SEMICONDUCTOR DEVICE WITH METAL FUSES

Abstract

A trench dummy element isolating region is formed in the fuse region of a semiconductor substrate. In the semiconductor substrate, a plurality of dummy element regions is formed so as to be enclosed by the trench dummy element isolating region. The occupancy rate of the plurality of dummy element regions in the fuse region is equal to or larger than a specific value. On the semiconductor substrate including the dummy element isolating region and dummy element regions, a plurality of metal fuses composed of multilayer metal wiring lines are formed via an interlayer insulating film. The plurality of dummy element regions are formed only below at least a part of the plurality of metal fuses.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a plan view of an LSI according to a first embodiment of the present invention;

FIG. 2 is a plan view schematically showing a pattern of the bottom-layer metal wiring and contact section in the LSI of FIG. 1;

FIG. 3 is a plan view schematically showing a pattern of a trench dummy element isolating region provided below the 4-layer metal wiring in the LSI of FIG. 1;

FIG. 4 is a sectional view showing a first step in an LSI manufacturing method shown in FIGS. 1 to 3;

FIG. 5 is a sectional view to help explain a step following FIG. 4;

FIG. 6 is a sectional view to help explain a step following FIG. 5;

FIG. 7 is a sectional view to help explain a step following FIG. 6;

FIG. 8 is a sectional view to help explain a step following FIG. 7;

FIG. 9 is a sectional view to help explain a step following FIG. 8;

FIG. 10 is a plan view of an LSI according to a second embodiment of the invention;

FIG. 11 is a plan view of an LSI according to a third embodiment of the invention; and

FIG. 12 is a sectional view of an LSI according to a fourth embodiment of the invention.

Claims

1. A semiconductor device with metal fuses comprising: a semiconductor substrate which has a fuse region;a trench dummy element isolating region which is formed in the semiconductor substrate;a plurality of first dummy element regions which is formed in the semiconductor substrate, said plurality of first dummy element regions being enclosed by the trench dummy element isolating region and whose occupancy rate in the fuse region is equal to or larger than a specific value; anda plurality of metal fuses which is composed of multilayer metal wiring lines and which is formed via an interlayer insulating film in the fuse region on the semiconductor substrate including the trench dummy element isolating region and first dummy element regions,wherein said plurality of first dummy element regions is formed only below at least a part of said plurality of metal fuses.

2. The semiconductor device according to claim 1, wherein each of said plurality of first dummy element regions has the same planar shape as that of the corresponding one of the metal fuses above in the same plane position as that of the metal fuse.

3. The semiconductor device according to claim 1, wherein each of said plurality of first dummy element regions has a smaller planar shape than that of the corresponding one of the metal fuses above in the same plane position as that of the metal fuse.

4. The semiconductor device according to claim 1, wherein each of said plurality of first dummy element regions is formed to extend to below a fuse control circuit wiring line junction connecting with each of said plurality of metal fuses.

5. The semiconductor device according to claim 1, wherein the substrate surface of each of said plurality of first dummy element regions formed below each of said plurality of metal fuses is turned into salicide.

6. The semiconductor device according to claim 1, wherein the substrate surface of each of said plurality of dummy element regions formed below each of said plurality of metal fuses is not turned into salicide.

7. The semiconductor device according to claim 1, wherein the total of the areas occupied by the first dummy element regions in the fuse region is 20% or more of the area of the fuse region.

8. The semiconductor device according to claim 1, wherein the fuse region is provided in the trench dummy element region, a plurality of second dummy element regions being formed in the trench dummy element region.

9. A semiconductor device with metal fuses comprising: a semiconductor substrate which has a fuse region;a trench dummy element isolating region which is formed in the semiconductor substrate;a plurality of first dummy element regions which is formed in the semiconductor substrate, said plurality of first dummy element regions being enclosed by the trench dummy element isolating region and whose occupancy rate in the fuse region is equal to or larger than a specific value; anda plurality of metal fuses which is composed of multilayer metal wiring lines and which is formed via an interlayer insulating film in the fuse region on the semiconductor substrate including the trench dummy element isolating region and first dummy element regions,wherein said plurality of first dummy element regions is formed below all of said plurality of metal fuses.

10. The semiconductor device according to claim 9, wherein each of said plurality of first dummy element regions has the same planar shape as that of the corresponding one of the metal fuses above in the same plane position as that of the metal fuse.

11. The semiconductor device according to claim 9, wherein each of said plurality of first dummy element regions has a smaller planar shape than that of the corresponding one of the metal fuses above in the same plane position as that of the metal fuse.

12. The semiconductor device according to claim 9, wherein each of said plurality of first dummy element regions is formed to extend to below a fuse control circuit wiring line junction connecting with each of said plurality of metal fuses.

13. The semiconductor device according to claim 9, wherein the substrate surface of each of said plurality of first dummy element regions formed below each of said plurality of metal fuses is turned into salicide.

14. The semiconductor device according to claim 9, wherein the substrate surface of each of said plurality of first dummy element regions formed below each of said plurality of metal fuses is not turned into salicide.

15. The semiconductor device according to claim 9, wherein the total of the areas occupied by the first dummy element regions in the fuse region is 20% or more of the area of the fuse region.

16. The semiconductor device according to claim 9, wherein the fuse region is provided in the trench dummy element region, a plurality of second dummy element regions being formed in the trench dummy element region.

17. A semiconductor device with metal fuses comprising: a semiconductor substrate which has a fuse region;a trench dummy element isolating region which is formed in the semiconductor substrate;a plurality of first dummy element regions which is formed in the semiconductor substrate, said plurality of first dummy element regions being enclosed by the trench dummy element isolating region and whose occupancy rate in the fuse region is equal to or larger than a specific value;a plurality of multilayer metal wiring lines formed via an interlayer insulating film in the fuse region on the semiconductor substrate; anda plurality of metal fuses which is formed on said plurality of multilayer metal wiring lines and is electrically connected to said plurality of multiplayer metal wiring lines in a one-to-one correspondence,wherein said plurality of first dummy element regions is formed below all of said plurality of metal fuses.

18. The semiconductor device according to claim 17, wherein each of said plurality of first dummy element regions has the same planar shape as that of the corresponding one of the metal fuses above in the same plane position as that of the metal fuse.

19. The semiconductor device according to claim 17, wherein the total of the areas occupied by the first dummy element regions in the fuse region is 20% or more of the area of the fuse region.

20. The semiconductor device according to claim 17, wherein the fuse region is provided in the trench dummy element region, a plurality of second dummy element regions being formed in the trench dummy element region.