阅读说明：本技术 一种先晶粒切割后双面电镀的晶粒生产方法 (Method for producing crystal grains by cutting crystal grains first and then electroplating on two sides ) 是由 严立巍 李景贤 陈政勋 于 2020-03-27 设计创作，主要内容包括：本发明公开一种先晶粒切割后双面电镀的晶粒生产方法,晶粒生产方法包括以下步骤：S1：晶圆键合,晶圆的正面完成金属垫工艺后,在晶圆上形成金属层,将晶圆的正面通过粘合剂键合在环形玻璃载板上；S2：减薄、S3：中间工艺、S4：背面切割、S5：蚀刻工艺、S6：粘合剂去除,采用氧气电浆蚀刻晶粒上的粘合剂,在粘合剂上形成凹槽使金属层露出；S7：电镀,对晶粒的双面进行电镀；S8：解键合,通过解键合将晶粒从玻璃载板上脱离。本发明双面电镀的晶粒生产方法通过中空的玻璃载板对晶粒双面电镀一次完成,取代传统的双面分布电镀的方式,提高了晶圆的生产效率,有利于降低晶圆的生产成本。(The invention discloses a method for producing crystal grains by cutting crystal grains firstly and then electroplating on two sides, which comprises the following steps: s1: bonding the wafer, forming a metal layer on the wafer after the front surface of the wafer is subjected to a metal pad process, and bonding the front surface of the wafer on the annular glass carrier plate through an adhesive; s2: thinning, S3: intermediate process, S4: back side cutting, S5: etching process, S6: removing the adhesive, etching the adhesive on the crystal grains by adopting oxygen plasma, and forming a groove on the adhesive to expose the metal layer; s7: electroplating, wherein the two sides of the crystal grain are electroplated; s8: and (5) bonding, and separating the crystal grains from the glass carrier plate through bonding. The crystal grain production method of double-sided electroplating completes double-sided electroplating of the crystal grains at one time through the hollow glass carrier plate, replaces the traditional double-sided distribution electroplating mode, improves the production efficiency of the wafer, and is beneficial to reducing the production cost of the wafer.)

1. A method for producing crystal grains by cutting crystal grains and then electroplating on two sides is characterized by comprising the following steps:

s1: wafer bonding

After the front surface of the wafer (1) is subjected to a metal pad process, forming a metal layer (2) on the wafer (1), and bonding the front surface of the wafer (1) on an annular glass carrier plate (3) through an adhesive (4);

s2: thinning

Thinning the back of the wafer (1);

s3: intermediate process

Performing yellow light, ion injection, dry ash removal, wet stripping and back metal sputtering/evaporation on the back of the wafer (1);

s4: back side cutting

Cutting the back surface of the wafer (1), and forming a crystal grain (5) after the wafer (1) is cut;

s5: etching process

Performing a yellow light process, etching the opposite surface of the glass carrier plate (3) on which the crystal grains (5) are fixed by hydrofluoric acid, forming through holes (6) on the glass carrier plate (3), wherein the through holes (6) are opposite to the crystal grains (5), so that the glass carrier plate (3) becomes a glass carrier plate with a window opened in the middle;

s6: adhesive removal

Etching the adhesive (4) on the crystal grain (5) by adopting oxygen plasma, and forming a groove (7) on the adhesive (4) to expose the metal layer (2);

s7: electroplating of

Electroplating the two sides of the crystal grain (5);

s8: debonding

The crystal grains (5) are separated from the glass carrier plate (3) through bonding.

2. The die cutting-before-double-sided electroplating die production method as claimed in claim 1, wherein the adhesive (4) in S1 bonds the wafer (1) and the glass carrier (3) together by UV bonding/thermal bonding.

3. The method for die cutting followed by double-sided electroplating according to claim 1, wherein the thinning in S2 is etching/grinding.

4. The method for producing a die by die cutting followed by double-sided electroplating according to claim 1, wherein the cutting method in S4 is diamond cutting/laser cutting/plasma cutting.

5. The method of claim 1, wherein said step of S8 is performed by laser debonding.

Technical Field

The invention relates to a crystal grain production method, in particular to a crystal grain production method of firstly cutting crystal grains and then electroplating on two sides.

Background

The production process of the power semiconductor and the optical device comprises the steps of firstly completing etching on the front side of a wafer, bonding the wafer on a glass carrier plate after a metal deposition process, and carrying out back side thinning, yellow light process and back side metal deposition process. The carrier plate is glass with the thickness of 400-700 microns, and the front surface of the wafer cannot be subjected to the yellow light etching, electroplating and other processes, so that the yellow light etching, electroplating and other processes are performed in a grading manner.

