JP2002100589A - Production method for semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable thin finish working of a semiconductor wafer without cracking or chipping the semiconductor wafer and to form a metal electrode film on the back side of the semiconductor wafer without cracking or chipping the thinned semiconductor wafer, with which a semiconductor device is formed on the principal surface of the semiconductor wafer. SOLUTION: After the semiconductor device is formed on the principal surface of the semiconductor wafer, a wafer surface protecting adhesive tape with reinforcing frame is stuck onto the principal surface of the semiconductor wafer. In such a state, the back side of the semiconductor wafer is worked and the semiconductor wafer is finished to be thin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing technique, and more particularly, to a first principal surface (front surface) of a semiconductor wafer.
The present invention relates to a technique which is effective when applied to a technique of forming a semiconductor element on a surface of a semiconductor wafer and forming a second main surface (back side) of the semiconductor wafer having the semiconductor element formed on the front surface into a thin finish.

[0002]

2. Description of the Related Art As a method of manufacturing a semiconductor device, there is a processing method in which a semiconductor element is formed on a main surface of a semiconductor wafer, and then a semiconductor wafer rear surface is thin-finished to form a semiconductor device rear surface electrode on the semiconductor wafer rear surface. Further, there is a method of cutting into a semiconductor chip size to function as a semiconductor device.

Recently, there has been an increasing demand for mounting a semiconductor device (semiconductor chip) on a thin package, as represented by an IC card, and a semiconductor chip having a thickness of 50 μm is required for a memory IC or LSI without a back electrode. I have.

On the other hand, a semiconductor device having a back electrode having a transistor structure that operates as a semiconductor element by moving an electrically conductive carrier in a thickness direction of a semiconductor chip is required to have a semiconductor chip thickness of 100 μm or less. For example, Japanese Patent Application Laid-Open No. 10-92778 (Document 1)
There is.

[0005] This document 1 discloses a method of thinning a back surface of a semiconductor wafer in which semiconductor elements are formed on a main surface of the semiconductor wafer,
The present invention relates to a method for manufacturing a semiconductor device in which electrodes need to be drawn from the back surface of a semiconductor wafer substrate.

In particular, the present invention relates to a method for solving the problem of cracking or chipping of a semiconductor wafer which occurs when the diameter of the semiconductor wafer is increased and the finished thickness of the semiconductor wafer is reduced to 100 μm or less.

More specifically, after depositing a metal electrode film on the back surface of a semiconductor wafer, an electrically conductive adhesive tape is attached to the back electrode film, and in a state where the electrically conductive tape is attached,
Dicing to semiconductor chip size.

Further, the semiconductor chip is die-bonded in a state where the electric conductive tape is stuck.

After depositing a metal electrode film on the back surface of the semiconductor wafer, a 100 μm
Since the thinned semiconductor wafer can be handled as described below, cracking of the thinned semiconductor wafer can be prevented.

[0010]

The method of manufacturing a semiconductor device described in Document 1 is a process from a process of depositing a metal electrode film on the back surface of a thinned semiconductor wafer to a process between dicing and die bonding. However, it is possible to prevent the semiconductor wafer from cracking or chipping, but it is impossible to prevent the semiconductor wafer from cracking or chipping after the semiconductor wafer back surface thinning processing step to the semiconductor wafer back surface electrode forming step.

An object of the present invention is to provide a method of manufacturing a semiconductor device for thinly processing a semiconductor wafer without cracking or chipping of the semiconductor wafer.

Another object of the present invention is to provide a thin semiconductor wafer having semiconductor elements formed on the main surface of the semiconductor wafer without causing cracks or chipping on the back surface of the semiconductor wafer.
An object of the present invention is to provide a semiconductor device manufacturing method for forming a metal electrode film.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0014]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

As a first means, after a semiconductor element is formed on a main surface of a semiconductor wafer, an adhesive tape for protecting a wafer surface with a reinforcing frame (a reinforcing frame) (a wafer surface protecting member with a reinforcing frame) is attached to the main surface of the semiconductor wafer. wear. In this state, the back surface of the semiconductor wafer is processed, and the semiconductor wafer is thinly finished.

As a second means, after a semiconductor element is formed on a main surface of a semiconductor wafer, an adhesive tape for protecting a wafer surface with a reinforcing frame (a reinforcing frame) (a wafer surface protecting member with a reinforcing frame) is attached to the main surface of the semiconductor wafer. wear. In this state, the back surface of the semiconductor wafer is processed, and the semiconductor wafer is thinly finished.

Further, a metal film is formed on the back surface of the thin-finished semiconductor wafer to which the adhesive tape for protecting the wafer surface with a reinforcing frame (a reinforcing frame) (a wafer surface protecting member with a reinforcing frame) is attached.

As a third means, after semiconductor elements are formed on the main surface of the semiconductor wafer, an adhesive tape for protecting the wafer surface with a reinforcing frame (a reinforcing frame) (a wafer surface protecting member with a reinforcing frame) is attached to the main surface of the semiconductor wafer. wear. In this state, the back surface of the semiconductor wafer is processed, the semiconductor wafer is thinly finished, and the wafer surface protection adhesive tape with the reinforcing frame (reinforcement frame) (the wafer surface protection member with the reinforcement frame) is attached to the thinly finished semiconductor wafer back surface. A metal film is formed.

