JPH0529467A - Fuse for redundant circuit use - Google Patents

Abstract

PURPOSE:To prevent fuses from being burnt-out up to their adjacent fuses when the fuses are burnt out with a laser beam and to make small the intervals between the fuses and the adjacent fuses by a method wherein a laser beam irradiation window formed zigzag is provided on the fuses. CONSTITUTION:Mutually adjacent fuses 3A and 3B, which are respectively connected through contacts 2 with a wiring 1, are formed and a laser beam irradiation window 4 for fuse burning-out use is formed zigzag thereon. In the case the fuse 3A is cut with a laser beam, the laser beam is emitted on an opening part of this irradiation window 4. Even in the case the same laser beam is emitted, a cuttable laser output to the fuse 3A in the opening part of the window 4 and a cuttable laser output to the fuse 3B at a part, which is out of the opening of the window 4, are different from each other. As a result, even if the position of irradiation of the laser beam is shifted and the laser beam is emitted on the fuse 3B, which is out of the opening part of the window 4 and is projected on the fuse 3A, the fuse 3B is never cut by mistake. Thereby, the intervals between the fuses 3A and 3B can be made small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a redundant circuit fuse, and more particularly to a redundant circuit fuse for a semiconductor integrated circuit.

[0002]

2. Description of the Related Art A conventional redundant circuit fuse has a structure in which, as shown in FIG. 3, fuses 3 are arranged at equal intervals and a linear irradiation window 5 is opened in a direction perpendicular to the fuses. there were. The fuse 3 was connected to the corresponding wiring 1 via the contact 2.

[0003]

This conventional redundant circuit fuse has a drawback that adjacent fuses are cut due to the positional deviation of the laser beam of the fuse cutting laser device. In addition, the larger the size of the laser beam in order to eliminate a mistake in cutting the fuse, the more likely the above-mentioned defects occur. Further, there has been a problem that if the distance between the fuses is increased to avoid this problem, the size of the semiconductor integrated circuit inevitably increases.

[0004]

A fuse for a redundant circuit of the present invention has a first redundant circuit, which is a redundant circuit in use, and a second redundant circuit, which is an unnecessary redundant circuit, arranged at equal intervals. First and second fuses respectively connected to the first and second redundant circuits, and an irradiation window for irradiating the second fuse with a laser beam for separating the second redundant circuit. In a redundant circuit fuse of a semiconductor integrated circuit, which is provided, the irradiation window is formed in a zigzag shape so as not to irradiate the first fuses adjacent to each other with the second fuse blown by the laser beam. .

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a first embodiment of a redundant circuit fuse of the present invention.

In FIG. 1, fuses 3A and 3B connected to a wiring 1 and a contact 2 are formed adjacent to each other, and an irradiation window 4 of a laser beam for blowing a fuse is formed in a zigzag pattern on the fuses 3A and 3B. Has been done. When the fuse 3A is cut by the laser beam, the laser is applied to the portion where the irradiation window 4 is open.

Even when the same laser beam is emitted, the fuse 3A in the opening portion of the irradiation window 4 and the fuse 3B in the portion outside the opening of the irradiation window 4 have different laser outputs that can be cut, and therefore the laser irradiation position is displaced. Even if the fuse 3B adjacent to the fuse 3B that is out of the opening of the irradiation window 4 is irradiated with the laser, it is not accidentally cut.

Further, since the diameter of the laser beam is increased in order to avoid mistaken cutting of the fuse 3A due to the deviation of the laser beam irradiation position, there is no fear that the adjacent fuse 3B is easily cut.

Further, since it is difficult for the adjacent fuse 3B to be blown, the space between the fuse 3A and the fuse 3A can be reduced.

FIG. 2 is a plan view showing a second embodiment of the redundant circuit fuse of the present invention.

In the present embodiment, the fuse 3A that is actually cut is adjacent to the wiring 1 made of a different material. Therefore, by using a material that is harder to cut than the fuse 3A for this wiring 1, the adjacent fuse 3A is irradiated. It is less susceptible to laser cutting and the like.

[0012]

As described above, the redundant circuit fuse of the present invention is provided with the laser beam irradiation window formed in a zigzag shape, so that when the fuse is blown by the laser beam, the adjacent fuse is blown. There is an effect that it is possible to prevent it from being cut off. Further, there is an effect that the interval between the fuses can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of a redundant circuit fuse of the present invention.

FIG. 2 is a plan view showing a first embodiment of a redundant circuit fuse of the present invention.

FIG. 3 is a plan view showing an example of a conventional redundant circuit fuse.

[Explanation of symbols]

 1 Wiring 2 Contact 3, 3A, 3B Fuse 4, 5 Irradiation window

Claims (1)

Claim: What is claimed is: 1. A first redundant circuit, which is a redundant circuit in use, and a second redundant circuit, which is an unnecessary redundant circuit. The first and second redundant circuits are arranged at equal intervals. Redundant circuit of semiconductor integrated circuit including first and second fuses respectively connected to the redundant circuit, and an irradiation window for irradiating the second fuse with a laser beam for separating the second redundant circuit Fuse for a redundant circuit, comprising: a second fuse that is blown by the laser beam, and the irradiation window formed in a zigzag shape so as not to irradiate the first fuse adjacent to each other.