A wafer processing method

Abstract

The present invention discloses a wafer processing method, which belongs to the field of wafer processing technology, and includes: providing a wafer; coating photoresist on the upper surface of the wafer; the edge of the upper surface of the wafer has at least one non-glue area, and removing the photoresist located in the non-glue area; allowing the mask to be bonded to the wafer; photolithography processing; and separating the wafer from the mask. By removing the photoresist in the non-glue area, a step difference will be formed on the surface of the wafer, and a gap will exist between the edge of the wafer and the mask. After photolithography, during the separation process of the wafer and the mask, it is easier for external air to enter the bonding interface from the gap, so that the negative pressure at the interface between the wafer and the mask can be released normally, and the wafer and the mask can be separated smoothly.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and in particular to a wafer processing method. Background Art

[0002] In the discrete device manufacturing process, contact exposure machines are still widely used. During the contact photolithography process, the wafer is fixed by the vacuum suction holes on the wafer stage. The wafer and the mask plate after coating with photoresist need to fit tightly. At the end of the photolithography, the wafer and the mask plate are separated by the vacuum suction at the bottom.

[0003] When the wafer and the mask are tightly attached, the air at the interface is squeezed out. When detaching, the wafer deforms slightly and forms a negative pressure at the interface. The wafer is pressed against the mask by the external air pressure and cannot be detached normally.

[0004] A detection method for wafer edge exposure process is disclosed in Chinese patent application number: CN201210063076.X, which provides a test wafer, and sets at least one positioning icon group near the edge of the test wafer surface; coats the test wafer surface with photoresist, and performs wafer edge exposure process; uses a mask to perform full pattern exposure on the photoresist on the test wafer surface; develops the photoresist; determines whether the removal width of the wafer edge photoresist meets the process requirements based on the position relationship between the boundary position of the patterned photoresist and the positioning icon group, and determines whether the exposure intensity of the wafer edge exposure process meets the process requirements based on whether there is residual photoresist outside the boundary of the patterned photoresist. After photolithography, the wafer and the mask cannot be separated smoothly in this technical solution. In view of this, this application is proposed. Summary of the invention

[0005] In order to solve at least one aspect of the technical problems existing in the background technology, the present invention proposes a wafer processing method to effectively solve the above technical problems.

[0006] The present invention provides a wafer processing method, comprising:

[0007] providing a wafer;

[0008] coating a photoresist on the upper surface of the wafer;

[0009] The edge of the upper surface of the wafer has at least one non-glue area, and the photoresist located in the non-glue area is removed;

[0010] Laminating the mask plate with the wafer;

[0011] Photolithography processing;

[0012] The wafer is separated from the mask.

[0013] Preferably, there are a plurality of adhesive-free areas, which are distributed at intervals around the circumference of the wafer.

[0014] Preferably, the glue-free area extends from the edge to the middle of the wafer.

[0015] Preferably, the width of the glue-free area along the radial direction of the wafer is 1-3 mm.

[0016] Preferably, the photoresist located in the resist-free area is removed by using a resist remover.

[0017] Preferably, the debonding agent is acetone.

[0018] The beneficial effects brought about by one aspect of the present invention are:

[0019] By removing the photoresist in the non-resist area, a step difference will be formed on the wafer surface, and there will be a gap between the edge of the wafer and the mask. After photolithography, during the separation process of the wafer and the mask, the outside air can easily enter the bonding interface from the gap, so that the negative pressure at the interface between the wafer and the mask can be released normally, and the wafer and the mask can be separated smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A top view of the wafer disclosed in the present invention;

[0021] Figure 2 The present invention is disclosed in the flowchart. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other; the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left" and "right" indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the positions or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations 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.

[0024] Reference Figure 1, 2 The present invention provides a wafer processing method, comprising:

[0025] A wafer 1 is provided; and a photoresist 2 is coated on the upper surface of the wafer 1 .

[0026] The edge of the upper surface of the wafer 1 has at least one non-resist area 101 , and the photoresist 2 located in the non-resist area 101 is removed.

[0027] The mask plate is bonded to the wafer 1; photolithography is performed; and the wafer 1 is separated from the mask plate.

[0028] In this embodiment, by removing the photoresist 2 in the non-resist area 101, a step difference is formed on the surface of the wafer 1, and a gap is formed between the edge of the wafer 1 and the mask. After photolithography, during the separation process of the wafer 1 and the mask, the outside air can easily enter the bonding interface from the gap, so that the negative pressure at the interface between the wafer 1 and the mask can be released normally, and the wafer 1 and the mask can be separated smoothly.

[0029] Furthermore, the number of the adhesive-free areas 101 is multiple and is spaced around the circumference of the wafer 1. This facilitates the release of negative pressure at the interface between the wafer 1 and the mask, and facilitates the separation of the wafer 1 from the mask. There is no limit to the number of adhesive-free areas 101, which can be 2, symmetrically arranged, or more, as long as it does not affect normal photolithography processing.

[0030] Furthermore, the adhesive-free area 101 extends from the edge to the middle of the wafer 1, so as to facilitate the release of negative pressure at the interface between the wafer 1 and the mask.

[0031] Furthermore, the width of the non-resist area 101 along the radial direction of the wafer 1 is 1-3 mm, which does not affect the photoresist 2 in the middle area. The shape of the non-resist area 101 is not limited and can be regular or irregular.

[0032] Further, the photoresist 2 located in the non-resist area 101 is removed by using a debonding agent. Further, the debonding agent is acetone. After the photoresist 2 is coated on the wafer 1, a portion of the photoresist 2 can be wiped off along the edge of the wafer 1 by using acetone to form a non-resist area 101 on the surface of the wafer 1. This facilitates the separation of the photolithography wafer 1 from the mask.

[0033] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A wafer processing method, characterized in that: include: providing a wafer; coating a photoresist on the upper surface of the wafer; The edge of the upper surface of the wafer has at least one non-resist area, and the photoresist located in the non-resist area is removed, so that a step difference is formed on the surface of the wafer, and there is a gap between the edge of the wafer and the mask; Laminating the mask plate with the wafer; Photolithography processing; separating the wafer from the mask; There are a plurality of adhesive-free areas, which are distributed at intervals around the circumference of the wafer; The glue-free area extends from the edge to the middle of the wafer; Among them, after photolithography, during the separation process of the wafer and the mask, external air can enter the bonding interface from the gap, so that the negative pressure at the interface between the wafer and the mask can be released normally, and the wafer and the mask are separated.

2. The wafer processing method according to claim 1, characterized in that: The width of the non-glue area along the radial direction of the wafer is 1-3 mm.

3. The wafer processing method according to claim 2, characterized in that: The photoresist in the resist-free area is removed by using a resist remover.

4. The wafer processing method according to claim 3, characterized in that: The debonding agent is acetone.

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