JPS63287033A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent breakdown of a wiring, by forming a conducting metal pattern on a metal pattern on a semiconductor substrate, covering the pattern with an insulating film, flattening the surface with an applying material, etching the surface so as to expose the upper surface of the conducting metal, and providing a wiring metal. CONSTITUTION:A resist mask 3 is applied on a metal pattern 2 on a semiconductor substrate 1. A metal film 5a is formed on the entire surface. The resist 3 and the unnecessary metal film 5a are removed by lift-off. Thus a conducting metal pattern 5 is formed. Then an insulating film 6 is formed. Photoresist 7 is applied so that the upper part becomes flat. Then RIE is performed, and the upper surface of the conducting metal pattern 5 is exposed. After the unnecessary resist is removed, a wiring metal 8 is formed. In this constitution, breakdown of the wiring does not occur even if a fine conducting part is formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a semiconductor device that ensures electrical continuity between patterns formed in a lower layer and an upper layer of an insulating film. .

(Prior Art) FIGS. 2(a) to 2(e) are process cross-sectional views showing a conventional manufacturing method of this type of semiconductor device, in which 1 is a semiconductor substrate, and 2 is a semiconductor device formed on this semiconductor substrate 1. A metal pattern, 3 is a photoresist, 4 is an insulating film, and 8 is a wiring metal.

゛Next, the manufacturing process will be explained.

First, as shown in FIG. 2(a), an insulating film 4 is formed on the entire surface of the semiconductor substrate 1 on which the metal pattern 2 is formed, and then, as shown in FIG. 2(b), an insulating film 4 is formed on the insulating film 4. After applying the photoresist 3, an opening in the photoresist 3 is provided at a desired portion using a normal photolithography method. Next, as shown in FIG. 2(C), RI is performed using the photoresist 3 as a mask.
The insulating film 4 is removed by etching using E or the like. Next, the photoresist 3 is removed to obtain an opening in the insulating film 4 as shown in FIG. 2(d). Next, as shown in FIG. 2(e), wiring metal 8 is formed.

(Problems to be Solved by the Invention) In the conventional manufacturing method of a semiconductor device, after forming an opening in the insulating film 4 in the step shown in FIG. There were problems such as poor coverage of the wiring metal 8 at the stepped portion, and step breaks in the wiring metal 8 occurring.

This invention was made to solve the above-mentioned problems, and it is possible to reliably connect the wiring metal and the underlying pattern by obtaining electrical continuity without forming steep steps in the insulation film. It is an object of the present invention to provide a method for manufacturing a semiconductor device that can easily integrate patterns.

[Means for solving problems]

The method for manufacturing a semiconductor device according to the present invention includes a step of forming a conductive metal pattern on the upper layer of a metal pattern formed on a semiconductor substrate, and after forming an insulating film on the entire surface, flattening it with a coating material and etching it. The upper surface of the conductive metal pattern is exposed, and a wiring metal is formed on the upper layer.

[Effect]

In this invention, before forming an insulating film, a conductive metal pattern is formed on an existing metal film, and then an insulating film is formed, and the top surface of the conductive metal pattern is flattened with a coating material and etched. Since the wiring metal is formed after exposing the insulating film, the insulating film is flattened, and the wiring metal can be formed without going over the step of the insulating film.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1(a) to (h). In FIG. 1, the same reference numerals as in FIG. The conductive metal pattern 6 formed on the conductive metal pattern 5 is an insulating film formed on the entire surface after forming the conductive metal pattern 5, and 7 is a photoresist coated for planarization.

Next, this manufacturing process will be explained.

First, as shown in FIG. 1(a), a photoresist 3 is applied onto a semiconductor substrate 1 on which a metal pattern 2 is formed. Next, normal mask alignment exposure and development are performed to form a resist pattern as shown in FIG. 1(b). Next, as shown in FIG. 1(C), a metal film 5a is formed on the entire surface. Next, as shown in FIG. 1(d), the unnecessary metal film 5a is removed together with the photoresist 3 by lift-off, thereby obtaining the conductive metal pattern 5. next,
As shown in FIG. 1(e), an insulating film 6 is formed on the entire surface,
Furthermore, photoresist is applied to the upper layer so that the upper surface is flat.

Next, as shown in FIG. 1Cf, etching is performed using RIE or the like to expose the upper surface of the conductive metal pattern 5. next,
Remove the unnecessary photoresist and remove it as shown in Figure 1 (g).
You will get a pattern like . Thereafter, wiring metal 8 is formed as shown in FIG. 1(h).

In the above embodiment, a photoresist was used as the film used for planarization, but the film does not need to be a photoresist as long as it is an etchingable coating material.

〔Effect of the invention〕

As explained above, the present invention includes a step of forming a conductive metal pattern on the upper layer of a metal pattern formed on a semiconductor substrate, and after forming an insulating film on the entire surface, flattening it with a coating material and conducting it by etching. Since the upper surface of the general metal pattern is exposed and the wiring metal is formed on the upper layer, the wiring metal can be formed without going over the step of the insulating film. Therefore, even if a minute conductive portion is formed, there is no disconnection of the wiring metal, and a highly reliable product can be obtained.

[Brief explanation of drawings]

FIG. 1 is a process sectional view of a method of manufacturing a semiconductor device showing an embodiment of the present invention, and FIG. 2 is a process sectional view of a conventional method of manufacturing a semiconductor device. In the figure, 1 is a semiconductor substrate, 2 is a metal pattern, 3 is a photoresist, 5 is a conductive metal pattern, 6 is an insulating film, 7 is a photoresist, and 8 is a wiring metal. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Fig. 1 Fig. 1

Claims (1)

[Claims] The process of forming a conductive metal pattern on the upper layer of the metal pattern formed on the semiconductor substrate, and after forming an insulating film on the entire surface, it is flattened with a coating material, and the top surface of the conductive metal pattern is exposed by etching. A method of manufacturing a semiconductor device, comprising forming a wiring metal in an upper layer.