CN116031191A

CN116031191A - Clamping device for wafer

Info

Publication number: CN116031191A
Application number: CN202211515406.4A
Authority: CN
Inventors: 田凯佳
Original assignee: Tojingjianke Haining Semiconductor Equipment Co ltd
Current assignee: Tojingjianke Haining Semiconductor Equipment Co ltd
Priority date: 2022-11-29
Filing date: 2022-11-29
Publication date: 2023-04-28

Abstract

The invention provides a clamping device of a wafer, which is used for automatically adjusting the wafer to a central position, and comprises the following components: the wafer platform is used for placing a wafer, and the bottom of the wafer platform is vertically connected to the rotating platform through a connecting rod; and the wafer alignment parts are provided with alignment blocks, the alignment blocks are abutted with the side circumference of the wafer, the alignment blocks are uniformly distributed along the circumference of the wafer, the bottoms of the wafer alignment parts are fixedly connected to a rotary platform through support rods, the wafer alignment parts are also provided with eccentric blocks, and when the rotary platform drives the whole clamping device to rotate, the eccentric blocks pull or push the alignment blocks under the action of centrifugal force so that the alignment blocks are matched to move the wafer, so that the wafer is automatically centered.

Description

Clamping device for wafer

Technical Field

The present invention relates to a wafer clamping device, and more particularly, to a wafer clamping device for automatically adjusting a wafer to a centered position.

Background

During processing of semiconductors, it is often desirable to center the wafer. In the prior art, centering of the wafer is often achieved by a pre-alignment device. The pre-alignment device is a device for detecting and compensating a position error generated in a process of loading a wafer, and detects the edge of the wafer by rotating the wafer, thereby calculating an eccentric amount of the wafer to compensate. For the compensation of the eccentric amount, there are two general ways, one is to pre-load a moving platform in a wafer pre-alignment device, and perform displacement compensation by the movement of the platform; the other is to perform displacement compensation by the offset of the grabbing position of the subsequent manipulator.

However, in either of the above-mentioned eccentric amount compensation methods, there are drawbacks in that the device is complicated in structure and high in cost, and in particular, in the scheme of compensating for the offset of the gripping position of the subsequent manipulator, the requirements on the degree of freedom of the mechanism, motion control and position accuracy of the manipulator are high, and when there is a large-scale eccentricity, the error after compensation is also large.

In order to overcome the defects in the prior art, the invention provides the clamping device for the wafer, which utilizes the difference of centrifugal forces born by the clamping device at the edge to adjust the position of the wafer when the wafer eccentrically rotates, so that the wafer can be automatically adjusted to the centering position, the device has a simple structure, is easy to realize and is beneficial to saving the cost and mass production popularization while ensuring a good centering alignment effect.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In order to overcome the above-mentioned drawbacks, the present invention provides a wafer clamping apparatus, comprising: the wafer platform is used for placing a wafer, and the bottom of the wafer platform is vertically connected to the rotating platform through a connecting rod; and the wafer alignment part is provided with an alignment block, the alignment block is abutted with the side circumference of the wafer, the alignment blocks are uniformly distributed along the circumference of the wafer, the bottom of the wafer alignment part is fixedly connected to the rotary platform through a supporting rod, the wafer alignment part is also provided with an eccentric block, and when the rotary platform drives the whole clamping device to rotate, the eccentric blocks pull or push the alignment block under the action of centrifugal force so as to enable the alignment blocks to be matched to move the wafer, thereby realizing the automatic centering of the wafer.

In an embodiment, preferably, in the wafer clamping device provided by the invention, the wafer alignment part further includes a horizontally placed and elongated fixing block, the bottom of the fixing block is fixedly connected with the supporting rod, one end of the fixing block, which is far away from the wafer, is connected with the eccentric block so that the eccentric block rotates with the joint of the eccentric block and the supporting rod as a rotation axis in the rotation process, one surface of the alignment block, which is far away from the wafer, is provided with a push rod parallel to the fixing block, one end of the fixing block, which is close to the wafer, is provided with a mounting part so as to sleeve the push rod, and the eccentric block is connected with the push rod through a connecting rod.

In an embodiment, preferably, in the wafer clamping device provided by the invention, the eccentric block is pendulum-shaped, and a center of gravity of the eccentric block coincides with the rotation axis.

In one embodiment, preferably, in the wafer clamping device provided by the invention, the connecting rod is connected to the top of the eccentric block, and the connecting rod and the push rod are located above the fixed block.

In an embodiment, preferably, in the wafer clamping device provided by the invention, the support rods adjacent to the wafer alignment parts are connected by springs.

