JPS62106623A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve the performances of electrode by a method wherein a first metallic film is formed by evaporation in the oblique directions on a substrate, next a second metallic film smaller than the first metallic film is evaporated in the vertical direction onto the first metallic film successively to form multiple metallic films. CONSTITUTION:When a first metallic film 7 is evaporated, an evaporation source is moved so that evaporation beams may be emitted in the arrow directions C, D. The first metallic film 7 larger than the electrode pattern on upper end part of an overhangingly formed resin layer 2 is formed on a semiconductor substrate 1. Next a second metallic film 8 is formed by evaporation only on the first metallic film 7 using another evaporation source with vertical evaporation beams in the arrow direction E to the surface of substrate 1. Through these procedures, the second metallic film 8 does not stick on the surface of substrate 1 so that the electrode performances may be assured by the first metallic film 7 only to be improved notably as a result.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a semiconductor device in which electrodes are formed using a lift-off method.

[Conventional technology]

FIG. 2 is a cross-sectional view of an electrode made of a multilayer metal film formed using a conventional vapor deposition method, in which 1 is a semiconductor substrate, 2 is a tree III layer on which an electrode pattern is formed, 3 is a first metal film, and 4 is the second metal film, 5 is the first metal film on the resin M2, and 6 is the same (indicates the second metal film).

In an electrode made of a multilayer metal film formed using a conventional vapor deposition method, when a first metal film 3 and a second metal film 4 are formed using a vacuum vapor deposition method, each metal film is 3,4
Since the evaporation sources are different, the directions of the evaporation beams are different as shown by arrows A and B.

Therefore, when the second metal film 4 is deposited after the first metal film 3 is deposited, the second metal film 4 is shifted from the position of the first metal film 3 and a part of the second metal film 4 adheres to the surface of the semiconductor substrate 1. It is formed by

[Problem that the invention seeks to solve]

The electrode made of a multilayer metal film formed using the conventional lift-off method has the second metal film 4 attached to the surface of the semiconductor substrate 1 as described above, so the electrode is made of only the first metal film 3. performance cannot be obtained, so with Schottky electrode,
There were problems such as changes over time such as deterioration of the cutting after heat treatment.

This invention was made to eliminate the above-mentioned gap (vertex), and an object of the present invention is to obtain a method for manufacturing a semiconductor device having a multi-JΔ metal film that can obtain electrode performance only with the first metal film. do.

[Means for solving problems]

The method for manufacturing a semiconductor device according to the present invention includes forming an electrode made of a multilayer metal film on a semiconductor substrate by a vacuum evaporation method;
forming a first metal film using an evaporation beam from an evaporation source from an oblique direction using a patterned resin layer on a semiconductor substrate as a mask; A step of forming a second metal piece 9 having a smaller area than the first metal film by applying a vapor deposition beam from a direction perpendicular to the conductor substrate.
A required number of multilayer metal films are formed on the semiconductor substrate.

[Effect]

In this invention, a second metal film having a smaller area than the first metal film is formed on the first metal film, and the electrode performance is improved without the second metal film adhering to the semiconductor substrate. Obtained by the first metal film.

〔Example〕

FIG. 1 is a cross-sectional view of an electrode made of a multilayer metal film, for example a two-layer round metal film, formed using a vapor deposition method according to an embodiment of the present invention. In Figure 2, the same symbols as in Figure 2 indicate the same parts.

A method for forming the multilayer metal film shown in FIG. 1 will be described below. When depositing the first metal film 7 in FIG. 1, the deposition source may be moved so that the direction of the deposition beam is in the direction of arrows C and D, or the deposition source may be fixed at multiple locations. conduct. Alternatively, an overhanging shape may be formed by one or more methods in which vapor deposition is performed while moving the semiconductor substrate 1 so that the vapor deposition beam from one fixed vapor deposition source has the directions of arrows C and D with respect to the semiconductor substrate 1. A first metal film 7 having an area larger than the electrode pattern portion at the upper end of the resin layer 2 is formed on the semiconductor substrate 1. Next, a second metal film 8 is deposited on the surface of the semiconductor substrate 1 using an evaporation source whose evaporation beam direction is perpendicular to the arrow E, and the second metal film 8 is deposited only on the first metal film 7. A metal film 8 is formed.

Note that when both the first metal film 7 and the second metal film 8 are deposited with the deposition source set in the vertical direction of the semiconductor substrate 1, if the deposition beam is an ideal vertical beam, the second metal film 8 (not in contact with the semiconductor substrate 1. However, in this method, the first metal film 7 and the second metal film 8 have the same size, so the evaporation source of the second metal film 8 and the semiconductor substrate 1
The relative position of the metal film 7 must be the same as that of the first metal film 7. In the current apparatus, the relative positions of the evaporation source and the semiconductor substrate 1 are changed, and the first metal film 7 and the second metal film 8 are separated.
It is nearly impossible to deposit from the same direction with high precision.

Therefore, in this invention, in order to further expand the degree of freedom,
The first metal film 7 is made thicker than the second metal film 8 (formed &
How to wear it. Furthermore, the first metal film 7 is not deposited in two steps, but is formed in a continuous process.

By using the above method, the second metal film 8 is not attached to the surface of the semiconductor substrate 1, so that electrode performance can be obtained only by the first metal film 7. Therefore, when a Naronyotto key electrode is formed from a multilayer metal film using the method described above, deterioration due to cutting after heat treatment is reduced and reliability is increased.

Ohmic electrodes also have low resistivity.

Note that in the above embodiment, the multilayer metal film consists of the first and second layers.
Although the method for forming the metal films 7 and 8 in layers has been described, if lift-off is possible, it is also possible to form a multilayer metal film with three or more layers by gradually making the angle between the evaporation source and the semiconductor substrate closer to perpendicular. be.

〔Effect of the invention〕

As explained above, in this invention, on the semiconductor substrate surface,
A first metal film is formed by evaporating from an oblique direction. 1) A second metal film smaller than the first metal film is evaporated from a perpendicular direction on the first metal film to sequentially form a multilayer metal film. Since the second and subsequent metal films can be formed only on the first layer of gold 1i4 film, there is no possibility that the second and subsequent metal films will adhere to the semiconductor substrate. There is an effect that a semiconductor device having an electrode with improved performance can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a method for forming electrodes in a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional method for forming electrodes in a semiconductor device. In the figure, 1 is a semiconductor substrate, 2 is a resin layer on which an electrode pattern is formed, 7 is a first metal film, and 8 is a second metal film. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 1 8 Second capsular membrane

Claims (1)

[Claims] a step of forming a first metal film on the semiconductor substrate by an evaporation beam from an evaporation source in an oblique direction using a resin layer formed with a desired electrode pattern on the semiconductor substrate as a mask; forming a second metal film having a smaller area than the first metal film on the metal film using a vapor deposition beam from a direction perpendicular to the semiconductor substrate, thereby forming a required number of multilayer metal films on the semiconductor substrate; 1. A method of manufacturing a semiconductor device, characterized by forming a semiconductor device.