JPS6279629A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To flatten the dampproof surface of the titled semiconductor device by a method wherein, after the surface has been flattened with a phosphorus glass film or a borophosphate glass film, a dampproof insulating film is formed thereon. CONSTITUTION:The insulating film 2 having the required pattern is formed on a semiconductor substrate 1, a borophosphate glass film 4 is formed thereon, and the recesses and the projections generated on the surface are flattened by performing a heat treatment. Then, the dampproof insulating film 5 such as an oxide film is formed thereon by performing a chemical vapor deposition (CVD) method or a sputtering method. As a result, the upper surface is flattened further, and the dampproof property is greatly improved. A phosphorus glass film may be used instead of the above-mentioned borophosphate glass film.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for flattening the surface of a concavo-convex pattern formed on a semiconductor substrate in a method of manufacturing a semiconductor device.

[Conventional technology]

FIG. 2 is a cross-sectional view showing a semiconductor substrate whose surface has been flattened by the conventional method 41, in which a first insulating film (2) of a desired pattern is formed on the semiconductor substrate (1) by film formation, photolithography and etching. When the film is formed, the surface becomes uneven. If an aluminum (At) wiring is formed directly on this, the At wiring is likely to be disconnected because the edges of the unevenness are steep. To avoid this, a method of forming phosphorus glass PM (3)k on the first insulating film (2) has been used for a long time to make the uneven surface of the first insulating film (2) as flat as possible.

FIG. 3 is a cross-sectional view showing a semiconductor substrate whose surface has been completely planarized by the second conventional method, in which a boron phosphorus glass film (4) is formed in place of the phosphorus glass film (3) in the conventional example shown in FIG. This material has a better flow than phosphorus glass and can be made even more flat. Flattening using such a phosphorus glass film (3) or a boron phosphorus glass film (4) will be essential for the formation of semiconductor elements with higher density, which will be required in the future, and for flattening the base when forming multilayer wiring. [Problems to be Solved by the Invention] However, the phosphorus glass membrane and the boron phosphorus glass membrane lack moisture resistance, and in particular, the borophosphorus glass membrane has a problem that it is even worse than the phosphorus glass membrane.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a method for flattening a surface using a phosphorus glass film or a boron phosphorus glass film and having good moisture resistance. .

[Means for solving problems]

In the method of manufacturing a semiconductor device according to the present invention, after flattening the surface with a phosphorus glass film or a boron phosphorus glass film,
A moisture-resistant insulating film is formed thereon.

[Effect]

In the present invention, the required surface flattening can be achieved using a phosphorus glass film or a phosphorus glass film, and the moisture resistance lacking in these films can be achieved by forming a moisture resistant insulating film thereon.

[Embodiment] FIG. 1 is a sectional view showing a semiconductor substrate whose surface has been planarized by a method according to an embodiment of the present invention, and the same reference numerals as in the conventional example indicate equivalent parts. Similar to the second conventional example shown in FIG.
After completely forming the boron phosphorus glass film (4) on the uneven surface that has formed on the surface and flattening it by heat treatment, a second moisture-resistant insulating film such as an oxide film is further applied on top of it. (5
) is formed by CVD or sputtering. This further flattens the top surface and significantly improves moisture resistance.

In addition, although the boron phosphorus glass film was used in the above embodiment, a phosphorus glass film may also be used.

〔Effect of the invention〕

As explained above, in the present invention, by forming a phosphorus glass film or a boron phosphorus glass film on the surface of a semiconductor substrate having an uneven pattern, the surface can be easily flattened. Since a transparent insulating film is formed, a moisture-resistant flat surface with no head can be obtained, and even if all metal wiring is formed thereon, occurrence of disconnection can be avoided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a semiconductor substrate whose surface has been planarized by the method of one embodiment of the present invention, and FIGS. 2 and 3 are semiconductor substrates whose surfaces have been completely planarized by the conventional first and second methods, respectively. FIG. In the figure, (1) is a semiconductor substrate, (2) is an uneven pattern (first insulating film), (3) is a phosphor glass film, (4) is a polo/phosphor glass film, and (5) is a moisture-resistant insulating film. (Second insulating film) - Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (2)

[Claims] (1) After forming a phosphorus glass film or a boron phosphorus glass film on the uneven pattern formed on the semiconductor substrate and subjecting it to the necessary heat treatment, the method further includes the step of forming a moisture-resistant insulating film thereon. A method for manufacturing a semiconductor device, characterized in that: (2) The method for manufacturing a semiconductor device according to claim 1, characterized in that an oxide film is used as the moisture-resistant insulating film.