Apparatus, systems, and methods for providing self-extraction gripping for end effectors.

Abstract

An apparatus, system, and method for a wedge-shaped gripper adapted to provide self-extraction gripping for an end effector adapted to hold a semiconductor wafer or other substrate such as a rectangular panel. The apparatus, system, and method may include two inner jaws, both of which are at least mechanically associated with a robot base; two outer arms, both of which are associated with the inner jaws via at least one arm cam; and a plurality of wedge-shaped grippers. Each wedge-shaped gripper may include: a spring; a cam mounted on the spring; and a cam travel path, the cam being slidably associated with the cam travel path. Contraction of the inner jaws and subsequent arm cam drive of the outer arms apply pressure to the circumferential edge of the semiconductor wafer, such that the circumferential edge travels along the cam travel path of each cam and resists a spring pressing each cam. The jaws may close synchronously around the center point of the substrate, thereby keeping the substrate centered.

Description

Technical Field

[0001] This invention relates to the transport and handling of articles such as semiconductor wafers, and more particularly to apparatus, systems, and methods for providing self-extracting grips for end effectors. Background Technology

[0002] The use of robotics has been recognized as a manufacturing expedient, particularly in applications where manual operation is inefficient and / or unsatisfactory. One such application is in the semiconductor industry, where robots and automated stations are used to handle and hold wafers throughout various process steps. These steps can include, for example, chemical mechanical planarization (CMP), etching, deposition, passivation, and a variety of other processes, where a sealed and / or “clean” environment must be maintained to limit the possibility of contamination and ensure that various specific process conditions are met.

[0003] Current practices in the semiconductor industry for automating the handling of these wafers typically involve using end effectors operatively connected to robots, for example, to load semiconductor wafers from loading stacks into various processing ports that correspond to the aforementioned exemplary process steps. Robots are used to configure the end effectors to retrieve wafers from specific ports or stacks, for example, before and / or after processing in the relevant processing chamber, and / or to associate the wafers with stations, such as station chucks for placing the wafers.

[0004] Therefore, wafers can be moved between stations for additional processing by robots associated with end effectors. When a given wafer processing is complete, the robot can move the processed wafer from its station and return the processed semiconductor wafer to the loading port. Stacks of multiple semiconductor wafers are typically processed in this way during each process run.

[0005] Known technologies also include robots that flip and rotate wafers and similar substrates, for example, for inspection during or after processing. However, the typical type of end effector actually used in the prior art is an edge-gripping wafer processor. In an edge-gripping wafer processor, the wafer is handled only minimally, and the peripheral contact between the end effector and the wafer is only at the outer circumference of the wafer. Typically, this edge gripping is provided by mechanical wedges associated with the distal and proximal portions of the end effector (relative to the corresponding robot base of the end effector, where the robot movement and power of the end effector arm are provided).

[0006] However, these wedge-shaped guides may apply unnecessary friction to the held wafer, or insufficient friction if the wafer is laterally flipped or rotated, thus potentially providing unpredictable release and / or release positioning of the wafer due to friction caused by excessive or insufficient wedges. Furthermore, since the wedge clamps typically cover a portion of the outer circumference of the wafer, these edge clamps or wafer tools passing near them may create obstructions on the wafer, potentially damaging it. For example, if the wafer experiences friction and travels with the wedge clamp past the release point instead of being removed from the clamp in time, the wafer and / or structures on it will be damaged.

[0007] Due to the passive, automatic release characteristic of wedge clamps, friction frequently occurs. That is, a typical edge-gripping design compromises the wedge angle to approximately 75°, preventing excessive friction and allowing for automatic release. However, this angle limits the ability to flip or rotate the wafer associated with the wedge clamp, partly because the angle is insufficient to hold a flipped or rotated wafer. This problem is exacerbated with thin, flexible, and large wafers, which may require more overlap around the circumference to hold the wafer due to its flexibility within the clamp, and a steeper wedge angle is needed to reliably capture the wafer. This can lead to the wafer automatically releasing at an unexpected time.

