JPS6089943A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To facilitate electrical insulation to the Si substrate by sequentially forming SiO2, silicide under the tungsten or molybdenum film. CONSTITUTION:After the tungsten film 1 is vacuum-deposited on a Si crystal substrate 2, this sample is heated up to a temperature ranging from 500 to 1,200 deg.C under the H2O ambient including H2O of 1ppm to 50%. Thereby, first tungsten W reacts with silicon Si and WSi2 film 4 is formed and then SiO2 film 3 is formed on the surface of film 4 by H2O in H2. Since W is not oxidized by H2+H2O, silicide and SiO2 are formed without oxidation of W. In case Mo is used in place of W, the same reactions are carried out. Thereby, a sufficient available insulation resistance for practical use can be obtained between the film 1 and film 4. Moreover, since W or Mo wiring is formed as the buried wiring, any protrusion and recess due to the wirings are not formed on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of manufacturing a semiconductor device using a W or MO film as an electrode or wiring.

[Background of the invention]

Conventionally, there is a known technique in which an insulating film such as 810g or 8isN4 is formed on an 81 substrate, and then MO or W wiring is formed to electrically insulate the MO or W wiring from the Si substrate. When performing multilayer wiring, there is a problem in that the surface unevenness accompanying the wiring causes contact between the p2 wirings where the MO and W wirings are cut at the stepped portions.

[Purpose of the invention]

An object of the present invention is to solve the above-mentioned conventional problems and to solve the problems of the Mo-? W
An object of the present invention is to provide a method for manufacturing a semiconductor device that can facilitate electrical insulation with a Si substrate by sequentially forming 810 g of silicide under the peritoneum.

[Summary of the invention]

In order to achieve the above object, the present invention provides 11) containing 50% of H, +0 from 11) Pm after depositing W or MO on Si.
Heat at 500C to 1200C in 12C. In this way, W and Mo first react with Si to create silicide (W
S l x , MoS + 2, etc.) and then H
Sigh is formed on the silicide surface by 1120 in 2. Since W and Mo are not oxidized by the above gas (120 Hz O), the above silicide and SiO+ are formed without oxidizing W1MO'/.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to Examples.

[Example 1] As shown in FIG. 1(a), a W film 1 is formed on a Si crystal substrate 2.
When a sample deposited with a thickness of 35 Qnm was heated at 1000C for 120 minutes in I2 (containing 20 cm of H2O), the first
As shown in Figure (b), W film 1 (thickness: 130 nm), 5iO2 film 3 (thickness: 2000 m), and tungsten silicide (WS i 2 ) film 4 (thickness: 8501 m) are sequentially applied.
was formed. 8i02 between W film 1 and silicide film 4
Measuring the dielectric strength voltage of membrane 3 is 2 to 5 M V/on
Met. This value is the withstand pressure of a normal thermal 510z film (~10
Although this value is slightly lower than that of MY/clrr), it is sufficient for practical use. Also, the thickness of the 5RO2 film is 11! You can adjust the amount by changing the amount of H2O in it, the heating temperature, and the time.

[Example 2] As shown in FIG. 2(a), a W film 1 is formed on a Si crystal substrate 2.
After depositing 1QQnm of 8102 on it to a thickness of 350 nm, the SiO2 film at appropriate locations is removed by etching using a conventional photolithography (IJ) polisher. Next, 100 in H2 containing 10 inches of H20
When heated OC for 60 minutes, as shown in FIG. 2(b), in the exposed part of W, an 8102 film 3' (thickness 10100 nm, silicide film 4 (thickness: 700 nm), 5i02 film 3
In the portion covered with , only the silicide film 4 (thickness: 800 nm) was formed because the diffusion of H2O was suppressed.

Next, as shown in FIG. 2(C), a 5j02 film 3'' with a thickness of 1100 nm was deposited by the CVD method.In this example, a W buried wiring was formed using a SiO□ film diffusion mask. Since the W wiring is formed in a buried manner, surface irregularities associated with the wiring do not occur.

〔Effect of the invention〕

According to the present invention, after a W and MO film is deposited on a Si substrate, a 5in2 film can be formed under the W and MO film in an annealing process. As seen in the example, if Sing, PSG, Si2N4, etc. are used as a H2O diffusion mask, the above reaction can be selectively caused, so it can be used for embedded wiring, etc., and it can be used for multilayer wiring and three-dimensional devices. Can be applied to wiring. The manufacturing process can also be carried out using a normal electric furnace, so its productivity and economic efficiency are extremely high.

[Brief explanation of drawings]

FIGS. 1 and 2 are process diagrams showing different embodiments of the present invention. 1... Tungsten film, 2... Silicon single crystal, 3
゜3/, 3//...silicon oxide film, 4...
Tungsten Xiu 1 Figure N2 Figure 1';)';)1-

Claims (1)

[Claims] Tungsten (W) or molybdenum (
Mo) Step of forming a metal film, and successively forming a silicon dioxide (SiOx) film and a silicide film under the tungsten or molybdenum metal film by heating at a temperature of 500 to 1200 C in H2 containing 50% of 11□0 from ippm. 1. A method of manufacturing a semiconductor device, the method comprising the step of forming a semiconductor device.