A sheet unloading device for a polishing machine to improve backside scratch

Abstract

The utility model discloses a kind of for improving back scratch's unloading device of polishing machine, including unloading bridge, unloading knife and unloading drive mechanism, the upper surface height of unloading bridge is level with the upper surface height of carrier;Unloading bridge is located at the side of carrier, and the inner side of unloading bridge and carrier contact is arc-shaped;Unloading device further includes blowing mechanism, blowing mechanism is set to the middle of carrier and wafer, for blowing to the middle of carrier and wafer.This application provides unloading device, while unloading, can blow compressed air to reduce the pressure of wafer and carrier contact point, reduce unloading scratch;By the shape of unloading bridge and carrier contact surface is set to arc, when wafer is pushed from carrier to unloading bridge when unloading, accurate positioning can be achieved, reduce the probability of unloading scratch due to inaccurate positioning, to improve product yield and economic benefit, reduce wafer loss, reduce production cost.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor manufacturing technology, specifically relating to a wafer unloading device for improving back-side scratches on a polishing machine. Background Technology

[0002] CMP (chemical mechanical polishing) is an indispensable step in the surface planarization process of silicon substrates, and single-wafer polishing machines are a process to achieve atomic-level flatness of silicon substrates.

[0003] The general operation process of a single-wafer polishing machine is as follows: 1. Wax is applied in the wax application area, that is, the back side of the wafer is applied to the circular block carrier (hereinafter referred to as Block) with special wax; 2. The target removal amount and a better flatness parameter are achieved through three processes: coarse polishing, medium polishing and fine polishing.

[0004] In the production of single-wafer polishing machines, wafer unloading is required after fine polishing is completed. The unloading device consists of a shovel blade (made of Peek material) fixed by a shovel blade holder, which holds the block and then uses an electric cylinder to shovel the wafer off the block and send it into the cassette.

[0005] Due to varying back-side structures of the silicon substrates depending on customer requirements, some are polycrystalline silicon layers, while others are oxide layers. The two structures differ in hardness, with oxide layers being significantly harder. This means that during wafer removal, the wafer is supported at three points: two wafer scrapers and the block surface. Typically, the block is made of SiC, which has very high hardness and can easily scratch the back of the wafer when in contact with the oxide layer. Utility Model Content

[0006] The purpose of this invention is to provide a disc removal device for polishing machines to improve back scratches in order to overcome the shortcomings of the prior art.

[0007] The objective of this utility model is achieved through the following technical solution: A wafer unloading device for improving back-side scratches on a polishing machine includes an unloading air bridge, an unloading blade, and an unloading drive mechanism. The unloading blade is reciprocated under the action of the unloading drive mechanism, extending between a carrier and a wafer to scoop the wafer from the carrier and push it to the unloading air bridge. The upper surface of the unloading air bridge is at the same height as the upper surface of the carrier. The unloading air bridge is located on one side of the carrier, and the inner surface of the unloading air bridge that contacts the carrier is arc-shaped, so that the unloading air bridge and the carrier can fit tightly together. The wafer unloading device further includes an air blowing mechanism, which is positioned between the carrier and the wafer and is used to blow air into the middle of the carrier and the wafer.

[0008] Preferably, the front part of the wafer unloader that contacts the wafer is made of PEEK material, and the rear part is made of stainless steel material.

[0009] Preferably, the unloading bridge has a groove, and the air blowing mechanism is located in the groove.

[0010] Preferably, the blowing mechanism includes a blowing pipe, which is inclined upward so that the blowing direction is inclined upward.

[0011] Preferably, there are two wafer unloading blades, which are arranged symmetrically on the left and right sides; the blade length of the two wafer unloading blades is greater than the radius of the wafer.

[0012] Preferably, the unloading drive mechanism includes an unloading knife holder, a slide bar, a slider, and an electric cylinder; The unloading blade holder is connected to the slider and is used to fix the unloading blade; The slider is mounted on the slide rod and connected to the output end of the electric cylinder. Under the action of the electric cylinder, it can drive the unloading knife to move back and forth along the slide rod.

[0013] Preferably, the unloading drive mechanism further includes a vertical connecting rod, the upper and lower ends of which are respectively connected to the unloading knife fixing frame and the slider.

[0014] Preferably, the unloading knife is fixed to the unloading knife fixing frame by being clamped by the unloading knife fixing block and the unloading knife fixing plate.

[0015] Preferably, the unloading device further includes a base; The carrier and the unloading drive mechanism are located on the base.

