Wafer support device

Abstract

The application discloses a wafer support device, which comprises a base, a vertical positioning structure, a rotary positioning structure, a sample support and a plurality of support structures; the vertical positioning structure is arranged at the center of the base, and the vertical positioning structure is provided with a driving shaft moving in the vertical direction; the rotary positioning structure is arranged above the vertical positioning structure and is connected with the driving shaft of the vertical positioning structure, and the rotary positioning structure is used for rotating around the central vertical axis; the adsorption surface of the sample support comprises a support part and a non-support part, the non-support part is lower than the support part, and the projection area of the non-support part in the horizontal plane accounts for more than half of the surface area of the sample support; and the plurality of support structures are uniformly distributed around the base and are used for supporting the sample support. Reflection interference of the support part can be reduced when the wafer is supported.

Description

Technical Field

[0001] This application relates to the field of wafer inspection technology, and in particular to a wafer support device. Background Technology

[0002] In existing wafer inspection equipment, wafers are primarily supported and fixed by mechanically clamping the wafer edges using grippers, or by using electrostatic adsorption or vacuum adsorption to keep the wafer firmly attached to the adsorption pad. During the inspection process, on the one hand, the wafer needs to be reliably supported to minimize warpage, and on the other hand, a sufficiently large gap needs to be maintained between the area of ​​the wafer to be inspected and the wafer adsorption pad to reduce the interference of light reflected from the surface of the wafer adsorption pad into the optical path of the test.

[0003] However, while edge clamping can provide a gap, it results in significant wafer warping and deformation; electrostatic adsorption and vacuum adsorption methods, due to the large contact area between the wafer and the adsorption disk, cause the reflected light from the surface of the adsorption disk to severely interfere with the measurement results. Utility Model Content

[0004] To address the aforementioned issues, this application provides a wafer support device that can reduce interference with measurement results while ensuring support stability.

[0005] The technical solution adopted for this purpose is a wafer support device, which specifically includes: a base, a vertical positioning structure, a rotary positioning structure, a sample support component, and multiple support pillar structures;

[0006] The vertical positioning structure is located at the center of the base, and the vertical positioning structure has a drive shaft that moves in the vertical direction;

[0007] A rotary positioning structure is disposed above the vertical positioning structure and connected to the drive shaft of the vertical positioning structure. The rotary positioning structure is used to rotate around a central vertical axis.

[0008] The adsorption surface of the sample support includes a supporting part and a non-supporting part. The non-supporting part is lower than the supporting part, and the projected area of ​​the non-supporting part in the horizontal plane accounts for more than half of the surface area of ​​the sample support.

[0009] The multiple support structures are evenly distributed around the base to support the sample support components.

[0010] In a preferred embodiment of this application, the sample support may be further configured as a disc-shaped structure.

[0011] In a preferred embodiment of this application, the supporting portion and the non-supporting portion may be further configured as a fan shape.

[0012] In a preferred embodiment of this application, the sample support may further include a negative pressure interface, which is used to connect to an external air tube to generate negative pressure.

[0013] In a preferred embodiment of this application, the sample support member may be further configured such that the support portion is provided with a negative pressure air groove, which is used to connect the support portion to the negative pressure interface and transmit negative pressure to the support portion.

[0014] In a preferred embodiment of this application, the negative pressure air groove can be further configured to be arc-shaped, and the radius of curvature of the arc is not less than 10mm.

[0015] In a preferred embodiment of this application, the sample support may be further configured such that the non-absorbent surface is provided with reinforcing ribs.

[0016] In a preferred embodiment of this application, the height difference between the supporting portion and the non-supporting portion can be further configured to be greater than 2 mm.

[0017] In a preferred embodiment of this application, it may be further configured to include a controller, which is connected to the vertical positioning structure and the rotary positioning structure and is used to drive the vertical positioning structure and the rotary positioning structure.

[0018] In a preferred embodiment of this application, it may be further configured to include a distance sensor for measuring the distance between the sample to be tested and the support structure.

