JPS5892252A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To allow a cutting process for a wiring in a short time and a clean manner without the necessity of large current conduction into another element and of providing a pad for cutting by a method wherein, via an insulation film coating the wiring, a part of the metal or alloy thereof is sublimated as a compound by the energy ray irradiation, and accordingly the wiring is cut. CONSTITUTION:The clearance G part of the wiring 2 constituted of polycrystalline Si is connected by the Mo wiring 3. After forming a required wiring pattern, the wiring pattern is coated with the insulation film 4 constituted of PSG and SiO2 or Si3N4, etc. The cutting is performed by selectively irradiating the energy ray to the Mo wiring 3 via the insulation film 4. When the Mo is heated to approx. 500 deg.C or more, the Mo suddenly turns into oxide MoO3 resulting in sublimation and is diffused into the atmosphere by passing through the insulation film 4. As a result, in the polycrystalline Si wiring 2, the electrical connection is broken at the clearance G, and accordingly, a cavity 5 is generated. The Mo wiring 3 is completely eliminated by the sublimation and has no deposits of scattered matter due to fusion.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a semiconductor device, particularly a read-only memory device (FR) that is reprogrammed by selectively cutting wiring.
OM) and a method for manufacturing a storage device that cuts redundant bits.

(2) Prior Art and Problems One of the methods for programming FROM in the prior art is to fuse the pin/fst or two 11m wiring in a large scale. In this case, the wiring, such as the polycrystalline silicon layer area, is formed in advance to be thin at the location where it is to be cut, but in order to melt such a silicon layer, a considerably larger amount of power is required than in the case of general use. Moreover, since the value of the necessary iir flow is not definite, the reproducibility of the process is poor. Since the silicon layer is cut by melting, there is a risk of a short circuit in L if the silicon scatters and adheres around the cut position.

Father, in addition to the above-mentioned FROM, a memory device (RWM) having a memory rewriting function also has redundant bits formed in advance,]E! At the end of the tlt purple manufacturing process, surplus redundant bits are selectively cut off, and the same method used for cutting the wires of the previous PFROM has been conventionally used for cutting the wires in this case.

Furthermore, for example, when programming a FROM by pooling part of the flow of the element manufacturing process, it is desirable to cover the wiring pattern with an insulating film as soon as the wiring is formed, in order to protect the wiring pattern, etc. When wiring is cut using the conventional method described above under a high-temperature coating, the reliability of cutting a single wire is low, and usually the wavelength of the wiring pattern due to high-temperature pus is reached or the required amount of the insulating film is cut. (3) Object of the Invention An object of the present invention is to manufacture a semiconductor device in which a part of the wiring is selectively cut after formation of a wiring pattern. In this method, after the wiring is blown into the insulating film, the power required for cutting is applied to the cutting part without going through other elements constituting the mosquito semiconductor device, thereby eliminating debris caused by cutting the wiring. An object of the present invention is to obtain a method for cutting the wiring without causing the wiring to adhere to the semiconductor device.

(4) Structure of the Invention The object of the present invention is to remove at least a portion of the wiring that may be cut using materials such as molybdenum (Mo), titanium (Ti), and vanadium (V).

Chromium (Cr), iron (Fe), cobalt (Co).

Nickel (NI), zirconium (Zr), niobium (N
b), Ruthenium (Ru), Rhodium (Rh), Palladium (Pd), Hafnium (Hf).

After forming an insulating film made of at least one metal selected from tantalum (Ta), osmium (Os), iridium (Ir), and platinum (Pt) or an alloy of the metal, and covering the wiring, By injecting energy S through the insulation B, at least a portion of the metal or alloy is selectively heated and sublimated as a compound, which is effective in cutting the nuclear wiring.

(5) Embodiments of the Invention The present invention will be specifically described below using embodiments with reference to the drawings.

FIG. 1 shows a sectional view of an embodiment of the present invention. In FIG. 1, 1 is the underlying silicon dioxide (SiOl) layer, and the layer 2, which can be selectively cut, is formed by chemical vapor deposition (ehemica vapor deposition).
By patterning a polycrystalline silicon layer with a thickness of about 200 to 400 nm formed by ion + CVD (hereinafter abbreviated as CVD), the wiring is cut at the planned cutting position with a width of about 3 μm, and the connection between the cut portions is cut. F.J.
G is formed to have a thickness of about 1 to 3 μm. The gap G portion of the wiring [2 made of polycrystalline silicon] is connected by a Mo wiring 3. This Me distribution #! 3 is a 100 to 300 nm thick Mo layer with a buttering solder and makes ohmic contact with the polycrystalline silicon metal ls2 at the overlapping part. After forming the required wiring pattern, phosphosilicate glass (ph-om
pho 51ticate gtass; PS below
G (abbreviated as □), 810m or silicon nitride (
The insulation 1[i4 made of SisN4) or the like is coated with the patterned wiring pattern, but the thickness of the insulation 1i114 is about 1 μm or less as in the prior art (b).

