Wafer handling end effector

Abstract

An end effector for supporting a wafer is disclosed. The end effector includes a body, a vacuum line formed in the body, a first support arranged for contacting an interior region of the wafer, at least one opening in communication with the vacuum line within a boundary of the first support, and at least one second support arranged for contacting an outer edge of the wafer.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to wafer handling in semiconductor processing. More specifically, the invention relates to an end effector for handling wafers. BACKGROUND

[0002] Semiconductor processing involves various processes performed on substrates, such as wafers, which are aligned to each other in order to manufacture semiconductor devices.

[0003] With the advancement of the semiconductor industry, an increase in the number of chips produced and an increase in throughput can become important factors in reducing manufacturing costs. This can be achieved by processing larger size substrates and / or processing multiple substrates at a time, such as batch processing.

[0004] For some processes, multiple substrates can be subjected to increased heat. This can cause a certain degree of warping to occur at the circumferential edges of the substrates. This can then require careful handling of such warped substrates in further processes in the manufacturing, particularly when they are batch processed.

[0005] Certain wafer types are prone to warping even without being subjected to increased heat, and can have specific handling requirements, such as wafers that have been subjected to backgrinding leaving a thin inner region and thicker edges.

[0006] Therefore, there can be a need for improving handling of substrates. SUMMARY

[0007] The present summary is provided to introduce a selection of concepts in a simplified form. These concepts are further described below in the detailed description of example embodiments of the disclosure. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0008] It can be an object of the present disclosure to provide an end effector for improving handling of warped substrates. It can be a further object of the present disclosure to provide an end effector capable of handling both warped substrates and standard substrates.

[0009] In a first aspect, the present disclosure relates to an end effector.

[0010] The end effector can comprise a body, a vacuum line formed in the body, a first support arranged to contact an inner region of a wafer, at least one opening in communication with the vacuum line within a boundary of the first support, and at least one second support arranged to contact an outer edge of the wafer.

[0011] The first support arranged to contact an inner region of the wafer can comprise a central raised region and at least one circular raised region arranged concentrically with the central raised region, such that a closed volume is formed between the wafer and the first support when the wafer is supported on the first support.

[0012] The first support arranged to contact an inner region of the wafer can comprise a central raised region and at least two circular raised regions arranged concentrically with the central raised region, such that a closed volume is formed between the wafer and the first support when the wafer is supported on the first support.

[0013] The vacuum line can be in communication with the closed volume.

[0014] The end effector can comprise a first vacuum line in communication with a first closed volume between the central raised region and an adjacent concentric circular raised region, and a second vacuum line in communication with a second closed volume between two concentric circular raised regions.

[0015] The height of the at least one second support can be less than the height of the first support.

[0016] The body can have a fork shape with a main portion and two protruding portions, and the at least one second support can comprise a respective second support portion on the two protruding portions and a second support portion on the main portion.

[0017] The at least one second support can be substantially arc-shaped.

[0018] The at least one second support can be circular.

[0019] The at least one second support can protrude from a plane of the end effector while having an angle with the plane of the end effector of between 1 degree and 90 degrees. The angle can be between 10 degrees and 80 degrees, between 20 degrees and 70 degrees, between 30 degrees and 60 degrees, between 40 degrees and 50 degrees.

[0020] The end effector can comprise at least two second supports arranged to contact an outer edge of the wafer, and each of the at least two second supports can comprise a respective piezoelectric actuator configured to move the respective second support between a wafer clamping position and a wafer releasing position.

[0021] In the wafer clamping position, the second support can be closer to the first support than when in the wafer releasing position.

[0022] In the wafer clamping position, the second support can be further away from the first support than when in the wafer releasing position.

[0023] In the wafer clamping position, the distance of the second support to the first support can be the same as when in the wafer release position.

[0024] The body can have a fork shape with a main portion and two protruding portions, and the at least one second support comprising a piezoelectric actuator can be provided on one of the protruding portions, and the at least one second support comprising a piezoelectric actuator can be provided on the other of the protruding portions.

