Finishing device of polishing pad and processing equipment and method of silicon wafer positioning groove

Abstract

The invention provides a finishing device of a polishing pad and machining equipment and method.The finishing device comprises a mounting support, the mounting support is provided with telescopic rods arranged oppositely at intervals, and a fixing piece fixedly connected between the first ends of the telescopic rods in a lap joint mode so that a clamping groove can be formed by the fixing piece and the telescopic rods; the connecting seat is used for being rotationally connected with the center of the polishing pad located in the clamping groove; the trimming cutter assembly is arranged on the inner wall of the first end of the clamping groove, the trimming cutter assembly is at least provided with cutting edges which are oppositely arranged at intervals in the first direction, the distance between the cutting edges is gradually increased in the direction from the first end to the second end, and the cutting edges are used for trimming the edges of the polishing pad on the two axial sides of the polishing pad; according to the trimming device, the polishing pad can be trimmed, abnormal forms such as self deformation or burr bifurcation of the polishing pad are reduced, and then generation of waste silicon wafers is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductors, and in particular relates to a polishing pad dressing device, and a processing device and method for silicon wafer positioning grooves. Background Art

[0002] With the rapid development of integrated circuit manufacturing technology, the size of its substrate material semiconductor single crystal silicon wafers continues to increase, and the requirements for the polishing quality of the overall surface of the silicon wafers are becoming higher and higher.

[0003] Chemical mechanical polishing (CMP) technology is widely used in the edge polishing of silicon wafers. In recent years, many equipment manufacturers at home and abroad have been exploring new methods for polishing the edges of silicon wafers. For example, Speedfam, a Japanese polishing equipment manufacturer that appeared earlier, designed and produced the EP-300-XW 12-inch silicon wafer edge polisher. This type of edge polisher uses a circular polishing unit and a Notch (positioning)-polishing unit design. The circular polishing unit is designed as a hemispherical polishing cloth located in the four directions of the silicon wafer to polish the three edge surfaces of the silicon wafer product A-CF, B-CF, and TOP at the same time. The Notch polishing unit uses two Notch polishing pads to rotate at high speed to polish the silicon wafer positioning Notch groove surface. Compared with Speedfam, BBS Japan Kinmei Co., Ltd., which appeared later, has a more complex design of edge polishing equipment model E300 Ver2.0, which uses two circular polishing units and two Notch polishing units. The circular polishing unit of the E300 Ver2.0 edge polishing equipment uses centrifugal force and leverage to press 12 polishing cloths against the silicon wafer, and polish the three edge surfaces of the silicon wafer, A-CF, B-CF, and TOP, at the same time. The design principle of the Notch polishing unit is extremely similar to that of Speedfam's EP-300-XW 12-inch silicon wafer edge polishing machine, both of which use two parallel Notch polishing pads to rotate at high speed to polish the silicon wafer to locate the Notch groove surface, but the relative movement of the silicon wafer and the polishing pad during the processing is slightly different.

[0004] During Notch polishing unit processing, the circular polishing pad and the silicon wafer are perpendicular and tangent to each other. After a long period of contact with the silicon wafer and relative motion, the Notch polishing pad will undergo obvious changes in shape. For example, burr-like forks will appear on both sides of the polishing pad due to wear. During high-speed rotating polishing, the forks will contact the upper and lower surfaces of the silicon wafer (not the edge contour), and under the action of the polishing liquid, abnormal over-polishing areas will be generated around the Notch on the upper and lower surfaces. The generation of this abnormal area will directly affect the product quality of the front and back surfaces of the silicon wafer, seriously affect the product yield, and increase the factory's production costs.

[0005] Therefore, it is necessary to design a dressing device for a polishing pad, a processing device and method for a wafer positioning groove to dress the deformed area of the polishing pad, so as to ensure the processing quality of the wafer. Summary of the Invention

[0006] In view of some or all of the above technical problems existing in the prior art, a dressing device for a polishing pad of a wafer positioning groove, as well as a processing device and method for a wafer positioning groove are provided. The dressing device for a polishing pad of a wafer positioning groove can dress the polishing pad, thereby reducing abnormal forms such as self-deformation or burr bifurcation of the polishing pad, resulting in over-polished areas or other abnormalities around the Notch on the upper and lower surfaces of the wafer product, so as to realize automatic processing, repair and shaping, fundamentally reduce the generation of waste wafers, and improve the product yield and manufacturing efficiency of the wafers.

[0007] According to a first aspect of the present invention, a dressing device for a polishing pad of a wafer positioning groove is proposed, including:

[0008] A mounting bracket, the mounting bracket having telescopic rods arranged at intervals relative to each other in a first direction, a fixing member fixedly lapped between the first ends of the telescopic rods to form a clamping groove therewith, and connecting seats arranged at the second ends of the respective telescopic rods on both sides in the first direction of the clamping groove, the connecting seats being used for rotatably connecting with the center of the polishing pad located in the clamping groove,

[0009] A dressing tool assembly provided on the inner wall of the first end of the clamping groove, the dressing tool assembly having at least cutting edges arranged at intervals relative to each other in the first direction and the distance increasing gradually in the direction from the first end to the second end, the cutting edges being used for dressing the edges of the polishing pad on both axial sides of the polishing pad.

[0010] An actuating assembly for adjusting the length of the telescopic rods and thereby driving the dressing tool assembly away from or closer to the connecting seats.

[0011] In one embodiment, the dressing tool assembly includes tool bodies arranged at intervals relative to each other in the first direction. Each of the tool bodies includes an inclined section, a cutting hole is arranged on each inclined section, and a part of the wall of each cutting hole forms the cutting edge. The clamping groove includes a mounting groove portion provided on the fixing member, and the shape of the mounting groove portion matches that of the tool body for arranging the tool body.

[0012] In one embodiment, each of the tool bodies further includes a straight section arranged at the second end of the inclined section, and the cutting edge extends to the straight section along with the cutting hole.

[0013] In one embodiment, the extending direction of the cutting blade and the extending direction of the telescopic rod are distributed at a first angle, and the first angle is 15-30 degrees.

[0014] In one embodiment, the cutting hole is an elongated hole, and two inner walls of the cutting hole that are arranged opposite to each other in the second direction are both configured as the cutting edges.

[0015] In one embodiment, the tool body is made of a ceramic material.

[0016] In one embodiment, a controller is further included, the actuating assembly is connected to the controller, a pressure sensor located in the clamping groove is provided on the fixing member, the pressure sensor is connected to the controller, and the controller adjusts the length of the telescopic rod through the actuating assembly according to the pressure value detected by the pressure sensor.

[0017] In one embodiment, the actuating assembly includes an actuating motor and a lead screw mechanism, and the lead screw mechanism is used to operate under the drive of the actuating motor to drive the telescopic rod to adjust its length.

[0018] According to a second aspect of the present invention, a processing device for silicon wafer positioning grooves is provided, comprising:

[0019] A workbench for placing silicon wafers to be processed.

[0020] A mechanical arm, wherein the mechanical arm is provided with a power source for driving the polishing pad to rotate,

[0021] a polishing pad connected to the power source so as to rotate around a rotation axis under the action of the power source,

[0022] The above-mentioned polishing pad dressing device for the silicon wafer positioning groove,

[0023] Wherein, the connecting seat is arranged on the mechanical arm, the polishing pad extends to the clamping groove, and the rotation axis of the polishing pad is rotationally connected to the connecting seat.

[0024] According to a third aspect of the present invention, a method for processing using the above-mentioned silicon wafer positioning groove processing equipment is provided, comprising:

[0025] S01, installing the new polishing pad on the dressing assembly, and placing the silicon wafer to be processed on the workbench,

[0026] S02, adjusting the length of the telescopic rod so that the value of the pressure sensor is a preset pressure value M,

[0027] S03, starting the power source to drive the polishing pad to rotate. During the rotation of the polishing pad, if the real-time pressure value of the pressure sensor is less than M, the telescopic rod drives the dressing tool assembly to retract radially until the real-time pressure value of the pressure sensor is greater than or equal to M.

[0028] Compared with the prior art, the advantages of the present invention are that the edges on both sides of the axial direction of the polishing pad can be trimmed by means of the trimming tool assembly, thereby reducing the over-polishing area or other abnormalities around the Notch on the upper and lower surfaces of the silicon wafer product caused by abnormal shapes such as deformation of the polishing pad itself or burr bifurcation, thereby realizing automatic processing, repair and shaping, fundamentally reducing the generation of waste silicon wafers, and improving the product yield and manufacturing efficiency of silicon wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0030] Figure 1 A three-dimensional diagram schematically showing a device for dressing a polishing pad of a silicon wafer positioning groove according to an embodiment of the present invention;

[0031] Figure 2 A front view schematically shows a device for dressing a polishing pad of a silicon wafer positioning groove according to an embodiment of the present invention;

[0032] Figure 3 A side view schematically shows a device for dressing a polishing pad of a silicon wafer positioning groove according to an embodiment of the present invention;

[0033] Figure 4 A top view schematically shows a device for dressing a polishing pad of a silicon wafer positioning groove according to an embodiment of the present invention;

[0034] Figure 5 For Figure 1 A magnified image of point A;

[0035] Figure 6 A side view schematically shows a dressing tool assembly of a dressing device for a polishing pad of a silicon wafer positioning groove according to an embodiment of the present invention;

[0036] Figure 7 A front view schematically shows a dressing tool assembly of a dressing device for a polishing pad of a silicon wafer positioning groove according to an embodiment of the present invention;

[0037] Figure 8 A three-dimensional diagram schematically showing a tool body of a polishing pad dressing device for a silicon wafer positioning groove according to an embodiment of the present invention;

[0038] Fig. 9 A state diagram of a polishing pad is schematically shown.

[0039] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0040] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0041] The present application provides a device for trimming a polishing pad of a silicon wafer positioning groove. The device for trimming a polishing pad of a silicon wafer positioning groove is used for trimming a polishing pad. Figures 1 to 8 As shown, the dressing device includes a mounting bracket 1, a dressing tool assembly 2 and an actuating assembly (not shown in the figure). Structurally, the mounting bracket 1 has a telescopic rod 11, a fixing member 12 and a connecting seat 13. The telescopic rod 11 has two groups, and the two groups of telescopic rods 11 are arranged in a relative interval in a first direction (during use, the first direction is consistent with the axial direction of the polishing pad 200). The fixing member 13 is overlapped on the first end of the telescopic rod 11 (during use, the first end is consistent with the radial outer end direction of the polishing pad 200) to fix and connect the two groups of telescopic rods 11, and form a clamping groove 14 with the two groups of telescopic rods 11. The clamping groove 14 is mainly used to clamp the polishing pad 200. There are two connecting seats 13, which are respectively arranged at the second end of each telescopic rod 11 (during use, the second end is consistent with the radial inner end direction of the polishing pad 200), and are located on both sides of the first direction of the clamping groove 14. The connecting seat 13 is used to be rotatably connected to the rotation center of the polishing pad 200 located in the clamping groove 14. The trimming tool assembly 2 is arranged on the inner wall of the first end of the clamping groove 14. Specifically, the trimming tool assembly 2 has at least cutting blades 21 arranged relatively spaced apart in the first direction, and the distance between the two sets of cutting blades 21 arranged relatively gradually increases from the first end to the second end, and is used to adapt to the outer edge of the polishing pad 200, so as to trim the edges on both sides of the axial direction of the polishing pad 200 during the rotation of the polishing pad 200. The actuating assembly is used to adjust the length of the telescopic rod 11, thereby driving the trimming tool assembly 2 away from or close to the connecting seat 13, thereby adjusting the distance of the trimming tool assembly 2 relative to the axial center of the polishing pad 200 to meet the trimming needs.

[0042] In one embodiment, Figures 6 to 8As shown, the dressing tool assembly 2 includes two tool bodies 22, which are arranged at a relative interval in the first direction. That is, during use, one tool body 22 is located on the front side of the polishing pad 200, and the other is located on the back side of the polishing pad 200, so as to simultaneously dress both axial sides of the polishing pad 200. Each tool body 22 includes an inclined section 23, and a cutting hole 24 is provided on each inclined section 23, and a part of the wall of each cutting hole 24 forms a cutting edge 21. The setting of the inclined section 23 is adapted to the edge structure of the polishing pad 200. The radial projection of the cutting edge 21 in the polishing pad needs to have a certain length to meet the need of cutting the edge of the polishing pad 200. At the same time, the clamping groove 14 includes a mounting groove portion 15 arranged on the fixing member 12. The shape of the mounting groove portion 15 matches the tool body 22 for setting the tool body 22. That is, by optimizing and designing the structure of the fixing member 12, the installation and positioning of the tool body 22 becomes simple. It can be understood that the tool body 22 is set on the fixing member 12 through the tool mounting seat 25. For stable connection, each tool body 22 is provided with two tool mounting seats 25 spaced apart in the second direction (which is consistent with the circumferential direction of the polishing pad 200 during use), and the tool mounting seats 25 are connected to the fixing member 12, so that the tool body 22 is set on the fixing member 12.

[0043] In one embodiment, each tool body 22 further includes a straight segment 26 disposed at the second end of the inclined segment 23. Correspondingly, the cutting hole 24 extends to the straight segment 26, and the cutting edge 21 also extends to the straight segment 26 as the cutting hole 24 extends. On the one hand, the straight segment 26 can be added to clamp the polishing pad to prevent the polishing pad 200 from radially retreating during the cutting process, so as to ensure smooth trimming; on the other hand, the straight segment 26 also plays a role in trimming the polishing pad 200, so as to ensure the shape of the polishing pad 200.

[0044] In one embodiment, the extension direction of the cutting blade 21 and the extension direction of the telescopic rod 11 are distributed at a first angle, which is represented by α in the figure. Preferably, the first angle is 15-30 degrees, for example 25 degrees. That is to say, the extension direction of the cutting blade 21 forms a first angle with the radial direction of the polishing pad 200. In addition, the cutting hole 24 is configured as a long hole. The two inner walls of the cutting hole 24 that are relatively arranged in the second direction are both configured as cutting blades 21. The cutting blade 21 arranged in this way can bidirectionally and in real time shear the deformation area of ​​the polishing pad regardless of whether the polishing pad 200 rotates counterclockwise or clockwise. On each tool body 22, a plurality of cutting holes 24 can be arranged in parallel to form a plurality of cutting blades 21 to improve cutting efficiency.

[0045] Preferably, the tool body 22 is made of ceramic material. This arrangement can effectively prevent metal debris from being transferred to the silicon wafer, and is used to ensure the safety of silicon wafer processing.

[0046] In one embodiment, the dressing device further includes a controller (not shown) and a pressure sensor 4. The pressure sensor 4 is disposed on the fixing member 12 and is located in the clamping groove 14, and is used to contact the polishing pad 200 to obtain a pressure value. The controller is connected to the pressure sensor 4 to receive the pressure value of the pressure sensor 4. At the same time, the controller is connected to the actuating assembly, and the length of the telescopic rod 11 is adjusted through the actuating assembly according to the pressure value detected by the pressure sensor 4.

[0047] In one embodiment, the actuating assembly includes an actuating motor and a screw mechanism connected to the actuating motor. That is to say, the telescopic rod 11 of the present application is driven by a screw mechanism to adjust the length. The actuating motor and the screw mechanism of the actuating assembly are common driving components, and their structures and installation methods are foreseeable by those skilled in the art, and are not described in detail here. In order to balance the extension and retraction of multiple telescopic rods 11, each telescopic rod 11 is matched with a set of actuating motors and screw mechanisms, and different actuating motors are linked, so that the telescopic rods 11 maintain synchronous movement, ensuring the smoothness of the feeding or retraction of the dressing tool assembly.

