TWI832517B - Grinding device, grinding method and silicon wafer - Google Patents

Abstract

Embodiments of the present invention disclose a grinding device, a grinding method and a silicon wafer; the grinding device is used to double-side grind the silicon wafer, and the grinding device includes: two static pressure supports disposed oppositely on both sides of the silicon wafer, The two static pressure supports are used to support the silicon wafer in a non-contact manner by providing hydrostatic pressure; the two grinding wheels are arranged oppositely, and the two grinding wheels are used to grind the two main surfaces of the silicon wafer respectively; Wherein, the grinding device further includes: a pad disposed on a surface of one of the two static pressure supports facing the silicon wafer, the pad is used to prevent the one static pressure support from facing the silicon wafer. The surface of the sheet is contaminated; a cleaning module is used to clean the liner.

Description

Grinding device, grinding method and silicon wafer

The invention belongs to the field of semiconductor production technology, and particularly relates to grinding devices, grinding methods and silicon wafers.

In the semiconductor processing process, the drawn silicon rod needs to be cut into silicon flakes through a cutting step. The thickness of the silicon flakes obtained through the cutting step is usually set to leave a processing allowance for subsequent steps. In order to remove the mechanical damage caused by the cutting tools and mortar to the surface of the silicon wafer during the cutting process, and to achieve the purpose of subsequent effective thinning of the silicon wafer and control of surface flatness, a double-sided grinding process is required, that is, a grinding wheel made of, for example, diamond The surface of the silicon wafer is ground in equal proportions to remove the surface damage layer and thin the silicon wafer.

Double-sided grinding equipment mainly uses two grinding methods: horizontal grinding and vertical grinding. Among them, in double-sided grinding equipment using horizontal grinding, the silicon wafer is placed horizontally on a highly flat grinding table, and the grinding wheel automatically After grinding one side, the silicon wafer is turned over to grind the other side; in the double-sided grinding equipment that adopts vertical grinding method, the silicon wafer is supported by the overload material ring and stands upright on the double-sided grinding equipment. In the grinding machine, two grinding wheels are arranged on both sides of the silicon sheet in opposite directions, so that both sides of the silicon sheet can be ground simultaneously by feeding from both sides.

At present, for double-sided grinding equipment that uses vertical grinding, the surface of the static pressure support will be contaminated during the grinding process, causing impurities such as grinding wheel debris, silicon powder particles, etc. to be attached to the surface of the static pressure support. Therefore, when the static pressure support is When the surface of the component comes into contact with the surface of the silicon wafer, it will cause damage to the surface of the silicon wafer and affect the surface quality of the silicon wafer.

In order to solve the above technical problems, embodiments of the present invention are expected to provide a grinding device, a grinding method and a silicon wafer.

The technical solution of the present invention is implemented as follows: In a first aspect, embodiments of the present invention provide a grinding device for double-sided grinding of silicon wafers. The grinding device includes: Two static pressure supports disposed oppositely on both sides of the silicon chip, the two static pressure supports being used to support the silicon chip in a non-contact manner by providing hydrostatic pressure; Two grinding wheels arranged opposite each other, the two grinding wheels are respectively used to grind the two main surfaces of the silicon wafer; in, The grinding device also includes: A liner disposed on the surface of one of the two static pressure supports facing the silicon wafer, the liner is used to prevent the surface of the one static pressure support member facing the silicon wafer from being contaminated; A cleaning module is used to clean the liner.

In a second aspect, an embodiment of the present invention provides a grinding method. The grinding method is performed by using the grinding device according to the first aspect. The grinding method includes: The silicon chip is supported in a non-contact manner by providing hydrostatic pressure to two static pressure supports disposed on both sides of the silicon chip; The two main surfaces of the silicon chip are ground respectively by two opposite grinding wheels; Clean the liner provided on one of the two static pressure supports through the cleaning module; Place one main surface of the silicon wafer against the cleaned static pressure support and support the silicon wafer through the negative pressure provided by the static pressure support, so that the robot can reach the other main surface of the silicon wafer. vacuum adsorption to pick up the silicon wafer.

In a third aspect, embodiments of the present invention provide a silicon wafer manufactured by using the grinding device according to the first aspect.

Embodiments of the present invention provide a grinding device, a grinding method and a silicon wafer; the grinding device includes a liner disposed on a surface of a static pressure support facing the silicon wafer, and a cleaning module for cleaning the liner. For the static pressure support with a liner on the surface, the impurities generated during the grinding process, such as grinding wheel debris, silicon powder particles, etc., only come into contact with the liner and will not directly contaminate the static pressure support, and the contaminated The liner can be cleaned by the cleaning module. Therefore, when the negative pressure is provided through the first static pressure support member to support the silicon wafer to facilitate the robot to pick up the silicon wafer, the impact of impurities generated during the previous process on the silicon wafer is avoided. Damage is caused to the surface, improving the quality of the final silicon wafer.

