JPS62125680A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a gate length shorter than a hole width of a photoresist by inclining and dry etching a semiconductor substrate covered with an insulating film, narrowing the width of a recess hole as seen from a normal line, and then adding a gate metal. CONSTITUTION:An oxide film 2 is grown on a semiconductor substrate 1, a nitride film 3 is further grown thereon, a photoresist 5 coated, exposed and developed on the wafer formed with the insulating film to form a photoresist 5 having a hole. Then, the wafer is inclined in an anisotropically dry etching direction, anisotropically dry etched to etch the film 3 to form a hole different from the hole of the photoresist in the film 3. The film 2 is removed by set etching until arriving at the substrate 1, a recess is formed on the substrate 1 by etching, anodic oxidation method, and with the film 3 as a mask a gate metal 4 is added in the recess by a depositing method. Thus, an MESFET having a short gate length is simply manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a semiconductor device, and in particular to a method for manufacturing a semiconductor device, in particular, using an insulating film as a mask, recessed M r-, S F E T
The present invention relates to a method of attaching gate metal.

1' Conventional technology] Conventionally, when attaching metal to the recessed ME8 FET, first, an opening 11 was created in the insulating film using the resist I as a mask, but when opening L1 Because the semiconductor substrate was placed horizontally on a flat plate and the W-oriented l-ly etching was performed from the normal direction of the flat plate, the opening of the insulating film formed was formed after the photoresist was formed, as shown in Figure 3. , metal gate attached by vapor deposition
1-length could not be made shorter than the photoresist opening.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional gate metal attachment method, the gate length depends on the photoresist, so it is not possible to shorten the gate length to obtain a M E SF E T with good characteristics. There were problems such as a decrease in yield and an increase in cost and labor due to the miniaturization of the hexagonal resistor, which required lithography.

[-1] of the present invention is that the width of the opening 11 of the insulating film viewed from the normal direction of the wafer can be made shorter than that of the opening 1 of the resist I, and the gate length can be shortened. SFET
An object of the present invention is to provide a method for manufacturing a conductor device that can be easily manufactured.

[Means for Solving the Problems 1] The method for manufacturing a semiconductor device of the present invention includes a recessed MESF
In the process of manufacturing an ET, the insulating film covering the semiconductor substrate is removed by anisotropic dry etching using Photoresis I- as a mask, and when opening a recess, the semiconductor substrate is tilted and anisotropic dry etching is performed. The width of the recess opening 11 as seen from the normal direction of the semiconductor substrate is narrowed by performing a chemical trial and socing process, and the metals 1 to 1 are deposited using a vapor deposition method.
It has the characteristic that the gate length t' and Y is shorter than the opening width of the resistor I.

[Example] Next, an example of the present invention will be described with reference to the drawings. FIG. 1 shows an MP formed according to an embodiment of the present invention;
FIG. 2 is a vertical cross-sectional view of a partial process for explaining an embodiment of the present invention.
First, as shown in FIGS. 1 and 2, an oxide film 2 is grown on the upper surface of a semiconductor substrate 1, and then a nitride film 3 is grown on the top surface of the semiconductor substrate 1.
grow.

Next, the wafer on which the -J-distribution film was formed was exposed to a photo 1 film.
Heregis 1 to 5 are coated, exposed, and developed to form a sheet with openings) Heregis 1-5.

Next, as shown in FIG. 2, the wafer is placed at an angle with respect to the anisotropic dry etching direction, and the nitride film is etched by anisotropic dry etching. Different openings are formed in the nitride film.

Next, the oxide film 2 is removed by wet etching until it reaches the semiconductor substrate 1, and then etched.

A recess is formed in the semiconductor substrate 1 by an anodic oxidation method or the like.

Next, as shown in FIG. 1, using the nitride film 3 as a mask,
Goo 1-metal 4 is attached in the recess by a conventional vapor deposition method.

With the above, it is easy to obtain a length of Gou1 which is shorter than the width of the opening of the photoresist, and the thickness of the oxide film and nitride film,
By optimizing conditions such as the angle of inclination, it is also possible to offset the gates within the recess.

[Effect of invention]

As explained above, the present invention is a recess type MESFE.
In step 2, when opening the insulating film, the wafer is tilted, the photoresist is used as a mask, and the insulating film is anisotropically dry etched.
The width of the opening [1] of the insulating film viewed from the normal direction of the wafer can be made shorter than the opening of the photoresist 1~, and when gate metal is evaporated using this opening as a mask, MESFET with a short length of goo 1~ can be made. It is possible to easily manufacture a miniaturized semiconductor device with excellent performance at a high yield and at a low cost of 1~.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a =9- semiconductor device formed according to an embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view of a partial process for explaining an embodiment of the present invention. FIG. 3 is a cross-sectional view of a conventional semiconductor device after metal has been deposited. 1... Semiconductor substrate, 2... Oxide film, 3... Nitride film,
4... Gate metal, 5... Fol-Resist l~. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] In a method for manufacturing a semiconductor device, the method includes a step of removing an insulating film covering a semiconductor substrate using a photoresist as a mask and opening a recess by removing the insulating film by anisotropic dry etching using a photoresist as a mask. After narrowing the width of the recess opening seen from the normal direction of the semiconductor substrate by tilting the semiconductor substrate on which the mask is formed and performing anisotropic dry etching, gate metal is attached by vapor deposition, and photoresist is etched. A method for manufacturing a semiconductor device characterized by obtaining a gate length shorter than an aperture width.