Further, with a wafer surface protective adhesive tape with a reinforcing frame (a wafer surface protective member with a reinforcing frame) attached to the main surface of the thin-finished semiconductor wafer, a chip separating adhesive tape with a reinforcing frame is attached to the back surface of the thin-finished semiconductor wafer. paste.

The adhesive strength of the chip-separating adhesive tape with a reinforcing frame attached to the back surface of the thin-finished semiconductor wafer is compared with the surface protective adhesive tape with a reinforcing frame attached to the main surface of the thin-finished semiconductor wafer (wafer surface protecting member with reinforcing frame) Than the adhesive strength of
Construct with strong adhesive strength.

In this state, a chip separation adhesive tape with a reinforcing frame is adhered to the back surface of the thin-finished semiconductor wafer, and the surface protective adhesive tape with a reinforcing frame (wafer surface protecting member with a reinforcing frame) is peeled off from the main surface of the thin-finished semiconductor wafer. I do.

As a fourth means, the surface protective adhesive tape with a reinforcing frame of the third means (wafer surface protecting member with a reinforcing frame) is peeled off from the main surface of the thin-finished semiconductor wafer and then applied to the back surface of the thin-finished semiconductor wafer. The semiconductor chip separation area on the surface of the semiconductor wafer is separated and processed with the chip separation adhesive tape with the reinforcing frame attached.

According to the above-described first means, a wafer surface protection adhesive tape (a surface protection member with a reinforcement frame) with a reinforcement frame (reinforcement frame) is adhered to the main surface of the semiconductor wafer on which the semiconductor elements are formed. In addition, the semiconductor wafer back surface can be thin-finished.

As a result, after the semiconductor wafer is thin-finished, the amount of warpage and the amount of bending of the semiconductor wafer can be corrected by the surface protection adhesive tape with the reinforcement frame (the surface protection member with the reinforcement frame), and the rigidity of the semiconductor wafer can be increased. Can be.

Further, a method of handling a thin-finished semiconductor wafer is a semiconductor wafer handling method via a wafer surface protective adhesive tape with a reinforcing frame (a surface protective member with a reinforcing frame). The semiconductor wafer can be thin-finished without generation.

According to the above-described second means, the semiconductor wafer back surface is adhered to the semiconductor wafer main surface on which the semiconductor elements are formed, and the wafer surface protection adhesive tape with the reinforcement frame (surface protection member with the reinforcement frame) is adhered to the back surface. Can be thinned to form a metal film on the back surface of the semiconductor wafer.

As a result, after the semiconductor wafer thin finishing,
After forming a metal film on the back surface of a thin-finished semiconductor wafer, the amount of warpage or bending of the semiconductor wafer can be corrected with a wafer surface protection adhesive tape with a reinforcement frame (reinforcement frame surface protection member) and the rigidity of the semiconductor wafer is increased. Can be.

Further, a semiconductor wafer which has been thin-finished,
Alternatively, a method of handling a semiconductor wafer having a thin finish and a metal film formed on the back surface is a semiconductor wafer handling method via a wafer surface protective adhesive tape with a reinforcing frame (a surface protective member with a reinforcing frame). The semiconductor wafer can be thin-finished without cracking or chipping.

According to the above-described third means, the wafer surface protective adhesive with a reinforcing frame is applied to the semiconductor element surface of the semiconductor wafer after the thin finish processing or the semiconductor wafer having the thin finish processing and the metal film formed on the back surface. With the tape (surface protection member with reinforcing frame) attached, a chip-separating adhesive tape with a reinforcing frame, which has a stronger adhesive strength than the adhesive force of the wafer surface protective adhesive tape with a reinforcing frame, is attached to the back surface of the semiconductor wafer.

With the chip-separating pressure-sensitive adhesive tape with a reinforcing frame attached to the back surface of the semiconductor wafer, the wafer surface protective adhesive tape with the reinforcing frame attached to the semiconductor wafer element surface is peeled off.

As a result, a wafer surface protective adhesive tape with a reinforcing frame (a surface protecting member with a reinforcing frame) is applied from the element surface of the semiconductor wafer after the thin finishing or the semiconductor wafer having the thin finishing and the metal film formed on the back surface. ) Is peeled off, the chip-separating adhesive tape with a reinforcing frame becomes a reinforcing material, and does not cause cracking or chipping of the semiconductor wafer.
The wafer surface protection adhesive tape with a reinforcing frame can be peeled off.

According to the above-described fourth means, the semiconductor wafer after the thin finishing or the semiconductor wafer on which the thin finishing is performed and the metal film is formed on the back surface in a state where there is no crack or chip is provided with the reinforcing frame. Since the chip-separating adhesive tape is attached and the semiconductor chip separation area on the surface of the semiconductor wafer is separated and processed, high-quality semiconductor chips having no cracks or chips can be separated.

Hereinafter, the present invention will be described in detail together with embodiments (examples) with reference to the drawings. In all the drawings for describing the embodiments (examples), those having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) In this embodiment 1, although not particularly limited, for example, Au
A case in which the present invention is applied to a method for manufacturing a semiconductor wafer incorporating a semiconductor element having an electrode film will be described.

FIG. 1 shows a processing flow chart of the process.
FIG. 2 is a cross-sectional view of a main part of a semiconductor wafer element surface protection form [step of attaching a framed wafer surface protection tape (step 10 in FIG. 1).
2)], FIG. 3 is a schematic view of a wafer back surface grinding process in a state where a framed wafer surface protection tape is attached [Wafer back surface grinding process step (step 103 in FIG. 1)], and FIG. Schematic diagram of wafer back surface grinding process distortion removal by a single wafer spin wet etching method in the attached state [wafer back surface grinding process distortion removal process (step 10 in FIG. 1).
4)], FIG. 5 shows a schematic view of the formation of the wafer back surface electrode film in a state where the framed wafer surface protection tape is stuck [wafer back surface electrode film formation step (step 105 in FIG. 1)].

The outline of the flow of the manufacturing process of the semiconductor device will be described below with reference to FIG.

In the step 101 for forming semiconductor elements on the surface of the semiconductor wafer, the semiconductor elements are formed on the main surface of the semiconductor wafer by diffusing impurities from the main surface of the semiconductor wafer and forming an insulating film or a conductive film on the main surface. Form.

In the step of attaching a wafer surface protective tape with frame 102, a wafer surface protective tape with a reinforcing frame is attached to the main surface of the semiconductor wafer on which the semiconductor elements are formed.

In the wafer back surface grinding step 103, the semiconductor wafer back surface is ground in a state where the wafer surface protection tape with the reinforcing frame is stuck, and the semiconductor wafer is thinned.

The wafer back surface grinding distortion removal step 104
Removes the strained layer on the back side of the semiconductor wafer grinding process with the wafer surface protection tape with the reinforcing frame attached.

The wafer back side electrode film forming step 105 includes:
A back surface electrode film is formed on the back surface of the semiconductor wafer from which the grinding processing distortion layer has been removed while the wafer surface protection tape with the reinforcing frame is attached.

In a state where the wafer surface protection tape with the reinforcing frame is adhered to the above-described semiconductor wafer element surface, the semiconductor wafer on which the semiconductor elements are formed is thin-finished by a series of processes, whereby electrodes can be formed on the back surface of the semiconductor. .

With reference to FIG. 2, a description will be given of a mode of protecting the semiconductor wafer element surface (step 101 in FIG. 1) according to the first embodiment.

A heat-resistant protective adhesive tape 204 attached to a ceramic reinforcing frame 203 made of, for example, a ceramic material is attached to the semiconductor element forming surface 202 of the semiconductor element forming wafer 201.

Examples of the heat-resistant protective adhesive tape 204 include, for example, Icross tape model SB-6 manufactured by Mitsui Chemicals, Inc.
0P-CN-PT2 [base material: polyester resin, adhesive; acrylic adhesive] is used. This cross tape type SB-60P-CN-PT2 tape has a heat resistance temperature of 200
° C. However, the heat-resistant protective adhesive tape 204 is not limited to the cloth tape type SB-60P-CN-PT2.

Referring to FIG. 3, an outline of the wafer back surface grinding process (FIG.
Step 103) will be described.

To explain the structure, the semiconductor device forming wafer 201 before grinding the back surface together with the protective adhesive tape 204 with the reinforcing frame 203 is vacuum-sucked, and the rotating wafer vacuum suction rotary table 301 and the back surface of the semiconductor device forming wafer 201 are ground. The rotating grinding wheel 302 is formed.

Next, a method of grinding the back surface of the semiconductor element forming wafer 201 will be described. In the semiconductor wafer element surface protection mode shown in FIG. 2, the semiconductor element formation wafer 201 attached to the protective adhesive tape 204 with the reinforcing frame 203 is
The entire protective adhesive tape 204 with the reinforcing frame 203 is vacuum-sucked to the wafer vacuum suction table 301. In this state, the wafer vacuum suction table 301 is rotated at a low speed (20 to 6 per minute).
Then, the grinding wheel 302 is rotated at a high speed (3000 to 6000 revolutions per minute) to grind the back surface of the semiconductor element forming wafer 201.

Although not disclosed, the grinding heat generated at the time of grinding the back surface of the semiconductor element forming wafer 201 is removed while the pure water acts on the semiconductor element forming wafer 201 to remove the same.

Referring to FIG. 4, a description will be given of an outline (step 104 of FIG. 1) of grinding distortion removal on the back surface of the wafer by the single wafer spin wet etching method in a state where the wafer surface protection tape with a frame is attached.

The structure of the protective adhesive tape 204 with the reinforcing frame 203 is vacuum-sucked on the back side of the semiconductor device-formed wafer 201 after grinding, and the rotating wafer vacuum suction spin chuck 401 is rotated. Liquid 4 for wet etching
It is composed of an etching liquid drop nozzle 402 for dropping the liquid crystal 03.

Next, a description will be given of a method of removing distortion from grinding the back surface of a wafer by a spin wet etching method.

The semiconductor element-formed wafer 201, which has been subjected to the grinding and thin finish processing with the wafer surface protection tape with the auxiliary frame described in FIG. 3 attached, is vacuum-adhered to the wafer vacuum suction spin chuck 401 together with the protective adhesive tape 204 with the reinforcement frame 203. Adsorb. In this state, while rotating the wafer vacuum suction spin chuck 401 at about 200 to 500 revolutions per minute, the etching liquid 403 is dropped from the etching liquid drop nozzle 402 onto the ground surface of the back surface of the semiconductor element forming wafer 201 to form a grinding strain layer. Is removed by etching. As the etching solution, for example, when the semiconductor element forming wafer 201 is Si-based, a mixed chemical solution of hydrofluoric acid and nitric acid is used,
In the system, a mixed chemical solution of ammonia and hydrogen peroxide solution is used.

After the grinding process of the semiconductor element forming wafer 201 and the removal of the strained layer by etching, pure water is supplied to the etching processing surface of the semiconductor element forming wafer 201 from a not-shown pure water supply nozzle corresponding to the etch liquid drop nozzle 402. Then, the semiconductor element forming wafer 201 is washed with water. After the completion of the water washing, the wafer vacuum suction spin chuck 401 is moved to 200 / min.
Spin at 0-3000 rpm and spin dry.

With reference to FIG. 5, the outline of the formation of the electrode film on the back surface of the wafer (step 105 in FIG. 5) in the state where the wafer surface protection tape with the frame is stuck will be described.

The structure will be described. The protective adhesive tape 204 with the reinforcing frame 203 and the semiconductor element forming wafer 201 after the removal of the back grinding strain layer are cooled and the anode electrode 501 with a cooling function for applying a positive potential and the protective frame with the reinforcing frame 203 are applied. A wafer holder 502 is configured to hold the semiconductor element-formed wafer 201 together with the adhesive tape 204 after removal of the back grinding strain layer against the anode electrode 501 having a cooling function.

Further, a cathode electrode 5 for applying a negative potential
03, an AU target 5 for forming a back electrode film on the back surface of the semiconductor element forming wafer 201 after the removal of the back grinding strain layer.
04 is provided. Anode electrode 50 with cooling function
1 and a cathode electrode 503, a DC power supply 505 is connected, and a high voltage is applied.

On the other hand, the sputtering chamber 507 is evacuated 508 by a vacuum pump (not shown), and 10 ^-5 to 1 ^-5.
An Ar gas 509 is supplied to the sputtering chamber 507 from a gas supply device (not shown) while maintaining a high vacuum of about 0 ⁻⁶ Pa.

Next, a description will be given of a method of forming an electrode film on the back surface of a wafer in a state where the wafer surface protection tape with a frame is attached.

The semiconductor element-formed wafer 201 after the removal of the grinding strain layer described with reference to FIG. 4 is placed on the protective adhesive tape 204 with the reinforcing frame 203 together with the anode electrode 501 with a cooling function.
Then, the wafer is pressed and fixed by the wafer press 502.

The reinforcing frame 203 and the protective tape 204 are
By the anode electrode 501 with the cooling function, the temperature is always controlled to be equal to or lower than the heat resistant temperature of the protective tape 204. For example,
When using a cross tape type SB-60P-CN-PT2 manufactured by Mitsui Chemicals, Inc. (base material: polyester resin, adhesive; acrylic adhesive) as the protective tape 204, use this tape type SB-60P -CN-PT2
The heat resistance temperature of the tape is controlled to 200 ° C. or less.

In this state, the sputtering chamber 507 is evacuated 508 and gas is discharged under a high vacuum (10 ⁻⁵ to 10 ⁻⁶ Pa). After the gas is discharged, an Ar gas 509 is supplied. A high voltage is applied to the anode electrode 501 and the cathode electrode 503 having a cooling function to cause plasma discharge, and the positively ionized Ar gas 509 collides with the negative potential Au target 504, and Au atoms are sputtered, and the positive potential grinding strain layer is formed. Semiconductor element formation wafer 2 after removal
01, and an Au film is formed.

Embodiment 2 In this embodiment 2, although not particularly limited, for example, a vertical power MOSFET (Meta
l A case where the present invention is applied to a method of manufacturing an Oxide Semiconductor Field Effect Transistor) will be described.

FIG. 6 is a cross-sectional view of a main part of the semiconductor wafer (step 101 in FIG. 1) during the semiconductor device manufacturing process of FIG. 1. FIG. Sectional view of a main part of the wafer (step 103 in FIG. 1);
8 shows a cross-sectional view of a main part of the semiconductor wafer (process 105 in FIG. 1) in the manufacturing process of the semiconductor device in FIG. 1 subsequent to FIG.

As shown in FIG. 6, the semiconductor wafer 1 is made of, for example, n-type silicon single crystal, and a plurality of semiconductor chip formation regions are regularly arranged on the semiconductor element formation surface. For example, a vertical n-channel power MOSFET QV is formed.

The power MOSFET QV is an element that operates by moving carriers in the thickness direction of the semiconductor wafer 1. At this stage, the p-type semiconductor regions 18, 1
9, an n + -type semiconductor region 20, a gate insulating film 3, and a gate electrode 4. A p-type semiconductor region 18 in which impurities are distributed to the deepest position, and a p-type semiconductor region 18 formed so as to be shallower than it and to partially overlap gate electrode 4 in a plane.
The type semiconductor region 19 is a region that becomes a channel region of the power MOSFET QV.

The p-type semiconductor regions 18 and 19 contain, for example, boron and are electrically connected to each other. In the region of the p-type semiconductor region 19, an n + -type semiconductor region 20 is formed near the lower portion of the end of the gate electrode 4. This n + type semiconductor region 20 forms the source region of the power MOSFET QV. This n +
The type semiconductor region 20 contains, for example, phosphorus or arsenic.

