JPS6051263B2 - Manufacturing method of semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which an electrode is provided on a semiconductor crystal layer and an exposed portion of the semiconductor crystal layer is passivated.

In general, in semiconductor devices in which electrodes are arranged on a flat surface, the surface of the semiconductor active layer between the electrodes may be exposed, and the exposed semiconductor surface is Forming a passivation film is being practiced.

5102 and Si currently in use. There is a method of depositing N4, and a method of using an oxide film obtained by anodic oxidation of a semiconductor as a passivation film is also considered. Unlike conventional methods, this method forms a film by oxidizing the surface of the compound semiconductor that functions as the active layer, so it has the advantage that it does not require new materials for the film and can be performed using simple equipment. This method could not be put to practical use because current flows through the electrodes placed on the surface of the semiconductor, and the area under the electrodes is also oxidized, resulting in the semiconductor device having a structure different from the designed structure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor device that eliminates the above-mentioned conventional drawbacks.

According to the present invention, in manufacturing a semiconductor device in which an electrode is provided on a semiconductor crystal layer and an exposed portion of the semiconductor crystal layer is passivated, the semiconductor crystal layer portion on which the electrode is provided is made semi-insulating by proton irradiation. forming an electrode on the semi-insulating surface portion, converting the exposed surface portion of the semiconductor crystal layer into an oxide film layer by an anodizing method, and then performing heat treatment. A method for manufacturing a semiconductor device is obtained.

According to the present invention, it is possible to form a passivation film with good adhesion without preparing a new material for the passivation film, and moreover, the passivation film can be formed all the way to the bottom of the electrode, unlike conventional methods. Therefore, it is possible to easily manufacture a semiconductor device having a structure as designed.

Next, the present invention will be described with reference to the drawings, taking as an example a case where the present invention is applied to a method of manufacturing a Schottky barrier type GaAs field effect transistor.

1 to 5 are diagrams for explaining one embodiment of the present invention, and show cross sections of a semiconductor device at each main step. First, GaA epitaxially grown on a semi-insulating substrate 1.
By covering the S thin layer 2 with a plurality of rectangular photoresist films 3 and etching them, a plurality of mesa-shaped GaAs active layer groups are obtained (FIG. 1). Next, after removing the photoresist film 3, a new photoresist film 4 is applied, a pattern is cut, and proton irradiation is performed using the photoresist film as a mask to obtain a semi-insulating region 5 (FIG. 2). Next, Al metal is deposited and lifted off to obtain the gate electrode 6, and then a photoresist film 7 is applied again and a pattern is cut, and proton irradiation is performed using the photoresist film as a mask to form a semi-insulating region 8.
(Figure 3). Next, ohmic metal is deposited and lift-off is performed to obtain ohmic electrodes 9 and 10 (FIG. 4). Next, when anodic oxidation is performed while irradiating light onto the side of the wafer on which the passivation film will be formed, the area under the electrode is a semi-insulating region, so no anodic oxide solution or current flows through the electrode. Oxide film 11 is formed only on the desired semiconductor surface to act as a stopper for oxide film formation.
is formed (Figure 5). Next, heat treatment is performed to make the electrodes 9 and 10 electrically ohmic. At this time, by this heat treatment, the semi-insulating regions 5 and 8 formed by the two-ton rib irradiation return to semiconductor crystal layers exhibiting conventional electrical characteristics. Finally, each element is cut and separated using a diamond scriber or the like (FIG. 6).

As described above, according to the present invention, it is possible to accurately and easily manufacture a semiconductor device in which an electrode is provided on a semiconductor crystal layer and the exposed portion of the semiconductor crystal layer is passivated.

Note that the present invention uses not only compound semiconductors such as GaAs but also Si. ．． Needless to say, a single semiconductor such as Ge may be used.

[Brief explanation of the drawing]

FIGS. 1 to 6 are diagrams for explaining a case where the present invention is applied to manufacturing a Schottky barrier field effect transistor as an embodiment of the present invention, and show cross sections in each main process.

Claims (1)

[Claims] 1. In manufacturing a semiconductor device in which an electrode is provided on a semiconductor crystal layer and an exposed portion of the semiconductor crystal layer is passivated, the semiconductor crystal layer portion on which the electrode is provided is rendered semi-insulating by proton irradiation, and then A semiconductor characterized by comprising a step of forming an electrode on a semi-insulating surface, converting the exposed surface of the semiconductor crystal layer into an oxide film layer by anodizing, and then subjecting it to heat treatment. Method of manufacturing the device.