JPS584948A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve corrosion resistance by a method wherein an Al wiring is covered by an amorphous Si layer and then by a PSG layer. CONSTITUTION:An Al film 2' on an Si substrate 1 is deposited wth an amorphous Si layer 3' by the CVD method. A coating of PSG 4 is laid down after patterning. Or, an amorphous Si layer 3' and then a PSG layer 4 may be laid down after the formation of an Al wiring 2. This setup greatly improves the Al wiring corrosion resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device, and particularly to a semiconductor device in which an amorphous silicon film is formed as a protective film for aluminum (mut) wiring.

As the integration density of semiconductor devices continues to increase, the width of At interconnects has also decreased accordingly, and today, lines with fine line widths of Il'i3 (μm) or less have been put into practical use9. The wiring height and thickness also follow the trend of becoming extremely thin, ranging from 6000 (X) to 1 (am). A phosphorus silicate glass (PSG) layer is generally deposited as a protective film on such At wiring, and ps.

The layer not only serves as an insulating film for the Atmium wiring, but also functions to protect and assist the Atm wiring from the external atmosphere. However, in the current KfI atmosphere, FiP8
When G and moisture react, phosphoric acid is produced, and the problem arises that the nicks corrode the At wiring.Especially in the case of the latest ultra-thin wiring, corrosion can cause fatal accidents such as wire breakage. Countermeasures are desired. Furthermore, protrusions are generated on the surface of the AL due to the sintering of the 1 µL wiring, and these protrusions enter the P2O layer, aggravating the above-mentioned problem.

As a countermeasure against corrosion, the present invention provides amorphous silicon (amorphous S) on the top surface or the top surface and both side surfaces of the At wiring.
The purpose of the present invention is to provide a semiconductor device in which an amorphous 81 film is formed for the purpose of improving corrosion resistance by a double structure of a protective film for At wiring, in which a film is formed and a K PSG layer is formed thereon.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Figure j111 shows one film part of the AA wiring in the step of forming an At wiring and a protective film for manufacturing a semiconductor device according to the present invention. The substrate on which wiring is formed is, for example, a wafer. First, an aluminum film 2' is deposited by vapor deposition on the entire surface of the wafer 1.
(a)), and further deposit amorphous 81 genus 3' on top of it to a thickness of 200 to 1000 (X) [(b)
), here, the deposition of amorphous 81@3' is performed by the general KFif plasma chemical vapor deposition (CVD) method, and it is important to perform the deposition at a temperature below the softening temperature of Mut (approximately 450° C.). In addition, any other method may be used, such as the solar casing method, the electron beam evaporation method, or the ion beam deposition method.Subsequently, the amorphous 8I film is formed using a conventional technique depending on the amount of wiring. ∆ turning of J [3' and Aj film 2' is performed, At wiring 2 with amorphous s-metal 3 is formed thereon [(-)], and finally K P8G is formed on the entire surface of Urchin 8.
Grow layer 4 ((d)).

Through this process, a protective film layered with the amorphous Si film 3 and the PBG layer 402 is formed only on the upper surface of the HT wiring 2, and corrosion in the thinner direction, which is a problem, can be sufficiently prevented. If a complete corrosion-resistant structure is desired including the parts, another embodiment of the present invention shown in Fig. 2 can be used.

That is, in the process of forming the At wiring and protective film shown in FIG. The L film 2' is deposited (a)), and then the At wiring 2 is formed by wiring turning using a normal technique (b)), and then the amorphous S1 film 3' is deposited on the gold surface of the 611 surface. The amorphous 81 was deposited in the same manner as in the example shown in
(d)) Finally, grow a PaG layer 4 on the gold surface of the wafer surface. and both sides shall be protected by a double protective film.
As a result, corrosion resistance is significantly improved.

The formation of such an amorphous S1 film is based on Mut and Que^
.

It has the effect of suppressing protrusions that occur on the K A4 surface during heat treatment (sintering) performed to improve electrical connection with the surface, and in particular prevents these protrusions from damaging the P8G protective film and causing corrosion. When taken into consideration, this effect has great significance, and furthermore, it can be used as a protective film for the inboard pet portion that is directly exposed to the outside air. In addition, when it is necessary to lower the resistance of amorphous S1, #
f Doping with impurities is performed using conventional techniques.

The present invention utilizes amorphous s1 as described above to not only solve the problems of the prior art that occurred between the At wiring and the P2O layer, but also to solve the problems of the prior art between the At wiring and the P2O layer.
Since the semiconductor device according to the present invention is protected by the double structure of the film and the P2O layer, its reliability is improved.

[Brief explanation of the drawing]

FIG. 1 and FIG. 1N2 are perspective views, partially in cross section, of essential parts of aluminum wiring in process 11 for forming the semiconductor device of the present invention. l...Wafer, 2...Aluminum wiring, 2'...
・Aluminum l[,3,3'...Amorphous 81
j[,4...P2O layer. Figure 1 (e) Figure 2

Claims (1)

[Claims] In a semiconductor device in which a phosphorus/silicate/glass layer is formed on an aluminum wiring, an amorphous silicon film is formed on at least the upper surface of the aluminum wiring, and the phosphorus/silicate/glass layer is formed on the amorphous silicon film. A semiconductor device characterized by: