JPH06302688A - Semiconductor device and dicing method therefor - Google Patents

Abstract

PURPOSE:To prevent chipping at the time of cutting by providing a metal thin film on a dicing street of a wafer formed with chips, and cutting the street by a blade. CONSTITUTION:A metal thin film 4 is formed on a dicing street 3 in which a substrate 6 of a compound semiconductor wafer metallized with many equal chips 5 is exposed with the substrate 6, and the street 3 formed with the film 4 is cut by a blade. The film 4 is formed with excellent adhesive properties to the substrate 5 of the street 3, an impact vibration of the blade generated at the time of dicing is absorbed by the film 4 to be alleviated, and not affected to the substrate to be cut together with the thin film. Accordingly, a chip 7 having no chipping can be effectively obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound semiconductor device and a dicing method for the device.

[0002]

2. Description of the Related Art FIG. 4 is a plan view showing a compound semiconductor wafer in which a large number of chips are formed on the surface of a substrate by photoetching, vapor phase growth, etc., 11 is a wafer, and 12 is a wafer 11.
The chip pattern created above, and 13 is a dicing street between the chip patterns 12 and 12. 5 is a sectional view taken along line BB in FIG.
Is a compound semiconductor wafer substrate, and 15 is a chip metallization.

Generally, the wafer 11 has a thickness of about 600 μm,
A caliber having a diameter of about 3 to 6 inches is used, and several tens to several thousands of chip patterns 12 having various sizes within a range of 0.3 to 100 mm square are formed on it.
The width of the dicing street 13 is 100 to 150.
It is about μm, and the substrate 14 is exposed.

The compound semiconductor wafer 11 is diced in order to separate and use each of the chips one by one. The dicing is performed by a blade rotating on the dicing street where the compound semiconductor substrate 14 is exposed. It is done by cutting.

[0005]

However, in such a dicing method, the impact vibration to the substrate generated when the dicing street is cut by the blade is not limited to the cutting direction by the blade, and as shown in FIG. Crystal rupture around the cut chips, that is, chipping
There is a problem that 16 is generated.

Further, a chip obtained by cutting a wafer has a thickness of 60.
Since the thickness of 0 μm is too thick and is disadvantageous in terms of heat radiation and the like, the back surface of the wafer is ground after the completion of the wafer process to reduce the thickness to about 30 to 400 μm. At that time, the main surface of the wafer, on which the chips were metallized, was covered with a resist and then back grinding was performed, but since the use of an organic solvent is not preferable, the method of covering the main surface of the wafer with tape is recently adopted. is doing. However, if the dicing street region is exposed at that time, there is a problem that the step between the chip and the dicing street becomes large and the tape is peeled off.

In order to solve such a problem, as shown in FIG. 7 as a partial cross-sectional view of the dicing street area, in a wafer in which a chip area 22 is formed on a substrate 21, a dicing street area 23 having a width W is formed. A semiconductor device has been proposed in which an insulating film 24 containing an organic resin such as a polyimide resin is coated up to almost the same height as the chip surface (Japanese Patent Laid-Open No. 3-204935), but the organic resin is exposed on a dicing street, that is, exposed. Since the adhesiveness to the substrate 21 is poor, there is a problem that the organic resin adheres to the chip surface during dicing, and the adhered organic resin becomes an obstacle in the die bonding and wire bonding steps of the chip after dicing, resulting in strength deterioration.

The present invention has been made in order to solve the above problems, and a semiconductor device in which a metal thin film is formed on a dicing street where a compound semiconductor substrate of a compound semiconductor wafer on which a chip is formed is exposed, and The purpose of the present invention is to obtain a dicing method that does not cause crystal breakage (so-called chipping) in directions other than the cutting direction by dicing the metal thin film formed on the dicing streets when obtaining individual chips from this semiconductor device. To do.

[0009]

That is, the present invention is a semiconductor device characterized in that a metal thin film is formed on a dicing street where a substrate of a compound semiconductor wafer in which a large number of identical elements are metallized on the substrate is exposed. Provided is a dicing method for a semiconductor device, which comprises forming a metal thin film on a dicing street where a substrate of a compound semiconductor wafer is exposed and cutting the dicing street having the metal thin film formed thereon with a blade.

