JPS61180454A - Semiconductor device - Google Patents

Abstract

PURPOSE:To realize a high-density, high-integration wiring layer by a method wherein the middle section is made thicker of an insulting film formed in a semiconductor substrate and a wiring layer is provided in the thicker region. CONSTITUTION:An insulating-isolating region 2 is formed in a semiconductor substrate 1. The insulating-isolating region 2 consists of a thin insulating- isolating film 3 and thick insulating-isolating film 4. A wiring layer 5 is formed in the thick insulating-isolating film 4. By using this design, the wiring layer 5 may be bonded without difficulty to a substrate or to an impurity-implanted layer formed thereon, without causing the wiring area to be enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a semiconductor device in which wiring layers can be formed in a high-density, integrated manner.

BACKGROUND OF THE INVENTION Conventional wiring layers in semiconductor devices include diffusion layers formed by diffusing impurities of the opposite conductivity type to the semiconductor substrate, or polycrystalline silicon films formed on the semiconductor substrate with an insulating film interposed therebetween. A metal wiring layer is used.

However, in the case of a diffusion layer, an insulating layer is required to separate it from the diffusion layers of other elements. In addition, in the case of a polycrystalline silicon film or a metal wiring layer, since it is formed on a semiconductor substrate via an insulating film, an opening in the insulating film is required for connection to the element, and the Alignment margins were required for the connection portion and the aperture pattern, and for the aperture pattern and the wiring layer.

Problems to be Solved by the Invention These conventional wiring layers occupy a large area, making it difficult to obtain a high-density, highly integrated semiconductor device.

The present invention has been made in view of this point, and an object of the present invention is to provide a semiconductor device having a wiring layer capable of achieving high density and high integration.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention changes the thickness of the insulation isolation film in the isolation region between the semiconductor elements formed in the semiconductor substrate, so that the film thickness is thicker in the central part. A wiring layer is formed in a portion.

Effect of the present invention With the above-described structure, the wiring layer can be formed deep into the semiconductor substrate by forming the wiring layer in the isolation region between elements, which has conventionally been necessary, so that the area occupied on the surface is reduced. A high-density, highly integrated semiconductor device can be formed by forming a wiring layer biased toward one element side of the insulation isolation region and forming a connecting portion between the semiconductor substrate and the wiring layer under the insulation isolation region.

Embodiment FIG. 1 is a structural sectional view showing an embodiment of the wiring layer of the present invention. In FIG. 1, 1 is a semiconductor substrate, 2 is an insulating isolation region, 3 is a thin insulating isolation film, 4 is a thick insulating isolation film, and 6 is a wiring layer formed in the insulating isolation film. The thickness of the wiring layer 5 may be thinner than the thickness of the thin insulating isolation film 3, but the thickness of the first
As shown in the figure, if the film is formed thicker than the thin insulating isolation film 3, the current capacity can be increased for the same pattern width.

FIGS. 2 and 3 show other embodiments of the present invention, in which the wiring layer 5 is formed biased to either the left or right within the insulation isolation region 2, and the semiconductor substrate under the insulation isolation region 2 is 1 or an impurity layer diffused into a semiconductor substrate and a connection portion 11 to form an electrical connection portion.

FIG. 4 shows an example in which an embodiment of the present invention is applied to a complementary semiconductor device.
An n-type field effect element 9 made by forming a type impurity layer 6;
Wiring formed unevenly in an insulating isolation region 2 with a p-type field effect element 1o made by forming a p-type impurity layer 7 on an n-well 8 formed by deeply diffusing an n-type impurity layer on the substrate. This is a semiconductor device in which a layer 6 and a connection portion 11 with the n-well are formed.

Effects of the Invention As described above, according to the present invention, it is possible to easily connect the wiring layer and the semiconductor substrate or the impurity layer formed on the semiconductor substrate without significantly increasing the area for the wiring layer. A high-density, highly integrated semiconductor device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views of a semiconductor device having wiring layers according to another embodiment of the present invention, and FIG. 4 is a complementary semiconductor device. FIG. 3 is a cross-sectional view of a device in which an embodiment structure of the present invention is applied. 1... Semiconductor substrate, 3, 4... Insulating separation film, 5... Wiring layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
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Claims (2)

[Claims] (1) A semiconductor device characterized in that an insulating film formed in a semiconductor substrate has a thick central portion, and a wiring layer is formed in a part of the thick central insulating film. (2) The semiconductor device according to claim 1, wherein the wiring layer is formed at the end of the thick insulating film and is connected to the semiconductor substrate below the insulating film.