[0019] In summary, compared with the prior art, the beneficial effects of the technical solution provided by the embodiments of this application include at least the following: the wafer support device provided by this application includes a base, a vertical positioning structure, a rotary positioning structure, a sample support, and multiple support pillar structures; the vertical positioning structure is disposed at the center of the base, and the vertical positioning structure has a drive shaft that moves in the vertical direction; the rotary positioning structure is disposed above the vertical positioning structure and connected to the drive shaft of the vertical positioning structure, and the rotary positioning structure is used to rotate around the central vertical axis; the adsorption surface of the sample support includes a supporting part and a non-supporting part, the non-supporting part is lower than the supporting part, and the projected area of ​​the non-supporting part in the horizontal plane accounts for more than half of the surface area of ​​the sample support; the multiple support pillar structures are evenly distributed around the base for supporting the sample support. The sample support of the wafer support device provided in this application is divided into a support part and a non-support part. When the wafer to be tested is placed on the sample support for testing, the wafer to be tested corresponding to the non-support part is measured. Then, the sample support is rotated by the vertical positioning structure and the rotation positioning structure to rotate the non-support part to the area that has not yet been measured, and then the measurement is performed again. This can effectively reduce the interference of surface reflected light on the measurement results and improve the detection accuracy while ensuring the stability of the support. Attached Figure Description

[0020] Figure 1 A schematic diagram of a wafer support device provided as an exemplary embodiment of this application;

[0021] Figure 2 A schematic diagram of the structure of a wafer support provided in yet another exemplary embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the structure of the non-adsorption surface of a wafer support provided as another exemplary embodiment of this application.

[0023] Figure label:

[0024] 1. Base; 2. Vertical positioning structure; 3. Rotary positioning structure; 4. Sample support; 5. Column structure; 41. Support part; 42. Non-support part; 6. Wafer under test; 43. Negative pressure interface; 44. Negative pressure gas groove; 45. Reinforcing rib; 6. Distance sensor. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] In the description of this application, it should be understood that the orientations and positional relationships indicated by terms such as "center", "longitudinal", "horizontal", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description. Therefore, they should not be construed as limitations on this application.

[0027] In one exemplary embodiment of this application, a wafer support device is provided, please refer to... Figures 1 to 3 As shown, the wafer support device includes:

[0028] 1. Base; 2. Vertical positioning structure; 3. Rotary positioning structure; 4. Sample support; and 5. Multiple support pillars.

[0029] The base 1 is located at the bottom of the entire wafer support device. As the bottommost load-bearing device of the entire wafer support device, the base 1 is used to support all other structures on it. The base 1 is made of high-strength and thick material. The base 1 can be set as a disc-shaped structure or a square structure. In order to provide more support space, a square structure is preferred in this application.

[0030] Multiple support pillars are evenly distributed around the base to support the sample support components.

[0031] Specifically, the base 1 is a square base with a support structure 5 at each of its four corners, providing four support structures 5 to support the sample support. The symmetrically distributed four support structures 5 provide uniform support force, ensuring stable support of the sample support. Simultaneously, the interior of the four support structures 5 provides space for other structures. The lower end of the support structure 5 is fixedly connected to the base 1, while the upper end supports the sample support, which rests on the upper end of the support structure 5 in a movable state. The support structure 5 can be configured as a pin structure; specifically, the lower end of the support structure 5 is connected to the base 1 via a corner block, and the upper end of the support structure 5 is configured with a T-shaped contact block to increase the contact area with the sample support. The support structure supports the edge of the sample support through the T-shaped contact block, making the sample support more stable when resting on the support structure.

[0032] The vertical positioning structure 2 is located at the center of the base 1 and has a drive shaft that moves vertically. Specifically, the vertical positioning structure 2 is located at the center of the upper surface of the base 1 and is surrounded by the support structure 5. Exemplarily, the vertical positioning structure 2 can move up and down through the cooperation of a drive source, a guide screw, a lifting drive shaft, and a linear guide rail. The drive source is fixed at the center of the base 1, the output end of the drive source is connected to the lower end of the guide screw, the upper end of the guide screw is connected to the bottom end of the lifting drive shaft, and the connecting blocks on both sides of the lifting drive shaft lock the linear guide rail slider. The drive source can be a voice coil motor, a torque motor, or a linear motor.

