Double-sided grinding device and method

Abstract

The invention provides a double-sided grinding device and method, and belongs to the technical field of semiconductor manufacturing. The double-face grinding device comprises an upper fixed disc, a lower fixed disc, a bearing disc and a driving mechanism, the upper fixed disc and the lower fixed disc are oppositely arranged, and the bearing disc is arranged on the side, facing the upper fixed disc, of the lower fixed disc and comprises a plurality of workpiece bearing disc holes; the driving mechanism can drive the bearing disc to rotate relative to the upper fixed disc and the lower fixed disc; wherein the upper fixed disc is provided with at least one purified water flow guide hole facing the surface of the lower fixed disc, and the purified water flow guide hole is used for spraying purified water towards the lower fixed disc. According to the technical scheme, the problem that the ground silicon wafer is adsorbed on the upper fixed disc and falls to the surface of the lower fixed disc when rising to the air to cause fragments can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a double-sided polishing device and method. Background Art

[0002] The double-sided grinding process of silicon wafers is used to remove surface damage of silicon wafers that occurs during wire cutting in the molding process to improve the surface roughness of silicon wafers. During the double-sided grinding process, the silicon wafer contacts the surface of the upper / lower fixed plate, and performs cycloidal motion through the rotation of the internal gear (sun gear) and the external gear (ring gear). By supplying abrasive slurry, mechanical and chemical reactions occur on the grinding surface, as well as physical reactions caused by rotation and pressure, to achieve the purpose of grinding the surface of the silicon wafer. During the double-sided grinding process of silicon wafers, a plurality of criss-cross grooves are usually opened on the grinding fixed plate, and the grooves are connected to form a channel for throwing out the waste liquid generated during the grinding process from the edge of the fixed plate.

[0003] During the double-sided grinding of wafer, as the use time of the platen increases, the thickness of the platen and the depth of the grooves will become shallower and shallower, and the surface tension received by the wafer will gradually increase. There is a situation where the wafer is adsorbed on the upper platen when the plate is lifted after grinding, and falls to the surface of the lower platen when it rises into the air, resulting in fragments. Summary of the invention

[0004] The invention provides a double-sided grinding device and method, which can solve the problem that after grinding, a silicon wafer is adsorbed on an upper platen and falls onto the surface of a lower platen when it is lifted into the air, resulting in fragments.

[0005] In order to achieve the above object, the technical solution adopted by the embodiment of the present invention is:

[0006] A double-sided grinding device, comprising an upper fixed plate, a lower fixed plate, a bearing plate and a driving mechanism, wherein the upper fixed plate is arranged opposite to the lower fixed plate, the bearing plate is arranged on a side of the lower fixed plate facing the upper fixed plate and comprises a plurality of workpiece bearing plate holes; the driving mechanism can drive the bearing plate to rotate relative to the upper fixed plate and the lower fixed plate;

[0007] Wherein, the upper fixed plate is provided with at least one clean water guide hole on the surface facing the lower fixed plate, which is used for spraying clean water toward the lower fixed plate.

[0008] In some embodiments, the device further comprises:

[0009] A water purification room, used to provide purified water;

[0010] A clean water conduit connecting the clean water chamber and the clean water diversion hole is used to transport clean water from the clean water chamber to the clean water diversion hole.

[0011] In some embodiments, the device further comprises:

[0012] The flow divider arranged at the outlet of the clean water conduit is used to divide the clean water in the clean water conduit into a plurality of the clean water guide holes.

[0013] In some embodiments, the device further comprises:

[0014] The flow controller arranged on the clean water conduit is used to control the clean water flow in the clean water conduit.

[0015] In some embodiments, the angle between the axis of the clean water diversion hole and the plane where the upper fixed plate is located is 40°-60°.

[0016] In some embodiments, the upper fixed plate is provided with multiple circles of clean water diversion holes, the first end of at least one circle of clean water diversion holes close to the center of the upper fixed plate is inclined toward the center of the upper fixed plate, and the first end of at least one circle of clean water diversion holes away from the center of the upper fixed plate is inclined toward the direction away from the center of the upper fixed plate, and the first end is the end of the clean water diversion hole away from the lower fixed plate.

