JPS63221645A - Method for connection between wirings in semiconductor device - Google Patents

Abstract

PURPOSE:To remove a step difference between a through hole part and an insulating film and to prevent disconnection which is generated due to coverage defect in a second wiring, by connecting a first wiring with the second wiring through a through hole wiring film which is constant in thickness. CONSTITUTION:After a first separation insulating film 2 is formed on a semiconductor substrate 1, a first wiring layer is formed and prescribed patterning is performed to form a first wiring 3. Further, an insulating film 4 for the through hole wiring film formation is formed thereon, and part on the first wiring is removed to form a through hole wiring film 6 on a through hole part 5 and the insulating film 4 for through hole wiring film formation. Next, part of the through hole wiring film 6 is removed to form a new through hole wiring film 6. Next, a second separation insulating film 7 is formed in thickness enough to fill a step difference of the through hole wiring film 6. Next, the second separation insulating film 7 is removed until a surface of the through hole wiring film 6 becomes exposed. After the formation of the second wiring layer, then prescribed patterning is performed to form a second wiring 8, and the first wiring 3 is connected with the second wiring 8 via the through hole wiring film 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for connecting wires in a semiconductor device, and particularly to a method for connecting wires in a multilayer structure.

[Conventional Technique #] FIG. 2 shows an example of a conventional method for connecting interconnects in a multilayer structure of a semiconductor device.

In the figure, 1 is a substrate, and 2 is a first isolation insulating film.

3 is a first wiring, 5 is a through hole portion, 7 is a second isolation insulating film, and 8 is a second wiring.

Next, a method for connecting wires will be explained. Figure 2 (a)
After forming the first isolation insulation [12] on the substrate 1 as shown in FIG.
A first wiring layer is formed and predetermined patterning is performed to form the first wiring 3. Next, Figure 2(b) 1. :show f
Yo'5:, 11 arrangement [113 to 1st minute m1e edge 112
After forming the second female part 1311I7 thereon, a part of the second isolation insulating film 7 on the first wiring 3 is removed to form a through hole part 5. Further, after forming a second wiring layer on the through hole portion 5 and the second isolation insulating film 7, a predetermined patterning is performed to form a second wiring 8.

[Problems to be Solved by the Invention] In the conventional interconnection connection method, the second separation insulator 117 and the second
The wiring 8 has a similar film thickness, for example, 8000A to 10000A.
This has the disadvantage that the coverage of the second wiring 8 at the step of the through-hole portion 5 is poor, causing the second wiring 8 to be disconnected.

The present invention has been made to eliminate the above-mentioned drawbacks, and eliminates the level difference between the through-hole portion 5 and the insulating film.
It is an object of the present invention to obtain a wiring fastening structure that can prevent wire breakage caused by poor coverage of the second wiring 8.

[Means for Solving the Problems] The interconnection connection method according to the present invention connects a first interconnection and a second interconnection through a through-hole interconnection film having a constant thickness.

[Function] According to the wiring connection method of the present invention, the first wiring and the second wiring are connected by a through-hole wiring film having a constant film thickness, so that the level difference at the connection part that conventionally occurs can be eliminated. can.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
In the figure, 1 is a semiconductor substrate, 2 is a first isolation insulating film, 3 is a first wiring, 4 is an insulating film for through-hole wiring formation, 5 is a through-hole part, 6 is a through-hole wiring film, and 7 is a second isolation film. The insulating film 8 indicates the second wiring.

As shown in FIG. 1(a), after forming a first isolation insulating film 2 on a semiconductor substrate 1, a first wiring layer is formed and a predetermined patterning is performed to form a first wiring 3. Furthermore, an insulator lI4 for through-hole wiring IIIl formation is formed on the first isolation insulating film 2 and the first wiring 3, and after removing a portion on the first wiring to form a through-hole portion, the through-hole 5l is formed.
A through-hole wiring 116 is formed on s5 and the insulator 114 for through-hole wiring film formation. Next, as shown in FIG. 1(b), a part of the through-hole wiring 1lI6 of the through-hole wiring is removed, leaving the through-hole portion 5 and a portion outside thereof, to form a through-hole wiring 116. Then the first
As shown in FIG. 3C, a second isolation insulating film 7 is formed on the through-hole wiring film 6 and the through-hole wiring film-forming insulator 114 to a thickness that is sufficient to fill the step of the through-hole wiring 116. Next is the 1st v! As shown in A(d), the second isolation insulating film 7 is removed down to the surface of the through-hole wiring film 6 by, for example, an etch-back method.

Next, as shown in FIG. 1(e), after forming a second wiring pattern on the second isolation insulating film 7 and the through-hole wiring film 6, a predetermined patterning process is performed to form a second wiring 8. , the first wiring 3 and the second wiring 8 are connected via a through-hole wiring 116.

In the above embodiments, an example was described in which the semiconductor substrate was formed on a semiconductor substrate, but a conductor or insulator substrate other than the semiconductor substrate may be used. Furthermore, although the two-layer structure consisting of the first isolation insulating film, the first wiring, the second isolation insulating film, and the second wiring has been described,
It may also have a multi-layered structure.

[Effects of the Invention] As described above, according to the present invention, the wiring connection between the first wiring and the second wiring at the through-hole portion is achieved by forming a through-hole wiring film of a constant thickness in the through-hole portion. By doing so, there is no difference in level at the connection portion, and the occurrence of wire breakage can be prevented, so that highly reliable wiring connections can be made.

It can also be a reliable device.

[Brief explanation of the drawing]

FIG. 1 shows a wiring connection method according to the present invention, and FIG. 2 shows a wiring connection method according to a conventional method. In the figure, 1 is a substrate, 2 is a first isolation insulating film, 3 is a first wiring, and 4 is a through hole wiring I! A is an insulating layer for film formation, 5 is a through-hole portion, and 6 is a through-hole arrangement sum. 7 is a second isolation insulating film, and 8 is a second wiring. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (3)

[Claims] (1) preparing a semiconductor substrate, forming a first isolation insulating film on the substrate, and forming a first wiring on the first isolation insulating film;
After forming an insulating film for forming a through-hole wiring film on the first wiring and removing a part of the insulating film for forming a through-hole wiring film to form a through hole leading to the first wiring, the through-hole a through-hole wiring film of a predetermined thickness is formed by penetrating through the through-hole wiring film into contact with the first wiring, and with the upper surface of the through-hole wiring film exposed, the first through-hole wiring film is formed on the insulating film for forming the through-hole wiring film. 1. A method for connecting interconnects in a semiconductor device, comprising forming a second isolation insulating film, contacting an exposed portion of the through-hole wiring film, and forming a second interconnect film on the second isolation insulating film. (2) The interconnection connection method according to claim 1, wherein the semiconductor substrate is a conductor or insulator substrate other than a semiconductor substrate. (3) The interconnection connection method according to claim 1, wherein the interconnection film has a multilayer structure of three or more layers.