[0008] In certain embodiments, some semiconductor processing applications may require the use of a rotary wrist end effector. A rotary wrist end effector may require a steeper angle and a deeper wedge base for the wedge clamp, such that the rotation of the end effector does not improperly self-release the wafer from the wedge clamp. However, in this case, as a non-limiting embodiment, the deeper wedge base and steeper wedge clamp angle are substantially more likely to cause excessive friction at the desired release time, and thereby invalidate the wafer's self-release, resulting in a lack of desired release and / or damage to the wafer. Summary of the Invention

[0009] Some embodiments are and include means, systems, and methods for wedge grippers adapted to provide self-extraction gripping for an end effector adapted to hold a semiconductor wafer. The means, systems, and methods may include two inner jaws, the two inner jaws being at least mechanically associated with a robot base; two outer arms, the two outer arms being associated with the inner jaws via at least one arm cam system (e.g., may include a servo motor and a timing belt providing cam drive); and a plurality of wedge grippers, wherein two of the plurality of wedge grippers are respectively secured to each of the two inner jaws near the front end of the end effector (e.g., its robot base), and wherein two of the plurality of wedge grippers are respectively secured to each of the outer arms remote from the front end of the end effector.

[0010] Each of at least one of the distal and proximal wedge clamps may include: a spring; a cam loaded on the spring; and a cam travel path in which the cam is housed and guided, for example, slidably guided. Thus, the contraction of the inner jaws and the subsequent arm cam drive of the outer arm apply pressure to the circumferential edge of the semiconductor wafer, causing the circumferential edge to press against each cam's cam travel path along the cam travel path and against a spring pressing each cam, thereby loading the cams to clamp the semiconductor wafer within a plurality of edge clamps.

[0011] Therefore, the present invention provides at least one apparatus, system, and method for providing a wedge clamp adapted to provide self-extraction gripping for an end effector adapted to hold a semiconductor wafer. Attached Figure Description

[0012] Exemplary components, systems, and methods will be described below with reference to the accompanying drawings, which are given by way of non-limiting embodiments only, wherein:

[0013] Figure 1 This is a diagram of an end effector used to process semiconductor wafers;

[0014] Figure 2 This is a diagram of a chip processing system;

[0015] Figure 3A and Figure 3B The end effector and the chip processor are shown;

[0016] Figure 4 This is a diagram of an end effector with a wedge-shaped clamp;

[0017] Figure 5 This is a diagram of an end effector with a wedge-shaped clamp;

[0018] Figure 6This is an illustration of an end effector with a wedge-shaped gripper; and

[0019] Figure 7 and Figure 8 This is a diagram of an end effector with a wedge-shaped clamp. Detailed Implementation

[0020] The accompanying drawings and descriptions provided herein may have been simplified to illustrate aspects relevant to a clear understanding of the apparatuses, systems, and methods described herein, while other aspects that may be found in typical similar apparatuses, systems, and methods have been omitted for clarity. Therefore, those skilled in the art will recognize that other elements and / or operations may be desired and / or necessary for implementing the apparatuses, systems, and methods described herein. However, because such elements and operations are known in the art and do not contribute to a better understanding of the invention, a discussion of such elements and operations may not be provided herein for the sake of brevity. Nevertheless, the invention is considered to still include all such elements, variations, and modifications to the described aspects known to those skilled in the art.

[0021] The embodiments are provided throughout this document to ensure that the invention is thorough and fully conveys the scope of the disclosed embodiments to those skilled in the art. Numerous specific details, such as embodiments of specific components, apparatuses, and methods, are set forth to provide a thorough understanding of embodiments of the invention. However, it will be apparent to those skilled in the art that certain specific details disclosed are not necessary and that embodiments may be practiced in different forms. Therefore, the disclosed embodiments should not be construed as limiting the scope of the invention. As mentioned above, in some embodiments, well-known processes, well-known apparatus structures, and well-known technologies may not be described in detail.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. For example, as used herein, a component may be one or more unless the context clearly indicates otherwise. The terms “comprising” and “having” are inclusive and thus indicate the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless specifically determined as a preferred or desired order of execution, the steps, processes, and operations described herein should not be construed as requiring them to be performed in the particular order discussed or shown. It should also be understood that additional or alternative steps may be used in place of or in combination with the disclosed aspects.

[0023] When an element or layer is referred to as being “on,” “above,” “connected to,” or “linked to” another element or layer, unless otherwise explicitly stated, it may be directly on, above, directly connected to, or linked to the other element or layer, or there may be intermediate elements or layers present. Conversely, when an element or layer is referred to as being “directly on,” “directly above,” “directly connected to,” or “directly linked to” another element or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). Furthermore, as used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0024] Furthermore, although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or portion from another. Therefore, unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms, when used herein, do not imply order or sequence. Thus, without departing from the teachings of the embodiments, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion.

