JPH04280446A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To reduce a defective rate and to improve yield by conducting a semiconductor device functional test, then grinding a rear surface, and then dicing it. CONSTITUTION:A semiconductor functional test in which a probe 2 is brought into contact with an electrode pad, is conducted at a semiconductor wafer 1 in which an opening of a pad film to a passivation film is finished. Then, an UV curing tape 3 is adhered to a surface 1a of the wafer 1. Thereafter, a rear surface 1b of the wafer 1 is ground. Then, the rear surface 1b of the wafer 1 is etched. Subsequently, the tape 3 is irradiated with UV so as to reduce its adhesive strength. Then, a UV irradiation for removing organic contaminants is conducted. Thereafter, the wafer 1 is lightly etched. Then, the wafer 1 is adhered to a die bonding tape 4, and diced to be pelletized.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of manufacturing a semiconductor device, in which after pad windows are formed in a passivation film, a semiconductor device function test, backside grinding, and dicing are performed.

0002

[Prior Art] The so-called semiconductor wafer post-processing is performed after pad windows are opened in the passivation film of a semiconductor wafer.
Conventionally, this was done as follows. First, a resist film for surface protection is applied to the surface of the semiconductor wafer, a hard tape is applied to the surface of the resist film, the back side is ground in this state to make the thickness of the semiconductor wafer a predetermined value, and then the back side is ground. The back surface of the semiconductor wafer was etched to remove the grinding strain generated on the back surface of the semiconductor wafer and to reduce the warpage of the wafer, and then a semiconductor device function test [2PC (
A second pellet check) is carried out, and defective pellets are marked with dots using ink, and the ink is further burned into the wafer.Then, the back side of the semiconductor wafer is pasted onto a dicing tape and diced to pelletize the wafer.

0003

However, the above-mentioned conventional semiconductor wafer post-processing is becoming unable to meet the demand for thinner packages. This is because there is a demand to reduce the thickness of the package to, for example, 1 mm or less, but in order to meet this requirement, the thickness of the semiconductor pellet must be reduced to 250 to 200 μm or less. This is because if a semiconductor device function test is performed after grinding the back surface thinly, the semiconductor wafer is likely to crack or chip, resulting in poor yield and quality.

That is, in a semiconductor device function test, a probe is applied to the electrode pad of a semiconductor wafer to electrically check the function of the circuit, but in order to perform an accurate check, it is necessary to reduce the pressure of the probe on the semiconductor wafer. In other words, a certain level of stylus pressure is required. Therefore, if the semiconductor wafer is thin, it is more likely to crack and chip due to the stylus pressure.

The present invention has been made to solve these problems, and aims to prevent the occurrence of cracks and chips in semiconductor wafers, and also to prevent dots placed during semiconductor device function tests. The purpose is to reduce contamination of semiconductor wafer surfaces by marking ink.

[0006]

A method of manufacturing a semiconductor device according to claim 1 is characterized in that after performing a semiconductor device function test, back surface grinding is performed, and then dicing is performed. The method for manufacturing a semiconductor device according to claim 2 is the method for manufacturing a semiconductor device according to claim 1, in which backside grinding is performed with a surface protection tape affixed to the surface of the semiconductor wafer, and the surface protection tape is peeled off after backside grinding. It is characterized by

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a semiconductor device according to the present invention will be explained in detail below according to the illustrated embodiments. FIGS. 1A to 1I are cross-sectional views showing one embodiment of the method for manufacturing a semiconductor device of the present invention in the order of steps. (A) A semiconductor device function test is performed on the semiconductor wafer 1 after completing the pad window opening for the passivation film by applying the probe 2 to the electrode pad as shown in FIG. 1(A). Then, defective pellets are marked with ink dots. Then, after marking, the dot-marked orgasm is burned.