[0048] The present application also relates to a processing device for silicon wafer positioning grooves, which mainly processes the positioning grooves of silicon wafers through a polishing pad. Among them, the processing device includes a workbench, a mechanical arm, a polishing pad 200 and a trimming device. Among them, the workbench is used to place the silicon wafer to be processed. The mechanical arm is used to set the polishing pad 200. At the same time, a power source for driving the polishing pad 200 to rotate around its own center is provided on the mechanical arm. The polishing pad 200 is connected to the power source so as to rotate around the rotation axis under the action of the power source. The trimming device is set on the mechanical arm, and its clamping groove 14 is used to clamp the polishing pad 200, and its mounting seat 13 is rotatably connected to the polishing pad 200. In other words, a trimming device according to the present application is added to the processing device for silicon wafer positioning grooves in the prior art, which is used to trim the polishing pad 200 while the polishing pad 200 processes the silicon wafer positioning grooves, thereby ensuring the quality of the silicon wafer products.

[0049] The present application also relates to a method for processing a silicon wafer positioning groove using a silicon wafer positioning groove processing device. In the method, while the silicon wafer is processed using a polishing pad 200, the polishing pad is trimmed using a trimming device.

[0050] Specifically, a new polishing pad 200 is first installed, that is, the new polishing pad 200 is placed in the clamping groove 14, and the rotation axis of the polishing pad 200 is rotatably connected to the connecting seat 13. At the same time, the new polishing pad 200 is connected to the power source. In addition, the silicon wafer to be processed with the positioning groove is installed, that is, the silicon wafer is placed on the workbench.

[0051] Then, the length of the telescopic rod 11 is adjusted to ensure that the detection value of the pressure sensor 4 is the preset pressure value M.

[0052] Finally, the power source is started to drive the polishing pad 200 to rotate. During the rotation of the polishing pad 200, the silicon wafer is processed. At the same time, during the rotation of the polishing pad 200, if a burr-like bifurcation occurs, the trimming tool assembly works to trim the edge of the polishing pad 200. When the circular polishing pad 200 rotates, the pressure sensor 4 monitors the pressure value generated by the outer peripheral surface of the polishing pad 200 in real time. If the outer peripheral wall of the polishing pad 200 is worn and consumed during the polishing process, the real-time pressure value is less than the initial preset pressure value M, and the pressure sensor 4 will transmit a signal to the controller. After receiving the signal, the controller adjusts the actuator motor to drive the screw mechanism to operate, accurately shorten the length of the telescopic rod 11, and then drives the trimming tool assembly 2 to move radially along the polishing pad 200, directly controlling the amount of cutting and clipping. The trimming tool assembly 2 trims the deformed areas on both sides of the polishing pad 200. Until the peripheral wall of the polishing pad 200 contacts the pressure sensor 4 and the real-time pressure value is greater than or equal to the initial pressure value M, the pressure sensor 4 will transmit a signal to the controller. The controller adjusts the actuator motor and controls the screw mechanism to accurately stop shortening the length of the telescopic rod 11, thereby ensuring the distance between the trimming tool assembly 2 and the rotation axis of the polishing pad 200 and stopping real-time cutting of the polishing pad.

[0053] It can be seen that during the processing of silicon wafers, the polishing pad 200 that is deformed during the processing can be monitored and cut in real time, so that the axial cross section of the polishing pad 200 continues to maintain a uniform initial shape, thereby ensuring that the processed silicon wafer products meet the quality requirements. In the application, when the polishing pad 200 rotates around the axis of rotation, the trimming tool assembly is fixed, and the trimming blade 15 and the surface of the polishing pad 200 form a relative motion. The deformed polishing pad 200 that does not conform to the area enclosed by the trimming blade 15 will be automatically cut and trimmed in real time by the trimming blade 15. Fig. 9 As shown, after the dressing device, the axial cross-sectional shape of the polishing pad 200 can be significantly improved and controlled.