In order to help the review committee understand the technical features, content and advantages of the present invention and the effects it can achieve, the present invention is described in detail below in the form of embodiments with the accompanying drawings and attachments, and the drawings used therein are , its purpose is only for illustration and auxiliary description, and may not represent the actual proportions and precise configurations after implementation of the present invention. Therefore, the proportions and configuration relationships of the attached drawings should not be interpreted or limited to the actual implementation of the present invention. The scope shall be stated first.

In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical" The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description. , rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, features defined as “first” and “second” may explicitly or implicitly include one or more of the described features. In the description of the embodiments of the present invention, "plurality" means two or more than two, unless otherwise explicitly and specifically limited.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Referring to Figures 1 and 2, Figures 1 and 2 show a conventional grinding equipment 1. The grinding equipment 1 includes a carrier ring 11 for carrying the silicon wafer S, a first static pressure support 12, a second static pressure support Part 13, the first grinding wheel 14 and the second grinding wheel 15. During the grinding process of the silicon wafer S, the robot R adsorbs the silicon wafer S and loads it into the loading ring 11 of the grinding equipment 1. It is located in the loading ring 11 The first static pressure support 12 and the second static pressure support 13 on the left and right sides are close to the silicon chip S, and then the first grinding wheel 14 and the second grinding wheel 15 on the left and right sides of the carrier ring 11 are respectively The silicon wafer S is double-sided grounded through the through holes in the first static pressure support member 12 and the second static pressure support member 13. After the grinding is completed, the first static pressure support member 12 absorbs the ground silicon wafer S through vacuum. One main surface of the silicon chip S is kept in a vertical position, and the robot R extends into the grinding equipment 1 from above and absorbs the other main surface of the silicon chip S by pressing the silicon chip S against the first static pressure support 12, and then The first static pressure support member 12 releases the vacuum pressure, and the robot R breaks away from the first static pressure support member 12 to take out the silicon wafer S vertically. However, during the grinding process, due to the high-speed rotation of the grinding wheel, grinding wheel debris, silicon powder particles, etc. will splash with the grinding fluid on the static pressure support. Therefore, during the adsorption process of the silicon wafer S by the first static pressure support 12 , when the first static pressure support member 12 is in contact with the silicon chip S, the wheel debris, silicon powder particles, etc. existing on the surface of the first static pressure support member 12 facing the silicon chip may cause damage to the surface of the silicon chip S. Cause damage and affect the surface quality of the silicon wafer.

In order to solve the above problem, referring to Figure 3, an embodiment of the present invention provides a grinding device 10, which is used to double-side grind the silicon wafer S. The grinding device 10 includes: two sides of the silicon wafer S arranged oppositely Two static pressure supports (i.e., the first static pressure support 12 and the second static pressure support 13) on the side are used to support the silicon wafer S in a non-contact manner by providing hydrostatic pressure. ; Two grinding wheels (i.e., the first grinding wheel 14 and the second grinding wheel 15) arranged oppositely are used for the two main surfaces of the silicon sheet S (i.e., the first main surface S1 and the second main surface). S2) Grinding; wherein, the grinding device 10 also includes: a pad 16 disposed on the surface of one of the two static pressure supports facing the silicon wafer, the pad 16 is used to prevent the The surface of a static pressure support facing the silicon wafer is contaminated; the cleaning module 17 is used to clean the liner 16 .

Specifically, referring to FIG. 3 , the grinding device 10 includes a first static pressure support 12 , a second static pressure support 13 , a first grinding wheel 14 and a second grinding wheel 15 . The first static pressure support 12 and the first grinding wheel 14 The first main surface S1 of the silicon chip S is disposed, and the second static pressure support member 13 and the second grinding wheel 15 are disposed facing the second main surface S2 of the silicon chip S, wherein the first static pressure support member 12 faces the silicon chip. A liner 16 is provided on the surface of S. When the grinding device 10 is working, two static pressure supports provide hydrostatic pressure to the silicon wafer S to support the silicon wafer S. At the same time, the two grinding wheels press the silicon wafer S respectively. The two main surfaces of S are ground. Due to the existence of the liner, the grinding wheel debris, silicon powder particles, grinding fluid splashed with the rotation of the grinding wheel, etc. generated during the grinding process are blocked from the surface of the first static pressure support 12 The surface of the silicon wafer is in direct contact. After the grinding wheel completes the grinding operation and stops rotating, the cleaning module 17 can clean the liner 16 so that when the first static pressure support member 12 provides negative pressure to support the silicon wafer, it is convenient for the robot to pick up. When removing silicon wafers, it will not cause damage to the surface of the silicon wafers.

The embodiment of the present invention provides a grinding device 10; the grinding device 10 includes a pad 16 disposed on a surface of a static pressure support facing the silicon wafer S, and a cleaning module 17 for cleaning the pad 16, For the static pressure support with a liner 16 on the surface, impurities generated during the grinding process such as grinding wheel debris, silicon powder particles, etc. and the grinding fluid only come into contact with the liner 16 and will not directly contaminate the static pressure support. parts, and the contaminated liner 16 can be cleaned by the cleaning module 17, thereby, when the negative pressure is provided through the first static pressure support member 12 to support the silicon wafer to facilitate the robot R to pick up the silicon wafer S, the execution of the silicon wafer S is avoided. The impurities generated in the previous process cause damage to the surface of the silicon wafer S, thereby improving the quality of the finally obtained silicon wafer.

The liner 16 may, for example, be formed in the form of a soft film and be adhered to the surface of the hydrostatic support by, for example, adhesive means, in which case the liner 16 may optionally be configured to be capable of being removed by the cleaning module 17 Remove the static pressure support from the one. Specifically, referring to FIG. 3 , the cleaning module 17 can peel off the liner 16 as a whole from the static pressure support by clamping a part of the liner 16 , that is, cleaning the liner 16 from the static pressure support, which is also equivalent to In order to remove various impurities from the static pressure support, the surface of the static pressure support without the liner will not carry any impurities, so it can be ensured that no contamination will be caused to the surface of the silicon wafer where it is connected. When it is time to perform the next grinding operation, a clean pad 16 can be re-attached to the hydrostatic support, and the process is repeated.

In the above case, by way of illustration and not limitation, the material of the pad includes polyethylene polypropylene.

Alternatively, the liner 16 may also be configured to be reusable. In this case, optionally, referring to FIG. 4 , the cleaning module 17 is configured to clean the liner 16 by spraying a cleaning liquid onto the liner 16 . Pad 16, in this case, there is no need to completely clean the pad 16 after each round of grinding operation. Instead, the contaminated surface of the pad 16 can be cleaned by spraying cleaning fluid through the cleaning module 17. To clean the liner 16, not only the material cost can be reduced, but also the operating time can be saved and the production efficiency can be improved.

In order to facilitate the cleaning module 17 to clean the pad 16, optionally, the pad 16 is made of hydrophobic material and the cleaning liquid includes an abrasive liquid, whereby the cleaning liquid sprayed on the pad can carry The impurities on the pad quickly flow away from the pad by gravity. In addition, abrasive fluid can be used as a cleaning fluid. This not only simplifies the structure of the equipment and reduces the cost of modification, but also avoids other problems when the abrasive fluid is recycled. Substances mixed into the grinding fluid cause contamination of the grinding fluid.

In the above case, by way of illustration and not limitation, the material of the gasket includes polytetrafluoroethylene.

For a silicon wafer, the two main surfaces are the front and the back. Usually there are higher requirements for various parameters on the front of the silicon wafer. Therefore, optionally, the static pressure support member is connected to the back of the silicon wafer. Relative static pressure support, that is to say, when the silicon wafer is picked up by the robot, the back side of the silicon wafer will be in contact with the static pressure support, and the robot will vacuum the front of the silicon wafer, which can further ensure that the silicon wafer is The quality of the front side of the film.

According to an optional embodiment of the present invention, the two static pressure supports (ie, the first static pressure support 12 and the second static pressure support 13 ) both include static pressure holes formed on the surface facing the silicon chip S. , the static pressure hole is used to provide the static pressure, and the gasket is formed with a through hole corresponding to the static pressure hole, so that when the gasket is disposed on the one static pressure support member, the one static pressure support member The hydrostatic pressure can be provided via the static pressure hole and the through hole.

Specifically, referring to FIG. 5 , the first static pressure support member 12 is formed with a plurality of static pressure holes 121 , the second static pressure support member 13 is formed with a plurality of static pressure holes 131 , and the gasket 16 is disposed on the first static pressure support member. 12, and the gasket 16 is formed with a plurality of through holes 161, the number of the through holes 161 is the same as the number of the static pressure holes 121 and the diameter is greater than or equal to the diameter of the static pressure holes 121, the through holes 161 are arranged on the gasket 16 such that When the gasket 16 is disposed on the first static pressure support 12 , the static pressure hole 121 communicates with the through hole 161 , so that fluid can flow out from the static pressure hole 121 through the through hole 161 to provide hydrostatic pressure, so that even if the gasket 16 Covering the entire surface of the static pressure support member 12 still does not affect the hydrostatic pressure provided by the static pressure support member.

Referring to Figure 6, an embodiment of the present invention also provides a grinding method. The grinding method is performed by using the grinding device 10 described above. The grinding method includes: S01: Support the silicon wafer in a non-contact manner by providing hydrostatic pressure to two static pressure supports arranged on both sides of the silicon wafer; S02: Grind the two main surfaces of the silicon wafer through two opposite grinding wheels; S03: Use the cleaning module to clean the liner provided on one of the two static pressure supports; S04: Place one main surface of the silicon wafer against the cleaned static pressure support and support the silicon wafer through the negative pressure provided by the static pressure support, so that the robot can perform another operation on the silicon wafer. Vacuum adsorption on the main surface to pick up the silicon wafer.

Embodiments of the present invention also provide a silicon wafer, which is manufactured by using the above-described grinding device. Since the grinding device avoids the surface of the ground silicon wafer from being contaminated by the static pressure support, compared with Conventional technology can improve the quality of silicon wafers, especially the surface of silicon wafers.

It should be noted that the technical solutions recorded in the embodiments of the present invention can be combined arbitrarily as long as there is no conflict.

The above are only preferred embodiments of the present invention and are not intended to limit the implementation scope of the present invention. If the present invention is modified or equivalently substituted without departing from the spirit and scope of the present invention, the protection shall be covered by the patent scope of the present invention. within the range.

1:Grinding equipment 10:Grinding device 11:Carrying ring 12: First static pressure support 121:Static pressure hole 13:Second static pressure support 131:Static pressure hole 14:First grinding wheel 15:Second grinding wheel 16:Padding 161:Through hole 17: Clean up the module S: Silicon chip S1: first main surface S2: Second main surface R: manipulator S01-S04: Steps

Figure 1 shows a schematic diagram of a conventional grinding equipment; Figure 2 shows another schematic diagram of a conventional grinding apparatus; Figure 3 shows a schematic diagram of the grinding equipment provided by an embodiment of the present invention; Figure 4 shows a schematic diagram of a grinding equipment provided by another embodiment of the present invention; Figure 5 shows a schematic diagram of a grinding equipment provided by yet another embodiment of the present invention; Figure 6 shows a flow chart of a grinding method provided by an embodiment of the present invention.

10:Grinding device

12: First static pressure support

13:Second static pressure support

14:First grinding wheel

15:Second grinding wheel

16:Padding

17: Clean up the module

S: Silicon chip

S1: first main surface

S2: Second main surface

R: manipulator

Claims (10)

A grinding device used for double-sided grinding of silicon wafers. The grinding device includes: two static pressure support members disposed oppositely on both sides of the silicon wafer. The two static pressure support members are used to provide The hydrostatic pressure supports the silicon wafer in a non-contact manner; two opposite grinding wheels are used to grind the two main surfaces of the silicon wafer respectively; the grinding device also includes: disposed on the two A liner on a surface of one of the static pressure supports facing the silicon wafer, the liner is used to prevent the surface of the one static pressure support member facing the silicon wafer from being contaminated; a cleaning module, the cleaning module Group is used to clean this liner. The grinding device of claim 1, wherein the pad is configured to be removable from the one static pressure support by the cleaning module. The grinding device according to claim 2, wherein the material of the pad includes polyethylene polypropylene. The grinding device of claim 1, wherein the cleaning module is configured to clean the liner by spraying cleaning liquid onto the liner. The grinding device of claim 4, wherein the pad is made of hydrophobic material and the cleaning liquid includes abrasive liquid. The grinding device according to claim 5, wherein the material of the pad includes polytetrafluoroethylene. The grinding device according to any one of claims 1 to 6, wherein the one static pressure support member is a static pressure support member opposite to the back side of the silicon chip. The grinding device according to any one of claims 1 to 6, wherein the two static pressure supports each include a static pressure hole formed on a surface facing the silicon wafer, the static pressure hole is used to provide static pressure , and the gasket is formed with a through hole corresponding to the static pressure hole, so that when the gasket is disposed on the one static pressure support member, the one static pressure support member can provide water through the static pressure hole and the through hole The hydrostatic pressure. A grinding method, the grinding method is performed by using a grinding device according to any one of claims 1 to 8, the grinding method includes: providing two static pressure supports disposed on both sides of the silicon wafer by opposing The hydrostatic pressure supports the silicon wafer in a non-contact manner; the two main surfaces of the silicon wafer are ground by two opposite grinding wheels; the cleaning module is used to clean one of the two static pressure supports. Press the liner on the support member for cleaning; place one main surface of the silicon wafer against the static pressure support member that has been cleaned by the cleaning module and support the silicon wafer through the negative pressure provided by the static pressure support member, so that The manipulator can realize vacuum adsorption on the other main surface of the silicon wafer to pick up the silicon wafer. A silicon wafer produced by using a grinding device according to any one of claims 1 to 8.

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