[0025] The embodiment provides a self-retrieval wedge fixture for association with an end effector, which can be used in semiconductor processes. The disclosed wedge fixture ensures that the released component is released when needed and is substantially or completely held in the desired position when picked up by the end effector or when released from the end effector, for example, while remaining centered on the wedge fixture. Therefore, the semiconductor wafer or processed component is placed in the position intended for processing, rather than being randomly positioned, which could result in defective processing performed thereon or cause missed placement within the processing or stack.

[0026] More specifically, one or more of the disclosed edge clamps may be associated with two, three, or four “corners” held by the end effector on the wafer. The disclosed wedge clamps may include spring-loaded sliding cams or “pucks,” which, for example, definitively extract the wafer from the wedge clamps when the pressure applied by the opposing “corner” wedge clamps is released. That is, the disclosed wedge clamp extraction cams may be passive, at least because the wafer may be placed on one or more arms of the end effector, which may then automatically retract, causing the opposing wedge clamps to apply pressure to the circumference of the wafer or component.

[0027] As the end effector arm retracts, this application of the wedge grippers circumferentially enables the extraction cam to be "loaded" into the body of the corresponding wedge gripper. Subsequently, as the robot extends based on the end effector arm, the increase in distance between the relative wedge grippers at the relative "angles" of the end effector releases the loading pressure on the springs, thereby allowing the corresponding extraction cam to eject from the wedge gripper housing. This achieves the release of the wafer or component associated with the end effector. Of course, based on the discussion herein, those skilled in the art will understand that the extraction cam can be not only passive as disclosed, but also active, such as pneumatically or electrically driven.

[0028] Therefore, the disclosed extraction cam allows for spring loading of a wafer or component into the end effector, thereby improving reverse manipulation and providing enhanced positioning and target release of the wafer or component associated with the end effector. Furthermore, the improved positioning provided by the disclosed wedge clamp with an embedded extraction cam can significantly improve the self-guiding of the wafer upon release from the wedge clamp, whereby, as a non-limiting embodiment, the wafer can actively guide itself to a pallet mask pocket or wafer chuck.

[0029] It is worth noting that although the discussion here is directed to a cam-type retractable / expandable end effector suitable for handling semiconductor wafers of various sizes, those skilled in the art will understand that other end effector technologies can be employed, such as providing spring pressure to load the wafer into a wedge clamp and / or releasing the spring pressure to allow the wafer to self-release. Furthermore, it should be noted that the disclosed wedge clamp and extraction cam can be used with end effectors of single-wafer size or with the aforementioned end effectors capable of handling wafers of various sizes.

[0030] Figure 1 A wafer 10 associated with an end effector 12 is shown. The wafer 10 shown is held on the end effector 12 by a retainer 60 (shown in dashed lines), such as a plurality of wedge clamps.

[0031] Figure 2 An automated processing system 50 suitable for precisely handling semiconductor wafers of varying diameters, compositions, and physical properties is illustrated. The processing system 50 is capable of rapidly and sequentially processing substrates, such as wafer 10, for processing. The supplied substrate 10 can be manipulated or transferred on an end effector 12 between a stack 67 and various anchor points 103 for partial handling by, for example, a robot provided in a base 110, to perform the aforementioned manipulation and transfer. The anchor points 103 may include one or more chucks, for example, to clamp the substrate 10 when it is placed onto the chuck 103. Such clamping can be performed, for example, by using one or more vacuum devices 105.

[0032] The wafer 10 shown can be held on the end effector 12 by, for example, two pairs of opposing wedge clamps 14a, 14b, 16a, 16b. In short, each opposing pair 14a-b, 16a-b includes proximal wedge clamps 14a, 16a and distal wedge clamps 14b, 16b, thereby providing wedge clamps at the four "corners" of the held wafer 10.

[0033] Figure 3A It shows something similar to Figure 2 The front view of the end effector 12 shown. Figure 3A In the illustration, the end effector 12 includes a servo-driven fork 100 with internal and external jaws 102, 104 that move synchronously to the center to grip the wafer 10 placed within the four “corner” wedge-shaped clamps 14a-b, 16a-b shown.