At present, in the wafer manufacturing process, the steps of electroplating and cutting are carried out firstly, and double-sided electroplating is carried out step by step, the electroplated metal is noble metal, the cost is higher, an electroplated layer is formed on the surface of the wafer after electroplating, and then cutting is carried out, so that the wafer is easily damaged, the waste of the noble metal is caused, the yield of crystal grains is influenced, electroplating equipment is expensive, and the double-sided electroplating is carried out step by step, so that the production cost of the crystal grains is increased.

Disclosure of Invention

The invention aims to provide a method for producing crystal grains by cutting the crystal grains firstly and then electroplating two sides, wherein the electroplating on two sides of the crystal grains is completed at one time through a hollow glass carrier plate, so that the traditional double-side distribution electroplating mode is replaced, the production efficiency of a wafer is improved, and the production cost of the wafer is favorably reduced; the cutting is carried out firstly and then the electroplating is carried out, so that the damage of noble metal is reduced, and the yield of crystal grains is improved.

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

a method for producing crystal grains by cutting crystal grains and then electroplating on two sides comprises the following steps:

s1: wafer bonding

And after the front surface of the wafer is subjected to the metal pad process, forming a metal layer on the wafer, and bonding the front surface of the wafer on the annular glass carrier plate through an adhesive.

S2: thinning

And thinning the back of the wafer.

S3: intermediate process

And carrying out yellow light, ion implantation, dry ash removal, wet stripping and back metal sputtering/evaporation on the back of the wafer.

S4: back side cutting

And cutting the back surface of the wafer to form a crystal grain after the wafer is cut.

S5: etching process

And performing a yellow light process, etching the opposite surface of the glass carrier plate on which the crystal grains are fixed by using hydrofluoric acid, forming a through hole on the glass carrier plate, wherein the through hole is opposite to the crystal grains, so that the glass carrier plate is changed into a glass carrier plate with a window in the middle.

S6: adhesive removal

Etching the adhesive on the die with oxygen plasma to form a recess in the adhesive to expose the metal layer.

S7: electroplating of

Electroplating the two sides of the crystal grain.

S8: debonding

And separating the crystal grains from the glass carrier plate through debonding.

Further, the adhesive bonds the wafer and the glass carrier plate together by UV bonding/heat bonding in S1.

Further, the thinning method in S2 is etching/grinding.

Further, the cutting method in S4 is diamond cutting/laser cutting/plasma cutting.

Further, in S8, the bonding is released by a laser method.

The invention has the beneficial effects that:

1. the crystal grain production method of double-sided electroplating completes double-sided electroplating of the crystal grains at one time through the hollow glass carrier plate, replaces the traditional double-sided distribution electroplating mode, improves the production efficiency of the wafer, and is beneficial to reducing the production cost of the wafer;

2. the crystal grain production method of double-sided electroplating reduces the damage of noble metal by cutting and then electroplating, and is beneficial to improving the yield of crystal grains.

Drawings

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

FIG. 1 is a schematic view of a metal pad process configuration of the present invention;

FIG. 2 is a schematic view of a wafer bonding structure according to the present invention;

FIG. 3 is a schematic view of a thinning structure of the present invention;

FIG. 4 is a schematic view of a back side cutting configuration of the present invention;

FIG. 5 is a schematic diagram of an etching process of the present invention;

FIG. 6 is a schematic view of an adhesive removal configuration of 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 method for producing crystal grains by cutting crystal grains and then electroplating on two sides comprises the following steps:

s1: wafer bonding

The front side of the wafer 1 is subjected to a metal pad process, a metal layer 2 is formed on the wafer 1, the front side of the wafer 1 is bonded on an annular glass carrier plate 3 through an adhesive 4, and the wafer 1 and the glass carrier plate 3 are bonded together through the adhesive 4 through UV bonding/heating bonding.

S2: thinning

The back side of the wafer 1 is thinned by etching/grinding.

S3: intermediate process

The backside of wafer 1 is subjected to yellow light, ion implantation, dry ash removal, wet stripping, and backside metal sputtering/evaporation.

S4: back side cutting

And cutting the back surface of the wafer 1 in a diamond cutting/laser cutting/plasma cutting mode, wherein the wafer 1 is cut to form crystal grains 5.

S5: etching process

And performing a yellow light process, etching the opposite surface of the glass carrier plate 3 on which the crystal grains 5 are fixed by hydrofluoric acid, forming through holes 6 on the glass carrier plate 3, wherein the through holes 6 are opposite to the crystal grains 5, so that the glass carrier plate 3 becomes a glass carrier plate with a hollow window in the middle.

S6: adhesive removal

The adhesive 4 on the die 5 is etched by oxygen plasma to form a recess 7 in the adhesive 4 to expose the metal layer 2.

S7: electroplating of

Electroplating the two sides of the crystal grain.

S8: debonding

And debonding by adopting a laser mode, separating the crystal grains from the glass carrier plate 3, and carrying out subsequent production process.

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.