KR20030054904A - Method of forming a metal fuse in semiconductor device - Google Patents

Abstract

PURPOSE: A method for forming a metal fuse of a semiconductor device is provided to be capable of easily obtaining laser repair, and reducing the area of metal fuse by improving the stacked structure of metal fuse. CONSTITUTION: A plurality of lower conductive fuses(15) are formed on the first insulating layer(11). The second insulating layer(12) is formed on the first insulating layer. A plurality of upper conductive fuses(14) are formed on the second insulating layer without overlapping the lower conductive fuses(15), wherein the upper conductive fuses(14) bend to 90 degree. The third insulating layer(13) is formed on the resultant structure. The third insulating layer(13) is selectively removed to expose the upper conductive fuse(14) for laser repairing. The second insulating layer(12) is selectively removed to expose the lower conductive fuse(15) for laser repairing.

Description

Method of forming a metal fuse in semiconductor device

The present invention relates to a method for forming a metal fuse of a semiconductor device, by forming a metal fuse in a stack to reduce the area of the metal fuse in the chip (Chip), the upper metal fuse is refracted by the lower metal fuse by the laser The present invention relates to a method for forming a metal fuse of a semiconductor device that can be easily repaired.

In general, a method of repairing a fuse is performed by breaking a fuse made of a polysilicon layer or a metal layer using a laser beam to address redundancy. Is done by assigning

1 is a layout diagram of a metal fuse according to the related art.

As shown in FIG. 1, the first to fourth metal fuses 4 are formed of the same layer. If the first metal fuse 4 is repaired by a laser, the surrounding second to fourth metal fuses 4 should not be affected by the laser light.

2A is a cross-sectional view taken along the line A-A of FIG. 1.

As shown in FIG. 2A, after forming the first and second dielectric layers 1 and 2 on the semiconductor substrate, first to fourth metal fuses 4 are formed on the second dielectric layer 2. The third dielectric layer 3 is formed on the entire structure.

2B and 2C are cross-sectional views taken along line B-B of FIG. 1.

As shown in FIGS. 2B and 2C, after the photoresist 5 is coated on the semiconductor substrate, a photoresist pattern is formed by performing an exposure and etching process using a metal fuse mask. A portion of the third dielectric layer 3 is etched using the photoresist pattern to form a thin dielectric layer on the first to fourth metal fuses 4. This makes it easy to cut the metal fuse at the time of laser repair.

In the prior art, the laser light should not affect the surrounding metal fuse when cutting the metal fuse using the metal fuse using the laser. Therefore, the gap between metal fuses should be kept constant. As a result, the size of the entire chip is increased.

In addition, when the metal fuses are stacked in the prior art, when the upper and lower metal fuses are configured in parallel with each other, high precision is required when cutting the metal fuses using a laser beam. If wrong, a problem arises that the unwanted fuse can be blown.

Accordingly, an object of the present invention is to provide a metal fuse of the semiconductor device is formed by stacking the metal fuse in a stack and the upper metal fuse 90 ° to be deposited in order to solve the above problems.

According to one aspect of the present invention, the size of the chip can be reduced by forming the metal fuse in a stack.

According to another feature of the present invention, the upper metal fuse may be refracted to facilitate the repair of the lower metal fuse by the laser.

1 is a layout diagram of a metal fuse according to the prior art.

2A is a cross-sectional view taken along the line A-A of FIG. 1;

2B and 2C are cross-sectional views taken along the line B-B of FIG. 1.

3 is a layout diagram of a metal fuse formed in accordance with the present invention.

4 to 6 are plan views illustrating a process of removing a portion of the insulating film on the metal fuse so that the metal fuse according to the present invention can be easily cut by a laser.

7 is a cross-sectional view taken along the line X-X of FIG. 3 in accordance with the present invention.

