JPH02307224A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain metal electrode wirings having extremely small grain boundary and uniform orientation by providing a semiconductor substrate, an insulating film formed on the main face side of the substrate, a groove formed on the film, and electrode wirings formed on the groove. CONSTITUTION:A semiconductor substrate 4, an insulating film 5 formed on the main face side of the substrate 4, a groove 6 formed on the film 5, and electrode wirings 10 formed on the groove 6 are provided. The film 5 is formed on the main face of the substrate 4, the groove 6 is formed on the film 5, and a metal film 8 is then formed on the film 5 formed with the groove 6. Then, after the film 8 is annealed by a laser light 9, the film 8 annealed with the laser light is patterned in electrode wirings 10. For example, a wedge-shaped groove 6 is formed on the film 5 by a photochemical process, and the angle formed between the groove 6 and the side face 7 is formed at an angle (54.7 deg.) formed between the face (111) of the face centered cubic lattice of aluminum and the face (-1-11).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metal electrode wiring of a semiconductor device and a method of manufacturing the same.

= BACKGROUND TECHNOLOGY A! As an electrode wiring material for semiconductor devices! and its alloys have been used for a long time for the following reasons. A
! and its alloys have high electronic conductivity, are easy to form good ohmic contacts in both P-type and n-type Si contacts, are easy to microfabricate using photolithography, and have a stable oxide layer on the surface. It is possible to form a thin film with high purity, is less likely to corrode, and is inexpensive and can easily form a thin film with high purity.

Conventionally, AI thin i used for electrode wiring of semiconductor devices is
When forming on one wafer, sputtering method has mainly been used. A schematic cross-sectional view of an AI thin film shaped 5112 by this method is shown in FIG. It is well known that the A/thin film (1) thus formed is composed of an aggregate of single crystals;
The film thickness is 0.5 to 2.0. sm and very thin T:,
AI (D crystal grain (2) size and AA! Thin!! (1
) have almost the same thickness, and the microstructure has a shape in which crystal grains (2) cross the AI thin film (1), as shown in FIG. Note that there are grain boundaries (
8) It is distinguished by: Further, (4) is a substrate made of S1 single crystal, and (5) is an insulating film made of S1 oxide film or the like formed on substrate (4).

Semiconductor devices have made remarkable progress in recent years, with rapid progress toward higher integration and miniaturization, but this has also led to various problems with electrode wiring. One such obstacle is the movement of AI atoms (electromigration) due to the use of electrode wiring under high current densities.
There is a disconnection due to In electromigration,
The movement of AI atoms mainly occurs at the grain boundaries, and the smaller the average grain size, the more the volume of AI at the grain boundaries increases.
It is generally known that the amount of movement increases.

[Problem to be solved by the invention]

In the metal electrode wiring of a semiconductor device produced by the conventional method, many grain boundaries (8) are present. .

For this reason, when wiring is miniaturized and used under high current density, the possibility of wire breakage due to electromigration is extremely high.

The present invention was developed in view of the conventional problems as described above, and provides a semiconductor device having extremely few grain boundaries and uniformly oriented metal electrode wiring, and a method for manufacturing such a semiconductor device. The purpose is to

[Means to solve the problem]

A semiconductor device according to the present invention includes a semiconductor substrate, an insulating film formed on a main surface side of the semiconductor substrate, a groove formed on the insulating film, and an electrode wiring formed on the groove. I'm here.

A method for manufacturing a semiconductor device according to the present invention includes a first step of forming an insulating film on a main surface of a semiconductor substrate, a second step of forming a groove on the insulating film, and an insulating film in which the groove is formed. A third step of forming a metal film on the film, and the metal! The method includes a fourth step of annealing with in-laser light, and a fifth step of patterning the metal film annealed with the laser light into electrode wiring.

[Effect]

According to the present invention, a groove is formed in an electrode wiring base, a metal film is formed on the base, and the metal film is annealed with a laser beam. For this reason, the metallurgical film annealed by the laser beam is influenced by the grooves formed on the base, and a film with uniform orientation and large crystal grains is formed... [Example] The present invention The flow for forming metal electrode wiring of a semiconductor device related to the semiconductor device will be explained according to No. 1-9.
is an insulating film formed on the substrate (4) and made of, for example, a silicon oxide film. First, the insulating film (5) is
As shown in Figure (Bl), a wedge-shaped groove (6) is formed by photolithography.The side surface of the wedge-shaped groove (6) (
For example, the angle formed by (a) is the angle (
54.7°). Next, as shown in FIG. , to approximately 300°C.Then, as shown in Figure 1 (DI), under high vacuum (~1
0 Torr or less), the AI film (8) is annealed by irradiating it with a laser beam (9) or the like.

By skipping the annealing process using the laser beam (9), the AI film (8) forms a side surface (
7), the (111) plane is reoriented so that it becomes parallel to it. Next, as shown in wc1 diagram (El), the reoriented AI
The film (8) is patterned into desired wiring by photolithography.

AI wiring lines formed by the above method (as shown in Figures 2 and 3 (Al), the underlying trench (6)
Since the (111) plane is aligned with the side surface (γ) of the electrode wiring, the electrode wiring is uniformly oriented, and there are almost no grain boundaries present in conventional electrode wiring.

Note that, as shown in FIG. 4, in this method, the cross-sectional shape of the groove (6) formed in the underlying insulating film (6) is not limited to a wedge shape, and the size of the groove (6) Saya,
The density formed can also be changed depending on the value of the AI wiring formed thereon.

Furthermore, the wiring materials used include not only Aj but also Ou, AjSi, A/5iOu, AjO
It is also applicable to u, etc.

〔Effect of the invention〕

According to the present invention, since a groove is formed on the electrode wiring base and AtWl is formed thereon, it is possible to form an electrode wiring with extremely few grain boundaries by laser annealing. Therefore, electrode wiring with extremely high electromigration resistance can be obtained, and the reliability of the semiconductor device can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the flow of a method for manufacturing a semiconductor device according to the present invention. FIG. 2 is a partial vertical cross-sectional view of electrode wiring of a semiconductor device showing an embodiment of the present invention. Figure 3 (
A+ is a sectional view taken along the line ■-■ in FIG. 2. FIG. 3 5:3) is an enlarged view of the 6th part in FIG. 3 tA+. FIG. 4 is a perspective view showing another embodiment of the present invention. FIG. 5 is a partial vertical cross-sectional view of electrode wiring of a semiconductor device according to the prior art. In the figure, (4) is a substrate, (5) is an insulating film, (6) is a groove, (7) is a side surface of the groove, (8) is an aluminum film, (9) is a laser beam, and (9) is an electrode wiring. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) A semiconductor device including a semiconductor substrate, an insulating film formed on the main surface side of the semiconductor substrate, a groove formed on the insulating film, and an electrode wiring formed on the groove. (2) A first step of forming an insulating film on the main surface of the semiconductor substrate, a second step of forming a groove on the insulating film, and forming a metal film on the insulating film in which the groove is formed. The third step,
a fourth step of annealing the metal film with laser light;
a fifth step of patterning the metal film annealed by the laser beam into electrode wiring.