(B) Next, as shown in FIG. 1 (B),
A UV radiation curing tape 3 is attached to the front surface 1a of the semiconductor wafer 1. This is to protect the front surface 1a of the semiconductor wafer 1 during back grinding, and for example, SP-5
25, SP429, SP-45UM (all product names)
is used. The UV irradiation-curable tape 3 has strong adhesion to the front surface 1a of the semiconductor wafer 1, and not only has a strong ability to protect the front surface 1a of the semiconductor wafer 1 during back grinding, but also has strong acid resistance and protects the back surface 1b of the semiconductor wafer 1. Etching solution (mixed solution of HF and HNO3) during etching
less likely to be attacked by Therefore, the back surface etching thickness can be increased considerably, for example, from 30 to 50 .mu.m, as required, and this results in the effect that polishing distortion can be completely removed. Further, the UV radiation curable tape 3 has a property that its adhesive strength decreases when it is exposed to UV radiation. This property of the UV radiation curable tape 3 is extremely useful for the present semiconductor device manufacturing method. This is because the tape 3 can be easily peeled off. Specifically, 1000 [g/25
mm] strong adhesive strength can be increased by UV irradiation to 10~20[g
/25 mm] and can be peeled off very easily.

(C) Next, as shown in FIG. 1 (C),
The back surface 1a of the semiconductor wafer 1 is ground (BGR). This is, for example, #4 in the one pass method.
This is done by finishing it to #000 and finishing it to #1500 using an infeed method. Then, the thickness of the semiconductor wafer 1 is finished to be about 150 μm, for example.

(D) Next, as shown in FIG. 1 (D),
The back surface 1b of the semiconductor wafer 1 is etched. This etching is to remove distortions on the back surface 1b of the semiconductor wafer 1 caused by grinding the back surface of the semiconductor wafer 1. For example, a mixed solution of hydrofluoric acid HF and nitric acid HNO3 (HF:HNO3) is used.
3 = 1:10) as an etching solution, etching is performed to a thickness necessary to remove grinding distortion. For example, 7 to 1
If grinding strain can be sufficiently removed at 0 μm, the etching time is about 80 seconds. However, the thickness is 30-50μm
If the grinding strain cannot be removed without some etching, etching is performed for about 300 to 420 seconds. Incidentally, even if etching is performed for a long time in this way, the surface 1 of the semiconductor wafer 1 is
There is no risk that a will be eroded.

(E) Next, as shown in FIG. 1 (E),
U to reduce adhesion to UV irradiation curable tape 3
Perform V irradiation. This UV irradiation uses a high-pressure mercury lamp to emit ultraviolet rays with a wavelength of 365 nm at a rate of 50 to 100 mW in a nitrogen atmosphere.
cm2 for about 10 seconds/s. This increases the adhesive strength from 1000 (g/25 mm) to 10
It can be weakened to about 20 (g/25 mm).

(F) Next, as shown in FIG. 1 (F),
UV irradiation is performed to remove organic contamination. This UV irradiation is performed by irradiating 4 ultraviolet rays with a wavelength of 253.7 nm onto the back surface 1a of the semiconductor wafer 1 using a low-pressure mercury lamp in an oxidizing atmosphere.
The power is 0 mW/cm2 for about 5 to 10 minutes. This UV irradiation converts oxygen molecules O2 in the atmosphere into oxygen atoms O
This is done to decompose into +O, and the oxygen atoms O generated by the decomposition combine with oxygen molecules O2 to create ozone O3. Since this ozone O3 has strong oxidizing power to oxidize and decompose organic contamination, organic contamination can be cleaned by UV irradiation.

Note that the UV irradiation in steps (D) and (E) can be performed continuously using one UV irradiation device. However, it is sufficient to perform the UV irradiation in step (D) while purging the inside of the apparatus with nitrogen, and then to perform the UV irradiation in step (E) by introducing outside air to create an oxygen atmosphere. This is because the UV irradiation device is capable of irradiating ultraviolet rays from both the front side and the back side of the semiconductor wafer 1 using separate mercury lamps. Also, U
UV irradiation to reduce the adhesive strength of V-irradiation curable tape and UV to remove organic contamination from the backside of semiconductor wafers
The order of irradiation may be reversed. That is, UV irradiation to remove organic contamination from the back surface of a semiconductor wafer [(E in FIG. 1)
] may be performed first, and UV irradiation [(D) in FIG. 1] for reducing the adhesive strength of the UV irradiation-curable tape may be performed later.

(G) Next, as shown in (G) of FIG.
A semiconductor wafer 1 is light etched. This light etching is for removing lower oxides generated by oxidative decomposition due to UV irradiation in step (E), and is performed using a 1% hydrofluoric acid aqueous solution.

(H) Next, as shown in (H) of FIG.
The UV irradiation curable tape 3 is peeled off. This peeling can be performed easily and without causing any trouble to the semiconductor wafer 1, since the adhesive force of the UV irradiation-curable tape 3 has been reduced in the above-mentioned step (D).