[0034] Figure 3B yes Figure 3A A side view (profile illustration) of the end effector 12. As shown, the distal wedge-shaped clamps 14b and 16b (from the end effector base housing 110) are... Figure 3B (Not shown in the image) can extend the distance between corresponding pairs of wedge clamps 14b, 16a and their corresponding proximal wedge clamps 14a, 16a via a distal outward cam drive 150 from the housing 110 through grippers 102, 104. More specifically, the reduction in the distance between each pair of corresponding wedge clamps 14a-b, 16a-b affects the wafer 10 held therein (… Figure 3B Friction is applied to the circumferential edge of the wafer 10 between each pair of corresponding wedge clamps 14a-b, 16a-b, such that a spring (not shown in the image) is associated with each corresponding distal and proximal wedge clamp pair 14a-b, 16a-b. Figure 3BA loading pressure is applied (the spring is not shown in the image).

[0035] Now refer to another source Figure 4 The application of loading pressure caused by the reduction in the distance between each pair of wedge clamps 14a-b, 16a-b can spring-load the extraction cam 114 into the corresponding wedge housing 130, thereby clamping the circumferential edge 10a of the wafer within each corresponding wedge clamp 14a, b, 16a, b. It is noteworthy that this enhanced frictional clamping of the circumferential edge 10a of the wafer 10, compared to the prior art, allows for an increase in the available wedge angle, thereby improving wafer clamping.

[0036] More specifically, Figure 4 It shows Figure 3A and 3B A cross-sectional view of the end effector 12 shows the wafer 10 being held and the extraction cam 114 applied in each of the four corner wedge clamps 14a, b, 16a, b. As shown, each wedge clamp 14a, b, 16a, b can hold the circumferential edge 10a of the held wafer 10 when the end effector actuates the cam 155 to reduce the distance between each distal and proximal pair 14a-b, 16a-b of the wedge clamps.

[0037] Now refer to Figure 5 The clamping action, upon contraction, causes compression of the spring 120 associated with each extraction cam 114, thus allowing the application of each wedge to the circumferential edge 10a of the wafer 10, thereby clamping the wafer 10. Consequently, the increase in distance between each pair of wedge clamps 14a-b, 16a-b causes decompression of the spring 120 on each extraction cam 114, causing the extraction cam 114 to eject outward from the body of each wedge clamp 14a, b, 16a, b, thereby ejecting the previously clamped edge of the wafer 10.

[0038] More specifically, Figure 5 yes Figure 4 The illustration shows the proximal wedge clamps 16a and 16b. As shown, each of the wedge clamps 14a and 16a may include a recessed cam 114 within a sunk extraction cam guide 404, which allows the extraction cam 114 to be positioned in both compressed and decompressed positions. Furthermore, although the spring 120 of each respective extraction cam 114 may be physically associated with any aspect of the wedge clamp housing to provide a base for applying the spring force, the spring 120... Figure 4 The image shows one or more screws 410 associated with the corresponding portion of the edge clamping feature of the end effector 12 for screwing each wedge clamp onto the edge clamping feature of the end effector 12.

[0039] Figure 6 With similar Figure 5 The diagram shows a close-up of the furthest of the pair of wedge grips associated with the end effector 12, namely wedge grips 14b and 16b. As shown, the movement of the cam portion 155 of the end effector toward the end effector base 110 has compressed the extraction cam 114 into each corresponding wedge grip.

[0040] Figure 7 A top cross-sectional view of a wedge clamp 14a forming part of an end effector wafer clamping feature is shown. As shown, at the innermost part of the end effector clamping feature, an extraction cam spring 120 is loaded around a mounting screw 410 for the wedge clamp 14a.

[0041] Then, by applying pressure from the circumferential portion 10a of the wafer, the extraction cam 114 is pushed inward from a flush position with the edge of the inclined portion of the wafer chuck. The extraction cam 114 is located within a recessed guide 404 in the wedge-shaped chuck portion and the end effector clamping base portion, wherein the length of the recessed guide 404 is sufficient to allow the extraction cam 114 to be in a fully compressed and fully decompressed position based on the spring-loaded compression pressure applied to the extraction cam 114 by the wafer edge 10a.

[0042] Figure 8 It is sandwiched in Figure 7 A side view of the wafer 10 within the wedge clamp 14a. As shown, the disclosed wedge clamp 14a can have a steeper angle than wedge clamps in the prior art, partly due to the positive self-releasing pressure applied to the edge 10a of the clamped wafer by the disclosed extraction cam 114.