The drain region of the power MOSFET QV is formed by an n − type region of the semiconductor wafer 1 itself and an n + type semiconductor region to be formed below it (on the back side of the semiconductor wafer 1). You. The gate insulating film 3 and the gate electrode 4 are the same as those in the first embodiment and will not be described.

On the main surface of the semiconductor wafer 1, an interlayer insulating film 8a made of, for example, a silicon oxide film is formed, thereby covering the gate electrode 4. The first layer wiring 9a is formed on the interlayer insulating film 8a.
The first layer wiring 9a is electrically connected to a p-type semiconductor region 19 and an n + -type semiconductor region 20 through a connection hole 10a formed in the interlayer insulating film 8a. Interlayer insulating film 8
On a, a surface protection film 11 extending forward is covered, and a first layer wiring 9a is covered.

An opening is formed in a part of the surface protection film 11, and a region of the first layer wiring 9a exposed from the opening serves as a bonding pad BP (Step 101 in FIG. 1).

Subsequently, as shown in FIG. 7, a wafer surface protective adhesive tape 13 with a reinforcing frame is attached to the semiconductor element forming surface of the semiconductor wafer 1 (step 102 in FIG. 1).

An example of a method of attaching the wafer surface protective adhesive tape 13 with the reinforcing frame (reinforcing frame) is as follows.
As in FIG. 2, the semiconductor element forming surface of the semiconductor wafer 1
Wafer surface adhesive (A) 13a, heat-resistant tape substrate (A)
13b and a wafer surface protective adhesive tape 13 with a reinforcing frame constituted by a reinforcing frame not disclosed.

In this state, the back surface of the semiconductor wafer 1 on which no semiconductor elements are formed is ground and thin-finished (FIG. 1).
Step 103). By this processing, the semiconductor wafer 1
For example, it is thinned to a thickness of 100 μm or less.

Further, the back surface of the semiconductor wafer 1 is subjected to a wet etching process, for example, a thin finishing process to a thickness of 80 μm (step 104 in FIG. 1).

Thereafter, as shown in FIG. 8, a back surface conductive film 16 made of, for example, titanium / nickel / gold is formed on the back surface of the semiconductor wafer 1 by a sputtering process to form a back surface electrode (FIG. 1). Step 105).

The material of the electrode film on the back surface of the semiconductor wafer is not limited to titanium / nickel / gold, but may be titanium / nickel / silver or gold alone.

The method for forming the back electrode film is not limited to the sputtering method, but may be a vacuum deposition method, a CVD method, or a plating method.

(Embodiment 3) Steps 901 to 90 shown in FIG.
5 is a process 101 to 101 shown in FIG.
This is a processing step equivalent to step 105, and a detailed description is omitted.
Hereinafter, a chip separation adhesive tape attaching step 906 with a frame,
The framed wafer surface protection tape peeling step 907 and the semiconductor wafer dicing (chip formation) step 908 will be described.

Referring to FIG. 10, the processing method of the step 906 of attaching the framed chip separating adhesive tape will be described.

After the wafer back surface electrode film forming step 905, the protective tape 204 with the reinforcing frame 203 is adhered to the semiconductor device formation surface 202 of the semiconductor device formation wafer 201, and the semiconductor device formation wafer 201 Then, with a chip separation reinforcing frame 1001 made of stainless steel, a chip separation adhesive tape (dicing tape) 1002 is attached.

As a chip separation tape, for example, a UV-curable dicing tape type D-manufactured by Lintec Co., Ltd.
650 [base film; polyolefin, adhesive; acrylic UV curing type] is used.

Referring to FIG. 11, a description will be given of a processing method in the frame-faced wafer surface protection tape peeling step 907.

A chip separation reinforcing frame 1001 is provided on the conductor film 16 on the back surface of the semiconductor element forming semiconductor wafer 201.
With the chip separation adhesive tape 1002 adhered, the protective tape 204 with the reinforcing frame 203 is peeled off from the semiconductor element forming surface 202 of the semiconductor element forming wafer 201.

For example, as the protective adhesive tape 204, an Icross tape model SB-60P-C manufactured by Mitsui Chemicals, Inc.
Chip separation adhesive tape 1002 using N-PT2 [base material; polyester resin, adhesive; acrylic adhesive]
The protective adhesive tape 204 is heated to about 55 ° C. using a UV-curable dicing tape model D-650 (base film; polyolefin, adhesive; acrylic UV-curable type) manufactured by Lintec Corporation.

In this heated state at 55 ° C., the adhesive force of the protective adhesive tape 204 to the semiconductor element forming surface is about 180 g.
/ 25 mm, and the adhesive force of the chip-separating adhesive tape 1002 to the conductor film 16 on the back surface of the wafer is about 300 g / 2.
5 mm.

The protective tape 204 with the reinforcing frame 203 is peeled off from the semiconductor element forming surface 202 of the semiconductor element forming wafer 201 by utilizing the difference in adhesive strength between the protective adhesive tape 204 and the chip separating adhesive tape 1002.

Referring to FIG. 12, the processing method of the semiconductor wafer dicing (chip forming) step 908 will be described.

A chip separation reinforcing frame 1001 is provided on the conductor film 16 on the back surface of the semiconductor element forming semiconductor wafer 201.
With the chip-separating adhesive tape 1002 stuck, set it on an XY stage of a dicing apparatus not disclosed,
The chip separation area of the semiconductor element forming surface 202 is cut into a chip separation groove 1202 by a dicing grindstone blade 1201 rotated at a high speed (30,000 to 50,000 rotations per minute) to form a semiconductor chip.

In the first to third embodiments described above,
For the wafer surface protection tape with a reinforcing frame, all the processes of the wafer back surface processing step, the wafer back surface grinding processing step, and the wafer back surface electrode film forming step were described using an example of using one type of surface protection tape with a reinforcing frame. It is not limited.

For example, a wafer surface protection tape with a reinforcing frame may be re-attached for each step or between two or more steps.

(Embodiment 4) FIG. 13 is a flow chart showing a manufacturing process of a semiconductor device, in which the present invention is applied to a manufacturing process of a semiconductor device having no back electrode film such as a metal film on the back surface of a semiconductor chip. is there.

Specifically, the third embodiment (FIG. 9, FIG. 1)
0, 11 and 12), the wafer back surface grinding processing distortion removal step 90
4. This is a processing step in which the wafer back surface electrode film forming step 905 is omitted.

The process flow of manufacturing a semiconductor device will be briefly described.
1. Attaching a wafer surface protection tape with a frame 1302 to the semiconductor wafer element surface, a grinding step 1303 for the back surface of the wafer, a chip separating adhesive tape attaching step 1304, a wafer surface protection tape removing step 1305 with a frame, a semiconductor wafer dicing process (chip formation) In step 1306, semiconductor elements are formed on the main surface of the semiconductor wafer, and the back surface of the semiconductor wafer is thinly ground and further separated into thin semiconductor chips.

(Embodiment 5) FIGS. 14, 15 and 16 show
An embodiment of a reinforcing frame for a wafer surface protection adhesive tape is shown. Regarding the reinforcing frame for the chip separation adhesive chip, the same type of reinforcing frame as the reinforcing surface for the wafer surface protection adhesive tape is used. Regarding the reinforcing frame for the wafer surface protecting adhesive tape and the reinforcing frame for the chip separating adhesive tape, various materials and shapes can be applied without being limited to the reinforcing frame of the fifth embodiment.

Preferably, the reinforcing frame is provided with a semiconductor wafer positioning function on the shape side, and the reinforcing frame is made of a rigid material which does not deform the semiconductor wafer during semiconductor wafer handling and semiconductor wafer processing. It is preferable to select a material that does not contaminate the semiconductor wafer with unnecessary impurities and the like.

Further, the wafer surface protective adhesive tape with a reinforcing frame can be replaced for each semiconductor wafer processing step to process the semiconductor wafer.

FIG. 14 shows an embodiment of a circular reinforcing frame with an orientation flat, and a circular reinforcing frame 140 with a stainless steel orientation flat.
Is provided with a positioning orientation flat 141.

The circular reinforcing frame with the orientation flat is made of stainless steel. When used as a reinforcing frame for an adhesive tape for protecting the surface of a wafer, the step of grinding the backside of the semiconductor wafer, the step of removing the distortion of the backside of the semiconductor wafer by dry etching, the step of removing the semiconductor wafer, and the like. It is preferably used in the back electrode film forming step.

Further, the circular reinforcing frame with orientation flat is
It can be used as a reinforcing frame for a chip separation adhesive tape, and can be used in a semiconductor wafer dicing process and a semiconductor chip direct pickup die bonding process.

FIG. 15 shows an embodiment of a circular reinforcing frame with a notch. A notch 151 for positioning is provided on a circular reinforcing frame 150 with a notch made of fluororesin (for example, tetrafluoroethylene / verfluoroalkylvinyl ether copolymer).
Is provided.

The adhesive surface 153 of the circular reinforcing frame 150 with a notch made of a grease material, to which the adhesive tape 152 for wafer surface protection is adhered, is subjected to surface roughening treatment by plasma treatment or the like, so that the adhesive strength of the adhesive tape 152 for wafer surface protection is increased. Have been.

The notched circular reinforcing frame 150 is made of a fluorine resin having chemical resistance, and is preferably used in the step of removing the back surface distortion of the semiconductor wafer by wet etching.

The reinforcing frame shape shown in FIGS. 14 and 15 is similar to the shape of a semiconductor wafer (a semiconductor wafer with an orientation flat, a notch, a flat circular shape) (for example, reinforcement for a wafer surface protective adhesive tape for adhering a ψ150 mm semiconductor wafer). By setting the outer diameter of the frame to $ 200 mm), the reinforcing frame handling means for the wafer surface protection adhesive tape of each semiconductor wafer processing equipment to be used can be shared with the semiconductor wafer handling means.

FIG. 16 shows an embodiment of a rectangular reinforcing frame, in which a rectangular reinforcing frame 160 made of aluminum alloy and a notch 1 for positioning are used.
61.

This square reinforcing frame is made of an aluminum alloy.
When used as a reinforcing frame for a wafer surface protection adhesive tape, it is preferably used in a semiconductor wafer back surface grinding process, a semiconductor wafer back surface distortion removing process by dry etching, and a semiconductor wafer back surface electrode film forming process.

Further, the rectangular reinforcing frame 160 is used as a reinforcing frame for a chip separation adhesive tape, and can be used in a semiconductor wafer dicing process and a semiconductor chip direct pickup die bonding process.

In the above description, the case where the invention made mainly by the present inventor is applied to the manufacturing technique of a semiconductor device having a power MOSFET, which is the background of the application, has been described. However, the present invention is not limited to this. For example, the present invention can be applied to a technique for manufacturing a semiconductor device having another element such as a normal MOSFET or a bipolar transistor.

Furthermore, a DRAM (Dynamaic Random Acces
s Memory), SRAM (Static Random Access Memory)
Alternatively, a flash memory EEPROM (Electrical
The present invention can also be applied to the manufacturing technology of semiconductor memory products such as ly Erasable Programmable ROM)) and logic circuit products such as microprocessors.

In particular, since the semiconductor device can be reduced in thickness, the present invention is effective when applied to a method for manufacturing a semiconductor device for a product such as an IC card or a memory card which requires a reduction in thickness.

[0110]

Advantageous effects obtained by typical ones of the inventions disclosed by the present application will be briefly described as follows.
It is as follows. (1) According to the present invention, a semiconductor wafer can be thin-finished while reinforcing the semiconductor wafer with a protective adhesive tape with a reinforcing frame.
Processing such as handling of the semiconductor wafer can be performed without causing the semiconductor wafer to warp or bend. As a result, it is possible to prevent semiconductor wafer chipping and semiconductor wafer cracking that occur during semiconductor wafer handling due to semiconductor wafer warpage or bending that occurs when the semiconductor wafer is thinned.

(2) According to the present invention, a back electrode film can be formed on the back surface of a thin-finished semiconductor wafer while reinforcing the thin-finished semiconductor wafer with a protective adhesive tape with a reinforcing frame. As a result, warpage of the semiconductor wafer due to the residual internal stress of the back electrode film can be prevented. In addition, even during semiconductor wafer handling before and after the formation of the backside electrode film, the semiconductor wafer can be handled while being reinforced with a protective adhesive tape with a reinforcing frame, so that the semiconductor wafer does not chip or crack, and is made of a high-quality thin semiconductor. The back electrode of the wafer can be formed.

(3) According to the present invention, a semiconductor wafer having a thin finish and a semiconductor wafer having a thin finish and a back electrode formed thereon are reinforced with a protective adhesive tape having a reinforcing frame, and a chip separating adhesive having a reinforcing frame is provided. After sticking to a tape (dicing tape) and attaching the semiconductor wafer to a chip separation adhesive tape with a reinforcing frame (dicing tape), the protective adhesive tape with a reinforcing frame is peeled from the semiconductor wafer.

As a result, the thin-finished semiconductor wafer and the thin-finished semiconductor wafer having the back electrode formed thereon are bonded to a chip-separating adhesive tape with a reinforcing frame (dicing tape) without causing chipping or cracking. Can be Furthermore, since it can be diced into a semiconductor chip in a state of being attached to the chip-separating adhesive tape with frame (dicing tape), a thin semiconductor chip can be obtained with high quality without cracking.

[Brief description of the drawings]

FIG. 1 is a flowchart of a manufacturing process of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the semiconductor wafer surface protection mode according to the first embodiment.

FIG. 3 is a conceptual diagram of a grinding process on the back surface of a wafer.

FIG. 4 is a conceptual diagram of distortion removal in grinding of the back surface of a wafer.

FIG. 5 is a conceptual diagram of formation of a wafer back surface electrode.

6 is a fragmentary cross-sectional view of a semiconductor wafer during a manufacturing step of a semiconductor device (semiconductor device of FIG. 1) according to Embodiment 2 of the present invention;

7 is a fragmentary cross-sectional view of the semiconductor wafer during a manufacturing step of the semiconductor device of FIG. 1 following FIG. 6;

8 is a fragmentary cross-sectional view of the semiconductor wafer during a manufacturing step of the semiconductor device of FIG. 1 following FIG. 7;

FIG. 9 is a flowchart of a manufacturing process of a semiconductor device according to a third embodiment of the present invention.

FIG. 10 is a conceptual diagram of attaching a chip-separated adhesive tape with a frame.

FIG. 11 is a conceptual diagram of peeling of a surface-protected pressure-sensitive adhesive tape with a frame.

FIG. 12 is a conceptual diagram of a dicing process of a semiconductor wafer.

FIG. 13 is a flowchart of a manufacturing process of a semiconductor device according to a fourth embodiment of the present invention.

FIG. 14 is a view showing an example of a reinforcing frame for a wafer surface protection adhesive tape used in a method of manufacturing a semiconductor device according to Example 5 of the present invention.

FIG. 15 is a view showing another embodiment of a reinforcing frame for a wafer surface protection adhesive tape used in the method for manufacturing a semiconductor device of the fifth embodiment.

FIG. 16 is a view showing another embodiment of a reinforcing frame for a wafer surface protective adhesive tape used in the method for manufacturing a semiconductor device of the fifth embodiment.

