JP2913768B2 - Semiconductor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly, to a semiconductor device having a programmable element connected to a redundant bit.

[Conventional technology]

In recent years, the capacity of semiconductor devices, especially semiconductor memory devices, has been increased. However, as the storage capacity per chip has increased, it has become increasingly difficult to keep the manufacturing yield above a practical level. . This decrease in yield is often caused by the fact that a storage element of a few bits out of the total storage capacity is not operating. In order to remedy such defects and improve the yield, one of the devices is required. A technique has been adopted in which a redundant bit and a programmable element are provided in a unit, and a defective bit is switched to a redundant bit by, for example, disconnecting the programmable element.

For example, FIG. 5 shows a programmable element connected to this kind of redundant bit, and a part of an aluminum wiring formed on the semiconductor substrate 1 is constituted by a polycrystalline silicon film 5. The polycrystalline silicon film 5 is electrically connected to the aluminum wiring 10 by contacts 8 at both ends.

At the time of repairing the defect, by passing an overcurrent through the aluminum wiring 10 to the polycrystalline silicon film 5, the polycrystalline silicon film 5 itself is blown by the heat generated by the resistance of the polycrystalline silicon film 5. become.

In addition, a programmable element in which a part of the wiring is broken by a laser has been proposed, but the description is omitted here.

[Problems to be solved by the invention]

In a semiconductor device using such a polycrystalline silicon film 5 as a programmable element, a current is caused to flow through the polycrystalline silicon film 5 at the time of repairing a defect, and fusing is performed. Most (99.9%)
Is dissipated to the periphery and does not effectively act as heat for blowing the polycrystalline silicon film 5. For this reason, in order to generate the amount of heat required for fusing, it is necessary to supply extremely large electric power for a long time. This defect remedy is usually performed at the time of a sorting test of a semiconductor device or the like. However, since the current must be supplied for a long time, there is a problem that the sorting throughput is reduced.

In the conventional programmable element, since it is not specified which part of the polycrystalline silicon film 5 is blown, another wiring is arranged in a region where the polycrystalline silicon film 5 extends so as to intersect with the region. And there is a problem that the degree of freedom of wiring is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device capable of easily fusing a programmable element and increasing the degree of freedom of wiring.

[Means for solving the problem]

The semiconductor device of the present invention is provided with a heating wire wider than the fusing wire made of the same material as the fusing wire as a programmable element connected to the redundant circuit, intersecting with the fusing wire, and providing the heating wire. It is configured to heat a part of the fusing wire by energization.

[Action]

According to the present invention, a portion of the fusing wire is heated by the heat generated by energizing the heating wire, thereby increasing the amount of heat at a specific location of the fusing wire, and the fusing wire is quickly formed in this portion. It can be blown.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a view showing a first embodiment of the present invention. FIG. 1 (a) is a plan view, and FIG. 1 (b) is a cross-sectional view along the line AA. In the figure, reference numeral 1 denotes a semiconductor substrate on which a storage element is formed in a region (not shown). This semiconductor substrate 1
A heating polycrystalline silicon film 3 having a thickness of 0.2 μm is formed in a required pattern on the insulating film 2 provided on the surface of the substrate.
A second insulating film 4 such as PSG is formed to a thickness of 0.1 μm on the heating polycrystalline silicon film 3, and a fusing polycrystalline silicon film 5 as a programmable element is formed in a required pattern on the second insulating film 4. It is formed so as to intersect with the heating polycrystalline silicon film 3. On the polycrystalline silicon film 5 for fusing, 0.
A third insulating film 6 made of PSG having a thickness of 5 μm is formed. Then, contact holes 7 and 8 are formed in the second insulating film 4 and the third insulating film 6, respectively, and the heating polysilicon film 3 and the blowing polysilicon film are passed through the contact holes 7 and 8, respectively. Aluminum wiring 9 and 10 respectively
Connect.

Here, the width of the blowing polycrystalline silicon film 5 is made as narrow as possible so as to be easily blown, and the width of the heating polycrystalline silicon film 3 is made as wide as possible.

According to this configuration, when a defect is repaired in the semiconductor device, if a current is passed through the heating polysilicon film 3 through the aluminum wiring 9, the heating polysilicon film 3 is removed.
Is heated at the intersection, here the center, of the fusing polycrystalline silicon film 5. At the same time, when current is applied to the fusing polycrystalline silicon film 5, heat generated by the fusing polycrystalline silicon film 5 itself is applied, and the fusing of the fusing polycrystalline silicon film 5 is enabled by these heats. . In this case, it is needless to say that the fusing location of the fusing polycrystalline silicon film 5 is a location crossing the heating polycrystalline silicon film 3.

