zone of the workpiece. This reduces the possibility of damage to the front surface of the workpiece. Furthermore, the workpiece support system may include a universal joint that allows multiple rotational degrees of freedom.

[0007] According to one embodiment, a workpiece support system is disclosed. The workpiece support system includes: a workpiece holder rotatably coupled to a support arm; a workpiece holder rotatably mounted to the workpiece holder; wherein the workpiece holder includes: a workpiece retaining ring; and a plurality of workpiece clamps arranged along the diameter of the workpiece retaining ring, each of the plurality of workpiece clamps including a seat on which the bottom surface of a workpiece is supported, and a pivotable latch operable to clamp the front surface of the workpiece in a closed position and release the workpiece in an open position. In some embodiments, the workpiece retaining ring is rotatable about an tilt axis. In some embodiments, when in the closed position, the workpiece clamps hold the workpiece as the workpiece holder rotates at any tilt angle. In some embodiments, the workpiece holder is rotatable about a torsion axis. In some embodiments, when in the closed position, the pivotable latch covers only the edge exclusion area of ​​the workpiece. In some embodiments, each of the plurality of workpiece clamps includes: a seat attached to the inner diameter of the workpiece retaining ring, having a body and a top platform, wherein the body has a hollow channel therethrough, and the top platform supports the bottom surface of the workpiece. In some embodiments, each of the plurality of workpiece clamps includes a shaft through a hollow conduit, rigidly attached at its distal end to a pivotable latch and rigidly fixed at its proximal end to a lever. In some embodiments, a clamping actuator is connected to a clamping link, with each lever attached to the clamping link such that actuation of the clamping actuator causes all shafts to rotate between an open position and a closed position. In some embodiments, a return spring is connected to the clamping link, biasing the clamping link to one of the open or closed positions, and actuation of the clamping actuator rotates the shaft to the other of the open and closed positions. In some embodiments, each of the plurality of clamping actuators is connected to a lever of its respective workpiece clamp such that actuation of the plurality of clamping actuators causes all shafts to rotate between an open position and a closed position. In some embodiments, each of the plurality of return springs is connected to a lever of its respective workpiece clamp, biasing the lever to one of the open or closed positions, and actuation of the respective clamping actuator rotates the shaft to the other of the open and closed positions. In some embodiments, the workpiece retaining ring includes a cut along a portion of its front surface to allow for insertion and removal of the robotic arm.

[0008] According to another embodiment, a workpiece support system is disclosed. The workpiece support system includes a workpiece support; a workpiece holder rotatably mounted to the workpiece support; wherein the workpiece holder includes: a workpiece retaining ring; and a plurality of workpiece clamps arranged along the diameter of the workpiece retaining ring; each of the plurality of workpiece clamps includes: a seat attached to the inner diameter of the workpiece retaining ring, having a body and a top platform, wherein the body has a hollow channel passing through it, and the top platform supports the bottom surface of the workpiece; and a shaft through the hollow channel, rigidly attached at a distal end to a pivotable latch and rigidly fixed at a proximal end to a lever.

[0009] In some embodiments, when in the closed position, the pivotable latch covers only the edge exclusion area of ​​the workpiece. In some embodiments, a clamping actuator is connected to a clamping link, and each lever is attached to the clamping link such that actuation of the clamping actuator causes all axes to rotate between an open position and a closed position. In some embodiments, a return spring is connected to the clamping link, the return spring biasing the clamping link to one of the open or closed positions, and actuation of the clamping actuator rotates the axis to the other of the open and closed positions. In some embodiments, the workpiece support system includes a protective cover such that the clamping link is disposed between the protective cover and the bottom side of the workpiece retaining ring. In some embodiments, the workpiece holder and the workpiece clamp form a universal joint having two rotational degrees of freedom. In some embodiments, a plurality of clamping actuators are each connected to a lever of a corresponding workpiece clamp such that actuation of the plurality of clamping actuators causes all axes to rotate between an open position and a closed position. In some embodiments, multiple return springs are each connected to a lever of a corresponding workpiece fixture, wherein the return spring biases the lever to one of an open or closed position, and actuation of the corresponding fixture actuator rotates the shaft to the other of the open and closed positions.

