JPH02232927A - Electronic component - Google Patents

Abstract

PURPOSE:To manufacture an electronic component subjected to no wiring deterioration due to electromigration even when a fine wiring is formed by a method wherein a specific weight % of Li containing Al radical alloy is to contain Al3Li while the remaining part is to substantially contain pure Al. CONSTITUTION:A 0.01-3.0wt.% of Li containing Al radical alloy is to contain Li while the retaining part is to substantially contain pure Al on an Si substrate formed of a thermal oxide film of SiO2 by high-frequency sputtering process using a mosaic target of Al and Al-Li. This Li containing Al alloy thin film is formed to form a pattern 1 by etching process. This pattern 1 is composed of a wiring 3 e.g. in width of 0.8mum and length of 1000mum as well as a pad 2. In such a constitution, this pattern 1 can be provided with the excellent electromigration resistance by the processes enumerated as follws i.e., this pattern is supplied with the current in specified current density; the initial specific resistance value is measured; and the shape changes and the electric resistance are measured at the time when the electric resistance is rapidly increased in the wiring of a comparison pattern comprising Al-Cu-Si alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic component, and particularly to an electronic component using a novel material for wiring.

(Prior Art) In recent years, devices in the field of electronic equipment have become significantly smaller and more highly integrated, and as a result, electronic components have become increasingly smaller. As electronic components become smaller, there is an increasing demand for miniaturization of wiring that electrically connects each element included in the electronic component or wiring within a semiconductor device. Materials for wiring in such electronic components must have good conductivity, can easily form thin films for forming fine wiring, and have ohmic contact with semiconductor substrates when wiring is formed on semiconductor substrates such as silicon. It is required that contact be easily made. As a material that meets the above-mentioned requirements, n-based alloys have been widely used for wiring in electronic components.

On the other hand, materials for such wiring are required to have excellent electromigration resistance in addition to the properties described above. Electromigration is a phenomenon in which metal atoms constituting wiring collide with electrons under high current density, gain kinetic energy, and move in the same or opposite direction as the current. When such a phenomenon occurs, a serious problem arises in that there is a local excess or deficiency of metal atoms in the wiring. In other words, vacancies are generated in areas lacking metal atoms, and when these vacancies grow, they lead to wire breakage. In addition, in the excess area, protrusions occur on the surface of the wiring,
This is because short circuits may occur with adjacent wirings, element breakdown due to damage to the insulating film under the wiring, and corrosion due to damage to the protective layer.

In order to prevent such electromigration in conventional electronic components, for example, US Patent No. 3743
At-Cu-Si as shown in No. 894 etc.
At-Cu alloys such as alloys have been used as wiring materials. This is because in the kA-Cu alloy, the CuAt particles present at the n-grain boundary suppressed the movement of ht atoms and had the function of preventing electromigration.

However, as the wiring width has decreased in line with the miniaturization of electronic components in recent years, the frequency of occurrence of wiring defects due to electromigration has increased in such wiring. The development of materials was desired.

(Problems to be Solved by the Invention) As described above, conventional electronic components have had the problem that, as wiring becomes finer, wiring defects due to electromigration occur frequently.

The present invention aims to realize a highly reliable electronic component that has wiring that has excellent electromigration resistance and can withstand miniaturization.

[Structure of the invention]

(Means and effects for solving the problems) The present invention is an electronic component having wiring made of an Li-containing n-based alloy, and in particular, the Li-containing M-based alloy contains At, Ll,
This is an electronic component having wiring in which the remainder is substantially pure M.

In the electronic component of the present invention, by forming the wiring with the Li-containing M-based alloy, excellent electromigration resistance can be obtained even in fine wiring of, for example, about 1 μm or less. This is thought to be because the intermetallic compound At3Li precipitated at the M grain boundaries due to the addition of Li suppresses the movement of red atoms. Furthermore, Li-containing At-based alloys have superior electromigration resistance compared to other M-based alloys such as At-Cu alloys, but this is due to the fact that At and Li are compatible with the At metal lattice. The interface between the precipitate and the red metal lattice does not become a new M atom diffusion route. In addition, Az and Li precipitated at the M grain boundaries have the function of increasing the tensile strength of the alloy, which is thought to suppress wiring deformation such as vacancy generation and protrusion growth associated with electromigration. It will be done.

