JPS6255938A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve the coating property of an electrode metal and thereby to prevent the stage cut and contact fault thereof, by giving a gentle taper to the upper and lower ends of an opening of an insulating film. CONSTITUTION:A resist mask 3 is provided on an SiO2 film 2 formed on an Si substrate 1, and etching is conducted by an HF solution to form eaves 4 on the film 2 at the edge of an opening. A resist 5 is subjected to rotary coating to pack a space formed by the eaves 4. When the film 2 is etched by a dry etching method, a gentle taper 6 is formed on the lower side wall of the film 2. The resist 3 is removed, the whole surface of the substrate 1 is etched by an HF solution to remove the resist 5 remaining in the space formed by the eaves 4, and thereby a taper 8 is formed at the upper edge of the opening 7. According to this constitution, a gentle taper can be formed with excellent reproducibility and mass-productivity, and thus the stage cut and contact fault of a wiring metal are prevented.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method of manufacturing a semiconductor device.

BACKGROUND ART As a method for opening electrode windows in an insulating film, a wet method using a hydrofluoric acid solution is used for relatively large patterns, and a dry etching method is used for fine patterns. However, as patterns become finer, if a window is opened perpendicularly to the substrate using a dry etching method, the coverage of the electrode metal at the upper and lower ends of the opening becomes poor, resulting in disconnections in the electrode wiring and poor contact. For this reason,
The side wall of the electrode window needs to have a taper relative to the substrate, so there are methods to form a taper by changing the dry etching conditions, using multi-step etching conditions, or by using the degeneracy of the resist, which is a mask for selective etching. is being attempted.

Problems to be Solved by the Invention As described above, when forming an opening window in an insulating film, it is necessary to form a taper in order to improve the coverage of the electrode metal. Taper etching due to degeneracy has problems in that reproducibility is poor and mass production is poor.

The present invention is intended to solve these problems, and aims to form tapers at the upper and lower ends of an opening window with good reproducibility and good productivity.

Means for Solving the Problem In order to solve this problem, the present invention provides a step of attaching a resist 3 on the insulating film of a semiconductor substrate having an insulating film on the surface and opening the resist film. a step of shallowly etching an insulating film located within the opening of the resist film by an isotropic di-notching method; and a step of etching a film for etching shape correction by a spin coating method on the etched portion of the insulating film and the surface of the resist film. and a step of etching the etched shape correction film and the underlying insulating film by dry etching.

Effect: With this configuration, a gentle taper is formed at the upper and lower ends of the insulating film opening window, which improves the coverage of the electrode metal and eliminates step breakage and poor contact between the substrate and the electrode metal.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings.

First, in FIG. 1, a pattern is formed in the resist 3 in order to open a window in the insulating film 2 made of silicon dioxide on the substrate 1. Next, in Figure 2, approximately 100
Zero etching is performed to create an undercut portion 4 in the insulating film 2 at the end of the pattern of the resist 3.

Next, in Fig. 3, approximately 1000~
A coating film 5 was formed by 1,500 people. At this time, the centrifugal force during rotation of the spin coating method and the adhesive force between the coating film 5 and the resist 3 cause the coating film 5 to be applied thickly to the wall surface portion and thinly to the flat portion, and the undercut portion 4 is coated with the coating 1115. Buried. Next, in FIG. 4, the insulating film 2 is etched off using a dry etching method. In that case, a gentle taper 6 is formed in the sidewall portion below the insulating film 2. Next, as shown in FIG. 5, the resist 3 is removed, and the entire surface of the substrate 1 is etched with a hydrofluoric acid solution.
The remaining coating film 5 is etched off. As a result, as shown in FIG. 6, the upper and lower ends of the side walls of the electrode opening window 7 are provided with gentle tapers 6.8.

Incidentally, the coating film 5 is made of spinion glass (SOG).
is used, but a dry-etchable resist may be used instead.

Effects of the Invention As described above, according to the present invention, a gentle taper can be formed at the upper and lower ends of the side wall of the electrode opening window with good reproducibility and mass production, thereby significantly reducing the occurrence of disconnections in the wiring metal and poor contact with the substrate. reduced to

Furthermore, since the area of the opening window is faithfully transferred to the resist pattern, there is no need for mask correction.

[Brief explanation of drawings]

1 to 6 are process sectional views showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Insulating film, 3...Resist, 4
... Undercut portion, 5... Coating film, 6... Taper, 7... Electrode opening window, 8... Taper agent Yoshihiro Morimoto Figure 1 Figure 2 Figure 3 Figure 3 Figure 4] Figure 5 Figure 6

Claims (1)

[Claims] 1. A step of depositing a resist film on the insulating film of a semiconductor substrate having an insulating film on the surface and opening the resist film, and forming an insulating film located in the opening of the resist film, etc. a step of shallowly etching by a directional etching method; a step of forming an etching shape correction film on the etched portion of the insulating film and the surface of the resist film by a spin coating method; A method for manufacturing a semiconductor device, comprising a step of etching an insulating film using a dry etching method. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the etching shape correction film is formed of spinion glass. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the etching shape correction film is formed of a resist.