[0054] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made according to the embodiments of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polishing pad dressing device for a silicon wafer positioning groove, It is characterized in that include: The mounting bracket comprises telescopic rods arranged at intervals in a first direction, fixing members fixedly overlapped between first ends of the telescopic rods to form clamping grooves with the telescopic rods, and connecting seats arranged at second ends of each of the telescopic rods and located on both sides of the clamping grooves in the first direction, the connecting seats being used for rotatably connecting with the center of the polishing pad located in the clamping grooves, a trimming tool assembly arranged on the inner wall of the first end of the clamping groove, the trimming tool assembly having at least cutting edges arranged relatively spaced in a first direction and with a distance gradually increasing from the first end to the second end, the cutting edges being used to trim the edges of the polishing pad on both axial sides of the polishing pad, An actuating assembly is used to adjust the length of the telescopic rod so as to drive the trimming tool assembly away from or close to the connecting seat.

2. The polishing pad dressing device for silicon wafer positioning grooves according to claim 1, It is characterized in that The dressing tool assembly includes tool bodies that are relatively spaced apart in a first direction, each tool body includes an inclined section, each inclined section is provided with a cutting hole, a portion of the wall of each cutting hole forms the cutting edge, and the clamping groove includes a mounting groove portion provided on the fixing member, the shape of the mounting groove portion matches the tool body for setting the tool body.

3. The polishing pad dressing device for silicon wafer positioning grooves according to claim 2, It is characterized in that Each of the tool bodies further includes a straight section disposed at the second end of the inclined section, and the cutting edge extends to the straight section along with the cutting hole.

4. The polishing pad dressing device for silicon wafer positioning grooves according to claim 3, It is characterized in that An extension direction of the cutting blade and an extension direction of the telescopic rod are distributed at a first angle, and the first angle is 15-30 degrees.

5. The polishing pad dressing device for silicon wafer positioning grooves according to claim 4, It is characterized in that The cutting hole is a long hole, and two inner walls of the cutting hole that are arranged opposite to each other in the second direction are both configured as the cutting blades.

6. The polishing pad dressing device for silicon wafer positioning grooves according to any one of claims 2 to 5, It is characterized in that The tool body is made of ceramic material.

7. The polishing pad dressing device for silicon wafer positioning grooves according to any one of claims 1 to 6, It is characterized in that It also includes a controller, the actuating assembly is connected to the controller, the fixing member is provided with a pressure sensor located in the clamping groove, the pressure sensor is connected to the controller, and the controller adjusts the length of the telescopic rod through the actuating assembly according to the pressure value detected by the pressure sensor.

8. The polishing pad dressing device for silicon wafer positioning grooves according to any one of claims 1 to 7, It is characterized in that The actuating assembly comprises an actuating motor and a lead screw mechanism, wherein the lead screw mechanism is used to operate under the drive of the actuating motor to drive the telescopic rod to adjust its length.

9. A processing device for silicon wafer positioning grooves, It is characterized in that include: A workbench for placing silicon wafers to be processed. A mechanical arm, wherein the mechanical arm is provided with a power source for driving the polishing pad to rotate, a polishing pad connected to the power source so as to rotate around a rotation axis under the action of the power source, The polishing pad dressing device for silicon wafer positioning grooves according to any one of claims 1 to 8, Wherein, the connecting seat is arranged on the mechanical arm, the polishing pad extends to the clamping groove, and the rotation axis of the polishing pad is rotationally connected to the connecting seat.

10. A method for processing using the silicon wafer positioning groove processing equipment according to claim 9, It is characterized in that include: S01, installing the new polishing pad on the dressing assembly, and placing the silicon wafer to be processed on the workbench, S02, adjusting the length of the telescopic rod so that the value of the pressure sensor is a preset pressure value M, S03, starting the power source to drive the polishing pad to rotate. During the rotation of the polishing pad, if the real-time pressure value of the pressure sensor is less than M, the telescopic rod drives the dressing tool assembly to retract radially until the real-time pressure value of the pressure sensor is greater than or equal to M.

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