JPH0212826A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To maintain the superior deposition condition of an upper layer insulating film, even if the distance between wirings is shortened as a result of miniaturization, by a method wherein, after wiring material and an insulating film are stuck on the whole surface of a substrate and patterning is performed, a taper is formed by isotropically etching the insulating film. CONSTITUTION:In a wiring layer forming process of a semiconductor device, metal or metal compound 303 turning to a wiring layer is stuck to the upper whole surface of a substrate 301, and as insulating layer 304 is stuck to the whole surface. After a photoresist is stuck to the whole surface, and patterning of the resist is performed by photolithography, the insulating film 304 and the wiring material 303 are etched by using the resist 305 as a mask. By isotropically etching an insulating film 306, a taper is formed. For example, an Si oxide film or an Si nitride film is used as the above insulating film 304. When it is difficult for dry etching to taper-etch the insulating film 306, wet etching is used. Further, the wiring material 303 may be subjected to etching after the taper of the insulating film 306 is formed by isotropic etching.

Description

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

In particular, prior art technology involves depositing a wiring material over the entire surface of a substrate, patterning a resist on the wiring material using photophosphorography, and etching the resist into a mask. there were.

[Problems to be Solved by the Invention] FIG. 1 shows a cross-sectional structure in which a wiring material is formed using a conventional technique and an insulating film is deposited thereon. As can be seen from the figure, as the distance between interconnects becomes shorter due to miniaturization, it becomes difficult to fill the upper insulating film, and in extreme cases, holes may be formed. Such holes are unfavorable in terms of device reliability and are a constraint on miniaturization. Recently, when etching wiring materials, a method has been used to prevent this by applying a taper to the top of the wiring material using some wet etching. However, this method has problems in terms of control and As the resist becomes finer, there is a problem in which the upper resist is blown off during etching. There is also a method of tapering the wiring material using the dry etching method, but with current equipment,
I have to say it's impossible. The present invention overcomes the drawbacks of the prior art and provides a highly reliable structure. [Means for Solving the Problems] The present invention provides a method for forming a tapered part chisel of wiring materials such as metal in a dry etching method. This is based on the fact that, while it is quite difficult to perform Taber etching on oxidized S1 films and nitrided S1 films, it is relatively easy to perform Taber etching.

In addition, the fact that improving the deposition state of the insulating film on the upper part of the wiring material can be achieved by tapering only the upper corner of the wiring material without tapering the entire wiring material is also used.

[Example code] An embodiment of the present invention will be described with reference to FIG.

An insulating film 302 is formed on the substrate. Wiring material 303. A cross-section of the insulating film 04 deposited thereon with a resist 305 patterned by photolithography is shown in (α). This is subjected to anisotropic dry etching to obtain the cross-sectional view (b). Next, the insulating film is isotropically etched, and the insulating film 306 is tapered. After this, the resist is removed to obtain cross section (C). Here, as the insulating film 304, an oxide S1 film or a nitride S1 film is used. Further, when it is difficult to perform Taber etching of the insulating film by dry etching, ordinary wet etching can be used.

At this time, in the case of oxidation S1, an ammonium fluoride solution is used to avoid etching the underlying wiring material. The present invention may also include a method in which the wiring material 503 is etched after forming a taper in the insulating film 30B by isotropic etching.

[Effect of the invention] The cross section where the insulating film is deposited on the structure of cross section (C) is
As shown in the figure. The state of deposition of the insulating film 205 is greatly improved compared to the conventional example shown in FIG. 1, especially between the wiring materials, and the holes etc. that occur conventionally are completely eliminated. Therefore, a highly reliable element can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a structure according to a conventional manufacturing method. FIG. 2 is a sectional view showing a structure according to the manufacturing method of the present invention. FIGS. 5(α) to (C) are process cross-sectional views showing the manufacturing method of the present invention.

Claims (1)

[Claims] (1) In the process of forming a wiring layer of a semiconductor device, a process of depositing a metal or a metal compound that will become a wiring layer over the entire surface of the substrate;
A step of depositing an insulating film on the entire surface, a step of depositing a photoresist on the entire surface and patterning the resist by photolithography, a step of etching the insulating film and the wiring material using the resist as a mask, a step of etching the insulating film, etc. 1. A method of manufacturing a semiconductor device, comprising the step of directional etching and tapering.