Therefore, in this semiconductor device, an electric current is caused to flow simultaneously through the heating polycrystalline silicon film 3 and the fusing polycrystalline silicon film 5, and the fusing polycrystalline silicon film 5 is blown off by the heat generated by each of them. Fusing can be performed in a long time, and sorting throughput and the like can be improved.

Further, since the fusing portion is specified in the polycrystalline silicon film 5 for fusing, it is possible to intersect another wiring at another location, and the degree of freedom of wiring can be improved.

FIG. 2 is a plan view of a second embodiment of the present invention, and the same parts as those in the first embodiment are denoted by the same reference numerals.

In this embodiment, while the width dimension of the heating polycrystalline silicon film 3 is made sufficiently large compared to the width dimension of the fusing polycrystalline silicon film 5, the heating polycrystalline silicon film 3 and the fusing polycrystalline silicon Part of the aluminum wirings 9 and 10 connected to the film 5 is shared by the aluminum wirings 10 and the current supply lines are shared.

In this case, the same current is passed through the heating polycrystalline silicon film 3 and the fusing polycrystalline silicon film 5 at the same time, thereby fusing the polycrystalline silicon film 5 for fusing. Even if the same current is passed in this way, the heating polycrystalline silicon film 3 does not melt itself because the width dimension is increased and the heat resistance is increased. Thereby, simplification of the aluminum wiring can be achieved.

FIG. 3 is a plan view showing a third embodiment of the present invention. In this embodiment, a second polycrystalline silicon film 11 for heating is further formed on the upper layer of the polycrystalline silicon film 5 for fusing with a third insulating film 6 interposed therebetween. Connected to 13. Further, a lower heating polycrystalline silicon film 3 and a second heating polycrystalline silicon film
11 are formed so as to have V-shaped plane shapes in opposite directions, and are arranged so as to vertically sandwich a central portion of the polycrystalline silicon film 5 for fusing at respective intermediate portions.

According to this configuration, a current is passed through each of the heating polycrystalline silicon film 3 and the second heating polycrystalline silicon film 11, thereby heating the central portion of the fusing polycrystalline silicon film 5 from above and below. The blowing of the blowing polycrystalline silicon film 5 in this portion can be performed more quickly.

As shown in FIG. 4, a lower heating polycrystalline silicon film 3 and an upper second heating polycrystalline silicon film 11 are formed in a vertically overlapping pattern, The crystalline silicon films 3 and 11 may be commonly connected to the aluminum wiring 9. By doing so, both heating polycrystalline silicon films are passed through the aluminum wiring 9.
Electric currents can be simultaneously applied to 3 and 11, and the central portion of the polycrystalline silicon film 5 for fusing can be heated from above and below, respectively, and aluminum wiring can be simplified.

The heating wiring made of the heating polycrystalline silicon film may be made of a material other than polycrystalline silicon.

[Effects of the Invention] As described above, the present invention is configured to heat a part of the fusing wire by energizing the heating wire intersecting the fusing wire as a programmable element, The fusing wire can be quickly blown at a specific location, thereby improving the throughput and the degree of freedom in wiring.

Further, in the present invention, since the fusing wiring and the heating wiring are formed of the same material, the number of types of materials constituting the semiconductor device can be reduced, and both wirings can be manufactured by the same manufacturing technology. This is advantageous in reducing the price.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention. FIG. 1 (a) is a plan view, FIG. 1 (b) is a sectional view taken along line AA, and FIG. 2 is a second embodiment of the present invention. FIG. 3 is a plan view of a third embodiment of the present invention, FIG. 4 is a plan view showing a modification of the third embodiment, and FIG. 5 is a plan view of a conventional programmable element. DESCRIPTION OF SYMBOLS 1 ... Semiconductor substrate, 2 ... Insulating film, 3 ... Polycrystalline silicon film for heating, 4 ... Second insulating film, 5 ... Polycrystalline silicon film for fusing, 6 ... Third insulating film, 7, 8 ... Contact hole , 9,10
... aluminum wiring, 11 ... second heating polycrystalline silicon film, 12 ... contact hole, 13 ... aluminum wiring.

Claims (1)

(57) [Claims] 1. A semiconductor device in which a part of a wiring connected to a redundant circuit is constituted by a fusing wire, and a current is applied to the wiring to blow the fusing wire. A heating wire wider than the fusing wire is provided so as to intersect with the fusing wire, and a portion of the fusing wire is heated by energizing the heating wire. Semiconductor device.