[0043] The foregoing apparatus, systems, and methods may also include control over the various robotic and vacuum functionalities mentioned herein. As a non-limiting embodiment, such control may include manual control using one or more user interfaces, such as controllers, keyboards, mice, touchscreens, etc., to allow the user to input instructions to be executed by software code associated with the robot and the systems discussed herein. Alternatively, as is well known to those skilled in the art, system control may also be fully automated, for example, where manual user interaction occurs only for functions referred to in “setting up” and programming; that is, the user may only initially program or upload computational code to execute a predetermined sequence of movements and operations discussed herein. In manual or automatic implementations or any combination thereof, the controller may be programmed, for example, to associate known positions of the substrate, the robot, anchor points, and their relative positions.

[0044] It should also be understood that the systems and methods described herein can operate and / or be controlled by any computing environment. Therefore, it should not be assumed that the computing environment employed limits the implementation of the systems and methods described herein in computing environments with a wide variety of components and configurations. In other words, the concepts described herein can be implemented in a variety of computing environments using any of the various components and configurations.

[0045] Furthermore, the description of the invention is provided to enable any person skilled in the art to make or use the disclosed embodiments. Various modifications to the invention will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the invention. Therefore, the content of this invention is not intended to be limited to the embodiments and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An end effector capable of handling a semiconductor wafer, the end effector comprising: two inner jaws at least mechanically associated with a robotic base; two outer arms associated with the inner jaws via at least one arm cam; a plurality of wedge clamps, wherein two of the plurality of wedge clamps are each secured to each of the two inner jaws proximal to the robotic base, and wherein two of the plurality of wedge clamps are each secured to each of the outer arms distal to the robotic base, and wherein each of at least one of the distal and proximal wedge clamps comprises: a spring; a cam loaded on the spring; and a cam travel path into which the cam is slidably associated; wherein retraction of the inner jaws and subsequent arm camming of the outer arms exerts pressure to a circumferential edge of the semiconductor wafer such that the circumferential edge presses each of the cams along the cam travel path of each cam and against one spring of each cam, thereby loading the cams to clamp the semiconductor wafer within the plurality of wedge clamps.

2. The end effector of claim 1, wherein, the robotic base comprises a servo motor to drive at least the two inner jaws.

3. The end effector of claim 1, wherein, the two inner jaws and the two outer arms collectively comprise a fork.

4. The end effector of claim 1, wherein, all of the wedge clamps comprise the spring and the cam.

5. The end effector of claim 1, wherein, the two inner jaws are synchronized.

6. The end effector of claim 1, wherein, each of the wedge clamps is angled.

7. The end effector of claim 1, wherein, each of the springs is loaded around a respective one of the fasteners of its wedge clamp.

8. The end effector of claim 7, wherein, the fasteners comprise screws.

9. The end effector of claim 1, wherein, each of the cam travel paths is recessed within the wedge clamp.

10. The end effector of claim 1, wherein, the two outer jaws are rotatable 180 to 360 degrees by the robotic base.

11. A wedge clamp adapted to be secured to an end effector capable of handling a semiconductor wafer, the wedge clamp comprising: a housing; a cam movably mounted within the housing and capable of being fully compressed within the housing and capable of being at least partially decompressed outside the housing; a spring loadably pressing the cam, wherein the spring is fully loaded upon the pressing and is unloaded during the decompression.

12. The wedge clamp of claim 11, wherein, the spring is secured around a fastener.

13. The wedge clamp of claim 12, wherein, the fastener comprises a screw.

14. The wedge clamp of claim 11, wherein, the spring loading is generated by a circumferential edge of the semiconductor wafer.

15. The wedge clamp of claim 11, wherein, the spring loading is generated by retraction of the end effector.

16. The wedge clamp of claim 11, further comprising a cam travel path into which the movably mounting occurs.

17. The wedge clamp of claim 16, wherein, the cam travel path is recessed within the housing.

18. The wedge clamp of claim 17, wherein, the cam travel path uses a non-lubricated guide and a puck.

19. The wedge clamp of claim 11, wherein, the cam comprises a puck.

20. The wedge clamp of claim 11, wherein, the wedge clamp is associated with the end effector in pairs.

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