[Description of Reference Numerals] 101: semiconductor element surface semiconductor element forming step, 102
... Attaching process of wafer surface protection tape with reinforcing frame, 103
... wafer back surface grinding process, 104 ... wafer back surface grinding process distortion removal process, 105 ... wafer back surface electrode film forming process, 2
01: semiconductor element forming wafer, 202: semiconductor element forming surface, 203: reinforcing frame, 204: protective adhesive tape, 301
… Wafer vacuum suction rotary table, 302… rotary grinding wheel, 401… wafer vacuum suction spin chuck, 402…
Nozzle under etching droplet, 403 ... Etching liquid, 50
1 .... Anode electrode with cooling mechanism, 502 ... Wafer holder,
503: cathode electrode, 504: Au target, 50
5 ... DC power supply, 506 ... Insulation material, 507 ... Sputter chamber,
508: vacuum evacuation, 509: Ar gas, 1: semiconductor wafer, 2a: semiconductor region, 2b: semiconductor region, 3: gate insulating film, 4: gate electrode, 5: n-well, 6: semiconductor region, 7: semiconductor region .., 8a ... interlayer insulating film, 8b ... interlayer insulating film, 9a ... first layer wiring, 9b ... second layer wiring, 10a ...
Connection hole, 11: surface protective film, 11a: protective film, 11b ...
Protective film, 11c: Protective film, 12: Opening, 13: Wafer surface protective adhesive tape with reinforcing frame, 13a: Wafer surface adhesive (A), 13b: Heat-resistant tape base, 16: Wafer back surface conductive film, 901 Semiconductor wafer surface semiconductor element forming step, 902: Affixing wafer surface protection tape with reinforcing frame to semiconductor wafer element surface, 903: Wafer back side grinding step, 904: Wafer back side grinding processing distortion removal step, 905 ...
Wafer back surface electrode film forming step; 906: chip separating adhesive tape attaching step with reinforcing frame; 907: wafer surface protection tape removing step with reinforcing frame; 908: semiconductor wafer dicing (chip forming) step; 1002: chip separation adhesive tape, 1201: dicing grindstone blade, 1202: chip separation groove, 13
01: formation of semiconductor elements on the surface of the semiconductor wafer; 1302: affixing step of a wafer surface protection tape with a frame to the semiconductor wafer element surface; 1303: grinding step of the back surface of the wafer;
Step of attaching chip-separated adhesive tape with frame, 1305: Peeling step of wafer surface protection tape with frame, 1306: Semiconductor wafer dicing (chip formation) step, 20: Semiconductor area, QL: Power MOSFET, QV: Power MOS
FET, BP: bonding pad, 140: circular reinforcing frame with stainless steel orientation flat, 141: positioning orientation flat, 150: circular reinforcing frame with notch made of fu material,
152: Wafer surface protection adhesive tape, 153: Adhesive surface,
160 ... a square reinforcing frame made of aluminum alloy, 161 ... notch for positioning.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H01L 29/41 H01L 21/78 Q 29/44 B

Claims (6)

[Claims] 1. A first step of forming a semiconductor element on a first main surface (front surface) of a semiconductor wafer, and after the first step,
A second step of attaching a protective adhesive tape with a reinforcing frame to a first main surface of the semiconductor wafer, and after the second step,
A method for manufacturing a semiconductor device, comprising a third step of processing a second main surface (back surface) of the semiconductor wafer, wherein a protective adhesive tape attached to the first main surface of the semiconductor wafer is provided. A method for manufacturing a semiconductor device, comprising: providing a reinforcing frame for reinforcing a semiconductor device. 2. A first step of forming a semiconductor element on a first main surface (front surface) of a semiconductor wafer, and a protective adhesive tape attached to the first main surface of the semiconductor wafer for reinforcing the semiconductor device. A second step of providing a reinforcing frame for
After the step, a third step of attaching a protective adhesive tape with a reinforcing frame to the first main surface of the semiconductor wafer;
After the step, a fourth step of processing the second main surface (back surface) of the semiconductor wafer, and after the fourth step, the back surface of the semiconductor wafer protected by the wafer surface protection adhesive tape with a reinforcing frame And a fifth step of forming a metal film. 3. A first step of forming a semiconductor element on a first main surface (front surface) of a semiconductor wafer, and a protective adhesive tape attached to the first main surface of the semiconductor wafer is reinforced. A second step of providing a reinforcing frame for the semiconductor device, after the second step, a third step of attaching a protective adhesive tape with a reinforcing frame to the first main surface of the semiconductor wafer, and after the third step A fourth step of processing a second main surface (back surface) of the semiconductor wafer, and after the fourth step, reinforcing the back surface of the semiconductor wafer attached to the wafer surface protection adhesive tape with a reinforcing frame. A fifth step of attaching a chip-separating adhesive tape with a frame, and after the fifth step, with the back surface of the semiconductor wafer adhered to the chip-separating adhesive tape with a reinforcing frame, the wafer surface protective adhesive tape with a reinforcing frame A sixth step of peeling off 3. The method of manufacturing a semiconductor device according to claim 1, wherein: 4. A seventh step of separating the semiconductor chip separation area on the surface of the semiconductor wafer with the back surface of the semiconductor wafer adhered to the chip separation adhesive tape with a reinforcing frame after the sixth step. 4. The method of manufacturing a semiconductor device according to claim 3, wherein: 5. The step of processing the back surface of the semiconductor wafer is a grinding method, a polishing method, a chemical etching method, a physicochemical etching method, or a method combining two or more of these methods. The method of manufacturing a semiconductor device according to claim 1, wherein: 6. The step of forming a metal film on the back surface of the semiconductor wafer includes a vacuum deposition method, a sputtering method, and a CVD method.
6. A method according to claim 1, wherein the method is a (Chemical Vapor Deposition) method or a plating method.
13. The method for manufacturing a semiconductor device according to item 13.