JPS636847A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a metallic wiring layer without steps, by burying a metallic film in a groove formed in an insulation film. CONSTITUTION:A smooth coating film 2 is provided with a contact hole 3. A groove 6 is then formed in the contact hole 3 of the smooth coating film 2 so that a wiring layer is provided in the groove 6. A metallic film 4 is then formed by the spattering or vapor deposition and a photoresist layer 7 is provided on the metallic film 4. The photoresist 7 and the metallic film 4 are etched under such conditions as they are etched approximately at the same rate, whereby a metallic wiring layer 5 is formed in a condition that it is buried in the grove 6 formed in the smooth coating film 2. Finally, the residual photoresist 7 on the metallic wiring layer 5 is removed. In this manner, namely by forming the metallic wiring layer 5 such that it is buried in the smooth coating film, the metallic wiring layer 5 can be formed without steps and in a stable manner.

Description

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

[Conventional technology]

FIG. 2 is a cross-sectional view showing each step of a conventional method for manufacturing metal wiring for a semiconductor device.

Below, we will explain the conventional manufacturing method of a semiconductor device using this.First, as shown in FIG. 2(a), a silicon substrate (1) is used.
After forming a smooth coat III [2) on the main surface of the substrate by a chemical vapor deposition method (hereinafter referred to as CVD method) or a spin code method, predetermined contact holes (3) are formed by photolithography and etching. Next, as shown in FIG. 2(b), a metal film (
4) Form.

Next, as shown in FIG. 2(C), the metal film (4) is processed by photolithography and etching to form metal wiring (5).
form.

[Problem that the invention seeks to solve]

In the conventional manufacturing method of semiconductor devices, metal wiring is formed as described above, so that a step is created by the metal wiring in the protective layer (not shown) that covers the metal wiring, and when multilayer wiring is performed, the wiring width becomes thinner at this step. There have been problems in that wire breaks are likely to occur, and as the wiring width becomes narrower with miniaturization, the stability of the wiring deteriorates.

This invention has been made to solve the above-mentioned problems, and its purpose is to provide a method for manufacturing a semiconductor device that can repair metal wiring without steps.0 [Means for solving the problems] The method for manufacturing a semiconductor device according to the present invention includes a step of forming a groove provided on an electrode break-out hole and an insulating film, a metal film, and applying a resist on the metal film and the insulating film.
The metal film and the resist are etched under etching conditions that give the same etching speed. By embedding the film, metal wiring without steps can be formed.

[Major example]

FIG. 1 is a cross-sectional view of each step showing a method for manufacturing a semiconductor device according to an embodiment of the present invention. First, as shown in FIG. ) is a contact hole (3) which is a contact hole (3). However, in this embodiment, this contact hole (3) does not need to reach the silicon substrate (1), but may be formed to a predetermined depth. Next, as shown in Figure 1), a wiring groove (6) is completely formed in the contact hole (3) portion of the smooth coat film (2) by photolithography and etching again.
) The etching conditions for forming the contact hole (3) and the wiring groove (6) are selected so that the contact hole (3) reaches the silicon substrate (1).

As shown in FIG. 1(c), a metal film (4) is formed on the metal film (4) by a sputtering method, a vapor deposition method, etc., and a photoresist (7) is formed on the metal film (4) by a spin code method, etc. As shown in FIG. 1(d), the above photoresist (7)
and metal H(4)? , the metal wiring (5) is etched back under the conditions that the etching speed change of both is almost equal), and the metal wiring (5) is formed embedded in the wiring groove (6) formed in the smooth surface (f2). Figure 1 (
As shown in e), the metal wiring (5) is coated with the smooth coating film (2) to remove the photoresist (7) remaining on the metal wiring (5).
By embedding and forming the metal wiring in the semiconductor device, it is possible to obtain a method of manufacturing a semiconductor device that can form a stable metal wiring without a step.

In the above-mentioned large example, the metal wiring in direct contact with the silicon substrate (1) was shown, but similar effects can be expected for all metal wiring in a semiconductor device with a multilayer wiring structure.

In addition, although the case where the photoresist (7) is used during etchback is explained in the above-mentioned section 11t'l, it can be formed on the metal film (4) with flatness and is the same as the metal film. A similar effect can be expected when using other materials that can be etched at a relatively rapid rate.

Furthermore, the material used for the metal wiring (5) can be appropriately selected from semiconductors, aluminum, aluminum alloys, high contact point alloys, silicides of high contact point metals, or mixtures thereof.

〔Effect of the invention〕

As described above, according to the present invention, there is a step of forming a metal coating on the groove provided on the electrode extraction hole and the insulating film, applying a resist on the metal coating and the insulating film, and applying the resist on the metal coating and the insulating film. Since these were etched under etching conditions that resulted in equivalent etching speed,
It has the excellent effect of being able to obtain metal wiring without steps.

[Brief explanation of the drawing]

FIG. 1 is a step-by-step sectional view showing a semiconductor device manufacturing method according to an embodiment of the present invention, and FIG. 2 is an underwater step-by-step sectional view of a conventional semiconductor device manufacturing method. (1) is a silicon substrate, (2) is a discharged smooth coat film,
(3) is a contact hole, (5) is a metal wiring, (6) is a groove for wiring, and (7) is a resist. In the drawings, the same reference numerals indicate the same or corresponding parts. Figure 1 Figure 2 (b) Procedural amendment (voluntary) Showa year, month, day 2, title of the invention: Method of manufacturing a semiconductor device 3, representative of the person making the amendment: Moriya Shiki 6, invention of the specification subject to the amendment Detailed explanation column 6, content of amendment

Claims (2)

[Claims] (1) A step of forming an insulating film on the surface of a semiconductor substrate, a step of forming an electrode extraction hole in the insulating film and a groove on the electrode extraction hole, a step of forming a metal coating on the groove and the insulating film, A method for manufacturing a semiconductor device, which includes a step of applying a resist on a metal film and an insulating film, and a step of etching the metal film and the resist under etching conditions such that the metal film and the resist have the same etching rate. (2) The semiconductor device according to claim 1, wherein the metal film is a semiconductor, aluminum, an aluminum alloy, a high melting point metal, a silicide of a high melting point metal, or a mixture thereof. Production method.