[0025] According to a second aspect of the present invention, there is provided a wafer handling device comprising a wafer handling robot, an end effector according to the first aspect, a vacuum pump connected to the vacuum line of the end effector, and a control module configured to receive a wafer type of a wafer to be handled by the wafer handling device and to set the vacuum pump in an on state or an off state depending on the wafer type.

[0026] The end effector can be an end effector according to the first aspect, comprising a piezoelectric actuator, and the control module can be further configured to control the clamping state of the piezoelectric actuator depending on the wafer type.

[0027] An advantage of embodiments of the present invention is that wafer handling can be improved, in particular for warped wafers.

[0028] Advantageously, the reliability of wafer handling can be increased; such that wafer breakage or cracking can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0029] It should be understood that elements in the drawings have not necessarily been drawn to scale and that the dimensions of some of the elements can have been exaggerated relative to other elements for the sake of improving the understanding of the illustrated embodiments of the present disclosure.

[0030] Unless otherwise specified, like reference numerals will be used to refer to like elements throughout the drawings. Reference numerals in the claims are not to be understood as limiting the scope.

[0031] Figure 1a is a plan view of a first example embodiment of an end effector according to the present invention;

[0032] Figure 1b is a plan view of a second example embodiment of an end effector according to the present invention;

[0033] Figure 1c is a plan view of a third example embodiment of an end effector according to the present invention;

[0034] Figures 2a to 2f is a side view of an end effector according to an embodiment of the present invention;

[0035] Figure 3is a side view of an end effector according to embodiments of the present application;

[0036] Figure 4a and Figure 4b is a side view of an end effector including a piezoelectric actuator according to embodiments of the present application;

[0037] Figure 5 is a schematic view of a wafer handling apparatus according to embodiments of the present application. DETAILED DESCRIPTION

[0038] While certain embodiments and examples are disclosed herein, one of ordinary skill in the art will understand that the application extends beyond the specifically disclosed embodiments and / or uses of the application and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the application disclosed herein should not be limited by the particular disclosed embodiments described above.

[0039] As used herein, the term "substrate" can refer to any one or more underlying materials, including any one or more underlying materials that can be modified or on which a device, circuit, or film can be formed. A "substrate" can be continuous or discontinuous; rigid or flexible; solid or porous; and combinations thereof. A substrate can be in any form, such as a powder, a sheet, or a workpiece. A substrate in the form of a sheet can include wafers of various shapes and sizes. A substrate can be made of a semiconductor material, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0040] By way of example, a substrate in the form of a powder can have applications for pharmaceutical manufacturing. A porous substrate can include a polymer. Examples of workpieces can include medical devices (such as stents and syringes), jewelry, tooling devices, components for battery manufacturing (such as anodes, cathodes, or separators), or components of photovoltaic cells, among others.

[0041] A continuous substrate can extend beyond the boundaries of a processing chamber in which a deposition process occurs. In some processes, a continuous substrate can be moved through a processing chamber such that the process continues until the end of the substrate is reached. A continuous substrate can be supplied from a continuous substrate feed system to allow for the manufacture and output of the continuous substrate in any suitable form.

[0042] Non-limiting examples of continuous substrates can include a sheet, a nonwoven film, a roll, a foil, a web, a flexible material, a bundle of continuous filaments or fibers (such as ceramic fibers or polymeric fibers). A continuous substrate can also include a carrier or sheet on which a non-continuous substrate is mounted.

[0043] The illustrations presented herein are not meant to be actual views of any particular material, structure, or device, but are merely idealized representations that are employed to describe the embodiments of the present disclosure.

[0044] The particular implementations shown and described are illustrative of the application and its best mode and are not intended to otherwise limit the scope of the aspects and implementations in any way. Indeed, for the sake of brevity, conventional manufacturing, connecting, preparing, and other functional aspects of the systems can not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections can be present in a practical system, and / or absent in some embodiments.