The wiring is cut by selectively transmitting energy S+ to the Mo wiring 3 through the insulation film 4.

That is, the energy beam is hardly absorbed by the insulating film 4, and the laser beam absorbed by the Mo wiring 3 is, for example, an argon (Ar) laser (wavelength λ=488.2 nm, 51 nm).
4.5nm) ffit'1YAG laser (wavelength λ=1
．． A continuous wave of 0.06 μm or a beam diameter of about 0.06 μm is normally used, with the beam diameter being equal to or less than the length of the front rMo wiring 3. It is also possible to use a condensed flood light, but the spot diameter is controlled in the same way as the beam diameter.

The atmosphere in which this energy beam irradiation process is carried out may be normal 9Q when the insulating film 4 is made of PSG or an oxide such as 5101, but when the atmosphere is oxidizing, the purpose can be achieved with less power. It can be achieved that the insulating film 4 is 8
When it is 1sN4 or the like and does not contain oxygen, it is usually carried out in an oxidizing atmosphere.

When MO is heated to approximately 500° C. or higher for irradiation with generated energy, MO rapidly becomes an oxide M-Os, sublimates, passes through the insulating film 4, and diffuses into the atmosphere. As a result, as shown in FIG. 2, the polycrystalline silicon wiring 2 is
The W air connection is severed at , creating a cavity 5 -
As a result of the sublimation of M00g, the Mo alloy disappears completely, and the adhesion of scattered particles that was experienced in the melt cutting of polycrystalline silicon does not appear at all.

The above-mentioned heating of the MO arrangement fIs3 can be programmed after selecting the cutting location and can be carried out entirely automatically, for example by using an XY-direction traveling table controlled by a microcomputer. In such an automatic operation, it is extremely effective that the oxidation and sublimation of Mo be carried out in a short time and cleanly.

In the embodiment described above, the gap G of the polycrystalline silicon wiring 2 was connected to the Mo interconnection 3 by L, but even if the skeleton gap G was connected using tungsten (W) instead of MO, the same effect as in the embodiment described above can be obtained. Cutting of the engineered circuit occurs upon sublimation of the oxide WOI.

Further, in the above embodiment, the wiring Is2 is formed of polycrystalline silicon, but the wiring 2 may be formed of a conductor other than polycrystalline silicon. It is possible to obtain the same effect even if the barrier 11G is formed without being particularly provided and the energy beam is selectively irradiated only at the cutting position.

Moreover, as a material for connecting the gap G, the above-mentioned M is used.

Or not only W but also its oxides and other compounds are 10
It sublimates at a temperature of about 00°C or less and may be 4-carbon, such as titanium (Ti), vanadium (V), or chromium (C).
r), iron (Fe), cobalt (Co), nickel (Ni
), zirconium (2rL niobium (Nb), ruthenium (Ru), rhodium (Rh), palladium (Pd),
Hafnira A (Hf), Mental (Ta), Osmira A (01).

Examples include iridium (I r ), platinum (Pt), or alloys thereof.

(6) Effects of the Invention The present invention provides a method for manufacturing a semiconductor device in which a part of a wiring pattern is selectively cut. A manufacturing method in which an edge is formed on a metal alloy, and at least a part of the metal or alloy part 0: is sublimated as a compound by irradiation with an energy beam through an insulating film covering the skeleton wiring, and the wiring is cut. There is no need to pass a large current to other elements on the bottom of the semiconductor device, there is no need to provide pads for wiring and cutting, and the semiconductor device is protected by an insulating film. Quickly and cleanly
It is possible to perform wiring cutting processing, and the cutting processing of the present invention is well suited to automatic processing controlled by a computer, and is highly effective in improving the yield and reliability of the semiconductor device. has.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing embodiments of the present invention. In the figure, 1 is a 5-iot layer, 2 is a wiring made of polycrystalline silicon, 3 is a Mo wiring, 4 is an insulating film, and 5 is a cavity.

Claims (1)

[Scope of Claims] In a method of manufacturing a semiconductor device, in which a part of the wiring is selectively cut after forming a wiring pattern, at least a part of the wiring is made of molybdenum (Mo), tungsten (W), titanium (
Ti), vanadium (V). Rio A (Cr) + iron (Fe), cobalt (C
o). Nickel (Ni), zirconium (Zr), niobium (
Nb), ruthenium (Ru) + rhodium (Rh). Palladium (Pd), Hafnium (Hf), Mental (
Ta), osmium (Os), iridium (Ir)
, forming an edge on at least one metal selected from platinum (PT) or an alloy of the metal, forming an insulating film covering the wiring, and then irradiating an energy beam through one insulating IgII. 1. A method for manufacturing a semiconductor device, which comprises selectively heating at least a portion of the metal or the alloy to sublimate it as a compound and cutting the wiring.