JPH026091A - Laser beam processing device - Google Patents

Abstract

PURPOSE:To improve the quality of laser beam cutting and to miniaturize the processing device by forming the irradiation region of laser light to the length at which cutting is possible in the short side direction of an object to be cut and to the length shorter than the length of the short side direction in the long side direction. CONSTITUTION:The irradiation region A of the laser light to a fuse 11 is set at the time of cutting the fuse 11, etc., by using the processing laser light 12. Namely, the region is so set as to have the length X at which the fuse 11 can be cut in the direction along the short side of the fuse and the length Y shorter than the length X in the direction along the long side. Since the length Y along the long side direction of the fuse 11 can be shortened in this way, the length l1 of the fuse 11 is shortened. The disposition area of the fuse part 11 is, therefore, reduced as a whole. Further, the generation of the uncut part is prevented, as the length X in the short side direction is determined as the cuttable length. The quality of the laser cutting is thus improved and the processing device is miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a laser processing apparatus for cutting wiring of semiconductor integrated circuits with high precision.

2. Description of the Related Art Semiconductor integrated circuits are becoming more dense and highly integrated as microfabrication technology advances year by year. In particular, semiconductor memories are becoming more highly integrated through microfabrication, resulting in larger capacities. However, as the area of semiconductor chips increases, yields decrease due to pattern defects caused by dust and the like. Therefore, by cutting the wiring and fuses on the chip,
A redundancy repair technique is used in which a defective memory cell is replaced with a spare memory cell previously provided on the same chip, thereby converting the defective memory cell into a non-defective product.

Conventionally, this fuse is cut by cutting a fuse 1 having a length ρ2 in the long side direction and a length W in the short side direction, as shown in FIG. 2(a).
Then, a laser beam forming a square irradiation area 2 with side C or a laser beam forming a circular irradiation area 3 with diameter C was irradiated to heat and fuse.

Problems to be Solved by the Invention However, as large-capacity memories become available, the number of spare memory cells that are provided on the same chip increases, and the number of fuses 1 increases, resulting in the problem that the overall area occupied by the fuse portion increases. Ta. In order to reduce the area occupied by this fuse part, the length of the fuse 1 in the long side direction ρ2
Therefore, it is necessary to shorten the length W2 of the fuse 1 in the short side direction and reduce the fuse interval. In FIG. 2(a), the length ρ2 of the fuse 1 in the long side direction is determined by the length C of the laser beam irradiation and the margin length 2·e in the long side direction for the alignment error of the irradiated laser beam. .

Therefore, ρ2=C+2·e. Further, the length W2 of the fuse 1 in the short side direction is determined according to the minimum mask rule, and the interval between the fuses 1 is determined by the length of the irradiated laser beam in the short side direction of the fuse 1 and an alignment error. Therefore, by reducing the size of the irradiation area of the irradiated laser beam and the alignment error of the irradiated laser beam as much as possible, it is possible to reduce the area occupied by the fuse portion. The alignment error of the irradiated laser beam can be reduced by improving the hardware.

However, in order to shorten the length of the fuse in the long side direction, as shown in Figure 2 (b), the length of one side of the irradiation area is shortened, and d is shorter than C, so that the irradiation is performed at an angle of dXd. When a fuse is cut using a laser beam that forms area 4 or a laser beam that forms a circular irradiation area 5 with diameter d, an uncut portion 6 that is connected by the fuse material that has blown away occurs in the periphery, resulting in complete unnecessary cutting. The problem was that it became impossible to do so.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a laser processing device that can completely cut a fuse without creating an uncut portion, and also does not make it possible to reduce the arrangement area of the fuse portion. do.

Means for Solving the Problems In order to solve the above problems, the present invention provides a method in which the irradiation area of the processing laser beam on the cutting object cuts the cutting object in a direction along the short side of the cutting object. 1tli, and has a length shorter in the direction along the long side of the object to be cut than the length in the direction along the short side.

Effect With the above configuration, the length of the irradiation area along the long side direction of the fuse is reduced, thereby shortening the length of the fuse in the long side direction determined by the sum of the length of the irradiation area and the alignment error. Try to reduce the area where the parts are placed. By setting the length of the irradiation area along the short side of the fuse to a length that can cut the object to be cut, when the fuse is blown, an uncut part is formed from the fuse material that has blown away around the fuse. Perform a complete amputation.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. In Figure 1, the length in the long side direction is ρ1, and the length in the short side direction is W.
A processing laser beam 12 is irradiated onto the fuse 11 of 1, and the laser processing device that irradiates the processing laser beam 12 is configured so that the irradiation area A of the processing laser beam 12 on the fuse 11, which is the object to be cut, is the same as that of the fuse 11. The fuse 1 has a length X that allows the fuse 11 to be cut in the direction along the short side.
It is configured to have a length Y that is longer than X in the direction along the long side of 1. For example, if w1=1.2 μm, then X=4.0 μm and Y<4.0 μm.

The processing laser beam 12 passes through a rectangular hole placed between the laser beam paths to form a circular laser beam into a rectangular shape. Further, in order to form an elliptical shape like the irradiation area B, a lens is used which becomes an elliptical shape when the circular laser beam is focused.6 Hereinafter, the operation of the above configuration will be explained.

That is, the length Y' along the long side direction of the fuse 11 in the irradiation area A? ! -By making it shorter, Y+2・e−
By shortening the length Ω1 of the fuse 11 determined by ρ1, the overall layout area of the fuse portion is reduced.

Then, by setting the length X along the short side direction of the fuse 11 in the irradiation area A to a length that is one finger long enough to cut the fuse 11, the fuse 11 can be cut. ``When Rl-folded, it is possible to prevent the formation of uncut portions and perform complete cutting.

Effects of the Invention As described above, according to the present invention, by shortening the irradiation area of the processing laser beam in the long side direction of the object to be cut, the area in which the object to be cut is arranged can be reduced. As a result, the area of the device to be laser processed can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram showing a laser beam irradiation area of a laser processing apparatus according to an embodiment of the present invention, and FIG. 2 is a layout diagram showing a conventional laser irradiation area. 11...Fuse, 12...Processing laser beam, A, B
...irradiation area. Agent Yoshi Morimoto Private 2 (b) T) w,

Claims (1)

[Claims] 1. The irradiation area of the processing laser beam on the cutting target is
It has a length in the direction along the short side of the object to be cut that allows the object to be cut, and has a length in the direction along the long side of the object to be cut that is shorter than the length in the direction along the short side of the object to be cut. Laser processing equipment with length.