[0017] In some embodiments, the upper fixed plate is provided with three circles of clean water diversion holes, the first end of a circle of clean water diversion holes close to the center of the upper fixed plate is inclined toward the center of the upper fixed plate, and the first ends of two circles of clean water diversion holes away from the center of the upper fixed plate are inclined toward the direction away from the center of the upper fixed plate.

[0018] In some embodiments, the spraying pressure of the clean water diversion hole is 1.0-1.5 MPa.

[0019] The embodiment of the present invention further provides a double-sided grinding method, which uses the above-mentioned double-sided grinding device to grind a workpiece to be ground, and the method includes:

[0020] Loading the workpiece to be ground into the hole of the carrier plate; adjusting the relative positions of the upper plate and the lower plate so that the upper and lower surfaces of the workpiece to be ground are in contact with the upper plate and the lower plate, respectively; driving the carrier plate to rotate around its own axis and revolve around the center of the lower plate by the driving mechanism, and grinding the workpiece to be ground under the action of the grinding slurry;

[0021] After grinding the workpiece to be ground, the upper fixed plate is controlled to move away from the lower fixed plate, and at the same time, the clean water diversion hole is controlled to spray clean water toward the lower fixed plate and the workpiece to be ground, so that the workpiece to be ground is fixed in the supporting plate hole through the spraying pressure, and the surface of the workpiece to be ground is cleaned.

[0022] In some embodiments, the method further comprises:

[0023] Before grinding the workpiece to be ground, the clean water guide hole is controlled to spray clean water toward the lower fixed plate and the workpiece to be ground, so as to clean the surface of the workpiece to be ground.

[0024] The beneficial effects of the present invention are:

[0025] In this embodiment, at least one clean water diversion hole is provided on the side of the upper fixed plate facing the lower fixed plate, which can spray clean water in the direction of the lower fixed plate. In this way, after the workpiece to be ground is ground, the clean water diversion hole can be controlled to spray clean water toward the lower fixed plate and the ground workpiece. The workpiece is fixed in the hole of the supporting plate through the spraying pressure, and the surface of the workpiece is cleaned, thereby avoiding the problem that the workpiece is adsorbed on the upper fixed plate after grinding and falls to the surface of the lower fixed plate when it is lifted into the air, causing fragments; and this embodiment can clean the lower fixed plate in time, thereby extending the service life of the fixed plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram showing the structure of a double-sided grinding device according to an embodiment of the present invention;

[0027] Figure 2 A schematic diagram showing the structure of a water purification diversion hole according to an embodiment of the present invention;

[0028] Figure 3 A schematic plan view of an upper fixing plate according to an embodiment of the present invention is shown.

[0029] Reference numerals

[0030] 1 Water purification room

[0031] 2 Mixing chamber

[0032] 3 Dispersant chamber

[0033] 4 Grinding chamber

[0034] 5 Weight sensor

[0035] 6.7 Pump

[0036] 8.9 Flow controller

[0037] 10 Water purification pipe

[0038] 11 Grinding liquid guide tube

[0039] 12 Grinding liquid diverter

[0040] 13 Water diversion hole

[0041] 14 Sun gear

[0042] 15 Grinding liquid guide hole

[0043] 16 Workpiece bearing plate holes

[0044] 17 Shunt

[0045] 18 Telescopic device

[0046] 20 Upper fix

[0047] 21 Set the plate DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0049] An embodiment of the present invention provides a double-sided grinding device, the double-sided grinding device comprising an upper fixed plate, a lower fixed plate, a carrier plate and a driving mechanism, the upper fixed plate is arranged opposite to the lower fixed plate, the carrier plate is arranged on a side of the lower fixed plate facing the upper fixed plate and comprises a plurality of workpiece carrier plate holes; the driving mechanism can drive the carrier plate to rotate relative to the upper fixed plate and the lower fixed plate;

[0050] Wherein, the upper fixed plate is provided with at least one clean water guide hole on the surface facing the lower fixed plate, which is used for spraying clean water toward the lower fixed plate.