In an embodiment, in the wafer clamping device provided by the invention, a side section of an abutting portion between the alignment block and the wafer is L-shaped for abutting against a side periphery and a bottom edge of the wafer.

In an embodiment, preferably, in the wafer clamping device provided by the invention, the wafer platform is provided with a vacuum adsorption hole for adsorbing and fixing the wafer, and the vacuum state is broken when the clamping device rotates to adjust the position of the wafer.

In an embodiment, preferably, in the wafer clamping device provided by the invention, the rotating speed range of the rotating platform for driving the whole clamping device to rotate is 1000-2000r/min.

In an embodiment, preferably, in the wafer clamping device provided by the invention, the number of the plurality of wafer alignment parts is 3, the support rod is fixedly connected with the rotating platform through a flange and a screw so that the support rod forms a preset angle with the horizontal plane, and the preset angle and the vertical distance between the wafer platform and the rotating platform are determined according to the size adjustment of the wafer.

In an embodiment, optionally, in the wafer clamping apparatus provided by the present invention, the wafer is 8 inches in size, the preset angle is 60 °, and a vertical distance between the wafer stage and the rotating stage is 210mm.

According to the wafer clamping device, when the wafer eccentrically rotates, the wafer is adjusted by the difference of centrifugal force applied to the edge of the clamping device, so that the wafer is stressed and balanced, the wafer is automatically adjusted to the centering position, a good centering alignment effect is ensured, and meanwhile, the device is simple in structure, easy to realize and beneficial to saving cost and mass production popularization.

Drawings

The above features and advantages of the present invention will be better understood after reading the detailed description of embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily to scale and components having similar related features or characteristics may have the same or similar reference numerals.

FIG. 1 is a schematic view of an apparatus structure of a wafer clamping apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic view of the apparatus structure of a wafer stage and a rotating stage in a wafer clamping apparatus according to an embodiment of the present invention;

FIG. 3 is a side view of the wafer alignment portion and support bar of the wafer clamping apparatus according to one embodiment of the present invention;

FIG. 4 is a side view of an apparatus structure of a wafer alignment portion of a wafer clamping apparatus according to an embodiment of the present invention;

FIG. 5 is a top view of an apparatus structure of a wafer clamping apparatus according to an embodiment of the present invention;

FIG. 6 is a schematic view showing a height selection of a wafer clamping apparatus according to an embodiment of the invention; and

fig. 7 is a schematic view of an apparatus structure for supporting the angle of the supporting rod in the wafer clamping apparatus according to an embodiment of the invention.

For clarity, a brief description of the reference numerals is given below:

100 wafer

101 wafer platform

1011 vacuum adsorption hole

102 connecting rod

103 rotary platform

104 wafer alignment portion

1041 alignment block

1042 support bar

1043 eccentric block

1044 fixing block

1045 rotating shaft

1046 push rod

1047 mounting part

1048 connecting rod

1049 contact part

105 spring

Detailed Description

Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present specification, by describing the embodiments of the present invention with specific examples. While the description of the invention will be presented in connection with a preferred embodiment, it is not intended to limit the inventive features to that embodiment. Rather, the purpose of the invention described in connection with the embodiments is to cover other alternatives or modifications, which may be extended by the claims based on the invention. The following description contains many specific details for the purpose of providing a thorough understanding of the present invention. The invention may be practiced without these specific details. Furthermore, some specific details are omitted from the description in order to avoid obscuring the invention.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal", "vertical" as used in the following description should be understood as referring to the orientation depicted in this paragraph and the associated drawings. This relative terminology is for convenience only and is not intended to be limiting of the invention as it is described in terms of the apparatus being manufactured or operated in a particular orientation.

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, regions, layers and/or sections, these elements, regions, layers and/or sections should not be limited by these terms and these terms are merely used to distinguish between different elements, regions, layers and/or sections. Accordingly, a first component, region, layer, and/or section discussed below could be termed a second component, region, layer, and/or section without departing from some embodiments of the present invention.

Fig. 1 is a schematic device structure of a wafer clamping device according to an embodiment of the invention. Fig. 2 is a side view showing the structure of the wafer alignment part and the support rod in the wafer clamping device according to the embodiment of the invention.

