CN115810576A

CN115810576A - Double-side processing technology of ultrathin wafer

Info

Publication number: CN115810576A
Application number: CN202211395811.7A
Authority: CN
Inventors: 严立巍; 朱亦峰; 刘文杰; 马晴
Original assignee: Zhejiang Tongxinqi Technology Co ltd
Current assignee: Zhejiang Tongxinqi Technology Co ltd
Priority date: 2022-11-09
Filing date: 2022-11-09
Publication date: 2023-03-17

Abstract

The invention relates to the technical field of wafer processing, in particular to a double-sided processing technology of an ultrathin wafer, which is characterized by comprising the following steps of: s1, bonding an ultrathin wafer on an annular glass carrying disc; s2, uniformly coating polyimide on the ultrathin wafer, and curing to obtain a polyimide layer; s3, cleaning and removing the polyimide layer above the ultrathin wafer, and leaking one surface of the ultrathin wafer; s4, clamping the polyimide layer and the annular glass carrying disc by using a clamping roller, and fixing the ultrathin wafer; and S5, carrying out double-sided processing on the ultrathin wafer to realize double-sided processing operation. According to the double-sided processing technology, the annular glass carrying disc is designed to support and fix the ultrathin wafer, the boundary of the ultrathin wafer is wrapped and protected through the polyimide layer, the ultrathin wafer boundary fracture caused by direct clamping of the clamping roller is avoided, the ultrathin wafer is fixed, double-sided processing is not hindered, and the double-sided processing technology is suitable for being applied to production and processing of the ultrathin wafer.

Description

Double-side processing technology of ultrathin wafer

Technical Field

The invention relates to the technical field of wafer processing, in particular to a double-side processing technology of an ultrathin wafer.

Background

The wafer refers to a silicon wafer used for manufacturing a silicon semiconductor circuit, the raw material is silicon, and an ultra-thin wafer is widely used at present.

In the prior art, the invention with application number of cn201880018073.X, entitled double-side polishing method and double-side polishing apparatus for wafers, is disclosed, wherein flatness difference between wafers obtained by double-side polishing using a plurality of carriers for double-side polishing is suppressed, and the yield based on flatness is improved.

However, in the prior art, for example, in the double-side polishing mentioned in application No. cn201880018073.X, the ultra-thin wafer cannot be protected, and is easily broken and broken by the polishing force during the polishing process, which is not convenient for effectively polishing the ultra-thin wafer.

Disclosure of Invention

The invention aims to provide a double-side processing technology of an ultrathin wafer, which aims to solve the problems in the prior art.

The purpose of the invention can be realized by the following technical scheme:

a double-side processing technology of an ultrathin wafer is characterized by comprising the following steps:

s1, bonding an ultrathin wafer on an annular glass carrying disc;

s2, uniformly coating polyimide on the ultrathin wafer, and curing to obtain a polyimide layer;

s3, cleaning and removing the polyimide layer above the ultrathin wafer, and leaking one surface of the ultrathin wafer;

s4, clamping the polyimide layer and the annular glass carrying disc by using a clamping roller, and fixing the ultrathin wafer;

and S5, carrying out double-sided processing on the ultrathin wafer to realize double-sided processing operation.

Furthermore, an adhesive is annularly coated on the annular glass carrying disc in the step S1, and the annular glass carrying disc is bonded and fixed with the ultrathin wafer through the adhesive.

Further, the ring-shaped glass carrier disc in the S1 is formed by cutting the glass carrier disc through femtosecond laser.

Further, the processing steps of the ring-shaped glass carrying disc in the step S1 are as follows:

s1.1, bonding an ultrathin wafer on the front side of a glass carrying disc, and then coating and etching the back side of the glass carrying disc to obtain an annular light resistor, wherein the light resistor is positioned on the outermost side of the back side of the glass carrying disc;

s1.2, removing the area, which is not coated with the photoresist, in the middle of the glass carrying disc by femtosecond laser cutting to leak the adhesive;

and S1.3, removing the leaked adhesive by bonding, and cleaning the removed adhesive, namely leaking one surface of the ultrathin wafer.

Further, at least three clamping rollers are rotatably arranged on the processing equipment.

Further, the processing equipment processes the leakage surfaces of the ultrathin wafers on the polyimide layer and the annular glass carrying disc and is used for realizing double-surface processing.

The invention has the beneficial effects that:

1. according to the double-sided processing technology, the annular glass carrying disc is designed to support and fix the ultrathin wafer, the boundary of the ultrathin wafer is wrapped and protected through the polyimide layer, and the boundary fracture of the ultrathin wafer caused by direct clamping of the clamping roller is avoided;

2. the double-sided processing technology fixes the ultrathin wafer, does not interfere double-sided processing, has a simple structure and good processing stability, and is suitable for being applied to the production and processing of the ultrathin wafer.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a flow chart of the double-sided process of the present invention;

FIG. 2 is a bottom view of the annular glass carrier plate of the present invention;

FIG. 3 is a flow chart of the double-sided process of the present invention;

FIG. 4 is a top view of the annular glass carrier plate of the present invention;

FIG. 5 is a schematic view of the double-sided processing structure of the present invention;

FIG. 6 is a schematic view of a wafer double-side brushing process according to the present invention;

FIG. 7 is a schematic diagram of a wafer double-side plating process according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A double-side processing technology of an ultrathin wafer comprises the following steps:

as shown in fig. 1 and 2, S1, an annular glass carrier plate 3 is taken, an adhesive 2 is annularly coated on the glass carrier plate 3, and then the cut ultrathin wafer 1 is bonded on the annular glass carrier plate 3.

