JPS59228736A - Multilayer interconnection method - Google Patents

Abstract

PURPOSE:To prevent the disconnection in a stepwise difference of an interlayer insulating layer of an upper layer electrode by forming a quasi-electrode in addition to a lower layer electrode pattern on the lower layer of the stepwise difference of the interlayer insulating layer, thereby utilizing the stepwise fifference due to the quasi-electrode. CONSTITUTION:An interlayer insulating layer 1 is formed of a lower layer electrode wiring pattern having a lower layer electrode 5 and a polyimide resin, and an upper layer electrode 4 is formed through the layer 1, thereby forming a multilayer interconnection structure. A lower layer electrode 6 which is conducted with the electrode 4 is formed via a through hole 2 on the lower layer of the stepwise difference 3 of the structure. Further, a quasi-electrode 8 is formed adjacent to the electrode 6, a sharp rise of the difference 3 is eliminated, thereby flattening the difference 3 as a whole. Then, the disconnection in the difference 3 of the insulating layer of the electrode 4 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The object of the present invention is to prevent disconnection of the upper layer electrode at the stepped portion of the glabellar insulating layer in a multilayer wiring having a glabellar insulating layer made of polyimide resin.

In the conventional method, when polyimide resin kFfa is used as an interlayer insulation layer, an interlayer insulation layer pattern is formed by a photolithography process and through holes etc. are provided. Because of the increased height, there is a drawback that the upper layer electrode is likely to be disconnected at the step portion when forming the upper layer electrode. This drawback will be explained based on the drawings. FIG. 1 is a cross-sectional and plan view showing an example of a conventional multilayer wiring structure in which polyimide resin is used as an interlayer insulating layer. When forming the through hole 2 in the glabella insulating layer 1, a photolithography process is used, but in this case, it is inevitable that the stepped portion 3 of the through hole 2 will be raised to a thickness greater than the required thickness. . Because the raised edges are sharp, when the upper layer electrode 4 is deposited as shown in FIG.
The wire breaks at the stepped portion 3. Or the third
As shown in the figure, when the upper layer electrode 4 is formed by a photolithography process even if there is no disconnection during vapor deposition, the photoresist layer 7 at the step portion 3 is thin, so the upper layer electrode 4 at the step portion 3 is eroded by the etching solution. The wire was disconnected. In the conventional multilayer wiring structure using polyimide resin as described above, disconnection of the upper layer electrode is likely to occur due to sharp creases at the stepped portion of the glabella insulating layer.

The purpose of the present invention is to prevent disconnection of the upper layer electrode at such a stepped portion of the interlayer insulating layer, and the present invention is characterized in that a pseudo electrode is provided below the stepped portion in a manner similar to the lower layer electrode wiring pattern. . In this method, as shown in Figure 1, an interlayer secret layer made of polyimide resin is formed by reflecting all the steps caused by the lower electrode wiring pattern.
This means actively taking advantage of the fact that

The present invention will be explained in detail below based on the drawings. FIGS. 4 and 5 are diagrams showing preferred application examples of the present invention.

As shown in FIG. 4, the upper layer electrode 4 is
A pseudo electrode 8 is provided adjacent to the lower layer electrode 6 which is electrically connected to the lower layer electrode 6.

Although the protrusion of the interlayer insulating layer 1 at the stepped portion 3 is unavoidable in this case as well, since there is also a step due to the pseudo electric hardening 8, the stepped portion 3 does not have a sharp protrusion υ as in the conventional case. As a whole, the stepped portion 3 can be made flat. Alternatively, as shown in FIG. 5, the same effect can be achieved by widening the width of the portion of the lower layer electrode 5 adjacent to the lower layer electrode 6 that is parallel to the through hole 2 toward the through hole 2 side. .

As described above, according to the present invention, it is possible to soften the sharp embossment in the step portion of the interlayer insulating layer in a pseudo electrode in which the upper layer is provided as the lower layer by using the step, and polyimide resin can be used as the interlayer insulating layer. It is possible to prevent disconnection at the step portion of the interlayer insulating layer of the upper layer electrode, which is likely to occur when the upper layer electrode is exposed.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of a conventional multilayer wiring structure when polyimide resin is used as an interlayer insulation layer, Figures 2 and 3 are diagrams showing drawbacks of the conventional method, and Figures 4 and 5 are FIG. 3 is a diagram showing a preferred application example of the present invention. 1°. ft interlayer insulation layer 2° using polyimide resin. Through hole 3°. The step part of the interlayer R layer is 4°. Upper layer electrode 5°. Lower layer electrode 6°, lower layer electrode 7° with through hole. Photoresist layer 8°. Pseudo electrode and above Applicant Daini Seigokusha Co., Ltd. Agent Patent attorney Tsutomu Mogami

Claims (1)

[Claims] In a multilayer wiring structure consisting of a lower electrode wiring pattern, an interlayer insulating layer formed of polyimide resin, and an upper electrode wiring pattern, a pseudo electrode is provided in addition to the lower electrode wiring pattern in the lower layer of the stepped portion of the interlayer insulating layer. A multilayer wiring method characterized by the following.