8A to 8C are cross-sectional views taken along the line Y-Y of FIG. 7 for explaining a process in which the metal fuse according to the present invention exposes a portion of the metal fuse to facilitate cutting by a laser;

<Explanation of symbols for the main parts of the drawings>

1, 2, 3, 11, 12, 13: insulating film 4, 14, 15: metal fuse

5, 16, 17: photoresist

Forming a plurality of lower conductive fuses spaced apart from each other on the first insulating layer, forming a second insulating layer on the first insulating layer on which the lower fuse is formed, and forming the lower conductive fuses on the second insulating layer. And forming a plurality of upper conductive fuses which are bent to the left or right and spaced apart from each other, wherein a third insulating layer is formed on the entire structure, and the third insulating layer is formed by using the laser as the upper conductive fuse. And removing the second insulating layer to a depth capable of cutting the lower conductive fuse with a laser cuttable depth, and removing the second insulating layer to a depth that can be cut by a laser.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail.

3 is a layout diagram of a metal fuse according to the present invention.

7 is a cross-sectional view taken along line X-X of FIG. 3 according to the present invention.

3 and 7, the first to fourth metal fuses 14 of the A region and the fifth to seventh metal fuses 15 of the B region are alternately deposited. Moreover, it was comprised so that the 1st-4th metal fuse 14 of area | region A may be bent vertically.

Specifically, after the first insulating layer 11 is deposited to insulate the lower substrate, the fifth to seventh metal fuses 15 are deposited on the first insulating layer 11. After the second insulating layer 12 is deposited on the entire structure in which the fifth to seventh metal fuses 15 are deposited, the first to fourth metal fuses 14 are disposed in the A region above the second insulating layer 12. Is deposited so that it is bent in 90 ° shape. In this case, the first to fourth metal fuses 14 are alternately deposited with the fifth to seventh metal fuses 15. Thereafter a third insulating layer 13 is deposited over the entire structure.

4 to 6 are plan views illustrating a process of removing a portion of an insulating film on a metal fuse so that the metal fuse according to the present invention can be easily cut by a laser.

8A to 8C are cross-sectional views taken along the line Y-Y of FIG. 7 for explaining a process of exposing a part of the metal fuse so that the metal fuse according to the present invention may be easily cut by a laser.

4 and 8A, after the first photoresist 16 is coated on the third insulating layer 13, an exposure and etching process is performed using a mask for metal fuses to form the first photoresist ( 16) Form a pattern. A portion of the third insulating layer 13 including the A and B regions is etched using the first photoresist 16 pattern to have a thickness of about 6000 μs on the first to fourth metal fuses 14 of the A region. A thin insulating layer is formed. By removing the first photoresist 16 pattern, the metal fuse of the A region can be easily cut during laser repair.

As shown in FIGS. 5 and 8B, the second photoresist 17 is deposited in the region A, and then etched to form a part of the third insulating layer 13 and the second insulating layer 12 in the region B. FIG. To form a thin insulating layer having a thickness of about 6000 kPa on the fifth to seventh metal fuses 15 in the region B.

As shown in FIG. 6 and FIG. 8C, it is possible to easily cut the metal fuse of the B region during laser repair by removing the second photoresist 17 pattern of the A region.

By forming the metal fuses in a stack, a larger number of fuses can be formed in the same area. Also, the upper and lower portions of the metal fuses formed in a stacked structure are alternately formed to prevent the lower metal fuses from being cut by the strong laser beam. have. And by forming the upper metal fuse 90 ° can be easily cut the lower metal fuse.

As described above, the present invention can reduce the area occupied by the metal fuse in the chip by forming the metal fuse in a stack.

In addition, the upper and lower metal fuses are formed alternately to prevent the lower fuse from being cut when the upper metal fuses are cut.

Further, by refracting the upper metal fuse, the lower metal fuse can be easily cut by the laser.

Claims (3)

Forming a plurality of lower conductive fuses spaced apart from each other on the first insulating layer; Forming a second insulating layer on the first insulating layer on which the lower fuse is formed; Forming a plurality of upper conductive fuses formed on the second insulating layer so as not to overlap the lower conductive fuses and bent left or right and spaced apart from each other; Forming a third insulating layer on the entire structure; Removing the third insulating layer to a depth capable of laser cutting the upper conductive fuse; And And removing the second insulating layer to a depth capable of cutting the lower conductive fuse with a laser beam. The method of claim 1, The upper and lower conductive fuses are formed by metal or polysilicon. The method of claim 1, And the thin insulating layer on the upper and lower metal fuses has a thickness of 6000 kPa.