[0051] In this embodiment, at least one clean water diversion hole is provided on the side of the upper fixed plate facing the lower fixed plate, which can spray clean water in the direction of the lower fixed plate. In this way, after the workpiece to be ground is ground, the clean water diversion hole can be controlled to spray clean water toward the lower fixed plate and the ground workpiece. The workpiece is fixed in the hole of the supporting plate through the spraying pressure, and the surface of the workpiece is cleaned, thereby avoiding the problem that the workpiece is adsorbed on the upper fixed plate after grinding and falls to the surface of the lower fixed plate when it is lifted into the air, causing fragments; and this embodiment can clean the lower fixed plate in time, thereby extending the service life of the fixed plate.

[0052] like Figure 1-Figure 3 As shown, the double-sided grinding device of this embodiment includes a water purification chamber 1, a stirring chamber 2, a dispersant chamber 3, a grinding powder chamber 4, a weight sensor 5, a pump 6, a pump 7, a flow controller 8, a flow controller 9, a water purification conduit 10, a grinding liquid flow guide pipe 11, a grinding liquid diverter 12, a water purification diversion hole 13, a sun gear 14, a grinding liquid flow guide hole 15, a workpiece bearing plate hole 16, a diverter 17 and a telescopic device 18. In this embodiment, the workpiece to be ground can be specifically a silicon wafer.

[0053] Among them, the stirring chamber 2, the dispersant chamber 3, the grinding powder chamber 4, the weight sensor 5, the pump 7, the flow controller 9, the grinding liquid guide pipe 11, the grinding liquid diverter 12 and the grinding liquid guide hole 15 constitute a grinding liquid supply system. The weight sensor 5 identifies the weight of the material and automatically feeds the material into the stirring chamber 2 for mixing. The grinding liquid guide pipe 11 connects the stirring chamber 2 and the grinding liquid diverter 12. The grinding liquid is controllably transported to the grinding liquid diverter 12 through the pump 7 and the flow controller 9, and then enters the grinding liquid guide hole 15 through the diversion. Figure 3 As shown, the grinding liquid guide holes 15 are arranged in an array on the upper fixed plate.

[0054] In this embodiment, the clean water chamber 1, the pump 6, the flow controller 8, the clean water conduit 10, the diverter 17 and the clean water diversion hole 13 constitute a clean water supply system, wherein the clean water chamber 1 is used to store and provide clean water; the clean water conduit 10 connects the clean water chamber 1 and the clean water diversion hole 13, and can transport clean water from the clean water chamber 1 to the clean water diversion hole 13. In this embodiment, the clean water supply system and the polishing liquid supply system are independent of each other and will not affect the polishing work of the double-sided polishing device.

[0055] In addition, since there are a large number of clean water diversion holes 13 , a diverter 17 is provided at the outlet of the clean water conduit 10 , and the diverter 17 can divert the clean water in the clean water conduit 10 into the plurality of clean water diversion holes 13 .

[0056] In this embodiment, a pump 6 and a flow controller 8 are further provided on the clean water conduit 10 , and the clean water can be controllably transported to the clean water guide hole 13 through the pump 6 and the flow controller 8 .

[0057] In this embodiment, the telescopic device 18 can control the movement of the upper fixed plate 20 , thereby adjusting the distance between the upper fixed plate 20 and the lower fixed plate 21 .

[0058] In this embodiment, in order to ensure that the clean water sprayed from the clean water guide hole 13 can cover the entire upper surface of the lower fixed plate 21, Figure 2 As shown, the angle between the axis of the clean water guide hole 13 and the plane where the upper fixed plate is located can be 40°-60°, such as 40°, 42°, 44°, 45°, 47°, 49°, 50°, 52°, 54°, 55°, 57°, 59° or 60°. In some embodiments, the angle between the axis of the clean water guide hole 13 and the plane where the upper fixed plate 20 is located can be 45°, so that the clean water sprayed from the clean water guide hole 13 can cover the entire upper surface of the lower fixed plate 21, and the workpiece to be ground and the lower fixed plate 21 can be cleaned with less clean water; in addition, it can also facilitate the recovery of clean water.

