JPH05182969A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent an uneven part from being produced on a sidewall by a heat treatment after an aluminum interconnection having a layer structure has been formed. CONSTITUTION:After an aluminum interconnection has been formed, a high- pressure steam treatment and a heat treatment are executed or an oxygen plasma treatment is executed; time sidewall of an aluminum or aluminum-alloy film 4 is covered with an alumina film 6. Consequently, it is possible to prevent than uneven part from being produced on the surface of the sidewall of the aluminum or aluminum-alloy film due to the alumina film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device structure, and more particularly to a metal wiring structure.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional wiring structure of a semiconductor device has, for example, PV on a semiconductor substrate 1 and an insulating film 2.
After the titanium metal thin film 3, the aluminum-silicon-copper alloy thick film 4, and the tungsten-silicon compound thin film 5 are formed in this order by the D method, the respective films are formed into the same plane shape by, for example, a photolithography method. The structure was formed by patterning.

[0003]

In the conventional wiring structure of the semiconductor device, since the side wall of the thick film, which is the main wiring material of aluminum or aluminum alloy, is exposed on the side wall, the wiring is formed on the wiring after the wiring is formed. When an insulating protective film is grown on or a heat treatment is performed to stabilize the electrical characteristics, hillocks are transferred to the exposed surface of aluminum or aluminum alloy due to the migration of aluminum atoms.
When unevenness such as disappearance occurs and the wiring width and wiring spacing become submicron, the resistance of the wiring is large due to the disconnection of the aluminum or aluminum alloy layer or the contact with the adjacent wiring.
There was a problem that it caused an open circuit, a leak between wirings, and a short circuit.

[0004]

A thick film made of aluminum or an aluminum alloy is used as a main wiring material on a semiconductor substrate or an insulating film on the semiconductor substrate, and a thick film is formed above and below the main wiring material.
A thin film made of a refractory metal such as tungsten or titanium, an alloy of the refractory metal or a compound of the refractory metal and a non-metal such as silicon or nitrogen is formed into a multi-layered structure, which is patterned. In the formed wiring structure, there is a semiconductor device in which the side wall of the thick film made of aluminum or aluminum alloy is covered with alumina.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an embodiment of the present invention. On the semiconductor substrate 1 and the insulating film 2, for example, P (plasma) -CV
A titanium metal film 3 having a thickness of about 100 nm, a thick film 4 made of an aluminum-silicon-copper alloy as a main wiring material having a thickness of 1000 nm, and a tungsten-silicon compound film 5 having a thickness of 100 nm are formed by the D method. For example, each film is patterned into the same plane shape by a photolithography method to form wiring. The semiconductor device on which the wiring is formed is exposed to high-pressure steam of several hundreds of degrees Celsius and then subjected to heat treatment of several hundreds of degrees of Celsius, or exposed to low-temperature oxygen plasma, to form a sidewall of the aluminum-silicon-copper alloy film 4. Is coated with an alumina film 6 having a thickness of several tens to several hundreds nm.

[0006]

As described above, according to the present invention, aluminum in an aluminum or aluminum alloy formed on a semiconductor substrate and an insulating film, a metal having a high melting point and an alloy or a compound of the nonmetal with aluminum in a layered structure is used. Alternatively, since the side wall of the aluminum alloy layer has a structure coated with alumina, unevenness is less likely to occur even if atomic transfer of aluminum occurs due to heat treatment after the wiring is formed, and the wiring width and the wiring interval are about 0.5 μm. This has the effect of making it possible to reduce abnormalities in the resistance of the wiring and short circuits between wirings to 1/10 or less of the conventional level.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Insulating film 3 Titanium metal film 4 Aluminum-silicon-copper alloy film 5 Tungsten-silicon compound film 6 Alumina film

Claims (1)

[Claims] 1. A thick film made of aluminum or aluminum alloy is used as a main wiring material on a semiconductor substrate or an insulating film on the semiconductor substrate, and tungsten is provided above and below the main wiring material.
It is formed by forming a thin film of a refractory metal such as titanium, an alloy of the refractory metal or a compound of the refractory metal and a nonmetal such as silicon or nitrogen into a multi-layered structure, and patterning this. In the above wiring structure, the side wall of the thick film made of the above aluminum or aluminum alloy is covered with alumina.