[0016] The wafer unloading device provided in this application, by setting an air blowing mechanism, can blow compressed air to reduce the pressure at the contact point between the wafer and the carrier during wafer unloading, thereby reducing wafer unloading scratches; by setting the shape of the contact surface between the unloading bridge and the carrier to an arc shape, the wafer can be accurately positioned when it is pushed from the carrier to the unloading bridge during unloading, reducing the probability of wafer unloading scratches caused by inaccurate positioning, thereby improving product yield and economic benefits, reducing wafer loss, and lowering production costs. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of the unloading device provided in this application; Figure 2 This is a top view of the unloading device provided in this application; Figure 3 This is a three-dimensional structural diagram of the wafer unloading device after omitting the wafer; Explanation of reference numerals in the attached figures: 1-Base; 2-Electric cylinder; 3-Slider; 4-Slide rod; 5-Connecting rod; 6-Unloading knife holder; 7-Unloading knife holder; 8-Unloading knife holder plate; 9-Unloading knife; 10-Wafer; 11-Carrier; 12-Wax film; 13-Unloading air bridge; 14-Blowing mechanism. Detailed Implementation

[0018] This application provides a disc removal device for improving back-side scratches on a polishing machine, such as... Figures 1-3 As shown, it includes a wafer unloading bridge 13, a wafer unloading blade 9, and a wafer unloading drive mechanism. The wafer unloading blade 9 is connected to the wafer unloading drive mechanism and can reciprocate under the action of the wafer unloading drive mechanism, extending between the carrier 11 and the wafer 10 to scoop the wafer 10 out of the carrier 11 and push it to the wafer unloading bridge 13.

[0019] The upper surface of the wafer unloading bridge 13 is at the same height as the upper surface of the carrier 11, meaning the height of the wafer unloading bridge and the carrier are the same. This allows the wafer to be supported and positioned in the height direction when it moves towards the wafer unloading bridge. The wafer unloading bridge 13 is fixedly mounted on one side of the carrier, and the inner surface of the wafer unloading bridge 13 that contacts the carrier 11 is arc-shaped, allowing the wafer unloading bridge and the carrier to fit tightly together. This enables the wafer to be accurately positioned and moved smoothly when it is pushed from the carrier to the wafer unloading bridge by the wafer unloading blade, reducing the probability of wafer scratches caused by inaccurate positioning.

[0020] The wafer unloading device also includes an air blowing mechanism 14, which is positioned between the carrier and the wafer to blow air into the middle of the carrier and the wafer. By setting the air blowing mechanism 14, a small amount of compressed air can be introduced during the wafer unloading process, specifically at the moment of unloading (when there is three-point contact between the wafer unloader and the carrier surface), to provide upward support for the wafer, reduce the pressure at the contact point between the wafer and the carrier, and thus reduce back-side scratches.

[0021] Preferably, the front part of the wafer ejector blade 9 that contacts the wafer 10 is made of PEEK material, and the rear part is made of stainless steel. Using PEEK material at the front reduces scratches on the wafer, while using stainless steel at the rear enhances the strength of the wafer ejector blade.

[0022] Preferably, the unloading air bridge 13 is provided with a groove, and the air blowing mechanism 14 is provided in the groove, which can blow air between the carrier and the wafer.

[0023] Preferably, the blowing mechanism 14 includes a blowing pipe, one end of which is connected to an external air source, and the other end of which is inclined upward so that the blowing direction is inclined upward, thereby providing an upward support force to the wafer.

[0024] Preferably, there are two wafer unloading blades 9, arranged symmetrically on the left and right sides; the blade length of the two unloading blades is greater than the radius of the wafer, which can increase the contact area with the wafer, reduce the contact pressure, and reduce the scratch rate. Preferably, the wafer unloading drive mechanism includes a wafer unloading blade fixing frame 6, a slide bar 4, a slider 3, and an electric cylinder 2; the wafer unloading blade fixing frame 6 is connected to the slider 3 and is used to fix the wafer unloading blade 9; the slider 3 is set on the slide bar 4 and is connected to the output end of the electric cylinder 2, which can drive the wafer unloading blade 9 to reciprocate along the slide bar 4 under the action of the electric cylinder 2, thereby enabling wafer scraping.

[0025] Preferably, the wafer unloading drive mechanism further includes a vertical connecting rod 5, the upper and lower ends of which are connected to the wafer unloading blade holder 6 and the slider 3, respectively, connecting the slider and the wafer unloading blade holder to transmit motion. By setting the vertical connecting rod 5, the wafer unloading blade can be raised to the same height as the carrier, thereby allowing it to be inserted between the carrier and the wafer.