[0045] It is to be understood that the configurations and / or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense insofar as numerous variations are possible. The specific routines or methods described herein can represent one or more of any number of processing strategies. As such, various acts illustrated can be performed in the sequence illustrated, in other sequences, or omitted in some cases.

[0046] The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various processes, systems and configurations, and other features, functions, acts and / or attributes disclosed herein, as well as any and all equivalents thereof.

[0047] Reference throughout this specification to “an embodiment” or “some embodiments” does not necessarily refer to the same embodiment, although it can. Furthermore, the description, given above, of some embodiments has broad application. It is noted that the different features, structures, steps, or characteristics can be combined in any suitable manner in one or more embodiments, as would be apparent to one of ordinary skill in the art upon reading this disclosure.

[0048] Reference throughout this specification to “some embodiments” means that a particular feature, structure, step, or characteristic being described can be included in some embodiments of the application. Thus, the appearances of the phrase, “in some embodiments” in various places throughout this specification are not necessarily all referring to the same group of embodiments, although it can. Furthermore, the description, given above, of some embodiments has broad application. It is noted that the different features, structures, steps, or characteristics can be combined in any suitable manner in one or more embodiments, as would be apparent to one of ordinary skill in the art upon reading this disclosure.

[0049] Reference throughout this specification to “some embodiments” means that a particular feature, structure, step, or characteristic being described can be included in some embodiments of the application. Thus, the appearances of the phrase, “in some embodiments” in various places throughout this specification are not necessarily all referring to the same group of embodiments, although it can. Furthermore, the description, given above, of some embodiments has broad application. It is noted that the different features, structures, steps, or characteristics can be combined in any suitable manner in one or more embodiments, as would be apparent to one of ordinary skill in the art upon reading this disclosure.

[0050] It should be noted that, as used herein, the term “includes” is not meant to be interpreted as limiting as to the components, steps or parts enumerated after it. It is not meant to exclude other components, steps, parts, or groups thereof. Thus, it is interpreted as specifying the presence of stated features, steps or parts and not precluding the presence or addition of one or more other features, steps, parts or groups thereof. It should be noted that, as used herein, the term “comprises” does not exclude the presence of elements or steps other than those listed in a claim. Thus, it is interpreted as specifying the presence of stated features, steps or components, but not precluding the presence or addition of one or more other features, steps or components.

[0051] The terms first, second, third, etc. in the specification and claims are used to distinguish like elements. They do not necessarily describe a sequence, temporal or spatial, ordering or any other manner. It will be understood that the terms so used are interchangeable, and that the embodiments of the disclosure described herein are capable of operating in other sequences than described or illustrated herein.

[0052] The following terms are provided solely to assist in the understanding of the disclosure.

[0053] As used herein and unless otherwise specified, the term "warped substrate or warped wafer" can refer to a substrate or wafer whose geometry is deviated from its initial flatness state.

[0054] As used herein and unless otherwise specified, the term "central portion of a wafer" can refer to a portion of a wafer that can be covered away from its center extending at least 2 / 3 of its radius.

[0055] The disclosure will now be described by a detailed description of several embodiments of the disclosure. It is clear that other embodiments of the disclosure can be configured according to the knowledge of a person skilled in the art without departing from the technical teaching of the disclosure. The disclosure is only limited by the terms of the claims included herein.

[0056] Referring to Figures 1 to Figure 3 The end effector 1 according to embodiments of the disclosure comprises a body 2. The body 2 is preferably substantially planar. The end effector can be configured to be removably attached to a wafer handling robot (not shown). The wafer handling robot can transfer wafers between locations such as storage cassettes, boats, pedestals, cleaning stations or other wafer locations in a substrate processing apparatus by supporting the wafers on the end effector 1. The end effector 1 can be generally fork-shaped, having a main portion and two protruding portions. The end effector 1 can be generally disc-shaped or polygonal.

