JPS63150944A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To increase the adhesion of an insulating film grown onto a wiring and the wiring, and to improve reliability by attaching an silicon film onto at least the upper surface of an aluminum film used as the wiring and etching the aluminum film and the silicon film in the same pattern. CONSTITUTION:An insulating film 2 is applied onto an silicon substrate 1. A contact hole 10 is bored to the insulating film 2 on the predetermined position of a semiconductor element formed to the surface of the substrate 1. A polycrystalline silicon film 3 is grown in prescribed thickness, and an aluminum film 4 is attached onto the polycrystalline silicon film 3. An silicon film 5 is fast stuck onto the film 4. The polycrystalline silicon film 3, the aluminum film 4 and the silicon film 5 are patterned, thus shaping a lower layer wiring 11A. An insulating film 6 is applied onto the lower layer, wiring 11A, and a contact hole 10A is bored at a specified position. Accordingly, the silicon film 5 and the polycrystalline silicon film 3 are formed in the upper surface and lower surface of the lower layer wiring 11A, thus increasing the adhesion of the lower layer wiring 11A and the insulating film 6 as an upper layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a semiconductor device, and particularly to a method of forming wiring between semiconductor elements.

[Conventional technology]

The third method of forming wiring used in conventional semiconductor devices
This will be explained using figures. First, as shown in Figure 3 (a),
After covering a silicon substrate 1 with an insulating film 2, a contact hole 10 is formed in the insulating film 2 at a predetermined position of a semiconductor element.

Next, as shown in FIG. 3(b), the contact hole 10
A polycrystalline silicon film 3 is grown on the insulating film 2, and an aluminum film 4 is further deposited thereon.

Next, as shown in FIG. 3(c), polycrystalline silicon II!
3 and the aluminum film 4 are patterned to form interconnections 11.

In addition, when forming multilayer wiring, next
As shown in , an insulating film 6 (for example, a silicon nitride film) is coated on the entire surface, and a contact hole IOA is formed at a predetermined position of the insulating film 6.
Drill a hole. Next, as shown in FIG. 3(e), an aluminum film 7 containing silicon is deposited and patterned to form a second layer of wiring.

Polycrystalline silicon II! 3 and in place of the aluminum film 4 deposited thereon, there is also a method of forming wiring using an aluminum film containing silicon.

[Problem that the invention seeks to solve]

In the conventional semiconductor device wiring method described above, the wiring method shown in FIG.
), when forming a multilayer wiring, the insulating film 6 made of silicon nitride is grown directly on the lower layer aluminum wiring, but the adhesion between the insulating film 6 and the aluminum film 4 is weak. The disadvantage is that the insulating film easily peels off. In addition, since many hillocks occur in the lower aluminum film 4, when patterning the insulating film 6, the thickness of the resist becomes thinner in the hillock parts, so pinholes are likely to occur in the insulating film in the hillock parts. There is also. Furthermore, when wiring the upper layer aluminum wiring on the lower layer aluminum wiring through the contact hole of the insulating film 6, there is a drawback that the contact resistance between the lower layer aluminum wiring and the upper layer aluminum wiring increases, which reduces the reliability of the semiconductor device. There is a problem.

An object of the present invention is to provide a method for manufacturing a semiconductor device that eliminates the above-mentioned drawbacks and improves reliability.

[Means for solving problems]

The method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device in which wiring made of a metal layer is formed on a semiconductor substrate, and a silicon film is formed at least on the upper surface of the wiring, and in particular, a silicon film is formed on at least the upper surface of the wiring. An aluminum layer or an aluminum layer containing silicon is used as the material.

〔Example〕

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

FIGS. 1(a) to 1(e) are cross-sectional views of a semiconductor chip shown in order of steps for explaining a first embodiment of the present invention.

First, as shown in FIG. 1 (a), an insulating film 2 made of 5i02 or the like is coated on a silicon substrate 1. Subsequently, an insulating film 2 is formed on a predetermined position of a semiconductor element formed on the surface of the silicon substrate 1. A contact hole 10 is opened in 2.

Next, as shown in FIG. 1(b), after growing a polycrystalline silicon film 3 to a thickness of approximately 500 μm, an aluminum film 4 is grown on the polycrystalline silicon film 3 to a thickness of approximately 0.5 μm. Further, a silicon film 5 is deposited thereon to a thickness of about 300 nm.

