JPH01181444A - Semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To reduce wiring resistance, by constituting one region as a wiring region in a superconducting state in a specified temperature range, and using the other region as a non-wiring region in a normal conducting state. CONSTITUTION:On the surface of a semiconductor substrate 1, a superconducting compound thin film 2 is formed, a part of which is constituted by applying different component ratio to the compound, in order to differ in the transition critical temperature of superconduction. This region 5 is turned into a superconducting state in a specified temperature, and used as a wiring region. The other region is in a normal conducting state, and used as a non-wiring region. By forming the wiring of superconductor, the wiring resistance can be zero, so that the operating speed of a semiconductor integrated circuit is increased, the heat generation is reduced, and the performance of elements can be remarkably improved. Further, since the wiring structure is flat, the reliability of elements also can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor device, and particularly to its wiring structure and manufacturing method.

BACKGROUND ART FIGS. 2a to 2d are process cross-sectional views illustrating a method of forming a conventional wiring structure. As shown in FIG.
After forming 02, a resist 103 is coated, light exposure 105 is performed using a mask 104 (FIG. 2B), and development is performed to form a pattern on the resist 103 as shown in FIG. 2C. Next, the wiring material 102 is etched using the resist 1o3 as a mask to form a wiring pattern (FIG. 2d).

・Problems to be solved by the invention As semiconductor devices become smaller and more highly integrated, interconnect resistance becomes a problem in interconnect structures in conventional technology. However, it is difficult to achieve this goal due to difficulties in stabilizing the materials and processing technology.

On the other hand, as the density of devices increases, wiring is multilayered, but there are problems such as difficulty in formation due to steps in the wiring structure and reduction in reliability due to occurrence of disconnections, short circuits, etc.

The present invention provides a wiring structure with low resistance and high reliability in order to solve the conventional problems.

Means for Solving the Problems The present invention makes a part of a superconducting compound thin film formed on the surface of a semiconductor substrate have a different component ratio of the compound, so that the critical temperature for superconducting transition is different, and the superconducting transition critical temperature is adjusted to a predetermined temperature. Within the range, that region is set to a superconducting state and used as a wiring region, and the other region is set to a normal conducting state and used as a non-wiring region.

It is known that among compounds exhibiting functional superconductivity, there are compounds whose superconducting transition temperature changes when their component ratios differ. Regions with different transition temperatures can be formed by ionizing and implanting atoms, which are one of the components, into a portion of a thin compound film exhibiting such properties formed on a semiconductor substrate. In a predetermined temperature range in which only this region becomes superconducting, it can be used as a wiring region.

Embodiment FIG. 1 is a process sectional view and a structural sectional view showing an embodiment of the present invention.

As shown in FIG. 1a, a compound 2 exhibiting superconductivity is formed on a semiconductor substrate 1. For example, a YBaCuO thin film is formed by electron beam evaporation or the like.

Next, as shown in FIG. 1, ion species 4 of atoms constituting one component of the compound are implanted into the compound thin film 2 using a mask 3 to form regions 5 having different component ratios. For example, YB
In the case of aCuO system, oxygen is implanted. After this, heat treatment may be performed if necessary.

The superconducting transition temperature T1 of the ion-implanted region is higher than the transition temperature T2 of other regions, and in the temperature range shown below, T, > T > T2 The ion-implanted region 5 is in a superconducting state, and the other regions are in a normal conducting state. shows. In this temperature range, the ion implantation region has zero resistance and most of the current flows through this region.

The wiring structure formed by the above method is shown in FIG. 1C. Ions are selectively implanted into the region 5 forming the wiring.

In the above wiring structure, by forming the wiring with a superconductor, the wiring resistance can be reduced to zero, the operating speed of the semiconductor integrated circuit can be increased, heat generation can be reduced, and the performance of the element can be greatly improved. Because the structure is flat,
The reliability of the device can also be improved.

Effects of the Invention Parts of the superconducting compound thin film formed on the surface of a semiconductor substrate according to the present invention are made to have different component ratios of the compound, so that the critical temperature for superconducting transition is varied, and the region is controlled within a predetermined temperature range. By using the wiring area as a superconducting state and the other area as a non-wiring area in a normal conducting state, it is possible to realize a highly reliable wiring structure with low wiring resistance through a simple process and a flat structure, and its practical effects are as follows. big.

[Brief explanation of the drawing]

1A and 1B are process sectional views explaining one embodiment of the present invention, FIG. 1C is a perspective view showing the wiring structure of the same embodiment,
FIGS. 2a to 2d are cross-sectional views of the process of forming a conventional wiring pattern. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 2... Superconducting compound thin film, 4... Ion species, 5... Wiring pattern. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (2)

[Claims] (1) Consisting of a superconducting compound thin film formed on the surface of a semiconductor substrate, having regions with different component ratios in the thin film,
A semiconductor device in which each of the regions has a different superconducting transition temperature, and within a predetermined temperature range, one of the regions is in a superconducting state and serves as a wiring region, and the other region is in a normal conducting state and serves as a non-wiring region. (2) By implanting ion species of atoms constituting one component of the compound into a part of the superconducting compound thin film formed on the surface of the semiconductor substrate, regions with different component ratios are formed in the thin film. A method of manufacturing a semiconductor device in which a wiring region and a non-wiring region are formed by using the same method.