[0033] A rotary positioning structure 3 is positioned above the vertical positioning structure 2 and connected to the drive shaft of the vertical positioning structure 2. The rotary positioning structure 3 is used to rotate around a central vertical axis. Specifically, the rotary positioning structure 3 can be selected through the cooperation of a drive source and a rotating disk. Exemplarily, the rotary positioning structure 3 includes a flange, a rotary drive shaft, a rotary drive source, and a rotating table. The flange is fixedly connected to the top end of the lifting drive shaft of the vertical positioning structure 2. The rotary drive shaft is connected to the flange. The output end of the rotary drive source is connected to the rotary drive shaft. The rotary drive shaft is connected to the rotating table. A sample support is directly fixed above the rotating table.

[0034] The sample support 4, positioned above multiple support pillars 5, supports the wafer under test. The adsorption surface of the sample support 4 is divided into a supporting portion 41 and a non-supporting portion 42. The non-supporting portion 42 is lower than the supporting portion 41, and its projected area in the horizontal plane occupies more than half of the surface area of ​​the sample support 4. Specifically, the non-supporting portion 42 is designed as a recessed area, lower than the supporting portion 41. Thus, when the wafer under test is placed on the sample support 4, the supporting portion 41 provides support force, ensuring the wafer is securely fixed. The non-supporting portion 42 effectively reduces reflected light interference from the sample support, improving detection accuracy.

[0035] In one possible implementation, to further reduce the interference of reflected light from the sample support on the measurement results, the non-support portion 42 can be configured as a hollowed-out form.

[0036] The wafer support device provided in this application operates as follows: When the wafer w to be tested is first adsorbed onto the sample support 4, the unsupported area of ​​the wafer w to be tested is measured, that is, the wafer to be tested corresponding to the unsupported part 42 of the sample support 4 is measured; after the first measurement is completed, the adsorption between the wafer w to be tested and the sample support 4 is released, and the vertical positioning structure 2 moves slowly downward along the vertical direction along with the sample support 4 and the wafer w to be tested until the wafer w to be tested separates from the sample support 4 and the wafer to be tested falls onto the support structure 5; at this time, the rotation positioning structure 3 drives the sample support 4 to rotate around the vertical axis in the horizontal plane at a certain angle, and the unsupported part 42 of the sample support 4 rotates to below the area of ​​the wafer to be tested that has not yet been measured; the vertical positioning structure 2 moves slowly upward along the vertical direction along with the sample support 4 until the wafer to be tested separates from the support structure 5, and the wafer to be tested falls onto the sample support 4, adsorbing the wafer w to be tested, and measuring the area of ​​the wafer to be tested that was not measured during the first measurement.

[0037] By setting the surface of the sample support as a support part and a non-support part, and coordinating the lifting of the vertical positioning structure and the rotation of the rotary positioning structure, the entire area of ​​the wafer under test is measured in two steps while ensuring that the wafer is securely fixed. This method can effectively reduce the interference of reflected light from the sample support during the measurement process.

[0038] In one feasible implementation, the sample support 4 is a disk-shaped structure. It should be noted that the diameter of the sample support 4 is smaller than the diameter of the inscribed circle formed by the four pillar structures 5, ensuring that the vertical positioning structure 2 and the rotary positioning structure 3 can move the sample support 4 to a position lower than the pillar structures 5, at which point the wafer to be tested can fall onto the pillar structures 5.

[0039] In one feasible implementation, the supporting and non-supporting parts are arranged in a fan shape. Specifically, the sample support is divided into 8 fan-shaped regions, with the supporting and non-supporting parts spaced apart. The angle of the fan-shaped region corresponding to the supporting part is 40°, and the angle of the fan-shaped region corresponding to the non-supporting part is 50°. This allows for a margin in the measurement area. During the second measurement, the sample support needs to rotate 45°, allowing sufficient travel and avoiding collision with the support structure during rotation.