Referring to fig. 1 and 2 in combination, the wafer clamping apparatus provided by the present invention includes: a wafer stage 101 for placing a wafer 100, the bottom of the wafer stage 101 being vertically connected to a rotating stage 103 by a connecting rod 102; and a plurality of wafer alignment parts 104, the wafer alignment parts are provided with alignment blocks 1041, the alignment blocks 1041 are abutted with the side circumference of the wafer 100, the alignment blocks 1041 are uniformly distributed along the circumferential direction of the wafer, the bottoms of the wafer alignment parts 104 are fixedly connected to the rotating platform 103 through support rods 1042, the wafer alignment parts 104 are also provided with eccentric blocks 1043, when the rotating platform 103 drives the whole clamping device to rotate, the eccentric blocks 1043 pull or push the alignment blocks 1041 under the action of centrifugal force so as to enable the alignment blocks 1041 to be matched to move the wafer 100, thereby realizing the automatic centering of the wafer 100.

In one embodiment, as shown in fig. 2, the wafer stage 101 may preferably be provided with vacuum suction holes 1011 for sucking and fixing the wafer 100, and the vacuum state is broken when the clamping device rotates to adjust the wafer position, and the vacuum suction may be turned on after the initial placement and the position adjustment of the wafer are completed, so that the wafer is kept fixed on the wafer stage.

The preferable rotating speed range of the rotating platform for driving the whole clamping device to rotate can be 1000-2000r/min.

In a preferred embodiment, as shown in fig. 1, the support rods 1042 adjacent to the wafer alignment parts 104 of the wafer clamping device provided by the present invention are connected by springs 105, so that the rigidity and reliability of the whole clamping device can be ensured under a certain working rotation speed.

The spring 105 can be a tension spring made of SUS304 stainless steel, and the height position of the tension spring can be correspondingly adjusted and replaced according to the length of the support rod 1042 and the rotating speed of the clamping device.

FIG. 3 is a side view of an apparatus structure of a wafer alignment portion of a wafer clamping apparatus according to an embodiment of the present invention; fig. 4 is a schematic view of an apparatus structure of a wafer stage and a rotating stage in a wafer clamping apparatus according to an embodiment of the invention.

As shown in fig. 3 and 4, in a preferred embodiment, the wafer aligning portion 104 of the wafer clamping device provided by the present invention further includes a horizontally placed and elongated fixing block 1044, the bottom of the fixing block 1044 is fixedly connected with the supporting rod 1042, one end of the fixing block 1044 away from the wafer is connected with the eccentric block 1043 so that the eccentric block 1043 rotates about a connecting position of the two as a rotation axis 1045 during rotation, a push rod 1046 parallel to the fixing block 1044 is disposed on one surface of the aligning block 1041 facing away from the wafer, a mounting portion 1047 is disposed at one end of the fixing block 1044 close to the wafer so as to cover the push rod 1046, and the eccentric block 1043 is connected with the push rod 1046 through a connecting rod 1048.

Referring to fig. 4, in an embodiment, the eccentric block 1043 in the wafer clamping device according to the present invention is preferably pendulum-shaped, and its center of gravity is coincident with the rotation axis 1045. For example, the eccentric mass 1043 may be made of ASTM 304.

Fig. 4 shows a natural state of the eccentric block 1043 under no additional stress, and it can be appreciated that by the above arrangement, when the whole clamping device rotates, the eccentric block 1043 can freely rotate around the rotation shaft 1045 under the action of its own gravity and centrifugal force, so as to drive the connecting rod 1048 and the push rod 1046 to realize the front-back movement of the alignment block 1041, and since the plurality of alignment blocks 1041 are uniformly distributed along the side circumference of the wafer, each alignment block 1041 receives centripetal thrust with equal magnitude, thereby pushing the alignment block 1041 to adjust the wafer position by utilizing the principle of centrifugal force balance to realize centering alignment.

Meanwhile, as shown in fig. 4, in the preferred embodiment, the link 1048 is connected to the top of the eccentric mass 1043, and the link 1048 and the push rod 1046 are located above the fixed mass 1044.

In an embodiment, in the wafer clamping device provided by the present invention, the connecting rod 1048, the pushing rod 1046, the fixing block 1044 and the supporting rod 1042 may be made of 6061-T6, so that the weight of the alignment device may be reduced.

Meanwhile, the alignment block 1041 preferably can be made of antistatic PEEK material, so as to avoid adverse effects of static electricity generated during adjusting the wafer position on centering alignment. In addition, referring to fig. 4, in the preferred embodiment, the side section of the abutting portion 1049 between the alignment block 1041 and the wafer is L-shaped for abutting against the side periphery and the bottom edge of the wafer, so as to facilitate the wafer position adjustment.

Fig. 5 is a top view illustrating an apparatus structure of a wafer clamping apparatus according to an embodiment of the present invention. Fig. 6 is a schematic view showing a height selection of a wafer clamping apparatus according to an embodiment of the invention. Fig. 7 is a schematic view of an apparatus structure for supporting the angle of the supporting rod in the wafer clamping apparatus according to an embodiment of the invention.

