JPH0438827A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent dropout of resist in a photolithography step by sequentially forming an Al or Al alloy film, a tungsten silicide film, and an Si film on a semiconductor substrate through an insulating film, patterning them by using a mask of a photoresist film by an anisotropically dry etching method, and then removing the retaining Si film. CONSTITUTION:After an SiO2 film is formed on an Si substrate 6, an Al film 4, a WSix film 3, an Si film 2 are continuously formed, further coated with photoresist 1, and the resist is then patterned. In this case, since the film 2 and the resist 1 have high bonding strength, the dropout of the resist does not occur. Then, with the resist 1 after patterning as a mask the film 4, the film 3 and the film 2 are anisotropically dry etched, wired, and the resist 1 is then removed. Thereafter, the film 2 is removed by an anisotropically dry etching method.

Description

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

[Conventional technology]

Conventionally, electrode wiring has been formed in the manufacturing process of semiconductor devices by forming a single layer of Al or AJ alloy thin film as the electrode wiring material, but as the wiring width becomes smaller due to recent integration of devices, electromigration Serious reliability failures such as stress migration have occurred. As one solution to electromigration, a layered wiring structure in which a tungsten silicide (hereinafter referred to as WSix) thin film is formed on an AJ or AI alloy film has been proposed. However, conventionally, it has been difficult to pattern the wiring in the laminated structure for the following reasons.

In other words, WSix formed on Al or Aρ alloy film
Thin films are prone to resist missing in photolithography. This resist missing occurs when the resist 12 on the wafer 14 is exposed to UV light 11, as shown in FIG. Naphthoquinonediazide decomposes into indene carboxylic acid and generates N2 gas 13
occurs. Therefore, as shown in FIG. 2(b), when the contact strength between the resist and the substrate is low, the generated N2 gas 13 enters the resist-substrate interface and peels the resist from the substrate. As a result, as shown in FIG. 2(C), it is thought that this is a phenomenon in which the resist falls off after development and a missing portion 15 is generated. Therefore, there is a close relationship between resist chipping and the type of substrate, and in particular, thin films formed on A (or A) alloy thin films are considered to be one of the substrates most likely to cause resist chipping. ing.

[Problem to be solved by the invention]

The conventional method of forming electrode wiring in the manufacturing process of a semiconductor device described above has a problem in that electromigration and stress migration occur. Also, Al or A! ;! Even when forming a tIgi wiring having a laminated structure in which a WSix thin film is formed on an alloy thin film, there is a problem in that resist chipping is likely to occur due to photolithography.

[Means to solve the problem]

The method for manufacturing a semiconductor device of the present invention includes a step of sequentially forming A (or A (alloy film, tungsten silicide film, and 5iWi!) on a semiconductor substrate via an insulating film, and using a mask made of a photoresist film. The Si film, tungsten silicide film and Aρ
Alternatively, the method includes a step of patterning an Al alloy film, and a step of removing the exposed Si film after patterning by an anisotropic dry etching method.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of a semiconductor chip for explaining one embodiment of the present invention.

First, as shown in FIG. 1(a), Si
○After forming two films 5 by thermal oxidation, a 1.0 μm Aρ film 4, a 500-layer W Si x film 3, and a 500-layer Si film were formed using a sputtering device under the conditions of a power of 5 kW, a pressure of 15 mTorr, and a formation temperature of 200°C. 2 is continuously formed, and then photoresist 1 is applied. Next, as shown in FIG. 1(b), the resist is patterned using photolithography technology. At this time, Sig! Resist No. 2 and Resist No. 1 have high adhesive strength, so no resist dropout occurs.

Next, as shown in FIG. 1(c), using the patterned resist 1 as a mask, the Aρ film 4 and WSi x g!
3 and S1 film 2 by mixing Cρ-based gas and F-based gas at 80°C.
The wiring is processed by anisotropic dry etching under the conditions of 0 W and 10 Pa. Next, as shown in FIG. 1(d), the resist 1 is removed using a stripping agent mainly composed of an organic solvent. Next, as shown in FIG. 1(e), the Si film 2 was heated at 800 W.
, 10 Pa using an anisotropic dry etching method using F-based gas.

In the above embodiment, the Si film 2 was formed by sputtering, but the same chipping prevention effect can be obtained by forming SiM 2 by plasma CVD. The conditions for forming the S1 film by the plasma CVD method are as follows: source gas is SiH4, growth pressure is 0.1 Torr, growth temperature is 300''C, and PRF power is 1kW.The thickness of this 5iJli is 200mm.
If it is more than one person, it has the effect of preventing omissions.

〔Effect of the invention〕

As explained above, the present invention involves forming an Si film on a WSiX film in the process of forming an electrode wiring for a semiconductor device having a stacked structure in which a WSi x film is formed on an Al, A, & alloy film. The addition of this step has the effect of preventing resist chipping in the photolithography process.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a semiconductor chip for explaining an embodiment of the present invention, and FIG. 2 is a sectional view of a semiconductor chip for explaining resist missing. 1...Resist, 2...Si film, 3...WSix
M, 4...Aρ film, 5...SiO2 film, 6...S1 substrate, 11...U■ light, 12...resist, 13...
N2 gas, 14... wafer, 15... missing part.

Claims (1)

[Claims] A step of sequentially forming an Al or Al alloy film, a tungsten silicide film, and a Si film on a semiconductor substrate via an insulating film, and then forming the Si film and tungsten silicide by an anisotropic dry etching method using a mask made of a photoresist film. A method for manufacturing a semiconductor device, comprising the steps of patterning a film and an Al or Al alloy film, and removing a Si film left after patterning by an anisotropic dry etching method.