JPH0322537A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To contrive the improvement of ohmic characteristics between first layer and second layer Al wirings by a method wherein a film consisting of a conductive material is formed between the Al wirings. CONSTITUTION:A first layer Al wiring 8 is formed and thereafter, a conductive film consisting of a metal, such as Ti, W, Cu and the like, or a silicide, such as MoSi2, WSi2, TiSi2 and the like, is formed on the whole surface by a sputtering method add a photoengraving and an etching is performed to form a patterned film 9 consisting of a conductive material. An interlayer insulating film 10 consisting of an oxide film or a nitride film is formed by a plasma CVD method. Subsequently, after a photoresist is applied on the film 10, an etchback is performed by such an etching method as the selection ratio of the film 9 to the film 10 becomes a ratio of 1:1 until the surface of the film 9 consisting of a conductive material is exposed. Lastly, a second layer Al film is formed by a sputtering method, the photoresist is patterned, an etching is performed by a dry etching method and a second layer Al wiring 11 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a semiconductor device comprising multilayer wiring of two or more layers.

[Conventional technology]

FIGS. 2(a) to 2(d) are cross-sectional views showing the manufacturing flow of a conventional semiconductor device after one-layer wiring. In Figure 2,
1 is a semiconductor substrate, 2 is a well formed on this semiconductor substrate 1, 3 is a diffusion layer diffused into the well 2, 4 is a field oxide film for element isolation, 5 is a gate 1 oxide film, 6 is the gate 1 formed on the gate 1 oxide film 5,
7 is a smooth coater 1.8 is a first layer of aluminum wiring, 10 is an interlayer insulating film, and 11 is a second layer of aluminum wiring.

Next, the manufacturing process will be explained.

First, as shown in FIG. 2(a), a semiconductor substrate 1 is provided with a well 2, a diffusion layer 3, a field oxide film 4, a gate 1 and an oxide film 5.
, Game 1 and 6 are formed, and then smooth coat 1 is formed on the entire surface.
- 7 is formed, and after forming an opening at a predetermined position of this smoothcoat 1-7, the first layer of aluminum wiring 8 is formed. After that, as shown in FIG. 2(b), Plas7C
V D (Chemical Vapor Deposit)
An interlayer insulating film 10 made of an oxide film or a nitride film is formed by the oxide film or nitride film, and then, as shown in FIG. Then, through-holes are formed by dry etching using a gas such as CHF3, and finally the second layer A/L is formed.
After forming the resist layer 1 by the subvert method,
(not shown) is patterned, and using this as a mask, etching is performed by a dry etching method using chlorine-based gas to form the second layer of aluminum wiring 11.

[Problem to be solved by the invention]

A) The L-pin wiring of the conventional semiconductor device is formed as described above, so as the through-hole opening area becomes smaller as the miniaturization progresses, the second layer aluminum wiring 11 in the S/L-Pole portion becomes smaller. In addition, during anisotropic etching of the interlayer insulating film 10, the polymer-heavy film may adhere to the opening 1] of the through-hole/L and the side walls, causing the aluminum of the first and second layers to deteriorate. There were problems such as poor ohmic properties between the wirings 8 and 11.

The invention of B was made to solve the above-mentioned problems, and it is possible to manufacture a semiconductor device that does not form a polymeric film and has good 4-connectivity between aluminum wirings. The purpose is to obtain a method.

[Means to solve the problem]

Invention B: ζ The method for manufacturing a semiconductor device is to form a film made of a conductive material on a first layer of aluminum wiring, and form a second layer of aluminum wiring via this film.

[Effect]

In this invention, by forming a film made of a conductive material between the ANO L8 wirings in the first layer and the second layer, the ohm-isolation property between the ANO wirings is improved.

〔Example〕

An embodiment of the invention of B will be described below with reference to the drawings.

FIGS. 1(a) to 1(e) are cross-sectional views showing the manufacturing flow of a semiconductor device according to the present invention, and the same reference numerals as in FIG. 2 indicate the same parts.

First, as shown in FIG. 1(a), the first layer i+. i: After forming the wiring 8, as shown in FIG.
), metals (3) such as
) (4) Or MoS ltp WS l2, T i S
A conductive film made of silicide such as i2 is formed on the entire surface by a sputtering method, and photolithography and etching are performed to form a patterned film 9 made of a conductive material. Next, as shown in FIG. 1(c), an interlayer insulating film 10 made of an oxide film or a nitride film is formed by plasma CVD. Subsequently, as shown in FIG. 1(d), an interlayer insulating film 1 is formed.
After applying a photoresist (not shown) on the layer 0, the surface of the film 9 made of a conductive material is etched so that the selectivity with respect to the insulating film 10 is 1. Etch back is performed until it is exposed, and then the photo resist 1 remaining in the stepped portions such as the contact portion 1 with the diffusion layer 3 is removed. Finally, as shown in Fig. 1(e) 1ζ, a second layer of aluminum is formed by a sputtering method, the photo resist 1 (not shown) is buttered, and the etch is etched by a dry etching method. A two-layer aluminum wiring 11 is formed.

In the above embodiment, the case of two-layer wiring was explained, but the case of wiring of three or more layers may also be used. However, the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As explained above, the present invention is based on the first layer of cotton.
After buttering a film made of a conductive material other than the above to the required size, a CMR insulating film is formed on the entire surface, and then using Lens 1/Batano as a mask, it is patterned until the surface of the film made of a conductive material is exposed. Etching the interlayer insulation film,
After that, a second aluminum wiring is formed in contact with a film made of a conductive material, and these steps form a multilayered aluminum wiring, so the first and second layers can be connected without increasing the number of mask alignment steps. This has the effect of providing a semiconductor device with good ohmic properties between the aluminum wiring layers.

[Brief explanation of drawings]

FIG. 1 is a process cross-sectional view showing a method for manufacturing a semiconductor device according to an embodiment of the invention, and FIG. 2 is a process cross-sectional view showing a conventional method for manufacturing a semiconductor device. (5) (6) In the figure, 1 is the semiconductor substrate, 2 is the wafer, 3 is the diffusion layer, 4 is the field oxide film, 5 is the gate l/oxide film, 6
Reference numeral 1., 7 indicates a smooth coat 1., 8 indicates a first layer of aluminum wiring, 9 indicates a film made of a conductive material, 10 indicates an interlayer insulating film, and 11 indicates a second layer of aluminum interconnection. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] In a method for manufacturing a semiconductor device in which two or more layers of aluminum wiring are formed on a semiconductor substrate, after patterning the first layer of aluminum wiring, a film made of a conductive material other than aluminum is patterned on top of it to the required size. After that, an interlayer insulating film is formed on the entire surface, and then the interlayer insulating film is etched using the resist pattern as a mask until the surface of the film made of the conductive material is exposed. 1. A method of manufacturing a semiconductor device, comprising forming a second layer of aluminum wiring in contact with the aluminum wiring, and forming a multilayer aluminum wiring through these steps.