In this embodiment, the annular glass carrier disk 3 is cut by a femtosecond laser, and a circular cutting groove is formed in the middle of the annular glass carrier disk 3.

And S2, coating polyimide on the annular glass carrying disc 3 bonded with the ultrathin wafer 1, and curing to form a polyimide layer 4 wrapping the ultrathin wafer 1.

And S3, cleaning and removing the polyimide layer 4 above the ultrathin wafer 1 to form a cleaning tank, wherein one surface of the ultrathin wafer 1 is leaked out of the cleaning tank, and the polyimide remained on the edge of the ultrathin wafer 1 protects and fixes the ultrathin wafer 1.

As shown in fig. 3 and 4, S4, the ultra-thin wafer 1 is placed on a processing device 5, movable nip rollers 6 are rotatably disposed on the processing device 5, the number of the nip rollers 6 is at least three, and the nip rollers 6 fix the ultra-thin wafer 1 by adhering the polyimide layer 4 and the annular glass carrier 3.

In this embodiment, four nip rollers 6 are provided, and the surface is made of a flexible material.

And S5, the processing mechanism on the processing equipment 5 carries out double-sided processing on the ultrathin wafer 1 through the cleaning groove on the polyimide layer 4 and the cutting groove in the annular glass carrying disc 3, so that double-sided processing operation is realized.

In this embodiment, the double-side processing includes double-side grinding, double-side polishing, and the like, both sides of the wafer may be simultaneously processed, the double-side processing includes double-side brushing, electroplating, and chemical plating, and the processing mechanism includes a brushing roller.

In this embodiment, the ring-shaped glass carrier plate 3 may be cut in advance for use.

As shown in fig. 5, the cutting process may be performed after the ultra-thin wafer 1 is bonded, and the step of cutting the ring-shaped glass carrier plate 3 in S1 is as follows:

s1.1, bonding the ultrathin wafer 1 on the front side of a glass carrying disc 7, coating a layer of photoresist on the back side of the glass carrying disc 7, etching the photoresist in the middle part to obtain an annular photoresist, wherein the photoresist is positioned on the outermost side of the back side of the glass carrying disc 7.

S1.2, removing the area of the middle of the glass carrying disc 7 which is not coated with the photoresist by femtosecond laser cutting to form an annular glass carrying disc 3, and leaking the adhesive 2.

And S1.3, removing the leaked adhesive 2 by bonding and cleaning the removed adhesive 2, namely, leaking one surface of the ultrathin wafer 1.

The utility model provides a two-sided processing technology of ultra-thin wafer, ultra-thin wafer 1 directly places between the clamp roller 6 on the processing equipment 5, because thickness is thin, leads to 1 easy atress in ultra-thin wafer edge to collapse, utilizes the mode of polyimide coating, wraps up the protection to the edge of ultra-thin wafer 1, realizes the stable processing of ultra-thin wafer 1, presss from both sides 6 surperficial flexible materials that adopt of roller.

However, when the polyimide and the glass carrying disc 7 fix the ultrathin wafer 1, double-sided processing of the ultrathin wafer 1 cannot be realized, the glass carrying disc 7 is cut by laser, the middle part of the glass carrying disc 7 is removed, and the annular glass carrying disc 3 is obtained, so that the bonding surface of the ultrathin wafer 1 leaks out, when the front surface is processed, the back surface can be processed, double-sided processing is realized, and the double-sided processing comprises double-sided brushing, electroplating and chemical plating.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.

Claims

1. A double-side processing technology of an ultrathin wafer is characterized by comprising the following steps:

s1, bonding an ultrathin wafer (1) on an annular glass carrying disc (3);

s2, uniformly coating polyimide on the ultrathin wafer (1), and curing to obtain a polyimide layer (4);

s3, cleaning and removing the polyimide layer (4) above the ultrathin wafer (1) and leaking one surface of the ultrathin wafer (1);

s4, clamping the polyimide layer (4) and the annular glass carrying disc (3) by using a clamping roller (6) with a flexible surface, and fixing the ultrathin wafer (1);

and S5, carrying out double-sided processing on the ultrathin wafer (1) to realize double-sided processing operation.

2. A double-side processing process for an ultra-thin wafer according to claim 1, wherein an adhesive (2) is annularly coated on the annular glass carrier plate (3) in S1, and the annular glass carrier plate (3) is bonded and fixed with the ultra-thin wafer (1) through the adhesive (2).

3. A double-sided process for processing ultra-thin wafers as claimed in claim 1, wherein the ring-shaped glass carrier disk (3) in S1 is formed by femtosecond laser cutting of the glass carrier disk (7).

4. A double-sided process for processing ultra-thin wafers as claimed in claim 3, wherein the processing steps of the ring-shaped glass carrier plate (3) in S1 are as follows:

s1.1, bonding an ultrathin wafer (1) on the front side of a glass carrying disc (7), and then coating and etching the back side of the glass carrying disc (7) to obtain an annular light resistance, wherein the light resistance is positioned on the outermost side of the back side of the glass carrying disc (7);

s1.2, removing the area, which is not coated with the photoresist, in the middle of the glass carrying disc (7) by femtosecond laser cutting to leak the adhesive (2);

s1.3, removing the leaked adhesive (2) through bonding removal, and cleaning the removed adhesive (2), namely, leaking one surface of the ultrathin wafer (1).

5. A double-sided process for processing ultra-thin wafers as claimed in claim 1, wherein at least three of said nip rollers (6) are rotatably disposed on a processing apparatus (5).

6. A double-sided process for processing ultra-thin wafers as claimed in claim 5, wherein the processing equipment (5) processes the polyimide layer (4) and the exposed surface of the ultra-thin wafer (1) on the ring-shaped glass carrier plate (3) for double-sided processing.