JPH01169942A - Semiconductor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device, and more particularly to a semiconductor device having a wiring cutting link for programming by cutting the wiring using a laser.

[Conventional technology]

In recent years, as semiconductor integrated circuits have become more highly integrated, an increasing number of semiconductor integrated circuits have built-in programming elements that allow circuit changes after the element is fabricated. Particularly in large-capacity memories, it is becoming increasingly common to replace defective memory elements with spare memory elements to improve yield. Typically, this programming involves cutting wires using a laser. This technology is described in, for example, the ``Proceedings of the National Electron Conference.
ingof National Electron C
onference) Volume 36 (published in 1982) No. 3
85-389''.

Specifically, as shown in FIG. 2(a), the Po1y-8i wiring 13 formed on the Si substrate 11 via the 5i02 film 12 is covered with a phosphor glass layer 14 to insulate it, and the Po1y-8i wiring 13 is
Pulsed light 16 of a YAG laser (wavelength: 1.06 μm) or its second harmonic (wavelength: 0.53 μm) is applied to the link portion in which both ends of the i-wiring 13 are connected to the A1 wire 15.
Programming is performed by irradiating the Po1y-8i wiring 13 with melting and cutting it. As shown in the plan view of FIG. 2(b), the width W of the Po1y-8i wiring 13 forming the wiring cutting link is generally negative.

[Problem that the invention seeks to solve]

In such a link structure with a wiring width like this, the heat of the irradiated laser light tends to escape to the outside due to heat transfer in the direction of the wiring, so it is recommended to cut the wiring by irradiating it with a high-power laser beam as pulsed light. It is taken. However, if the circular area 17 in FIG. 2(b) that sufficiently covers this link part is irradiated with a strong laser beam, not only will the Poly-5i wiring 13 be cut, but the underlying Si substrate 11 will also be damaged. could potentially damage the reliability of the device.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such drawbacks and provide a semiconductor device in which wiring can be cut without damaging the substrate.

[Means for solving problems]

The above object is achieved by providing two or more portions in the wire cutting link with widths that are unequal to other portions.

Examples of implementation include two or more parts in the wire cutting link that are narrower than other parts, and two or more parts in the wiring cutting link that are wider than other parts. There is something.

[For production]

By configuring the wiring cutting link as described above, the heat of the laser beam irradiated on the link part is suppressed from escaping to the outside due to heat transfer in the wiring direction, and more heat is retained in the irradiated area. The link portion can be easily melted and cut using low-power continuous light that does not damage the underlying Si substrate.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a wiring pattern of a program element according to an embodiment of the present invention. In this embodiment, on the Si substrate, two parts (hereinafter referred to as , called the constriction) 3a, 3
b. When a continuous wave laser beam such as an Ar laser is irradiated onto the circular region 4 including the normal width W between the constrictions 3a and 3b of the link 3, heat transfer to both ends of the irradiated portion is reduced to the constriction 3a. , 3b, it is intensively heated to a high temperature, and the center portion 5 is melted and cut. Despite this, the laser beam irradiated is continuous light,
Since the peak power value is low, no damage is caused to the underlying Si substrate.

FIG. 3 shows another embodiment in which the shapes of the constricted portions 3a and 3b in the above embodiment are different, and any of (a) to (b) is effective.

Another embodiment shown in FIG. 4 is an example in which the wiring cutting link 3 is provided with three constrictions 3a, 3b, and 3c, with the central constriction 3c entering the laser beam irradiation area 4. . In this way, the wiring can be cut with lower power, and the underlying Si substrate is less likely to be damaged.

FIG. 5 shows two parts 3d near both ends of the wiring cutting link 3 that are wider than other parts (hereinafter referred to as wide parts);
3a is shown, and any of (a) to (d) is effective as the wiring pattern. In this embodiment, by irradiating a continuous wave laser beam onto a wide region 4 including the wide width portions 3d and 3e of the link 3, and increasing the absorbed heat at the wide width portions 3d and 3e, By preventing heat from escaping in the direction of the wiring, the center part 5 can be easily melted and cut. This makes it possible to cut the wiring using continuous light with a low peak power value, without damaging the underlying Si substrate.

FIG. 6 shows another embodiment in which the wide portions 3d and 3e are arranged differently, in which a wire with a normal width W is diagonally placed in the center of the wire cutting link 3, and a gap 6.7 of the same width as the wire width is provided on both sides of the wire.
By arranging the wide parts 3d and 3e that largely cover the Si substrate while leaving a large area of It has a structure that makes it difficult for people to escape. By doing this.

Furthermore, the center part 5 can be melted and cut with low power,
The possibility of damaging the underlying Si substrate is further reduced, resulting in a highly reliable device.

〔Effect of the invention〕

According to the present invention, when cutting wiring using a laser for programming, it is possible to reduce the heat that escapes from the center of the wiring cutting link in the wiring direction, and the link can be melted and cut using a lower power laser beam. Because you can
Programming can be performed without damaging the underlying Si substrate.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention in which a wiring cutting link is provided with constricted portions at two locations, and FIG. 2(a) is a plan view of an embodiment of the present invention. 3(b) is a sectional view and a plan view of a conventional wiring cutting link, and FIGS. 3(a) to 3(d) are plan views of other embodiments of the present invention in which the shape of the constriction of the wiring cutting link is different. FIG. 4 is a plan view of another embodiment of the present invention in which the wiring cutting link has narrowed portions at three locations, and FIGS. 5(a) to (d) show wide portions in two locations on the wiring cutting link. FIG. 6 is a plan view of another embodiment of the present invention provided with a different arrangement of the wide portion. DESCRIPTION OF SYMBOLS 1...External wiring, 2...Guard ring, 3...Wiring cutting link, 3a, 3b, 3c
"<Fin part, 3d. 3e...Wide part, 4...Laser beam irradiation area, 5...
- Melted cutting part. Fig. 1 Fig. 3cL, 3b < Hirena Fig. 2 ((llL) C4o) 83 Fig. (α) (b) (C) (cL') Section 4- Section 3 Tetsuki gland incision - hr ring 55
Guest story 1 no analysis 4-cho M, 3b, 3c

Claims (1)

[Claims] 1. A semiconductor device having a wiring cutting link for programming, characterized in that the wiring cutting link is provided with two or more parts whose widths are unequal to other parts. Semiconductor equipment. 2. The semiconductor device according to claim 1, wherein the wiring cutting link has two or more portions having a width narrower than other portions. 3. The semiconductor device according to claim 1, wherein the wiring cutting link has two or more portions having a width wider than other portions.