[0059] In some embodiments, in order to ensure the cleaning effect of the workpiece to be ground and the lower fixed plate 21, and to fix the workpiece to be ground in the hole of the bearing plate, a plurality of circles of clean water diversion holes 13 can be provided on the upper fixed plate 20, and the first end of at least one circle of clean water diversion holes 13 close to the center of the upper fixed plate 20 is inclined toward the direction close to the center of the upper fixed plate, and the first end of at least one circle of clean water diversion holes 13 away from the center of the upper fixed plate 20 is inclined toward the direction away from the center of the upper fixed plate 20, and the first end is the end of the clean water diversion hole 13 away from the lower fixed plate 21, so that the clean water sprayed from the clean water diversion hole 13 can cover the entire upper surface of the lower fixed plate 21, and the workpiece to be ground and the lower fixed plate 21 can be cleaned with less clean water; in addition, the sprayed clean water is concentrated on the surface of the lower fixed plate 21, and will not be sprayed to other areas outside the lower fixed plate 21, so that the clean water can be recovered by providing a clean water recovery container under the lower fixed plate 21, which is conducive to the recovery of clean water.

[0060] The circle of clean water diversion holes mentioned above can be understood as a plurality of clean water diversion holes distributed in an annular shape in the upper fixed plate with the center of the upper fixed plate as the center. In addition, the distribution of the clean water diversion holes does not have to be annular, as long as they can completely cover the lower fixed plate.

[0061] In some embodiments, Figure 1 As shown, the upper fixed plate 20 can be provided with three circles of clean water diversion holes 13, the first end of a circle of clean water diversion holes 13 close to the center of the upper fixed plate 20 is inclined toward the direction close to the center of the upper fixed plate, and the first ends of two circles of clean water diversion holes 13 away from the center of the upper fixed plate 20 are inclined toward the direction away from the center of the upper fixed plate 20.

[0062] In this embodiment, in order to ensure that the spraying pressure of the clean water diversion hole 13 does not damage the surface of the workpiece to be ground, the spraying pressure of the clean water diversion hole 13 can be 1.0-1.5MPa, specifically 1.0MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa or 1.5MPa.

[0063] The embodiment of the present invention further provides a double-sided grinding method, which uses the above-mentioned double-sided grinding device to grind a workpiece to be ground, and the method includes:

[0064] The workpiece to be ground is loaded into the hole of the carrier plate; the relative positions of the upper plate and the lower plate are adjusted so that the upper and lower surfaces of the workpiece to be ground are in contact with the upper plate and the lower plate, respectively; the carrier plate is driven to rotate around its own axis and revolve around the center of the lower plate by a driving mechanism, and the workpiece to be ground is ground under the action of the grinding slurry;

[0065] After grinding the workpiece to be ground, the upper fixed plate is controlled to move away from the lower fixed plate, and at the same time, the clean water diversion hole is controlled to spray clean water toward the lower fixed plate and the workpiece to be ground, so that the workpiece to be ground is fixed in the supporting plate hole through the spraying pressure, and the surface of the workpiece to be ground is cleaned.

[0066] In this embodiment, at least one clean water diversion hole is provided on the side of the upper fixed plate facing the lower fixed plate, which can spray clean water in the direction of the lower fixed plate. In this way, after the workpiece to be ground is ground, the clean water diversion hole can be controlled to spray clean water toward the lower fixed plate and the ground workpiece. The workpiece is fixed in the hole of the supporting plate through the spraying pressure, and the surface of the workpiece is cleaned, thereby avoiding the problem that the workpiece is adsorbed on the upper fixed plate after grinding and falls to the surface of the lower fixed plate when it is lifted into the air, causing fragments; and this embodiment can clean the lower fixed plate in time, thereby extending the service life of the fixed plate.

[0067] In this embodiment, the workpiece to be ground may be a silicon wafer.

[0068] In this embodiment, before the grinding process begins, the clean water supply system of the double-sided grinding device is started, and as the telescopic device 18 moves downward, the distance between the upper fixed plate 20 and the lower fixed plate 21 decreases, and the clean water guide hole 13 is controlled to spray clean water toward the lower fixed plate 21 and the workpiece to be ground, so as to clean the surface of the workpiece to be ground and the upper surface of the lower fixed plate 21; the telescopic device 18 continues to move downward, the clean water supply system is closed, the upper fixed plate 20 contacts the workpiece to be ground, and the grinding liquid supply system of the double-sided grinding device is started, and the workpiece to be ground is ground under the action of the grinding slurry; during the grinding process, the clean water ... When the work is completed, the grinding liquid supply system of the double-sided grinding device is closed, and the clean water supply system of the double-sided grinding device is started again. As the telescopic device 18 moves upward, the distance between the upper fixed plate 20 and the lower fixed plate 21 increases, and the spraying pressure generated by spraying clean water through the clean water guide hole 13 fixes the ground workpiece in the carrier plate hole, thereby avoiding the problem that the ground workpiece is adsorbed on the upper fixed plate and falls to the surface of the lower fixed plate when it is lifted into the air, causing fragments; and this embodiment can clean the ground workpiece, remove the residual grinding particles on the ground workpiece in time, and improve the quality of the workpiece.