Implementation Method

[0011] As described above, in some systems it may be necessary to process the back side of the workpiece without contacting the available area of ​​the front surface.

[0012] Figure 1 shows a workpiece support system for achieving this objective. The workpiece support includes a base 100, which includes a locking mechanism supported on a rotatable shaft 101. The base 100 is detachably coupled to the rotatable shaft 101 such that rotation of the rotatable shaft 101 about axis 102 causes a corresponding rotation of the base 100. Furthermore, linear translation of the rotatable shaft 101 in the height or Z direction (i.e., parallel to axis 102) causes a corresponding linear movement of the base 100. The base 100 contacts a support arm 105. The distance from the center of the locking mechanism to the support arm 105 may be greater than the radius of the workpiece to be supported. The base 100 and the support arm 105 may be made of aluminum.

[0013] The support arm 105 is used to create separation in the height or Z direction between the base 100 and the workpiece holder 120 in the operating position, as described in more detail below.

[0014] A torsion motor 110 is attached to a support arm 105. The torsion motor 110 may include a shaft that passes through the support arm 105 and is attached to the workpiece holder 130. In other embodiments, the torsion motor 110 may be connected to the workpiece holder 130 via one or more gears. In some embodiments, the torsion motor 110 is located on the side of the support arm 105 opposite to the workpiece holder 130. This protects the torsion motor 110 from the ion beam during workpiece processing.

[0015] Due to its connection with the torsion motor 110, the workpiece holder 130 is capable of rotating about the torsion axis 111. In some embodiments, the torsion motor 110 is a direct drive, such as a stepper motor. In this case, the torsion motor 110 can easily determine the amount of torsion experienced by the workpiece holder 130. In other embodiments, an encoder can be used to determine the amount of torsion experienced by the workpiece holder 130. In other embodiments, there may be a linkage, such as one or more gears, between the torsion motor 110 and the workpiece holder 130. If a linkage is used, an encoder or a stepper motor can be used to monitor the amount of torsion.

[0016] The workpiece holder 130 may be C-shaped. In some embodiments, the workpiece holder 130 may have a semi-circular shape, wherein the inner diameter of the semi-circle is larger than the outer diameter of the workpiece holder 120. The workpiece holder 130 may include two rotary joints aligned with connection points 123 on the workpiece holder 120. These rotary joints allow the workpiece holder 120 to rotate about a tilt axis 121, which is the primary orientation axis for positioning the workpiece for loading / unloading and for processing the front and back sides of the workpiece. During processing, the workpiece holder 120 can be set to any tilt angle by rotation about the tilt axis 121. The positions of the rotary joints in the workpiece holder 130 and the connection points 123 in the workpiece holder 120 are such that the tilt axis 121 passes through all connection points and may coincide with the diameter of the workpiece holder 120.

[0017] The workpiece holder 120 has a circular hollow shape, slightly larger than the diameter of the workpiece it is intended to hold. As described above, the workpiece holder 120 has two connection points 123 with diameters opposite each other. Each connection point 123 is aligned with a corresponding rotary joint in the workpiece support 130. Although this embodiment uses two rotary joints, in other embodiments, a single rotary joint may be used if sufficient mechanical strength is available.

[0018] The tilt motor 140 may be configured on the support arm 105 or the workpiece holder 130. In one particular embodiment, the tilt motor 140 is located on the workpiece holder 130, and a flange 131 is formed on the workpiece holder 130 to protect the tilt motor 140 from the incident ion beam. The tilt motor 140 may be a stepper motor. In other embodiments, the tilt motor 140 may include an encoder to monitor the amount of tilt experienced by the workpiece holder 120.

