JPH07231040A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve the reliability of a semiconductor device which has a fuse by reducing the depth of holes generated on the protecting film and the interlayer insulating film under the protecting film at the time of fusing the fuse. CONSTITUTION:A semiconductor device comprises a fuse which is formed of a conductive film 9 on the topmost layer insulating film 8 on a semiconductor substrate 1. Therefore, the conductive film 9 is the barrier metal film inserted between a pad 10 and a bump 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a fuse blown semiconductor integrated circuit device.

When forming a convex bump on an aluminum (Al) pad which is an external lead terminal of an integrated circuit, a barrier metal film is inserted between the pad and the bump to prevent a reaction between the pads.

The present invention relates to a device having a barrier metal film between a pad and a bump, which requires a fuse for a redundant circuit, a fuse for finely adjusting variations in element characteristics due to a wafer process. Can be used for analog LSIs that require

[0004]

2. Description of the Related Art FIGS. 2A and 2B are explanatory views of a conventional fuse. In FIG. 2 (A), 1 is a semiconductor substrate, 2 is a first layer interlayer insulating film, 3 is a first layer wiring, 4 is a second layer interlayer insulating film, 5 and 6 are interlayer connecting conductors (VIA), and 7 is The second layer wiring, 8 is the uppermost protective film.

The fuse is formed by using the second layer wiring 7, and is connected to the cut portion of the first layer wiring by the interlayer connecting conductor 5. Further, the uppermost protective film is formed thin on the fuse by a photolithography process to facilitate the cutting of the fuse.

For example, in a memory LSI, as one of means for giving a redundant signal, an aluminum provided inside the LSI is used.
A signal is given by irradiating a fuse composed of (Al) wiring and a polysilicon film with an energy beam such as a laser beam, and cutting the fuse to electrically open it.

FIG. 2B shows a state in which the fuse is blown by the irradiation of laser light.

[0008]

In the fuse having the structure of the conventional example, when the fuse is blown, a hole that penetrates the protective film 8 and reaches the underlying interlayer insulating film is opened, and this hole is the element of the chip. Since it is on the area, the reliability of the device has been significantly reduced.

Further, in order to facilitate the cutting of the fuse, it is necessary to prepare a photomask for the lithography process for removing a part of the protective film. An object of the present invention is to reduce the depth of the holes formed in the protective film and the interlayer insulating film thereunder when the fuse is blown, and improve the reliability of the device.

[0010]

Means for Solving the Problems To solve the above problems, 1) a semiconductor device having a fuse made of a conductive film 9 formed on an uppermost insulating film 8 deposited on a semiconductor substrate 1, or 2 3. The semiconductor device according to 1), wherein the conductive film 9 is a barrier metal film inserted between the pad 10 and the bump 11.

[0011]

In the present invention, the barrier metal film formed between the pad and the bump is formed on the uppermost layer of the uppermost protective film. Therefore, if the fuse is formed by using this barrier metal film, the barrier metal film will be the maximum. Since it exists in the upper layer, it is possible to minimize the depth of the holes formed in the protective film and the interlayer insulating film below it when the fuse is blown.

Further, since the barrier metal film is present in the uppermost layer, there is no need for a lithography process for removing a part of the protective film formed on the upper layer of the barrier metal film unlike the conventional example, and the pad is formed. After that, the extra barrier metal is usually removed by the lithography process, but the fuse formation can be realized by inserting the fuse pattern into the mask used in the process, thus reducing the manufacturing process.

[0013]

1 (A) to 1 (C) are explanatory views of a fuse of an embodiment of the present invention. In FIG. 1 (A), 1 is a semiconductor substrate,
2 is the first interlayer insulating film, 3 is the first wiring layer, 4 is the second interlayer insulating film, a phosphosilicate glass (BPSG) film containing boron, 5, 6
Is an inter-layer connection conductor (VIA), 7 is a second layer wiring, 8 is an uppermost insulating protective film, 9 is a barrier metal film of titanium (Ti) / palladium (Pd) laminated film, or Ti / nickel (Ni ) Laminated film, 10
Is a pad made of Al alloy film or the like (which may be a power supply pad or a signal pad), and 11 is a bump made of gold (Au), lead tin (PbSn) or the like.

The fuse is formed using the barrier metal film 9 as follows. First, a protective film 8 is opened by using a lithographic technique, and an interlayer connecting conductor is formed at a cut portion of the first layer wiring.
The connection portion of the second-layer wiring 7 connected by 5, 6 is exposed, a barrier metal film 9 is formed on the entire surface of the substrate so as to cover the connection portion, and this is patterned.

At the same time in the above process, the protective film 8 is opened to expose the pad 10, and the barrier metal film 9 is formed thereon.
Are formed, and the bumps 11 are formed thereon. Figure 1 (B) shows the state in which the fuse is blown by the irradiation of laser light.

As shown in the figure, in the embodiment, since the fuse is in the uppermost layer, the holes caused by the blowout of the fuse are shallow. FIG. 1C is a plan view of the fuse of the embodiment.

In this example, the fuse formed of the barrier metal film 9 has a narrow cutting position to facilitate the cutting. Although the fusing by the laser beam is described in the embodiment, according to the present invention, since the fuse exists in the uppermost layer,
Since it can be formed to extend outside the element region, it is also possible to directly contact the probes at both ends of the fuse to pass an electric current, and to melt the fuse by Joule heat.

Further, in the present invention, since the fuse exists in the uppermost layer, not only the wiring is cut but also the focused ion beam is used.
(FIB) It is also possible to connect the wiring by a device,
It is also possible to reproduce the fuse.

[0019]

According to the present invention, it is possible to reduce the depth of the holes formed in the protective film and the underlying interlayer insulating film when the fuse is blown, and improve the reliability of the device.

Further, since the fuse forming position can be freely selected, various cutting methods can be used and wiring can be connected. Further, it is possible to reduce one lithography process for forming the fuse.

[Brief description of drawings]

FIG. 1 is an explanatory view of a fuse according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a conventional fuse.

[Explanation of symbols]

1 Semiconductor substrate 2 1st layer interlayer insulating film 3 1st layer wiring 4 2nd layer interlayer insulating film 5, 6 Interlayer connection conductor (VIA) 7 2nd layer wiring 8 Topmost protective film 9 Barrier metal film Ti / Pd Laminated film or Ti / Ni laminated film 10 Pad 11 Bump made of Au, PbSn, etc.

Claims (2)

[Claims] 1. A semiconductor device having a fuse made of a conductive film (9) formed on an uppermost insulating film (8) deposited on a semiconductor substrate (1). 2. The conductive film (9) comprises a pad (10) and a bump (1).
The semiconductor device according to claim 1, which is a barrier metal film inserted between 1).