JPS63124551A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To connect an n-type conductor and a p-type conductor having different conductivity types stably by using a polysilicon wiring film, by forming a high-melting-point film or a silicide film thereof at an opening part. CONSTITUTION:The following are included in the title device: an n-type silicon substrate 11; a p-type impurity diffused layer 12, which is formed on a part of said substrate; a field insulating film 13, which covers the inactive region of the substrate 1; an interlayer insulating film 14, in which an opening is provided for the p-type impurity diffused layer 12; a silicide film 15 comprising high-melting-point metal (e.g., tungsten) covering said opening part; and a polysilicon wiring film 16, which is connected in an ohmic mode to the p-type impurity diffused layer 12 through the silicide film 15 and in which n-type impurities are added. Namely, the n-type impurity diffused layer 12 and the n-type polysilicon wiring film 16 are connected through the tungsten silicide film 15 at one opening part. Thus the two conductor parts 12 and 16 can form the very stable connecting part regardless of their conductivities.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit device, and particularly to the structure of polysilicon wiring.

[Conventional technology]

In semiconductor integrated circuit devices, it is difficult to directly connect semiconductor layers of different conductivity types, such as a p-type impurity diffusion layer on a substrate and an n-type polysilicon wiring, so such a connection is difficult. Conventionally, aluminum wiring, which is not subject to conductivity type, is typically used when necessary.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional wiring structure requires openings at the connection points between n-type and n-type semiconductor layers, and of course requires aluminum wiring to be mixed in, resulting in a disadvantage of reduced integration density. .

In view of the above circumstances, an object of the present invention is to provide an extremely stable connection structure capable of connecting n-type and n-type semiconductor layers having different conductivity types using polysilicon wiring instead of aluminum wiring. An object of the present invention is to provide a semiconductor integrated circuit device.

[Means for solving problems]

According to the present invention, a semiconductor integrated circuit device includes a semiconductor substrate;
- conductivity type impurity diffusion layer formed on the semiconductor substrate P; a high melting point gold film or its silicide film covering the opening of the impurity diffusion layer; The method includes providing a polysilicon wiring film electrically connected to the impurity diffusion layer and having a conductivity type opposite to that of the impurity diffusion layer.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a semiconductor integrated circuit device showing one embodiment of the present invention. According to this embodiment, the semiconductor integrated circuit device of the present invention includes an n-type silicon substrate 11, a ρ-type impurity diffusion layer 12 formed on a portion of this substrate, and an inactive region of the substrate 1 that covers the n-type silicon substrate 11. Field insulation 115113 and interlayer insulation WA14 forming an opening in the ρ-type impurity diffusion layer 12
A silicide film 15 of a high melting point metal (for example, tungsten) covers this opening, and a polysilicon wiring film 16 doped with an n-type impurity is ohmically connected to the ρ-type impurity diffusion layer 12 via this silicide film 15. include.

That is, this embodiment shows a case where the p-type impurity diffusion 12 and the n-type polysilicon wiring film 16 are connected through the tungsten silicide layer 415 in one opening. p-type impurity diffusion layer 12 and n-type polysilicon wiring lB1 with different
Since the silicide film 15 of a high melting point metal is interposed between the two conductive layers and the conductive layer 16, the two conductive layers form an extremely stable connection regardless of their conductivity type.

FIG. 2 is a cross-sectional view showing another embodiment of the present invention. This embodiment shows a case where it is implemented in a semiconductor integrated circuit with an OMO3 structure, and an n-channel MO3 formed on a p-type semiconductor substrate 21. Field effect transistor and field insulating film 2
It consists of a p-channel MO8 field effect transistor formed on a 3.5 OI (silicon-on-insulator) substrate. Here, 22.27 and 28 indicate the n-type impurity diffusion layer (drain region), gate oxide film, and gate electrode of the n-channel MO3 field effect transistor, respectively, and 29.30.31 and 32 indicate the p-channel MO3 field effect transistor.
3 Field effect 1 channel region of helangister (single crystallized n-type Sol substrate).

A p-type impurity diffusion layer (drain region), a gate oxide film, and a gate electrode are shown, respectively. Further, 24a and 24b are the first and second interlayer insulating films, respectively.
5 is a silicide film of a high melting point metal such as tungsten, 2
6 is an n-type polysilicon wiring film. That is, according to this embodiment, the p-type impurity diffusion layer 30 forming the drain region of the p-channel MO9 field effect transistor is connected to the n-type polysilicon interconnection film 26 via the refractory metal silicide film 25 covering the opening. Further, a circuit connection is made to an n-type impurity diffusion layer 22 forming a train region of an n-channel field effect transistor. In this case as well, since the silicide film 25 of a high-melting point metal is interposed between the p-type impurity diffusion layer 30 and the n-type polysilicon wiring film 26, the two conductive layers have an extremely stable connection regardless of their conductivity type. form a section.

In each of the above embodiments, a case was explained in which a high-melting point metal silicide was used, but it is also possible to interpose a single film of a high-melting point metal so that the conductivity types of the impurity diffusion layer and the polysilicon wiring film can be mutually controlled. Even if you change it, you can get exactly the same effect.

〔Effect of the invention〕

As explained in detail above, according to the present invention, by forming a high melting point metal film or its silicide film in the opening, an additional area is used for the n-type conductor and the p-type conductor of different conductivity types. Because it can be stably connected using a polysilicon wiring film without any problems, it is suitable for semiconductor integrated circuits, especially complementary type (
This can have a significant effect on improving the integration density of CMOS type) element semiconductor devices.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a semiconductor integrated circuit device showing one embodiment of the invention, and FIG. 2 is a sectional view showing another embodiment of the invention. 11... N-type silicon substrate, 12.30... P-type impurity diffusion layer, 13.23... Field insulating film, 14
, 24a, 24b--interlayer insulating film, 16.
26...n-type polysilicon wiring film, 27.31...
Gate oxide film, 28.32... Gate electrode, 29 River channel region (single crystal n-type SOI substrate), 21 yen
5+ figure

Claims (1)

[Claims] a semiconductor substrate, an impurity diffusion layer of one conductivity type formed on the semiconductor substrate, a high melting point metal film or its silicide film covering an opening of the impurity diffusion layer, and the high melting point metal film or its silicide film. A semiconductor integrated circuit device comprising a polysilicon wiring film having a conductivity type opposite to that of the impurity diffusion layer and electrically connected to the impurity diffusion layer through the impurity diffusion layer.