JPS58197845A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To deposit Al films completely arranged in the {111} direction, and to form wiring having high reliability by obliquely positioning a substrate to an evaporation source and forming films. CONSTITUTION:The Al films arranged in the {111} direction are formed by inclining the substrate. That is, the substrate is inclined at 30 deg. or more, and the oblique films, orientations thereof are arranged, in approximately several hundred Angstrom are formed perviously. The Al films, thickness thereof is arranged, are formed only by desired film thickness through a normal method. Since the orientation of foundation is arranged perviously at that time, the films formed onto the foundation succeed to the orientation of the foundation on growth, and are easy to grow. consequently, the film lastly formed is one sufficiently arranged in the {111} direction. Accordingly, Al wiring, in which hillocks are hardly generated and which is also strong against electromigration can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a method for forming an M wiring layer that is resistant to electromigration and has no hillocks and has particularly high reliability.

[Prior art and its problems] M is currently widely used as a wiring metal for semiconductor devices because of its low price, ease of film formation, and excellent processability. Although it has many of the advantages listed above, M still has significant problems as a wiring metal.041
With the improvement of wire thickness, finer wiring of 2μ or less has become necessary.

In order to realize fine wiring, it is first necessary to completely form a fine resist pattern on the nine films E formed. Then,
It is possible to form a 7J cut according to the resist dimensions, and the formed fine wiring is resistant to the current band width, which inevitably increases due to miniaturization. In addition to the need to have resistance, it is also important to suppress the occurrence of hillocks that cause poor interlayer insulation in multilayer wiring. It is difficult to form the crystal grains evenly, so it is best to form a uniform pattern. As a solution to this problem, an M film aligned in the 1ltl) direction has been shown to be resistant to electromybrain. (J-K Howard and R-
J-R+osi, IBM 'I'ech, Rep
22, 601 (March 1968), M, J
, Attardo and R. Rosenberg
.

J, Appm, phy, 41(6) (1970)
2381), it is also clear that such a film is difficult to form on hillocks.

Although it is possible to form an Aj film aligned in the (111) direction to some extent by controlling the deposition method, substrate temperature, deposition rate, etc., it is still not sufficient. Therefore, if it is possible to easily form a 9M film in the (111) direction, it will also be possible with sufficiently reliable wiring.

[Object of the invention] This invention improves the deficiencies of the conventional method described above.
It is an object of the present invention to provide a method that can deposit AJgl that is almost perfectly aligned in the (111) direction, thereby realizing highly reliable wiring.

[Summary of the Invention] The inventor discovered that when a pattern is formed with the substrate oblique to the evaporation source, a film is formed that aligns in the (111) direction.

FIG. 1 shows the method and causes of death. In the figure, numeral 11 indicates an M evaporation source and 12 indicates a substrate. As shown in the figure, this is a method of forming a film with the substrate 12 tilted with respect to the evaporation source 11. When the angle α between the normal to the curtain plate and the evaporation source exceeds 30°, (1
11) It becomes easier to align in the direction. In Figure 2, α is OO and 45
These are the results of X41 diffraction of a film formed when (1
11) It is shown that a strong 9- is formed in the direction.

This phenomenon can be caused by film formation methods such as electron beam, i
s, regardless of sputtering method. Also, the type of membrane is pure A-7! K does not depend on hood, 8i or M alloy film added with Cu.

However, with this method of forming a film on a diagonal substrate, it is difficult to form a film with uniform a[11[ over the entire substrate.

In the present invention, a substrate is first tilted to form a film with a uniform orientation and a thin film thickness of about several hundred^, and then a film with a uniform orientation is formed using a normal method as a core. This is a method to form a film with a uniform thickness.

[Effects of the Invention] According to the present invention, since the M film aligned in the (10) direction is uniformly formed, the occurrence of hillocks is greatly reduced.
A strong wiring is formed in the electromigration layer.

[Embodiment of the Invention] By making the substrate oblique, An aligned in the (111) direction! l[, Q1 is formed. However, if the substrate is tilted, the film thickness will be non-uniform, leading to problems with wiring. In the method according to the invention, the substrate is first
The film is tilted more than 0 to form a diagonal film with a uniform orientation of several hundred amperes. Then, use the A'R,') method to extract the information!
11 AI films with a desired thickness are formed. At this time, since the orientation of the base is already aligned, the film formed thereon will easily grow by inheriting the orientation of the base during growth. Therefore, the final film formed is (111)
This results in a film that is well aligned in the direction. For this reason, an M wiring that is resistant to electromigration and has fewer hillocks can be realized.

Note that K forming the oblique substrate K11l does not depend on the formation method such as vapor deposition or sputtering. Also, pure M.

It is also effective for a 9M alloy film to which impurities such as 84 and Cu are added, and it does not depend on the species aK of Aj.

[Brief explanation of drawings]

Figure 1 shows the method of forming a film by compressing a substrate.
In the figure, 11 indicates an M evaporation source, and 12 indicates a substrate. Also second
Figures (a) and (b) are characteristic diagrams of the X-ray diffraction results for a membrane that is tilted and a membrane that is not, respectively. Kanae

Claims (1)

[Claims] Manufacture of a semiconductor device characterized by forming a thin wiring metal layer by tilting the semiconductor substrate with respect to a metal vapor deposition source in advance in the step of providing a metal film serving as wiring on a semiconductor substrate on which elements are formed. Method.