JPS5835929A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a glass coating having the high dampproof property for a semiconductor device by a method wherein the film consisting of silicate glass is selectively treated with heat by irradiation of an energy beam, and selective etching is performed according to the difference of etching speed to be generated by hydrofluoric acid to form a pattern. CONSTITUTION:The PSG film 2 is made to grow on a substrate 1 according to the CVD method holding at the thermal decomposition temperature of 425 deg.C, a metal mask 3 having the prescribed openings is put thereon, and the film 2 is irradiated to perform the selective heat treatment using continuous wave CO2 gas laser of about 3mm. luminous flux diameter making the scanning speed at about 0.4cm/sec. The etching speed to be performed using hydrofluoric acid at the part treated with heat is made slower than the part not treated with heat by this way, the mask 3 is removed, etching is performed on the whole surface using the etching liquid of H2O:HF=39:1, and the part not treated with heat being covered with the mask 3 is removed. Accordingly the resist treatment is unnecessitated, and the progress of work is shortened, while cleanness is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to silicate glass (5i) in semiconductor devices.
related to different pattern formation methods.

Phosphosilicate glass (ph-ospho
-811icate -glass, hereinafter abbreviated as PSG) or borosilicate glass (Boro -8iji
Silicate glasses such as Cate-Gjams (hereinafter abbreviated as BSG) are used.

PEG and BSG have good adhesion to wiring metals, have a coefficient of thermal expansion close to that of wiring metals, and are unlikely to cause cracks, and can usually be produced at temperatures below 500°C. 0 PSG is produced as follows by a chemical vapor deposition method (hereinafter abbreviated as CVD method), which allows easy control of the impurity concentration in the produced glass by changing the concentration of impurity gas. ; 5iHa+2tan(m+60t→si
otomi・P, OJL+5H1O BSG; 5iHa+B鵞H・+501→SIO Y・B, O, +5H鵞O When forming a shiba turn on the silicate glass film formed as described above, conventionally a photoresist was used as a mask. Generally, a method is used in which the film is formed and then selectively etched using an etching solution containing hydrofluoric acid (HF) as a main component.

An object of the present invention is to obtain a manufacturing method for forming a pattern made of silicate-glass without using a resist.

The object of the present invention is to
This is achieved by selectively heat-treating the silicate glass by selectively irradiating it with H and selectively etching the heat-treated portions with a slower etching rate with hydrofluoric acid than the non-heat-treated portions. .

The present invention will be specifically explained below with reference to the drawings of an example of the BAt model. As shown in the cross-sectional view in FIG.
．． It was allowed to grow into 3μ buds.

Next, a metal mask 3 was placed on the PSG film 2, and 50J
The PSG film 2 is irradiated through the mask 3 with a beam diameter of about 3 mm and a scanning speed of about 0.4α/s6c from a continuous wave carbon dioxide (CO,) laser of Heat treatment was performed.

PSGJ subjected to the selective heat treatment described above [2 has a composition H
, O:HF=39:1 etching solution was used to remove the portions covered by the mask 3 that were not etched during the heat treatment, resulting in a pattern 4 made of PSG as shown in the cross-sectional view in FIG. I got it. The thickness of pattern 4 is about 800 nm, and the etching time in this example is 10
The etching rate was approximately 130 nm/s for the non-heat-treated portion and approximately 50 nm/s for the heat-treated portion.

In the embodiment described above, the entire surface was irradiated with COt laser light through the mask 3, but it is also possible to perform direct drawing without using the mask 3.

It is also possible to selectively etch down to the underlying layer using the PSG pattern formed by the above method as a mask.

As explained above, the present invention forms a pattern by selectively heat-treating WX (silica)-glass by irradiating it with energy beams, and performing selective etching based on the difference in etching speed with hydrofluoric acid. This not only shortens the manufacturing process and improves product cleanliness by eliminating the need for resist processing steps, but also improves moisture resistance (through heat treatment of silicate glass) and stabilizes the semiconductor surface. It also has an effect on conversion.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing embodiments of the present invention. In the figures, 1 is a substrate, 2 is a PSG film, 3 is a mask, and 4 is a cross-sectional view showing an embodiment of the present invention.
is composed of PSG (showing the turn 0 Figure 1 Figure 2

Claims (1)

[Claims] The silicate glass film can be selectively heat-treated by energy beam irradiation, and the silicate glass film can then be etched with a solution containing hydrofluoric acid. A method of manufacturing a semiconductor device, the feature of which is to form a pattern that differs from the portions subjected to heat treatment.