JPH0336751A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To flatten an interlayer film, etc., at low temperature or for a short time by employing a film with tension stress as a second film and heat-treating said film at a temperature where a first film gets fluid. CONSTITUTION:A pattern 2 is formed with polycrystalline silicon for example on one principal surface of a semiconductor substrate 1, on which pattern a PSG film including about 9wt.% phosphorus pentoxide for example is deposited as a first film 3 by CVD process. A molybdenum silicide film is formed on the first film 3 as a second film 4 by magnetron sputtering for example and heat-treated at 1000 deg.C in the nitrogen atmosphere for 5 minutes for example for flattening thereof. Thereupon, the PSG film 3 is fluid at 1000 deg.C and the molybdenum film 4 has tension stress at 1000 deg.C additionally to fluidity of the film itself, so that the fluidity is promoted for satisfactory flattening for a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for planarizing an insulating coating on a pattern having steps.

BACKGROUND ART Conventional method for manufacturing semiconductor devices FIGS.
This will be explained using step-by-step sectional views of C).

As shown in FIG. 2(a), a pattern 12 made of, for example, polycrystalline silicon was formed on the whole surface of the semiconductor substrate 11. As shown in FIG. FIG. 2(b) shows a silicon oxide film (containing about 9 wt% phosphorus pentoxide: PSGI) on the pattern 12.
) 13 was deposited by the CVD method, and the step portion of the silicon oxide film 13 was flattened by heat treatment at 1000° C. for 30 minutes in a nitrogen atmosphere, for example, as shown in FIG. 2(c).

Problems to be Solved by the Invention Conventional technology requires heat treatment at high temperatures for a long time to obtain good flatness of interlayer films, etc. There has been a problem in that impurities used in the emitter diffusion layer of a transistor diffuse into a semiconductor substrate and the like, causing variations in device characteristics and hindering miniaturization.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a method for manufacturing a semiconductor device that can realize planarization of an interlayer film or the like at a lower temperature or in a shorter time than the conventional method.

Means for Solving the Problems The method for manufacturing a semiconductor device of the present invention provides a first method for manufacturing a semiconductor device such as an interlayer insulation film.
The method includes a step of forming a second film on the film, and a step of heat-treating the first film and the second film.

Function In the structure of the present invention, by using a film having tensile stress in the 21st film I and performing heat treatment at a temperature at which the first film becomes fluid, flattening can be achieved only by the fluidity of the first film itself. In contrast, flattening can be promoted by the tensile stress of the second film in addition to the flow force of the first film itself, and good flatness can be obtained in a shorter time than conventionally.

EXAMPLE Below, an example of the present invention will be explained with reference to FIGS. 1(a) to (d).
) will be explained according to the step-by-step cross-sectional diagrams.

As shown in FIG. 1(a), a pattern 2 of polycrystalline silicon or the like having a thickness of 500 nm was formed on the entire surface of a semiconductor substrate 1. As shown in FIG. In FIG. 1(b), a PSG film containing, for example, about 9 wt% phosphorus pentoxide was deposited as a first film 3 on the pattern 2 to a thickness of 800 nm by the CVD method. FIG. 1(c) shows a second film 4 on the first film 3.
For example, a molybdenum silicide film with a thickness of 200 nm was formed by magnetron sputtering. Figure 1 (d
), for example, 1. A heat treatment was performed at OO0° C. for 5 minutes to flatten the surface. At this time, the PS
The G film 3 is fluid at 1000° C., and in addition to the fluidity of the film itself, the molybdenum silicide film 4 has tensile stress at 1000° C., which promotes fluidity and achieves good planarization in a short time.

In this example, a silicon oxide film containing phosphorus was used as the first film 3, and a molybdenum silicide film was used as the second film 4. This can be achieved by appropriately selecting a film that has tensile stress during heat treatment. Further, the heat treatment temperature may be appropriately set depending on the film types of the first film 3 and the second film 4.

When the present invention is applied to flattening the glabellar insulating film, it can be easily realized by simply adding a step of selectively removing the second film 4 following the above embodiment.

Effects of the Invention The semiconductor device manufacturing method of the present invention allows interlayer films to be flattened at a lower temperature or in a shorter time than conventional methods, suppresses the depth and lateral expansion of impurity diffusion layers, and improves MO8 type transistors and It is possible to achieve miniaturization and high-density integration of bipolar transistors.

[Brief explanation of drawings]

FIGS. 1(a) to 1(d) are process-order sectional views showing the manufacturing process of a semiconductor device according to an embodiment of the present invention, and FIG.
a) to (c) are step-by-step sectional views showing manufacturing steps of a conventional example. 1... Semiconductor substrate, 2... Batten such as polycrystalline silicon, 3... First film, 4...
...Second membrane.

Claims (6)

[Claims] (1) A step of forming a first film on a pattern having steps on a semiconductor substrate, a step of forming a second film having tensile stress in a heat treatment step on the first film, and a step of forming a second film having tensile stress on the first film and A method for manufacturing a semiconductor device, comprising a step of heat treating two films. (2) The method for manufacturing a semiconductor device according to claim (1), wherein the first film becomes fluid by heat treatment. (3) The method for manufacturing a semiconductor device according to claim (1), wherein the first film is a silicon oxide film. (4) The method for manufacturing a semiconductor device according to claim (3), wherein the silicon oxide film contains at least one of phosphorus, boron, and arsenic. (5) The method for manufacturing a semiconductor device according to claim (1), wherein the heat treatment is performed at a temperature higher than a temperature at which the first film becomes fluid. (6) The method for manufacturing a semiconductor device according to claim (1), wherein the heat treatment is performed at a temperature lower than the temperature at which the second film becomes fluid.