[0040] In one feasible implementation, the sample support further includes a negative pressure interface for connecting to an external air pipe to generate negative pressure. Specifically, the negative pressure interface can be located on the sample support and connected to the external air pipe of an external vacuum pump. The negative pressure interface generates negative pressure in the central region of the sample support, causing the wafer under test to adhere tightly to the sample support through the Bernoulli effect.

[0041] In one feasible implementation, the support portion of the sample support is provided with negative pressure gas grooves for connecting the negative pressure interface to the support portion and transferring negative pressure to the support portion. Specifically, a network of negative pressure gas grooves is formed in the support portion of the sample support, allowing negative pressure to be uniformly transferred to the entire support portion through the negative pressure gas grooves, thereby ensuring that the wafer under test is uniformly and stably attached to the surface of the sample support and effectively suppressing wafer warpage.

[0042] In one feasible implementation, the negative pressure air groove is arc-shaped, with a radius of curvature of not less than 10 mm. The arc-shaped negative pressure air groove better matches the fan-shaped structure of the support part.

[0043] In some feasible implementations, the non-absorption surface of the sample support is provided with reinforcing ribs. These ribs reduce processing deformation of the sample support.

[0044] In some feasible implementations, the height difference between the supporting part and the non-supporting part is greater than 2 mm, so as to distinguish the sample image and the background image of the sample support in the detection image.

[0045] In some feasible embodiments, the wafer support device provided in this application further includes a controller, which is connected to the vertical positioning structure and the rotary positioning structure, and is used to drive the vertical positioning structure and the rotary positioning structure. Understandably, the controller can be located inside the wafer support device or connected externally, and is not shown in the figures.

[0046] In some feasible embodiments, the wafer support device provided in this application further includes a distance sensor for measuring the distance between the sample under test and the support structure. The proximity sensor can be positioned near the upper end of the support structure.

[0047] The foregoing description illustrates and describes preferred embodiments of this application. As previously stated, it should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept of this application through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. A wafer support device, characterized in that, include: The base consists of a vertical positioning structure, a rotary positioning structure, a sample support, and multiple support pillars. The vertical positioning structure is located at the center of the base, and the vertical positioning structure has a drive shaft that moves in the vertical direction; A rotary positioning structure is disposed above the vertical positioning structure and connected to the drive shaft of the vertical positioning structure. The rotary positioning structure is used to rotate around a central vertical axis. The adsorption surface of the sample support includes a supporting part and a non-supporting part. The non-supporting part is lower than the supporting part, and the projected area of ​​the non-supporting part in the horizontal plane accounts for more than half of the surface area of ​​the sample support. The multiple support structures are evenly distributed around the base to support the sample support components.

2. The wafer support device according to claim 1, characterized in that, The sample support is a disc-shaped structure.

3. The wafer support device according to claim 2, characterized in that, The supporting and non-supporting parts are configured in a fan shape.

4. The wafer support device according to claim 1, characterized in that, The sample support also includes a negative pressure interface, which is used to connect to an external air tube to generate negative pressure.

5. The wafer support device according to claim 4, characterized in that, The sample support component has a negative pressure air groove in its support portion, which is used to connect the support portion to the negative pressure interface and transfer negative pressure to the support portion.

6. The wafer support device according to claim 5, characterized in that, The negative pressure air trough is arc-shaped, and the radius of curvature of the arc is not less than 10mm.

7. The wafer support device according to claim 1, characterized in that, The non-adsorption surface of the sample support is provided with reinforcing ribs.

8. The wafer support device according to claim 1, characterized in that, The height difference between the supporting part and the non-supporting part is greater than 2mm.

9. The wafer support device according to claim 1, characterized in that, It also includes a controller, which connects the vertical positioning structure and the rotary positioning structure and is used to drive the vertical positioning structure and the rotary positioning structure.

10. The wafer support device according to claim 1, characterized in that, It also includes a distance sensor for measuring the distance between the sample under test and the support structure.

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