[0057] The end effector 1 comprises a vacuum line 3 formed in the body 2. The vacuum line 3 can comprise only one channel 4. The vacuum line 3 can comprise a main channel and two or more secondary channels branching from the main channel. The vacuum line 3 can be a channel 4 in the body 2 at the end of the end effector 1 can have an opening 5 and an opening 7 at a location where a first support 8 is disposed at the end 6 of the end effector 1 attached to the wafer handling robot. The opening 5 can be attached to a vacuum pump in order to evacuate the channel 4 when the opening 7 is closed.

[0058] The end effector 1 comprises a first support 8 for contacting an inner region of the wafer. The first support 8 can be positioned to be able to align with the center of the wafer to be supported on the end effector 1. The first support 8 can be positioned such that the opening 7 is within an outer boundary B of the first support. For example, the first support 8 can comprise a central circular raised region or protrusion 81 and a concentric circular raised region or protrusion 82 centered on the central protrusion 81, and the opening 7 can be disposed between the central protrusion 81 and the concentric protrusion 82. Referring to Figure 1b , the first support 8 can comprise a central circular raised region or protrusion 81, a first concentric circular raised region or protrusion 82, and a second concentric circular raised region or protrusion 83, the first and second concentric protrusions 82, 83 being centered on the central protrusion 81, the first concentric protrusion 82 being positioned between the central circular protrusion 81 and the second concentric protrusion 83. The vacuum line 3 can have a first opening 71 between the central protrusion 81 and the first concentric protrusion 82 and a second opening 72 between the first concentric protrusion 82 and the second concentric protrusion 83. Referring to Figure 1c , the vacuum line 3 can comprise a main channel 41 and at least two secondary channels 42, 43 branching from the main channel 41 and connected with the first and second openings 71, 72, respectively. The first support preferably comprises a resiliently deformable material, such as (but not limited to) polytetrafluoroethylene (PTFE).

[0059] Referring to Figure 2a and Figure 2b When the wafer 10 is supported by the first support 8, the opening 7, 71, 72 can enclose a volume V above the end effector 1 bounded by the wafer 10 and the first support 8. That is, once the volume V is evacuated, there is no air that can enter the channel 4 through the opening 7, 71, 72. This can create a vacuum suction effect that holds the wafer 10 in contact with the end effector 1, not just the normal reaction of the first support 8 to the gravitational force caused by the mass of the wafer 10. By holding the wafer 10 with a vacuum force, the end effector 1 can be able to move at a greater speed than when no vacuum force is provided, as the vacuum force can help prevent the wafer 10 from slipping on the end effector 1 when the end effector 1 accelerates or decelerates.

[0060] The end effector 1 comprises at least one second support 11 arranged for contacting an outer edge of the wafer. The second support 11 can comprise a raised region or protrusion. The second support 11 has a height hi that can be less than a height h2 of the first support 8. The second support 11 can comprise, for example, a resiliently deformable material such as PTFE or a ceramic such as alumina. Referring to Figure 2a and 2bDue to the height difference of the first support 8 and the second support 11, a flat wafer 10 with little or no backgrinding can be supported only by the first support 8. Referring to Figures 2c to 2e a wafer 10 that has been subjected to backgrinding leaving a relatively thin inner region 15 and relatively thicker outer edges 16 can be supported by the first support 8 in the inner region 15 of the wafer and by the second support 11 at the edges 16. The wafer 10 can be supported by contacting the second support 11 outside the outer edges 16 Figure 2c The wafer 10 can be supported by contacting the second support 11 at the bottom of the outer edges 16 Figure 2d The wafer 10 can be supported by contacting the second support 11 inside the outer edges 16 Figure 2e The wafer 10 can be supported by contacting the second support 11 inside and outside the outer edges 16 Figure 2f

[0061] Referring to Figure 3 The second support 11 can protrude from the end effector 1 at an angle a of less than 90 degrees from the plane of the end effector. This can allow the use of the same end effector 1 to support wafers of different diameters.

