JPH03219631A - Manufacture of semiconductor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention relates to a method for manufacturing a semiconductor device, and particularly to an etching method for tapering an absolutely all I semiconductor device. [Summary of the Invention 1 The present invention provides an excellent method for etching an insulating film. 1l
A resist pattern is formed on the ll with a contact angle of 90 degrees or less between the resist and the main surface of the semiconductor, and the insulating film is etched halfway by etching with absolute ttt+i and a resist selectivity of 3 or less, and then wet etching is performed. By etching the insulating film to the final stage, a tapered etching hole (hereinafter referred to as a contact) is formed, and furthermore, it is possible to form a tapered etching hole (hereinafter referred to as a contact), and furthermore, it is possible to form a tapered etching hole (hereinafter referred to as a contact). It is something that makes things better. [Conventional Techniques] Conventional methods for forming contact portions are 1. For example, when an insulating film is dry etched, the contact portion is not tapered as shown in Fig. 2, and the wiring of the wiring electrode to be wired afterwards is The fit of the parts was also not very good. [Problems to be Solved by the Invention 1] The coverage of the wiring electrode in the conventional contact part is not very good, and in order to improve this, for example, as shown in Fig. 3,
PSG or flow technology is used. However, even if reflow technology were used, although the angle (304) of the upper part of the contact would be improved, the contact angle (305) with the semiconductor surface would not be much improved, and as a result, the coverage of the wiring electrode would not be improved. The invention is intended to solve these problems, and what is its purpose? The object of the present invention is to provide a method of etching a contact portion that provides good coverage of the wiring electrode by tapering the contact portion. [Means for Solving the Problems] A method for forming a semiconductor device of the present invention includes a step of forming a predetermined pattern with a resist in which the contact angle between the resist and the main surface of the semiconductor is 90 degrees or less, and forming an insulating film. The method is characterized by a step of etching the absolute a++* partway through etching with a low selectivity of the resist and a resist, and then a step of etching the insulating film to the final stage by wet etching.

【Example】

FIG. 1 is a diagram showing the main steps in one embodiment of the semiconductor device of the present invention. Hereinafter, a method for manufacturing a semiconductor device according to the present invention will be explained with reference to FIG. (FIG. 1(a)) (101) is a substrate, for example, a Si substrate. (102) is an insulating film formed on the main surface of the substrate, and is formed with 1, for example, 5i02 of, for example, 5000A. (103) is a resist, which is formed on (102) to a thickness of, for example, 10,000 Å. In order to reduce the contact angle with (102), heat (for example, 150° C., 30 minutes) is applied after forming the pattern. (Figure 1(b)) Next, selectivity ratio between absolute nlI and resist (
= Etching speed of insulating film / Etching speed of resist) is a small etching, such as sputter etching, and since the etching selectivity is small, the shape of the resist remains unchanged! It becomes the etched shape of I. However, since it is not possible to confirm that the etching has been completed on the Si substrate, in the present invention, etching is performed halfway through the insulating film. (Fig. 1 (C)) Next, wet etching is performed using a mixed acid of IF and NH4F. Since wet etching is isotropic etching, the tapered shape of sputter etching is maintained as it is. Moreover, etching stops at the Si surface. In this way, the etched shape of the tapered contact portion is obtained. Furthermore, since the etching shape depends on the resist pattern shape, any etching shape can be selected by controlling the resist pattern shape. Effects of the Invention J As described above, according to the present invention, in the method of manufacturing a semiconductor device, a predetermined pattern is formed with a resist in order to ensure insulation, and the contact angle between the resist and the main surface of the semiconductor is 90 degrees or less. a step of etching the insulating film and resist to the middle by etching with a selectivity ratio of 3 or less, and then a step of etching the insulating film to the resist to the middle, and then wet etching,
Since the process of etching the insulating film to the final stage is combined with the process of forming the ferroelectric film, it is possible to perform tapered etching, and furthermore, the coverage at the contact part of the wiring electrode that is formed after that is reduced. It has the effect of becoming.

[Brief explanation of drawings]

FIGS. 1(a) to 1(c) are main process diagrams of the method of manufacturing a semiconductor device of the present invention, and FIGS. 2 and 3 are sectional views of a conventional contact portion. (101) ・ ・ ・ ・ ・ (102) ・ ・ ・ ・ ・ (103) ・ ・ ・ ・ ・ (203) (303) (304) ・ ・ ・ ・ ・ ・Si substrate, insulating film, resist, wiring electrode, Angle at the top of the contact (305) Greater than the contact angle with the semiconductor surface of the contact

Claims (1)

[Claims] (1) a step of forming an insulating film on the main surface of the semiconductor; a step of forming a predetermined pattern with a resist on the insulating film in which the contact angle between the resist and the main surface of the semiconductor is 90 degrees or less; and the insulating film. manufacturing a semiconductor device, comprising the steps of: etching the insulation film halfway through etching with a resist selectivity of 3 or less; and then etching the insulation film to the end through wet etching. Method.