JPH05166810A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor device which is capable of inhibiting the generation of cracks of a photoresist and forming a projected electrode in a stable manner. CONSTITUTION:A bump 6, which serves as a projected electrode to make an electrical connection to the outside, is formed on a semiconductor device 1. This bump 6 is formed in rectangular shape where an angle theta which exceeds 120 deg. is provided at the corners.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device,
In particular, the present invention relates to an electrode shape of a bump electrode (hereinafter referred to as a bump) formed on a semiconductor element for extracting an electrode by using a TAB (Tape Automated Bonding) technique.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing an example of a conventional semiconductor device. In the figure, 1 is a semiconductor element and 2 is a thick metal film such as Au for electrical connection to the outside. It is a bump formed on the top.

Next, a conventional method of forming the bump 2 will be described with reference to FIGS. 6 (a) to 6 (f). First, as shown in FIG. 6A, the metal film 3 made of, for example, Ti—W / Au is coated on the semiconductor element 1 by 1000 Å. Then, as shown in FIG. 6B, the photoresist 4 is coated to a thickness of about 25 μm. After that, exposure and development are performed using a photomask (not shown) having a desired pattern, and as shown in FIG. 6C, an opening 4a equivalent to the pattern of the photomask is formed in the photoresist 4. At this time, the opening 4a has a rectangular shape as shown in FIG. Further, for example, Au is electroplated using the metal film 3 as a cathode to form bumps 2 on the metal film 3 in the opening 4a of the photoresist 4 as shown in FIG.
u is deposited to about 20 μm.

Therefore, as shown in FIG. 6E, the photoresist 4 is peeled off, and then the exposed metal film 3 is removed as shown in FIG. Of Au having the same shape as the opening 4 a of the photoresist 4.
Bumps 2 are formed.

Here, when forming the thick film bumps 2, it is necessary to form the photoresist 4 to be thicker than the bumps 2. Since the film thickness is 10 μm or more, the photoresist is formed. No. 4 does not use a rubber resist, but normally uses an acrylic resist.

[0006]

Since the conventional semiconductor device has the rectangular bumps 2 formed on the semiconductor element 1 as described above, the openings of the photoresist 4 formed on the semiconductor element 1 are formed. When depositing a thick metal film for forming the bumps 2 in the bump 4a, the deposition growth of the metal film is forcibly prevented by the side wall portion of the opening 4a of the photoresist 4, so that the side wall portion of the opening 4a is formed. Is pressed and photoresist 4
A stress is generated inside, and this stress concentrates on the corners of the opening 4a, and cracks 5 are generated in the photoresist 4 as shown in FIG. As a result, there is a problem that a metal film grows along the cracks 5 and the bumps 2 are short-circuited, or the photoresist 4 between the adjacent openings 4a is separated during the plating process.

The present invention has been made in order to solve the above problems. When bumps are deposited and grown, the occurrence of cracks at the corners of the openings of the photoresist is suppressed and shorts between the bumps are generated. It is an object of the present invention to obtain a semiconductor device capable of preventing bumps, preventing the photoresist from peeling, and stably forming bumps.

[0008]

In the semiconductor device according to the present invention, the shape of the protruding electrode formed on the semiconductor element is a rectangular shape having a chamfered corner of 120 ° or more.

[0009]

According to the present invention, the chamfer provided at the corner of the bump electrode relaxes the concentration of the internal stress generated in the photoresist at the corner when the bump electrode is formed due to the precipitation growth of the bump electrode. This prevents the photoresist from cracking due to stress concentration on the corners.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Example 1. 1 is a perspective view of a main part of a semiconductor device showing a first embodiment of the present invention. In the figure, the same or corresponding parts as those of the conventional semiconductor device shown in FIG. .. In the figure, reference numeral 6 denotes a bump formed on the semiconductor element 1 having a rectangular shape with chamfers 6a having an angle θ at the corners.

Next, the manufacturing method of the first embodiment will be described. After coating the photoresist 4 on the semiconductor element 1 coated with the metal film 3 made of Ti-W / Au, exposure and development are performed using a photomask having a desired pattern,
As shown in FIG. 2, a rectangular opening 4a having a chamfered portion 4b is formed at a corner of the photoresist 4. Then, Au is electroplated using the metal film 3 as a cathode to deposit about 20 μm of Au in a shape similar to the shape of the opening 4a, and then the photoresist 4 and the exposed metal film 3 are peeled off to remove the semiconductor. The bump 6 is formed on the element 1.

Here, when the bump 6 having a thickness of 10 μm or more is deposited, the angle θ of the chamfer 6a of the bump 6 is set to 1
If the angle is less than 20 °, cracks occur at the corners of the opening 4a of the photoresist 4 due to the internal stress of the photoresist 4 generated during the metal deposition growth of the bump 6, and the metal film grows along the crack 5. As a result, the bumps 6 are short-circuited, or the photoresist 4 between the adjacent openings 4a is peeled off during the plating process. Further, when the angle θ of the chamfer 6a of the bump 6 is 120 ° or more, the concentration of the internal stress of the photoresist 4 generated during the metal deposition growth of the bump 6 on the corners of the opening 4a is suppressed, and the occurrence of the crack 5 is prevented. I was able to prevent it.

As described above, according to the first embodiment, the shape of the bump 6 formed on the semiconductor element 1 is 120 at the corner.
Since it has a rectangular shape having a chamfer 6a with an angle θ of not less than °, when forming bumps 6 of a thick film having a thickness of 10 μm or more,
Stress concentration at the corners of the opening 4a of the photoresist 4 is reduced, the occurrence of cracks 5 is suppressed, and there is no short circuit between the bumps 6 or peeling of the photoresist 4 during the electroplating process, and a stable thick film is obtained. The bump 6 can be formed.

Example 2. In the first embodiment, the bump 6 has a rectangular shape with chamfers 6a at the corners. However, in the second embodiment, as shown in FIGS. 3 and 4, the bump 6 has a corner shape. A rectangular shape having an arc 6b at the center is provided, and the same effect is obtained.

[0015]

As described above, according to the present invention, since the shape of the protruding electrode formed on the semiconductor element is a rectangular shape having a chamfer at an angle of 120 ° or more, the protruding electrode is formed on the semiconductor element. During the formation of electrodes, the generation of cracks at the corners of the photoresist opening is suppressed, and the peeling of the photoresist during the process of forming the bump electrodes and the gap between the bump electrodes due to the deposition growth of the metal film along the cracks occur. There is an effect that a semiconductor device capable of preventing a short circuit can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a semiconductor device showing a first embodiment of the present invention.

FIG. 2 is a plan view of an opening of a photoresist in the semiconductor device showing the first embodiment of the present invention.

FIG. 3 is a main part perspective view of a semiconductor device showing a second embodiment of the present invention.

FIG. 4 is a plan view of an opening of a photoresist in a semiconductor device showing a second embodiment of the present invention.

FIG. 5 is a main part perspective view showing an example of a conventional semiconductor device.

6A to 6F are process cross-sectional views showing a method of forming a protruding electrode in a conventional semiconductor device.

FIG. 7 is a plan view showing an opening of a photoresist in a conventional semiconductor device.

FIG. 8 is a plan view showing a state in which a crack is generated during bump formation in a conventional semiconductor device.

[Explanation of symbols]

 1 semiconductor element 6 bump (protruding electrode) 6a chamfer 6b arc (chamfer)

Claims (1)

[Claims] 1. A semiconductor device in which a protruding electrode is formed on a semiconductor element, wherein the protruding electrode is 120 at a corner.
A semiconductor device having a rectangular shape having a chamfer at an angle of ° or more.