JPH0419706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high quality alumina insulating film.

Insulating films play an important role as components of solid-state devices such as semiconductors and their integrated circuits. Therefore, a technique for easily, reliably, and accurately shaping this insulating film is extremely important. In the production of semiconductor devices using silicon, silicon oxide and silicon nitride are commonly used as insulating films, and selective processing methods have also been developed.

In recent years, as compound semiconductor devices have appeared, there is also a need to lower the device manufacturing temperature.
Various insulating films and their deposition methods have been tried. Alumina (aluminum oxide) film is one such film, and it is attracting attention because it can be deposited with high quality at a relatively low temperature. The requirements for an insulating film as a component of a solid-state device are: it must be mechanically, chemically, and electrically stable; it must have good adhesion to the other material; it must be a uniform film; it must be easy to process. There are many things that can be mentioned.

Normally, these properties are greatly influenced by the deposition conditions of the insulating film, so it has been difficult to set conditions such as etching time to reliably form and process the film.

The present invention was made with the aim of overcoming these drawbacks and providing a high quality alumina insulating film. Examples of the alumina insulating film of the present invention will be described below.

FIG. 1 shows an embodiment of the present invention, which is a substrate made of a semiconductor or a metal other than titanium, on which a titanium or titanium-containing alloy layer 2 is formed, and an alumina film 3 in contact with the upper surface of the substrate. was formed.

According to this configuration, the alumina film 3 has good adhesion to the titanium or titanium-containing alloy layer 2 and has excellent mechanical, chemical, and electrical properties.
An alumina film with excellent properties as a whole can be obtained.

FIG. 2 shows another embodiment of this invention,
While the embodiment shown in FIG. 1 is formed in the order of the substrate 1, the titanium or titanium-containing alloy layer 2, and the alumina film 3, the embodiment shown in FIG. alloy layer 2 containing titanium;
The alumina film 3 is formed in this order.

FIG. 3 shows still another embodiment of the present invention, in which an alumina insulating film is formed in this order: a substrate 1, an alumina film 3, and a titanium or titanium-containing alloy layer 2.

Next, a method of utilizing the alumina insulating film according to the present invention will be explained with reference to FIGS. 4a and 4b.

Figure 4a shows titanium or an alloy layer 2 containing titanium.
Since an alumina insulating film is used which is patterned according to the etching process and an alumina film 3 is formed thereon, the photoresist 4 is also patterned in the same manner as the titanium or titanium-containing alloy layer 2.

Normally, the alumina film is etched with phosphoric acid, but the alumina in the portion that is in contact with the titanium or titanium-containing alloy layer 2 is resistant to phosphoric acid. Therefore, as shown in Figure 4a,
If the structure is such that the parts other than the parts to be etched are in contact with titanium or the alloy layer 2 containing titanium, only the parts not in contact with titanium or the alloy layer 2 containing titanium are etched, as shown in FIG. 4b. . If the etching time can be controlled appropriately, the portion of the titanium or titanium-containing alloy layer 2 is not necessarily necessary and can be shaped according to the pattern of the photoresist 4. However, although the etching time is usually longer than the appropriate time, since the alumina film 3 in contact with the titanium or titanium-containing alloy layer 2 is chemically resistant,
Even if the etching time is sufficiently longer than necessary, the formed pattern will not be distorted. That is, selective etching is reliably and accurately performed.

As explained above, the alumina insulating film of the present invention is composed of a titanium or titanium-containing alloy layer and an alumina film in contact with it, so it has excellent alumina insulation mechanically, chemically, and electrically. A membrane is obtained. Therefore, the use of this alumina insulating film has excellent effects such as enabling selective etching with high reliability without causing distortion of the shaped pattern.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of one embodiment of this invention, FIGS. 2 and 3 are sectional views showing other embodiments of this invention, and FIGS. 4a and 4b are ways of using this invention. FIG. 3 is a cross-sectional view before and after etching for explaining an example. In the figure, 1 is a substrate, 2 is titanium or an alloy layer containing titanium, and 3 is an alumina film.

Claims (1)

[Claims] 1. An alumina insulating film comprising a titanium or titanium-containing alloy layer and an alumina film provided in contact with the titanium layer.