[0069] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments, since they are basically similar to the product embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the product embodiments.

[0070] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0071] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” or “under” another element, it can be “directly on” or “under” the other element or intervening elements may be present.

[0072] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0073] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A double-sided grinding device, characterized in that: The double-sided grinding device comprises an upper fixed plate, a lower fixed plate, a bearing plate and a driving mechanism, wherein the upper fixed plate is arranged opposite to the lower fixed plate, the bearing plate is arranged on a side of the lower fixed plate facing the upper fixed plate and comprises a plurality of workpiece bearing plate holes; the driving mechanism can drive the bearing plate to rotate relative to the upper fixed plate and the lower fixed plate; Wherein, the upper fixed plate is provided with at least one clean water guide hole on the surface facing the lower fixed plate, which is used for spraying clean water toward the lower fixed plate.

2. The double-sided grinding device according to claim 1, characterized in that: The device also includes: A water purification room, used to provide purified water; A clean water conduit connecting the clean water chamber and the clean water diversion hole is used to transport clean water from the clean water chamber to the clean water diversion hole.

3. The double-sided grinding device according to claim 2, characterized in that: The device also includes: The flow divider arranged at the outlet of the clean water conduit is used to divide the clean water in the clean water conduit into a plurality of the clean water guide holes.

4. The double-sided grinding device according to claim 2, characterized in that: The device also includes: The flow controller arranged on the clean water conduit is used to control the clean water flow in the clean water conduit.

5. The double-sided grinding device according to claim 1, characterized in that: The angle between the axis of the purified water diversion hole and the plane where the upper fixed plate is located is 40°-60°.

6. The double-sided polishing device according to claim 1, characterized in that: The upper fixed plate is provided with a plurality of circles of clean water diversion holes, the first end of at least one circle of clean water diversion holes close to the center of the upper fixed plate is inclined toward the direction close to the center of the upper fixed plate, and the first end of at least one circle of clean water diversion holes away from the center of the upper fixed plate is inclined toward the direction away from the center of the upper fixed plate, and the first end is the end of the clean water diversion hole away from the lower fixed plate.

7. The double-sided grinding device according to claim 6, characterized in that: The upper fixed plate is provided with three circles of clean water diversion holes, the first end of a circle of clean water diversion holes close to the center of the upper fixed plate is inclined toward the direction close to the center of the upper fixed plate, and the first ends of two circles of clean water diversion holes away from the center of the upper fixed plate are inclined toward the direction away from the center of the upper fixed plate.

8. The double-sided grinding device according to claim 1, characterized in that: The spraying pressure of the clean water diversion hole is 1.0-1.5MPa.

9. A double-sided grinding method, characterized in that: A workpiece to be ground is ground using the double-sided grinding device according to any one of claims 1 to 8, the method comprising: Loading the workpiece to be ground into the hole of the carrier plate; adjusting the relative positions of the upper plate and the lower plate so that the upper and lower surfaces of the workpiece to be ground are in contact with the upper plate and the lower plate, respectively; driving the carrier plate to rotate around its own axis and revolve around the center of the lower plate by the driving mechanism, and grinding the workpiece to be ground under the action of the grinding slurry; After grinding the workpiece to be ground, the upper fixed plate is controlled to move away from the lower fixed plate, and at the same time, the clean water diversion hole is controlled to spray clean water toward the lower fixed plate and the workpiece to be ground, so that the workpiece to be ground is fixed in the supporting plate hole through the spraying pressure, and the surface of the workpiece to be ground is cleaned.

10. The double-sided grinding method according to claim 9, characterized in that: The method further comprises: Before grinding the workpiece to be ground, the clean water guide hole is controlled to spray clean water toward the lower fixed plate and the workpiece to be ground, so as to clean the surface of the workpiece to be ground.

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