[0019] Furthermore, in some embodiments, the tilt motor 140 is connected to a tilt motor coupling 141. The tilt motor coupling 141 is located on the workpiece holder 130 near one of the rotary joints. The tilt motor coupling 141 couples rotation from the tilt motor 140 to one of the rotary joints. One embodiment uses a push-pull arrangement of coils, where rotation of the tilt motor 140 is coupled to a pulley, which serves as the tilt motor coupling 141. Of course, the tilt motor coupling 141 can be implemented in other ways. In another embodiment, the tilt motor coupling 141 may not be used. Instead, the tilt motor 140 may be located on the side of the workpiece holder 130 (at the location shown by the tilt motor coupling 141).

[0020] In one embodiment, the connection point is a hole in the sidewall of the workpiece holder 120. Shafts are attached to the rotary joint and inserted into the connection point on the workpiece holder 120. These shafts pivotally support the workpiece holder 120.

[0021] In some embodiments, one of the shafts is connected to a tilting motor coupling 141. In one embodiment, the shaft may have teeth and engage with grooves similarly configured on the workpiece holder 120. In some embodiments, the shaft may be connected to a pulley that rotates the shaft. Thus, rotation of the tilting motor 140 causes a corresponding rotation of the workpiece holder 120.

[0022] Figure 2A shows the workpiece support system of Figure 1, wherein the tilt motor 140 causes the workpiece holder 120 to rotate 90°. Note that in this embodiment, the back side of the workpiece 300 may be exposed to the incident ion beam 360. Figure 2B shows the workpiece support system of Figure 1, wherein the tilt motor 140 causes the workpiece holder 120 to rotate 90° about the tilt axis 121, and the torsion motor 110 causes the workpiece support 130 to rotate about the torsion axis 111.

[0023] Therefore, the workpiece support 130 and the workpiece gripper 120 constitute a gimbal assembly with two degrees of freedom. The workpiece support 130 is rotatable about a torsion axis 111. The workpiece gripper 120 is mounted on the workpiece support 130 and is rotatable about an inclined axis 121 orthogonal to the torsion axis 111. Furthermore, when mounted on the rotatable axis 101, the workpiece support system provides three rotational degrees of freedom and linear translation in one direction. Therefore, the workpiece support system provides the same configurability as a conventional platform. Of course, other structures can be used to create a gimbal assembly with two degrees of freedom.

[0024] Figures 3A and 3B show enlarged views of the workpiece holder 120. Figure 3A is a top view, and Figure 3B is a bottom view. In this disclosure, the bottom surface of the workpiece holder 120 is defined as the surface facing the ion beam 360 during the processing of the back side of the workpiece 300, while the top surface is the surface on which the workpiece 300 is placed.

[0025] Note that during processing, the top side of the workpiece holder 120 may face away from the ion beam 360, while the bottom side faces the ion beam 360. The workpiece holder 120 includes a workpiece retaining ring 200 with an inner diameter slightly larger than the workpiece 300 it is designed to support. The workpiece retaining ring 200 may be constructed of aluminum or ceramic. In some embodiments, a polymer may be used. The workpiece retaining ring 200 includes two connection points 123 as described above. Furthermore, the workpiece retaining ring 200 includes a cutout 122 located at the leading edge of the workpiece retaining ring 200. The cutout 122 allows a robotic arm to place the workpiece on the workpiece holder 120 and then disengage it from the workpiece support system. The width and height of the cutout 122 are selected to allow the robotic arm to pass through the space between the workpiece and the workpiece retaining ring 200 without contacting these components. In another embodiment, the workpiece retaining ring 200 is open on the front side without the cutout 122.

[0026] The workpiece holder 120 also includes a plurality of workpiece clamps 210, which will be described in more detail below. A clamping actuator 230 may also be disposed on the top surface of the workpiece retaining ring 200. The clamping actuator 230 is connected to the clamping link 240, as explained in more detail below.

[0027] As described above, the bottom surface of the workpiece holder 120 faces the ion beam during processing. Therefore, a protective cover 250 may be disposed on the bottom surface of the workpiece holder 120. The protective cover 250 may be made of graphite or alumina. The protective cover 250 is removed in Figure 3B to allow for the illustration of the assembly disposed between the protective cover 250 and the workpiece retaining ring 200. However, the protective cover 250 is shown in Figure 2A.