[0026] Preferably, the unloading blade 9 is fixed to the unloading blade holder 6 by being clamped by the unloading blade fixing block 7 and the unloading blade fixing plate 8. Further, the unloading blade fixing block 7 and the unloading blade fixing plate 8 clamp the stainless steel part of the unloading blade 9, and the rear ends of the unloading blade fixing block 7 and the unloading blade fixing plate 8 are fixed to the unloading blade holder 6 by screws.

[0027] Preferably, the unloading device provided in this application further includes a base 1; the carrier 11 and the unloading drive mechanism are both located on the base 1. The base 1 is used to fix the electric cylinder 2 and the slide bar 4, provide support for the carrier 11, load the unloading air bridge, and provide limit for the slider 3, etc.

[0028] Preferably, the unloading air bridge can be fixed to the base or polishing machine table via a shaft.

[0029] The working principle of this application is as follows: During polishing, wafer 10 is attached to carrier 11 by wax film 12. Unloading bridge 13 is fixed to one side of the carrier, and a wafer cassette is placed on the other side. When unloading is required after polishing, electric cylinder 2 drives slider 3 in the direction of the arrow, thereby moving the unloading blade 9 in the same direction to remove wafer 10 from carrier 11 and transfer it to unloading bridge 13. The unloading blade then continues forward along the surface of unloading bridge, pushing the wafer into the wafer cassette. Simultaneously, compressed air is blown through the air pipe to reduce the pressure at the contact point between wafer 10 and carrier 11, minimizing unloading scratches. The arc-shaped contact surface between unloading bridge 13 and carrier 11 allows for precise positioning of wafer 10 as it is pushed from carrier 11 to unloading bridge 13, reducing the probability of unloading scratches due to inaccurate positioning. This improves product yield and economic efficiency, reduces wafer loss, and lowers production costs.

[0030] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention. Clearly, those skilled in the art can make various alterations and modifications to the present invention without departing from its spirit and scope. Thus, if these modifications and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and modifications.

Claims

1. A wafer unloading device for improving back-side scratches in a polishing machine, comprising an unloading air bridge, an unloading blade, and an unloading drive mechanism, wherein the unloading blade is used to reciprocate under the action of the unloading drive mechanism, extending between a carrier and a wafer to scoop the wafer from the carrier and push it to the unloading air bridge; characterized in that, The upper surface of the unloading bridge is at the same height as the upper surface of the carrier; the unloading bridge is located on one side of the carrier, and the inner surface of the unloading bridge that contacts the carrier is arc-shaped, so that the unloading bridge and the carrier can fit tightly together. The wafer unloading device further includes an air blowing mechanism, which is positioned between the carrier and the wafer and is used to blow air into the middle of the carrier and the wafer.

2. The unloading device for improving back-side scratches on a polishing machine as described in claim 1, characterized in that, The front part of the wafer unloader that contacts the wafer is made of PEEK material, and the rear part is made of stainless steel.

3. The unloading device for improving back-side scratches on a polishing machine as described in claim 1, characterized in that, The unloading bridge has a groove, and the air blowing mechanism is located in the groove.

4. The unloading device for improving back-side scratches on a polishing machine as described in claim 1, characterized in that, The blowing mechanism includes a blowing pipe, which is inclined upward so that the blowing direction is inclined upward.

5. The unloading device for improving back-side scratches on a polishing machine as described in claim 1, characterized in that, The number of the wafer unloading blades is two, and they are arranged symmetrically on the left and right sides; the blade length of the two wafer unloading blades is greater than the radius of the wafer.

6. The unloading device for improving back-side scratches on a polishing machine as described in claim 1, characterized in that, The unloading drive mechanism includes an unloading knife holder, a slide bar, a slider, and an electric cylinder; The unloading blade holder is connected to the slider and is used to fix the unloading blade; The slider is mounted on the slide rod and connected to the output end of the electric cylinder. Under the action of the electric cylinder, it can drive the unloading knife to move back and forth along the slide rod.

7. The unloading device for improving back-side scratches on a polishing machine as described in claim 6, characterized in that, The unloading drive mechanism also includes a vertical connecting rod, the upper and lower ends of which are respectively connected to the unloading knife fixing frame and the slider.

8. The unloading device for improving back-side scratches on a polishing machine as described in claim 6, characterized in that, The unloading blade is fixed to the unloading blade mounting frame by being clamped by the unloading blade fixing block and the unloading blade fixing plate.

9. The unloading device for improving back-side scratches on a polishing machine as described in claim 1, characterized in that, It also includes a base; The carrier and the unloading drive mechanism are located on the base.

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