In the Li-containing red-based alloy that forms the wiring as described above, the Ll content ranges from 0.01 to a. OWtl preferably 0.01-1. It is desirable that Q W j Chi.

The reason for this is that regions with a high Ll content become brittle, and in particular, when the content exceeds 3.0 Wt%, AtLi begins to precipitate as an intermetallic compound, and this AzLi reduces the tensile strength of the alloy, making it difficult to electromigrate. This is because eye resistance may deteriorate. When Li is contained in an amount of 3.0 wt% or less based on K, excellent electromigration stain resistance can be obtained in proportion to the Li content. However, if this exceeds 1.0 Wt%, the electrical resistance will increase due to Li dissolved in the Asahi.
In particular, when wiring with low electrical resistance is required, it is desirable that the Li content is 1.0 Wt1 or less. On the other hand, Li
If the content of Li is too small, the effect of the present invention cannot be obtained, so the content of Li is set to o. It is desirable that it is oxwt or higher.

Furthermore, the electrical resistance value of Li-containing n-based alloys changes depending on K, such as whether the M grain boundary structure includes a triple grain boundary or a panpo grain boundary where grain boundaries exist in the form of cutting wiring.
Practically speaking, the content of Ll is desirably determined appropriately within the above range, taking into consideration the electrical resistance value. Moreover, in the electronic component of the present invention, Li-containing Ω constituting the wiring
Even if the base alloy contains a small amount of impurities such as Cu, Mg, 8i, Mn, Zn, Pd, etc., the same excellent electromigration resistance can be obtained. Considering the above, A
4. It is desirable that the material contains Li and the remainder is pure M.

The Li-containing n-based alloy according to the present invention can be applied as a material for wiring in various electronic components. In particular, for electronic components where At-Cu alloys have traditionally been used as wiring materials,
By applying the Li-containing M-based alloy, wiring having excellent electromigration resistance can be obtained and reliability can be improved.

Examples of such electronic components include semiconductor devices in which elements are mounted on a semiconductor substrate, thermal heads with heating elements, thin film circuits, etc. By applying the present invention to such electronic components, Significant effects can be expected.

(Example) Examples of the present invention are shown below.

First, AltoAA-Li (5.Owt%)O-r-
A film of a Li-containing M-based alloy having a composition as shown in Table 1 was deposited on an St substrate on which a thermal oxide film of B, sto, was formed by high-frequency sputtering using A thin film with a thickness of 8000 Å was formed, and a pattern was created using an etching method. The shape of the obtained pattern is schematically shown in FIG. Pattern ill is width 0.8μm 1 length 100
It consists of a 0 μm wiring (3) and a pad (2).

Further, as a comparative example, using pure M and kA-Cu-8i alloy targets, pure M and At-Cu-
8! Created an alloy pattern. 2 to these patterns
A current corresponding to a current density of 2×10 A/cd was applied at 00° C., and the initial resistivity value in the wiring was set to Boo.The shape change of each wiring was observed after a period of time had elapsed since the beginning of the current flow. The results are shown in Table 1.

As is clear from the table, in the wiring material according to the present invention, At
-Cu--Si alloy wiring exhibits little deterioration even during test times when it exhibits significant deterioration due to electromigration, and has superior electromigration resistance compared to conventional wiring materials.

Table 1 [Effects of the Invention] As detailed above, according to the present invention, it is possible to provide a highly reliable electronic component in which the wiring does not deteriorate due to electromigration rays even when fine wiring is formed. can.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the shape of a wiring pattern according to the present invention, which was used for testing in an example. 1...Pattern, 2...Pad, 3...Wiring, 4
···substrate. Agent Patent Attorney Noriyuki Chika Yudo Masaru Matsuyama

Claims (3)

[Claims] (1) An electronic component characterized by having wiring made of a Li-containing Al-based alloy. (2) In the Li-containing Al-based alloy, the Li content is 0
．． Claim 1 characterized in that the amount is 01 to 3.0 wt%.
Electronic components listed. (3) The electronic component according to claim 1, wherein the Li-containing Al-based alloy contains Al_3Li, and the remainder is substantially pure Al.