[0028] Figure 3B shows the clamping link 240 in more detail. The clamping link 240 is connected to the clamping actuator 230. In this way, any movement of the clamping actuator 230 causes the clamping link 240 to rotate accordingly. The clamping link 240 contacts a plurality of levers 211, wherein each workpiece clamp 210 includes one lever 211. Rotation of the clamping link 240 causes each lever 211 to move between an open position and a closed position, as described in more detail below. In some embodiments, the clamping link 240 is connected to a return spring 260. The return spring 260 biases the clamping link 240 toward one of two positions, while the clamping actuator 230 is used to move the clamping link 240 to the other position. For example, the return spring 260 may bias the clamping link 240 to the closed position so that a power failure will not cause the workpiece 300 to be released. The peg 251 extends from the bottom surface of the workpiece retaining ring 200 and is used to secure the protective cover 250 in place.

[0029] Although Figure 3B shows a single clamping actuator 230 controlling all workpiece clamps 210, other embodiments are possible. For example, a separate clamping actuator may be used for each workpiece clamp 210. Furthermore, in some embodiments, a separate return spring 260 may be associated with each workpiece clamp 210. Additionally, in some embodiments, the clamping actuator 230 may be configured on the bottom surface of the workpiece retaining ring 200.

[0030] The workpiece clamp 210 is shown in Figures 4A to 4B, 5A to 5B, and 6A to 6B. Figure 4A shows a side view of the workpiece clamp 210 in the open position, while Figure 4B shows a perspective view of the workpiece clamp 210 in the open position. The workpiece clamp 210 includes a seat 215 fixed to the inner wall of the workpiece retaining ring 200. The seat 215 includes a body 216 and a top platform 217. The top platform 217 extends beyond the body 216. When fixed to the workpiece retaining ring 200, the top platform 217 extends inward toward the center of the workpiece retaining ring 200. The body 216 includes a hollow conduit extending therethrough. A shaft 212 is inserted into the hollow conduit. The shaft 212 is rotatable within the hollow conduit and is rigidly coupled to a lever 211 at its proximal end and rigidly attached to a pivotable latch 213 at its distal end. A pivotable latch 213 is disposed on top of the top platform 217 and includes an indented portion 218 and an overhanging portion 219. The height of the indented portion 218 is equal to or slightly greater than the thickness of the workpiece 300 to be clamped. The overhanging portion 219 extends further than the indented portion 218. Note that in the open position, the overhanging portion 219 does not extend inward as the top platform 217. In this way, when the workpiece clamp 210 is in the open position, the workpiece is supported only on the top platform 217, as shown in Figure 6A.

[0031] Figure 5A shows a side view of the workpiece clamp 210 in the closed or latched position, while Figure 5B shows a perspective view of the workpiece clamp 210 in the latched position. In this position, lever 211 moves, causing pivotable latch 213 to rotate relative to seat 215. Overhang portion 219 rotates to extend over top platform 217, locking the workpiece in place, as shown in Figure 6B. When latched, workpiece 300 is secured between top platform 217 and the bottom surface of overhang portion 219. Furthermore, the overhang portion 219 is sized such that, when in the latched position, it extends only over the edge exclusion area of ​​workpiece 300. In some embodiments, the edge exclusion area is an annular region around the outer edge of the workpiece, with a width of 3 mm.

[0032] Although Figures 4A to 4B and Figures 5A to 5B show the seat 215 as a separate component, it is understood that in some embodiments, the seat, including the body 216, the top platform 217, and the hollow tube, may be an integral part of the workpiece retaining ring 200. Specifically, the seat 215 may be molded as part of the workpiece retaining ring 200. Note that in this embodiment, the seat 215 is still fixed to the inner diameter of the workpiece retaining ring 200.