[0062] Referring again to Figure 1a The end effector 1 can have a fork shape with a main portion 17 and two protruding portions 181, 182, and the at least one second support 11 can include respective second support portions 111, 112 on the two protruding portions and a second support portion 113 on the main portion.

[0063] The at least one second support 11 can be generally arcuate. For example, the at least one second support 11 can include a plurality of second supports 11, each of which is arcuate and centered on the first support 8. The at least one second support 11 can include a first set of second supports 11, each of which is arcuate and centered on the first support 8 at a first distance from the first support 8, and a second set of second supports 11, each of which is arcuate and centered on the first support 8 at a second distance from the first support 8, the second distance being different from the first distance, such that the edges 16 of the wafer 10 can be supported between the first and second sets of second supports 11. The at least one second support 11 can be a single second support that is circular and uninterrupted, centered on the first support 8. The at least one second support 11 can include two second supports, each of which is circular and uninterrupted, centered on the first support 8, and each of which has a different radius, such that the edges 16 of the wafer 10 can be supported between the two second supports.

[0064] ​The end effector 1 can include at least two second supports 11, and the at least two second supports can move between a wafer clamping position and a wafer release position. Movement of the second supports 11 can be achieved by including a piezoelectric actuator 19 in each second support 11. By applying a voltage to the piezoelectric actuator, the actuator expands or contracts, causing the second support to move.

[0065] For example, with reference to Figure 4a and 4b , the second supports 11 can each have an inward facing edge 21 and an outward facing edge 20, the inward facing edge 21 facing the first support 8, and the outward facing edge 20 facing away from the first support 8. The second supports 11 can be fixed such that the outward facing edge 20 does not move. When a voltage is applied to the piezoelectric actuator 19, the second support can expand in a direction towards the first support 8, and since the outward facing edge 20 is fixed, the inward facing edge 21 moves such that the distance between the inward facing edge 21 and the first support 8 decreases Figure 4b , for example to a distance sufficient to clamp the edge 16 of the wafer 10. This can allow the end effector 1 to adopt a wafer clamping position and a wafer release position. In some embodiments, the inward facing edge 21 can be fixed, and the second support 11 can expand in a direction away from the first support 8, and the wafer can be clamped in a position similar to that shown in Figure 2e . In some embodiments, the second support 11 can be fixed to the end effector 1 at the bottom edge, and the piezoelectric actuator 19 can be oriented to expand and contract in a direction away from the plane of the end effector 1 when a voltage is applied to the piezoelectric actuator 19, and the wafer can be clamped in a position similar to that shown in Figure 2d . Thus, the distance between the first support 8 and the second support 11 does not change when the end effector is in the wafer clamping or wafer release position.

[0066] In some embodiments, the body of the end effector 1 has a fork shape with a main portion 17 and two protruding portions 181, 182, and at least one second support 11 including a piezoelectric actuator 19 is disposed on one protruding portion 181, and at least one second support 11 including a piezoelectric actuator 19 is disposed on the other protruding portion 182.

[0067] The piezoelectric actuators 19 can be controlled by a voltage applied by a connection wire (not shown) that passes through the end effector 1 by wiring.

[0068] With reference to Figure 5Embodiments of the present invention provide a wafer handling device 30 comprising a wafer handling robot 31, an end effector 1, a vacuum pump 32 connected to a vacuum line of the end effector 1, and a control module 33 configured to receive a wafer type of a wafer to be handled by the wafer handling device and to set the vacuum pump to an on state or an off state depending on the wafer type. The wafer handling device 30 can be comprised in a semiconductor processing device (not shown) and the control module 33 can receive the wafer type from a central control module of the semiconductor processing device. The wafer handling device control module 33 can be configured to set the vacuum pump to the on state if the wafer type is a normal flat wafer type and to set the vacuum pump to the off state if the wafer type is a warped wafer type, e.g. a wafer that has been subjected to backside grinding. This can allow the wafer handling to be adapted to different wafer types. The control module 33 can be configured to control the position of the wafer handling robot 31 in addition to controlling the vacuum pump state, e.g. to move the wafer handling robot 31 to a wafer pick-up position, to turn on the vacuum pump and to pick up the wafer, to move the wafer to a wafer destination, and to turn off the vacuum pump.

