JPS60193362A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the generation of a hillock on the wiring layers of a semiconductor device by a method wherein films consisting of a high melting point metal or the nitride thereof are provided to the surfaces of the wiring layers consisting of Al or an Al alloy. CONSTITUTION:An insulating film 2 is formed on the main surface of a semiconductor substrate 1, and a film 6 consisting of a high melting point metal is formed thereon. Then a film 3 consisting of Al or an Al alloy is formed, and a film 7 consisting of a high melting point metal is formed thereon. Then patterning of the films 3, 6, 7 is performed to form wiring layers 3a, 3b. Then after a film 8 consisting of a high melting point metal is formed on the whole surface of the top part, out of the film 8, the parts of regions in parallel with the main surface of the substrate 2 are removed to leave only the side face parts 8a-8d. After then, after an interlayer insulating film 4 is formed, a film 5 to be used as a wiring layer is formed. When a semiconductor device is constructed in such a way, because the high melting point metal or the nitride thereof existing on the surfaces of the wiring layers consisting of Al or an Al alloy diffuses to the surfaces of the wiring layers according to posterior heat treatment to form an alloy with the Al, growth of a hillock is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a structure of a wiring layer of a semiconductor device.

[Prior art]

FIG. 1 shows a two-layer structure #i! as an example of a conventional semiconductor device. It is a cross-sectional view of Shinzo's product shown in the VC Binzo process piece for explaining the manufacturing method thereof. First, Figure 1 (a') V
As shown in C, silicon dioxide (s
An insulating film (2) made of D) such as ioQ) is formed, and a coating (3) made of VC aluminum or an aluminum alloy is formed thereon by sputtering or vacuum evaporation. Subsequently, the first wiring N! is patterned by patterning the film 31 using photolithography and etching as shown in FIG. 9(b) VC. Form 4(a) and (3b). Next, as shown in the same figure (c), for interlayer insulation, VcSiOa or Fia silicon y (SisN4) f
An insulating film made of zdβ)! 412 CjVD method or direct sputtering method, etc., and then, as shown in the same figure (dlVc), the wiring layer ill of conduit 2 is formed on the insulating film (4).After that, 813N 4-way 5l is formed by CVD method or direct sputtering method.
A protection layer (not shown) consisting of oll or the like is formed over the entire surface of the abutment.

The conventional semiconductor 11i+1 is configured as described above, and is electrically insulated by the first wiring layer (3a), (3b), the second wiring layer +51Fi, and the interlayer insulating film 141. . ) and the first and second arrangements 184 (
3a), (3h), 450 to anneal +51
There is peace of mind in performing heat treatment at around ℃, and it is also possible to
When forming by the VD method, it will undergo heat treatment at 300 to 400°C.

By this heat treatment, as shown in FIG. 2, the first distribution #hv!
Projections (referred to as "hillocks") on the sides and sides of the aluminum or aluminum alloy coating that is J (Friend), (
Hidden) has grown and the first distribution #I! The deterioration of the insulating properties between the layer (A) + ("b) and the second interconnection layer (51) was a major cause of a decrease in the yield of devices.

[Summary of Part 1J] This invention was made to eliminate the above-mentioned drawbacks of the conventional ones, and it is possible to reduce the surface Vc of a wiring layer made of aluminum or an aluminum alloy from a metal with a commercial melting point or its nitride. By forming a film that is stable, no hillocks occur during heat treatment! ! The purpose is to provide a semiconductor device with 1ci.

[Examples of inventions] An example of an actual gun according to the present invention will be explained with reference to FIG.

Figure J3 is a sectional view showing the structure of an actual gun according to the present invention, along with an example of its manufacturing method, in order of manufacturing steps. First, as shown in Figure 3 (a+), the semiconductor leaf plate (
An insulating film (2) such as 5in2 is formed on the main surface of the film, and a film made of a high melting point metal such as titanium (T1) or tantalum (Ta) is formed on it by sputtering, vacuum evaporation, CVD, etc. (6) is formed. Next, a coating +a+ made of aluminum or an aluminum alloy is formed by a sputtering method, a vacuum evaporation method, a CVD method, etc. The hood (
7). Subsequently, as shown in FIG. 3(b) VC, a film (31, T6) was formed by photolithography and etching.
1 and +71 patterning is performed to form first wiring layers (3a) and (sb). Next, Figure 3 (cl.
As shown in Figure 3, after forming a film 181 made of a melting point metal such as T1 or Ta on the entire upper surface, the main part of the semiconductor substrate (2) of the film (8) is etched by anisotropic etching as shown in Fig. fJ3 (alVc). The portion of IIIJt that is almost parallel to the surface is removed, and the side parts (8a), (8b), (8c), (
Only Ekl) is left. After that, as in the conventional semiconductor device, an interlayer insulating film (4) is formed as shown in FIG. .

Next, I will explain the specific history of Shou Shuhei.

A TiW (T110) film of 100 OA was formed on the semiconductor vapor with a 5 iOa film on the surface by sputtering, a hl-sl (811%) film was formed on it by sputtering, and then D), [TIW (
After the Tl (1a%) film was broken down to 100 OA, patterning was performed, and then a VC 5iaNa film of 1.2 and 11 m thick was formed on the entire surface by plasma CVD. This was heat-treated for 30 minutes in a 45σCNj gas atmosphere, but no formation of the above-mentioned AtSi III-Vc hillocks was observed.

Furthermore, T1 and Ta are used instead of the above-mentioned TiW as high melting point metals, and their nitrides such as TiN and T
In the case of using aN, no hillocks were observed at all.

This is because the refractory metal or its nitride interposed on the surface of the wiring layer made of aluminum or aluminum alloy diffuses into the long surface of the wiring layer during subsequent heat treatment (usually at 300 to 500°C) and becomes alloyed with aluminum. This is because the growth of hillocks is suppressed.

In addition, the above-mentioned example of furori was explained in the case where the entire surface of the wiring layer or the lower surface of the wiring layer is coated with melting point metal gold.
A coating made of a high melting point metal may be provided on i.

In addition, in the above actual gun, the semiconductor device 1ilVc with two-layer wiring f1 structure was explained, but it is also possible to
can.

〔Effect of the invention〕

As described below, the present invention has a VC configuration in which a film made of a high melting point metal or its nitride is provided on the surface of a wiring layer made of aluminum or an aluminum alloy.
Hero links do not appear on the wiring layer.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a conventional semiconductor device llt in the order of manufacturing steps, Fig. 2 is a cross-sectional view showing a state where hillocks have occurred, and Fig. 3 is a cross-sectional view showing an embodiment of the present invention together with an example of its jW manufacturing method. FIG. In the figure, +11 is the semiconductor substrate, (3R), (3b
) is a wiring layer, and +61, 171, +81 are high melting point metals or their nitrides). In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Figure 3 Procedural amendment (voluntary) 1. Indication of the case Japanese Patent Application No. 59-50814 3, Part 4, f (embedded 5, detailed description of the invention in the specification subject to the amendment 6, Contents of the amendment (1) to Hitoshi Katayama, representative of the person making the amendment) ) In the fourth line of page 8 of the specification, the phrase "decreased yield of devices" is corrected to "decreased yield and reliability of devices."

Claims (1)

[Claims] 1. A semiconductor device comprising a wiring layer made of aluminum or an aluminum alloy on a semiconductor substrate, characterized in that a coating made of a metal or a substitute thereof is formed on the surface of the wiring layer.