[0033] The controller may be connected to the torsion motor 110, the tilt motor 140, and the clamping actuator 230 to control the operation of the workpiece support system. The controller includes a processing unit and associated memory devices. This memory device contains instructions that, when executed by the processing unit, enable the controller to perform the functions described herein. This memory device may be non-volatile memory, such as flash memory (FLASH ROM), electrically erasable read-only memory (ERM), or other suitable devices. In other embodiments, the memory device may be volatile memory, such as random access memory (RAM) or dynamic random access memory (DRAM). The processing unit may be a general-purpose computer, a special-purpose computer, a microcontroller, or other types of circuitry.

[0034] After describing all the components of the workpiece support system, its operation will be described. First, as shown in FIG7A, the robotic arm 350 brings the workpiece 300 to the workpiece support system. The workpiece clamp 210 is in the open position. As shown in FIG7B, the robotic arm 350 then lowers, causing the workpiece 300 to be supported on the top platforms 217 of the seat 215, which support the workpiece 300 when the workpiece holder 120 is in the horizontal position. Note that the robotic arm 350 is adapted within the space defined by the cutout 122.

[0035] The robotic arm 350 further lowers to release the workpiece 300. At this time, the workpiece gripper 210 is in the open position, as shown in FIG6A. The robotic arm 350 then exits through the space defined by the cutout 122, as shown in FIG7C. The workpiece gripper 210 is then actuated to the latch position to secure the workpiece 300 in place, as shown in FIG6B. Note that the workpiece gripper 210 may be actuated before or after the robotic arm 350 is removed from the workpiece support system.

[0036] Figure 7D shows a top view of the workpiece 300 clamped to the workpiece support system. Once the workpiece 300 is clamped, the tilting motor 140 can rotate the workpiece holder 120 so that the back of the workpiece 300 faces the ion beam 360, as shown in Figures 2A to 2B.

[0037] The ion beam 360 can be generated using an ion source. The ion source can be an indirectly heated cathode (IHC) ion source. Alternatively, the ion source can be a capacitively coupled plasma source, an inductively coupled plasma source, a Bernas source, or other sources. Therefore, this disclosure does not limit the type of ion source.

[0038] In one embodiment, the ion source may be configured with the workpiece support system within a processing chamber. Ions can be extracted from the ion source and guided to the workpiece using extraction electrodes. In another embodiment, the ion beam can be generated using a beamline ion implantation system. The ion implantation system may include an ion source, extraction optics for extracting ions from the ion source, and a mass analyzer that modulates the ion path according to the charge and mass of the ions. Furthermore, downstream of the mass analyzer may be a mass resolving aperture for selectively passing ions with a desired mass-to-charge ratio. Further downstream may be one or more additional components for guiding the ion beam 360 to the workpiece 300. These components may include collimators and / or acceleration / deceleration stages. Of course, the beamline ion implantation system may also include other additional components.

[0039] Note that although Figures 2A and 2B show the back of workpiece 300 facing the ion beam, it can be understood that the tilting motor 140 can be actuated in the opposite direction, so that the front surface of workpiece 300 faces the ion beam 360. If the front surface of workpiece 300 is to face the ion beam 360, a second protective cover can be provided on the top surface of workpiece retaining ring 200. This second protective cover can be attached using a pin, similar to that used on the bottom surface.

[0040] As described above, the workpiece 300 can be oriented to any torsion angle or tilt angle using the torsion motor 110 and the tilt motor 140 respectively. In addition, the height and other tilt angles can be controlled by moving the rotatable shaft 101.

[0041] After processing, the workpiece 300 can be removed from the workpiece support system by performing this sequence in reverse order.

[0042] The system and method described herein have numerous advantages. This workpiece support system allows processing of any face of the workpiece 300 without contacting available areas on the workpiece. This allows processing of the front surface of the workpiece, followed by subsequent processing of the back surface, without damaging the nanostructures formed on the front surface. Furthermore, the two-degree-of-freedom gimbals allow the workpiece support system to take any orientation, allowing for tilted implantation if necessary.

[0043] The scope of this disclosure is not limited to the specific embodiments described herein. In fact, various other embodiments and modifications of this disclosure will become apparent to those skilled in the art from the foregoing description and drawings, in addition to the embodiments and modifications described herein. Therefore, these other embodiments and modifications are intended to be within the scope of this disclosure. Furthermore, although this disclosure has been set forth herein in the context of specific embodiments, in specific environments, and for specific purposes, those skilled in the art will recognize that its usefulness is not limited thereto and that this disclosure can be advantageously practiced in any number of environments for any number of purposes. Therefore, the appended claims should be interpreted in light of the full scope and spirit of this disclosure as set forth herein. [Simplified Explanation of the Diagram]

[0010] Reference is made to the accompanying drawings for a better understanding of this disclosure, which are incorporated herein by reference and in which: FIG1 illustrates a workpiece support system according to one embodiment. FIGS. 2A and 2B illustrate the workpiece support system of FIG1 at different tilt and torsion angles. FIGS. 3A and 3B illustrate a top view and a bottom view of a workpiece holder, respectively. FIGS. 4A and 4B illustrate a workpiece clamp in the open position. FIGS. 5A and 5B illustrate a workpiece clamp in the closed or locked position. FIGS. 6A and 6B illustrate a workpiece and a workpiece clamp in the open and closed positions, respectively. FIGS. 7A and 7D illustrate the procedure for loading a workpiece onto the workpiece support system.

Claims

1. A workpiece support system, comprising: a workpiece support; And a workpiece holder, rotatably mounted to the workpiece support; The workpiece holder includes: a workpiece retaining ring; and a plurality of workpiece clamps arranged along the diameter of the workpiece retaining ring; each of the plurality of workpiece clamps includes: a seat attached to the inner diameter of the workpiece retaining ring, having a body and a top platform, wherein the body has a hollow channel passing through it, and the top platform supports the bottom surface of the workpiece; and a shaft, through the hollow channel, rigidly attached at a distal end to a pivotable latch, and rigidly fixed at a proximal end to a lever.

2. The workpiece support system as claimed in claim 1, wherein when in the closed position, the pivotable latch covers only the edge exclusion zone of the workpiece.

3. The workpiece support system as claimed in claim 1, comprising a clamping actuator connected to a clamping link, wherein each of the levers is attached to the clamping link such that actuation of the clamping actuator causes all of the shafts to rotate between an open position and a closed position.

4. The workpiece support system as claimed in claim 3 further includes a return spring connected to the clamping link, wherein the return spring biases the clamping link to one of the open position or the closed position, and actuation of the clamping actuator rotates the shaft to the other of the open position and the closed position.

5. The workpiece support system as claimed in claim 3 further includes a protective cover, such that the clamping link is disposed between the protective cover and the bottom side of the workpiece retaining ring.

6. The workpiece support system as claimed in claim 1, wherein the workpiece support and the workpiece clamp form a universal joint having two rotational degrees of freedom.

7. The workpiece support system as claimed in claim 1, comprising a plurality of clamp actuators, each connected to the lever of a corresponding workpiece clamp, such that actuation of the plurality of clamp actuators causes all of the shafts to rotate between an open position and a closed position.

8. The workpiece support system of claim 7 further includes a plurality of return springs, each connected to the lever of a corresponding workpiece fixture, wherein the return spring biases the lever to one of the open position or the closed position, and actuation of the corresponding fixture actuator rotates the shaft to the other of the open position and the closed position.

9. The workpiece support system as claimed in claim 1, wherein the workpiece retaining ring is rotatable about an inclined axis.

10. The workpiece support system as claimed in claim 9, wherein, When in the closed position, the workpiece clamp can hold the workpiece in place even when the workpiece holder rotates at any tilt angle.

11. The workpiece support system as claimed in claim 1, wherein the workpiece support is rotatable about a torsion axis.

12. The workpiece support system as claimed in claim 1, wherein the portion of the workpiece retaining ring along its front surface includes a cutout to allow insertion and removal of a robotic arm.

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