CN-121989160-A - Wafer adsorption pad and manufacturing method thereof

CN121989160ACN 121989160 ACN121989160 ACN 121989160ACN-121989160-A

Abstract

The application provides a wafer suction pad and a method for manufacturing the same, which can prevent damage to a wafer and can position the wafer relative to a holding table with high precision. The silicon wafer (20) is further inclined by the silicon wafer (20) when the silicon wafer (20) is adsorbed on the mounting surface (12) due to the negative pressure of the air passage (13), while the plurality of raised portions (15) are each inclined in a predetermined direction (inclination direction (HD)) so that the center portion (third center axis (CA 3)) of the silicon wafer (20) does not deviate from the center portion (second center axis (CA 2)) of the mounting surface (12). This prevents the silicon wafer (20) from being damaged, and enables the silicon wafer (20) to be positioned with high accuracy relative to the holding table.

Inventors

KAWAHARA RYUNOSUKE
HIROYUKI ITOH

Assignees

日本金明积木式系统股份公司

Dates

Publication Date: 20260508
Application Date: 20251104
Priority Date: 20241105

Claims (3)

1. A wafer adsorption pad which is provided between a wafer and a holding table of a polishing device for polishing an outer edge of the wafer, the wafer adsorption pad comprising: a mounting surface mounted on the holding base; A mounting surface for placing the wafer; An air passage for communicating the mounting surface with the mounting surface; A plurality of void portions, the void portions being closed at the mounting surface side and open at the mounting surface side, and The plurality of protrusions are inclined in advance in a predetermined direction so that the center portion of the wafer does not deviate from the center portion of the mounting surface, and are further inclined by the wafer when the wafer is sucked to the mounting surface due to the negative pressure of the air passage.
2. The wafer suction pad of claim 1, wherein, The plurality of protruding portions are inclined in advance so that distal ends of the plurality of protruding portions face one side in the circumferential direction of the mounting surface with a center portion of the mounting surface as a center.
3. A method for manufacturing a wafer adsorption pad, which is provided between a wafer and a holding table of a polishing device and is made of an elastic material, wherein the polishing device polishes the outer edge of the wafer, the method comprising: a cutting step of cutting a round pad from a sheet having a plurality of void portions; a polishing step of polishing a side of the pad on which the wafer is placed to open the plurality of void portions, and An air passage forming step of forming an air passage penetrating the mat in a thickness direction of the mat, In the polishing step, while rotating the pad around the center of the pad, a polishing tool is pressed against the pad on the side on which the wafer is placed, and the plurality of protrusions formed on the pad on the side on which the wafer is placed are inclined in advance so that the tip ends of the plurality of protrusions face the pad on the circumferential direction side around the center of the pad.

Description

Wafer adsorption pad and manufacturing method thereof Technical Field The invention relates to a wafer adsorption pad and a manufacturing method thereof. Background For example, patent document 1 describes a polishing apparatus for polishing the outer edge of a semiconductor wafer as a workpiece. The polishing apparatus described in patent document 1 includes a work holding table for holding a work by suction under negative pressure, and a rotary head which rotates relative to the work holding table and has a polishing tool. Patent document 1 Japanese patent laid-open No. 2009-297842 In the technique described in patent document 1, a workpiece is directly placed on a workpiece holding table. Thus, there is a risk of damaging the workpiece. If the buffer material is disposed only between the workpiece and the workpiece holding table so as not to damage the workpiece, the center of the workpiece is shifted from the center of the workpiece holding table in accordance with the deformation of the buffer material when the workpiece is sucked. Therefore, the positional accuracy of the workpiece with respect to the workpiece holding table is lowered. Disclosure of Invention The invention provides a wafer adsorption pad capable of preventing damage to a wafer and positioning the wafer relative to a holding table with high precision. In one aspect of the wafer suction pad, the wafer suction pad is provided between a wafer and a holding table of a polishing device, and is made of an elastic material, the polishing device polishes an outer edge of the wafer, the wafer suction pad includes a mounting surface mounted on the holding table, a mounting surface on which the wafer is placed, an air passage that communicates the mounting surface with the mounting surface, a plurality of void portions that are closed at the mounting surface side and open at the mounting surface side, and a plurality of protrusions that are inclined in advance in a predetermined direction so that a center portion of the wafer does not deviate from the center portion of the mounting surface, and that are further inclined by the wafer when the wafer is sucked to the mounting surface due to a negative pressure of the air passage. In one aspect of the method for manufacturing a wafer suction pad, the wafer suction pad is provided between a wafer and a holding table of a polishing device, and is made of an elastic material, the polishing device polishes an outer edge of the wafer, the method for manufacturing a wafer suction pad includes a cutting step of cutting a round pad from a sheet having a plurality of void portions, a polishing step of polishing a side of the pad where the wafer is placed so as to open the plurality of void portions, and an air passage forming step of forming an air passage penetrating the pad in a thickness direction of the pad, wherein in the polishing step, a polishing tool is pressed to the side of the pad where the wafer is placed while rotating the pad around a center portion of the pad, and a plurality of protruding portions formed on the side of the pad where the wafer is placed are inclined in advance so that front end portions of the plurality of protruding portions face one side of the circumferential direction of the pad with the center portion of the pad as a center. Effects of the invention According to the present invention, a wafer suction pad capable of preventing damage to a wafer and accurately positioning the wafer with respect to a holding table can be realized. Drawings Fig. 1 is a view showing an application example of a wafer suction pad to a polishing apparatus. Fig. 2 is a diagram showing details of the wafer suction pad. Fig. 3 is a diagram illustrating positioning accuracy of the wafer suction pad according to an embodiment of the present invention. Fig. 4 is a flowchart showing a process of manufacturing the wafer suction pad. Fig. 5 is a diagram illustrating the "cutting step". Fig. 6 is a diagram illustrating the [ polishing step ]. Fig. 7 is an enlarged image showing a cross section of the pad before grinding. Fig. 8 is an enlarged image showing a cross section of the pad after grinding. Fig. 9 is a diagram illustrating [ an air passage forming step ]. Fig. 10 is a diagram illustrating the positioning accuracy of the wafer suction pad of the comparative example. Fig. 11 is a diagram illustrating a [ polishing step ] of a wafer suction pad according to a modification. Description of the reference numerals 10, Wafer suction pad, 11, mounting surface, 12, mounting surface, 13, air passage, 14, void, 15, raised portion (protrusion), 20, silicon wafer (wafer), 30, polishing device, 31, holding table, 52, square sheet (sheet), 55, rotary polishing tool (polishing tool), 200, wafer suction pad, 201, raised portion (protrusion), 250, rotary polishing tool (polishing tool), CA2, second center axis (center portion of mounting surface), CA3, third center axis (center portion of wafer), HD, oblique directi