Referring to fig. 5, 6 and 7 in combination, in the preferred embodiment, the number of the plurality of wafer alignment parts is 3, the support bar is fixedly connected with the rotating platform through a flange and a screw so that the support bar forms a preset angle α with the horizontal plane, and the preset angle α and the vertical distance h between the wafer platform and the rotating platform are adjusted and determined according to the size d of the wafer.

For example, for a 8 inch sized wafer, d is about 200mm, and accordingly, the predetermined angle α may be 60 °, and the vertical distance h between the wafer stage and the rotating stage may be 210mm.

It should be noted that the above dimension information is only exemplary, and is intended to illustrate that in the wafer clamping device provided by the present invention, the distance and dimension of each component may be adjusted according to the size of the wafer, so as to achieve an optimal stress to improve the alignment effect of the wafer, and not to limit the protection scope of the present invention. For other wafer products of different sizes, such as 4 inches, 6 inches, 12 inches, or 14 inches, the length of the support bars 1042 and the vertical distance h between the wafer stage and the rotating stage can be adjusted to accommodate the processing requirements of different wafers.

According to the clamping device for the wafer, when the wafer eccentrically rotates, the clamping device adjusts the position of the wafer by the difference of centrifugal force applied to the edge of the wafer, so that the wafer is stressed and balanced, the wafer is automatically adjusted to the centering position, a good centering alignment effect is ensured, and meanwhile, the device is simple in structure, easy to realize and beneficial to saving cost and mass production popularization. For example, the clamping device can be widely applied to various wafer prealignment devices, spin coating machines or other semiconductor processing equipment with wafers capable of rotating at high speed, and a better centering alignment effect is obtained.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wafer clamping apparatus for automatically adjusting a wafer to a centered position, the clamping apparatus comprising:

the wafer platform is used for placing a wafer, and the bottom of the wafer platform is vertically connected to the rotating platform through a connecting rod; and

the wafer alignment part is provided with alignment blocks, the alignment blocks are abutted to the periphery of the wafer, the alignment blocks are uniformly distributed along the periphery of the wafer, the bottom of the wafer alignment part is fixedly connected to the rotary platform through a supporting rod, the wafer alignment part is also provided with eccentric blocks, and when the rotary platform drives the whole clamping device to rotate, the eccentric blocks pull or push the alignment blocks under the action of centrifugal force so that the alignment blocks are matched to move the wafer, so that the automatic centering of the wafer is realized.

2. The clamping device of claim 1, wherein the wafer aligning portion further comprises a horizontally placed and elongated fixing block, the bottom of the fixing block is fixedly connected with the supporting rod, one end of the fixing block, which is far away from the wafer, is connected with the eccentric block so that the eccentric block rotates with the joint of the fixing block and the eccentric block as a rotation axis in the rotating process, a push rod parallel to the fixing block is arranged on one surface, which is far away from the wafer, of the aligning block, a mounting portion is arranged at one end, which is close to the wafer, of the fixing block so as to cover the push rod, and the eccentric block is connected with the push rod through a connecting rod.

3. The clamping device as claimed in claim 2, characterized in that the eccentric mass is pendulum-shaped with its centre of gravity coinciding with the rotation axis.

4. A clamping device as claimed in claim 3, characterised in that the connecting rod is connected to the top of the eccentric mass, the connecting rod and the push rod being located above the fixed mass.

5. The clamping apparatus of claim 1 wherein adjacent ones of said support rods of said wafer alignment section are connected by springs.

6. The clamping device of claim 1, wherein the side cross section of the abutment portion of the alignment block with the wafer is L-shaped for abutting against the side periphery and bottom edge of the wafer.

7. The clamping device of claim 1 wherein the wafer table has vacuum suction holes for sucking and holding the wafer and breaking the vacuum when the clamping device is rotated to adjust the wafer position.

8. The clamping device as claimed in claim 1, characterized in that the rotational speed of the rotating platform for rotating the entire clamping device is in the range of 1000-2000r/min.

9. The clamping device of claim 1, wherein the number of the plurality of wafer alignment parts is 3, the support bar is fixedly connected with the rotating platform through a flange and a screw so that the support bar forms a preset angle with the horizontal plane, and the preset angle and the vertical distance between the wafer platform and the rotating platform are determined according to the size adjustment of the wafer.

10. The clamping device of claim 9, wherein the wafer is 8 inches in size, the predetermined angle is 60 °, and a vertical distance between the wafer stage and the rotating stage is 210mm.