Next, as shown in FIG. 1(c), a polycrystalline silicon film 3
, the aluminum film 4 and the silicon film 5 are patterned to form a lower wiring 11A.

Next, as shown in FIG. 1(d), an insulating film 6 made of silicon nitride or the like is coated on the lower wiring 11A to a thickness of about 1 μm.
A contact hole 10A is opened at a predetermined position.

Next, as shown in FIG. 1(e), an aluminum film 7 containing silicon is deposited to a thickness of about 1 μm and patterned to form an upper layer wiring. Since the lower layer wiring 11A formed in this way has the silicon ryA 5A and the polycrystalline silicon film 3 formed on its upper and lower surfaces, the adhesion with the upper layer insulating film 6 is strong, and the bond with the upper layer wiring is also strong. Contact resistance becomes smaller.

FIGS. 2A and 2B are cross-sectional views of a semiconductor chip shown in the order of steps for explaining a second embodiment of the present invention.

By the same method as in the first embodiment, first, as shown in FIG.
As shown in the figure, an insulation 11! A2 is coated, and a contact hole is opened at a predetermined position in the insulating film 2. Next, an aluminum film 8 containing silicon is deposited to a thickness of about 0.5 μm, and a silicon film 5 is further deposited thereon to a thickness of about 300 μm. Subsequently, the aluminum film 8 containing silicon and the silicon film 5 are patterned to form a lower wiring 11B.

Next, as shown in FIG. 2(b), the lower wiring 11B is coated with an insulating film 6, a contact hole is opened, and an aluminum film 7 containing silicon is coated over the insulating film 6 by about 1 μm.
m is deposited and patterned to form upper layer wiring.

In this second embodiment, since aluminum containing silicon is used as the wiring material, the contact resistance with the silicon substrate 1 is low even without forming a silicon film on the lower surface of the lower wiring. The adhesion force with the upper insulating film 6 is strong as in the first embodiment.

〔Effect of the invention〕

As explained above, in the present invention, a silicon film is attached to at least the upper surface of an aluminum film used for wiring, and the aluminum film and the silicon film are etched in the same pattern, thereby forming an insulating film grown on the wiring. It has the effect of strengthening the adhesion of wiring and making it less likely to peel off.

Furthermore, when patterning an insulating film coated on an aluminum film, the insulating film also bulges in the hillock parts that occur on the aluminum film, so the resist becomes thinner in the hillock parts, and holes are easily formed in the resist during etching. There is a risk of pinholes occurring in the insulating film, but by using a wiring structure in which a silicon film is adhered to an aluminum film, the occurrence of hillocks is reduced, and pinholes occur when the insulating film is etched. It has the effect of reducing danger.

Furthermore, when the wiring according to the present invention is used as a lower layer wiring and is connected to an upper layer wiring made of an aluminum film containing silicon at the contact hole portion, the contact resistance between the lower layer wiring and the upper layer wiring is the same as that in the case where there is no silicon film. It has the effect of becoming smaller. Therefore, a semiconductor device with improved reliability can be obtained.

[Brief explanation of the drawing]

FIGS. 1(a) to (e) and FIGS. 2(a) and 2(b) are cross-sectional views of a semiconductor chip shown in the order of steps for explaining the first and second embodiments of the present invention. 3(a) to 3(e) are cross-sectional views of a semiconductor chip shown in order of steps for explaining a conventional method of manufacturing a semiconductor device. DESCRIPTION OF SYMBOLS 1... Silicon substrate, 2... Insulating film, 3... Polycrystalline silicon film, 4... Aluminum film, 5... Silicon film, 6... Insulating film, 7... Silicon Aluminum film containing 8, -8 A... Aluminum film containing silicon, 10. IOA...contact hole, 1
1... Wiring, 11A, 11B... Lower layer wiring. /θpu〉7ri L hole $ l Figure gA 2 times 3 Figures

Claims (2)

[Claims] (1) A method for manufacturing a semiconductor device in which a wiring made of a metal layer is formed on a semiconductor substrate, the method comprising forming a silicon film on at least the upper surface of the wiring. (2) The method for manufacturing a semiconductor device according to claim (1), wherein the metal layer is an aluminum layer or an aluminum layer containing silicon.