[0010]

According to the present invention, since the metal thin film is provided on the dicing street of the wafer on which the chips are formed, the impact vibration generated when the dicing street is cut with a blade or the like to separate the chips into individual dicing streets. As a result of being absorbed and relaxed by the metal thin film above, chipping in a direction other than the cutting direction by the blade can be prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 is a plan view of a compound semiconductor wafer according to the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. In the figure, 1 is a wafer, 2 is a chip pattern, and 3 is a dicing street on which a metal thin film 4 is formed. The metal thin film 4 is formed by chemical vapor deposition of Au, Ti, Ni, Mo, AuGe or the like by masking the chip pattern on the wafer.
It is formed on the substrate 6 on the dicing street 3 with good adhesion by plating or sputtering. This metal thin film 4 is a metallized chip 5 on a substrate 6 in FIG.
Although it is shown to be approximately the same thickness as that, since the thickness is too thin to prevent chipping during dicing, there is no effect of forming a metal thin film, and if it is too thick, the metal powder particles cut into the dicer blade are Since it may enter and block to cause damage to the blade and damage to the wafer, it is preferably in the range of 0.5 to several tens of μm, and the type of metal material used in this range and the metal material formed on the substrate. It is determined according to the thickness of the chip pattern.

A large number of chips 5 are metallized as described above, and the wafer 1 having the metal thin film 4 formed on the dicing streets 3 is fixed. For example, the blade width is 20 to 2.
The chip 5 is cut by rotating a 5 μm diamond blade (not shown) at a high speed (10000 to 70000 rpm) to run the center of the metal thin film 4 surface on the dicing street 3. In this invention, the metal thin film 4 is formed on the substrate 6 of the dicing street 3 with excellent adhesion, and shock vibration of the blade generated during dicing is absorbed by the metal thin film 4 and alleviated, and this is cut together with the metal thin film. The printed circuit board,
Therefore, the chip 7 without chipping (chip) as shown in FIG. 3 can be surely obtained.

According to the present invention, since stable cutting can be performed without chipping during dicing as described above, the dicing street width of 100 to 120 μm, which is required when dicing the dicing street of the conventional exposed substrate, is 30 to 30 μm. The size can be reduced to about 40 μm, and thus the number of chips to be produced can be increased for the same one wafer. Further, since the cutting speed can be increased during dicing, it contributes to the improvement of the efficiency of the dicing process.

[0014]

As described above, the present invention is a semiconductor device having a structure in which a large number of chips are formed and a metal thin film is formed on the dicing streets. By dicing the dicing streets having the metal thin film formed thereon, Since the stable cutting without chipping can be obtained, the dicing street width can be reduced, and accordingly, the number of chips in one wafer can be increased, and the defective rate in dicing can be significantly reduced to improve the yield. It has many advantages.

[Brief description of drawings]

FIG. 1 is a plan view of a compound semiconductor wafer showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged external view of a chip obtained by the dicing method of the present invention.

FIG. 4 is a plan view of a conventional compound semiconductor wafer.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is an enlarged external view of a chip obtained by a conventional dicing method.

FIG. 7 is a partial cross-sectional view of a dicing street region of a conventional compound semiconductor.

[Explanation of symbols]

 1 Compound Semiconductor Wafer 2 Chip Pattern 3 Dicing Street 4 Metal Thin Film 5 Chip Metallization 6 Semiconductor Substrate 7 Chip after Dicing

Claims (2)

[Claims] 1. A semiconductor device in which a metal thin film is formed on a dicing street where a substrate of a compound semiconductor wafer in which a large number of identical elements are metallized is exposed on the substrate. 2. A metal thin film is formed on a dicing street where a substrate of a compound semiconductor wafer in which a large number of the same elements are metallized on the substrate is exposed, and the dicing street on which the metal thin film is formed is cut by a blade. A method for dicing a semiconductor device.