(I) Next, the semiconductor wafer 1 is attached to a die-bonding tape 4 and pelletized by dicing as shown in FIG. 1(I). 1c, 1c, . . . are semiconductor pellets.

According to the present semiconductor device manufacturing method, since the semiconductor device function test is performed when the semiconductor wafer 1 is thick and has little warpage before back grinding, the probe 2, 2,...
The semiconductor wafer 1 is less likely to be chipped or cracked due to the stylus pressure. In addition, the semiconductor wafer 1 during back grinding
Since the UV irradiation curable tape 3 was used to protect the surface 1a, the baked marking ink dots that indicate defects when peeling off the UV irradiation curable tape 3 [step (H)] are removed from the UV irradiation curable tape 3. Since the marking ink dots are peeled off at the same time, there is no possibility that the surface of the semiconductor wafer 1 will be contaminated by the marking ink dots. Incidentally, in the past, since a semiconductor device function test was performed after back grinding, it was impossible to remove the marking ink dots even if the resist film for surface protection was peeled off.

Therefore, in the past, electrode pads were often contaminated with ink, which often resulted in defective wire bonding. In this respect as well, the present method for manufacturing a semiconductor device can be said to be excellent. In addition, in the manufacturing method of this semiconductor device, a water-soluble adhesive tape such as ICROSS tape (trade name manufactured by Mitsui Toatsu Chemical Co., Ltd.) may be used instead of the UV irradiation-curable tape as a means of protecting the surface of the semiconductor wafer during back grinding. There is an advantage that the marking ink dots can be peeled off together with the tape during peeling. However, this cannot be expected when a resist film is used as a surface protection means. Incidentally, when a water-soluble adhesive tape is used as a surface protection means, it can be easily removed by simply washing with pure water.

According to the present semiconductor device manufacturing method, since a resist film is not used as a means for protecting the semiconductor wafer, the cost of indirect materials (resist, resist stripping solution) is low, and pad contamination due to insufficient cleaning and Al There is no risk of deterioration of the wiring film surface. Therefore, yield and quality are improved, and workability is also improved.

[0020]

The method for manufacturing a semiconductor device according to claim 1 includes performing a semiconductor device function test by applying a probe to the surface of the semiconductor wafer, and then grinding the back surface of the semiconductor wafer.
After that, the semiconductor wafer is diced and pelletized. Therefore, according to the method for manufacturing a semiconductor device according to claim 1, since the semiconductor device function test is performed before back grinding to reduce the thickness of the semiconductor wafer, the semiconductor device function test is performed by stylus pressure from a probe during the semiconductor device function test or by the semiconductor device function test. This handling reduces the risk of semiconductor wafers being chipped or broken, reducing the defective rate and improving yield. A method of manufacturing a semiconductor device according to a second aspect of the present invention is characterized in that the backside grinding is performed with a surface protection tape attached to the front surface of the semiconductor wafer, and the surface protection tape is peeled off after the backside grinding is completed. Therefore, according to the method for manufacturing a semiconductor device according to the second aspect, ink marking dots indicating defects that are added during a semiconductor device function test can be removed together with the surface protection tape when the surface protection tape is peeled off. Therefore, it is possible to prevent the electrode pads and wiring on the surface of the semiconductor device from being contaminated by the ink marking dots. Furthermore, since resist is not used as a means of protecting the semiconductor wafer surface, the amount of resist itself and expensive indirect materials for the resist process, such as its stripping solution, can be reduced, and there is no need for troublesome work such as resist coating and cleaning. Become. Therefore, the number of work steps can be reduced. Therefore, material costs and work man-hours are reduced, and the cost of the semiconductor device can be reduced.

[Brief explanation of the drawing]

FIGS. 1A to 1I are cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device of the present invention in the order of steps;

[Explanation of symbols]

1 Semiconductor wafer 1c pellet 2 Probe 3　Surface protection tape

Claims (2)

[Claims] 1. A semiconductor device characterized by performing a semiconductor device function test by applying a probe to the surface of the semiconductor wafer, then grinding the back surface of the semiconductor wafer, and then dicing and pelletizing the semiconductor wafer. Production method. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the backside grinding is performed with a surface protection tape attached to the front surface of the semiconductor wafer, and the surface protection tape is peeled off after the backside grinding is completed. .