Static information storage and retrieval – Read only systems – Fusible
Reexamination Certificate
1999-07-12
2001-01-09
Dinh, Son T. (Department: 2824)
Static information storage and retrieval
Read only systems
Fusible
C365S225700, C257S529000, C257S209000
Reexamination Certificate
active
06172896
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to integrated circuit devices, and more particularly, to layout arrangements of fuse boxes for integrated circuit devices, such as integrated circuit memory devices.
BACKGROUND OF THE INVENTION
Integrated circuit memory devices are widely used in consumer and commercial systems. As is well known, memory devices may be tested in various manners using several test parameters for determining whether they operate properly. However, a memory device whose cells are partly defective can be used normally if the defective cells are replaced with redundancy memory cells. The memory cells and the redundancy memory cells are connected to control circuits through fuses. Thus, if there is a defective memory cell, the fuse connected to the defective memory cell may be blown. Then, the redundancy memory cells are driven so that the defective memory cells are replaced with the redundancy memory cells.
Fuses for use in memory devices include electrical fuses blown by electricity and laser fuses blown by a laser beam. Electrical fuses arc typically used in Electrically Erasable and Programmable Read Only Memory (EEPROM) devices and laser fuses are typically used in Dynamic Random Access Memory (DRAM) devices.
FIG. 1A
is a layout arrangement diagram in a laser fuse box of a conventional integrated circuit memory device. Referring to
FIG. 1A
, laser fuses
111
through
116
, used in a conventional memory device
101
, have uniform widths W
1
and pitches P
1
. Central portions
131
of the laser fuses
111
through
116
are blown by a laser.
As shown in
FIG. 1A
, if the pitches P
1
of the laser fuses
111
through
116
are each the same, reducing the size of the memory device
101
may reduce the pitches P
1
of the laser fuses
111
through
116
accordingly. If the pitches P
1
of the laser fuses
111
through
116
are reduced, laser fuses adjacent a specific laser fuse to be blown may be damaged.
FIG. 1B
is another layout arrangement diagram in a laser fuse box of a conventional memory device, which is disclosed in U.S. Pat. No. 5,747,869 to Prall et al. Referring to
FIG. 1B
, laser fuses
151
through
156
have narrow ends
151
a
through
156
a
, and wide ends
151
b
through
156
b
. Spaces S
1
and S
2
are beside the narrow ends
151
a
and
156
a
of the laser fuses
151
and
156
, as shown in FIG.
1
B. As the size of integrated circuit devices continues to decrease and the number of devices incorporated into integrated circuit devices continues to increase, it may be desirable to increase the laser fuse density. It also may be desirable to increase the laser fuse density without the need to reduce the pitch between fuses.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide integrated circuit devices in which when fuses are blown, the neighboring fuses need not be damaged.
It is another object of the present invention to provide integrated circuit devices that can increase the density of fuses.
These and other objects are provided according to the present invention, by a fuse box for an integrated circuit device that includes a plurality of spaced-apart fuses, each having a narrow end and a wide end and extending along a predetermined direction. The fuses occupy a rectangular area in the integrated circuit device, and at least one of the spaced-apart fuses has a bent central portion. By occupying a rectangular area, large spacing may be obtained between fuses, to reduce the likelihood of damage to adjacent fuses. Also, the density of the fuses may be increased.
More specifically, an integrated circuit device such as an integrated circuit memory device, includes a first fuse group such as a first laser fuse group including a plurality of first laser fuses each having a first narrow end, and a second opposite end which is wider. At least one of the plurality of first fuses includes a bent central portion. Pitches of the first end of the plurality of first laser fuses are narrow and pitches of the second end are wide. The plurality of first laser fuses are adjacent one another. A second fuse group such as a second laser fuse group includes a plurality of second laser fuses each having a first wide end, and a second opposite end which is narrower. At least one of the plurality of second fuses includes a bent central portion. Pitches of the first end of the plurality of second laser fuses are wide and pitches of the second end are narrow. The second plurality of laser fuses are adjacent one another. The bent portions preferably are oblique relative to the first and second ends.
The first ends of the laser fuses in the first laser fuse group are adjacent the first ends of laser fuses in the second laser fuse group. The second ends of the laser fuses in the first laser fuse group are adjacent the second ends of the laser fuses in the second laser fuse group. The central portions of the outer laser fuses of the first and second laser fuse groups are not bent, but straight. Accordingly, when a specific laser fuse is blown, neighboring laser fuses need not be damaged, and the density of the laser fuses may be increased.
REFERENCES:
patent: 5661331 (1997-08-01), Hebbeker et al.
patent: 5747869 (1998-05-01), Prall et al.
patent: 5844296 (1998-12-01), Murray et al.
Dinh Son T.
Myers Bigel & Sibley & Sajovec
Samsung Electronics Co,. Ltd.
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