[0069] The end effector can be an end effector comprising a piezoelectric actuator 19 in the second support 11 and the control module 33 can be further configured to control a clamping state of the piezoelectric actuator 19 depending on the wafer type. For example, the wafer handling device control module 33 can be configured to set the piezoelectric actuator 19 to a release state regardless of the wafer type, to move the wafer handling robot to a wafer pick-up position, to pick up the wafer by supporting the wafer on the first support, and to set the piezoelectric actuator 19 to a clamping state if the wafer type is a warped wafer type.

[0070] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, acts, and / or properties disclosed herein, as well as any and all equivalents thereof.

Claims

1. An end effector for supporting a wafer, comprising a body, a vacuum line formed in the body, a first support arranged for contacting an inner area of the wafer, at least one opening in communication with the vacuum line within the bounds of the first support, and at least one second support arranged for contacting an outer edge of the wafer.

2. The end effector of claim 1, wherein, The first support arranged for contacting an inner area of the wafer comprises a central raised area and at least one circular raised area arranged concentrically with the central raised area, such that when the wafer is supported on the first support, a closed volume is formed between the wafer and the first support.

3. The end effector of claim 1, wherein, The first support arranged for contacting an inner area of the wafer comprises a central raised area and at least two circular raised areas arranged concentrically with the central raised area, such that when the wafer is supported on the first support, a closed volume is formed between the wafer and the first support.

4. The end effector of claim 2 or 3, wherein, The vacuum line is in communication with the closed volume.

5. The end effector of claim 3, comprising: a first vacuum line in communication with a first closed volume between the central raised area and an adjacent concentric circular raised area; and a second vacuum line in communication with a second closed volume between two concentric circular raised areas.

6. The end effector of claim 1, wherein, The height of the at least one second support is less than the height of the first support.

7. The end effector of claim 1, wherein, The body has a fork shape with a main portion and two protruding portions, wherein the at least one second support comprises a respective second support portion on the two protruding portions and a second support portion on the main portion.

8. The end effector of claim 1, wherein, The at least one second support is substantially arc-shaped.

9. The end effector of claim 1, wherein, The at least one second support is circular.

10. The end effector of claim 1, wherein, The at least one second support protrudes from a plane of the end effector while having an angle with the plane of the end effector of between 1 degree and 90 degrees.

11. The end effector of claim 1, comprising at least two second supports arranged for contacting an outer edge of the wafer, wherein each of the at least two second supports comprises a respective piezoelectric actuator configured to move the respective second support between a wafer clamping position and a wafer release position.

12. The end effector of claim 11, wherein, When in the wafer clamping position, the second support is closer to the first support than when in the wafer release position.

13. The end effector of claim 11, wherein, When in the wafer clamping position, the second support is further away from the first support than when in the wafer release position.

14. The end effector of claim 11, wherein, When in the wafer clamping position, the second support is at the same distance from the first support as when in the wafer release position.

15. The end effector of claim 11, wherein, The body has a fork shape with a main portion and two protruding portions, wherein the at least one second support comprising a piezoelectric actuator is provided on one protruding portion and the at least one second support comprising a piezoelectric actuator is provided on the other protruding portion.

16. A wafer handling device comprising a wafer handling robot, an end effector according to any preceding claim, a vacuum pump connected to the vacuum line of the end effector, and a control module configured to receive a wafer type of a wafer to be handled by the wafer handling device and to set the vacuum pump in an on state or an off state depending on the wafer type.

17. The wafer handling device of claim 16, wherein, The end effector is according to any one of claims 11 to 15, wherein the control module is further configured to control a clamping state of the piezoelectric actuator depending on the wafer type.

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