JPH1032252A - Method for manufacturing semiconductor device - Google Patents

Abstract

(57) Abstract: An insulating film (3) is formed on a surface of a conductive type semiconductor substrate (5).
Is formed, and then a polycrystalline silicon film and a silicon oxide film are formed. Next, unnecessary silicon oxide films and polycrystalline silicon films are removed to form silicon oxide films 6 and gate electrodes 1 and 2. Next, an impurity is ion-implanted to form an impurity layer 4, and a silicon oxide film 7 is formed. Then, the silicon oxide film 7 and the insulating film 3 are removed to form a contact hole 8. A sidewall 10 is formed on the side surface of the gate electrode 1 or the gate electrode 2, and then a metal electrode 9 is formed. The margin between the gate electrode 1 and the contact hole 8 and the margin between the contact hole 8 and the gate electrode 2 can be reduced, and miniaturization can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device having an insulated gate transistor. In particular, it relates to a structure of a contact with a substrate.

SUMMARY OF THE INVENTION According to the present invention, in a method of manufacturing a semiconductor device having an insulated gate transistor, a contact hole is formed between a first gate electrode and a second gate electrode, and a conductive film is formed in the contact hole. Are connected, a first insulating film is formed on the first gate electrode and the second gate electrode, and a second insulating film is formed thereon, so that the contact hole and the gate in the mask alignment step are formed. Even if misalignment with the electrode occurs, a short circuit between the conductive film connected to the contact hole and the gate electrode can be prevented. Further, by forming a contact hole so as to leave two insulating films over the lower conductive film and extending the upper conductive film via the two insulating films extending over the lower conductive film, Even if overetching is performed to make contact between the substrate and the upper conductive film, there is no fear of leakage between the upper conductive film and the lower conductive film, and high reliability can be obtained.

[0003]

2. Description of the Related Art A conventional method for manufacturing a semiconductor device will be described with reference to FIG. In FIG. 2A, an insulating film 3 is formed on a semiconductor substrate of a first conductivity type, a polycrystalline silicon layer is formed by using a chemical vapor deposition method, and unnecessary portions are formed by photolithography. Is removed to form gate electrodes 1 and 2 of polycrystalline silicon. Next, using this gate electrode as a mask, a second conductivity type impurity is ion-implanted and then annealed to form a second conductivity type impurity layer 4. Next, after forming a first silicon oxide film 7 as shown in FIG. 2B, a contact hole 8 is formed by photolithography as shown in FIG. 2C. Thereafter, a metal electrode 9 is formed.

[0004]

However, in the above-mentioned prior art, when the masks for forming the gate electrodes 1 and 2 and the mask for forming the contact holes 7 are misaligned, the gate electrode 1 or the gate electrode 2 cannot be moved. Since the metal electrode 9 is short-circuited, it is necessary to provide a sufficient margin between the gate electrode 1 and the contact hole 8 and between the contact hole 8 and the gate electrode 2, and there is a problem that it is difficult to miniaturize. Therefore, the present invention solves such a problem, and an object of the present invention is to provide a gate electrode without a sufficient margin between the gate electrode 1 and the contact hole 8 and between the contact hole 8 and the gate electrode 2. An object of the present invention is to provide a semiconductor device in which the electrode 1 or the gate electrode 2 and the metal electrode 9 are not short-circuited.

[0005]

According to the present invention, there is provided a semiconductor device comprising:
A first insulating film provided on a semiconductor substrate, a first conductive film and a second conductive film provided separately on the first insulating film, and sandwiched between the first conductive film and the second conductive film; An impurity diffusion layer provided in the semiconductor substrate, a second insulating film having the same width as the first conductive film and the second conductive film, on the first insulating film, and at least on the second insulating film. A third insulating film provided over the entire surface in
A third conductive film extending over the insulating film; and a contact provided on the third insulating film on the impurity diffusion layer for electrically connecting the third conductive film to the impurity diffusion layer. It is characterized by having.

[0006]

1A to 1C are views showing an embodiment of the present invention.

The following is a detailed description with reference to the drawings. 1A, a first insulating film 3 is formed on a surface of a semiconductor substrate 5 of a first conductivity type, a first conductive film, for example, a polycrystalline silicon film is formed, and then a second conductive film is formed. An insulating film such as a silicon oxide film is formed. Then, unnecessary portions of the silicon oxide film and the polycrystalline silicon film are removed by photolithography to form a gate electrode composed of the silicon oxide film 6 and the polycrystalline silicon 1 and 2. At this time, the second insulating film may be etched using the photoresist as a mask, and then the photoresist may be removed, and then the first conductive film may be etched using the second insulating film as a mask. Next, the second conductivity type impurity is ion-implanted using the gate electrode as a mask and then annealed to thereby form the second conductivity type impurity layer 4.
To form Next, as shown in FIG. 1B, after a third insulating film, for example, a silicon oxide film 7 is formed, photolithography is performed so that the silicon oxide film 7 remains at least on the surface of the silicon oxide film 6. The contact hole 8 is formed by removing part of the silicon oxide film 7 and the first insulating film 3 by using the method. In this case, sidewalls 10 of silicon oxide film 7 are formed on the side surfaces of gate electrode 1 or gate electrode 2. Next, a second conductive film, for example, a metal electrode 9 is formed.

[0008]

As described above, according to the present invention, even if the gate electrode 1 and the contact hole 8 approach each other due to misalignment of the mask, the insulation on the gate electrode is achieved by the silicon oxide films 6 and 7. The gate electrode side surface is kept insulated by the silicon oxide film 10 remaining as a sidewall on the side surface of the gate electrode, and a short circuit between the gate electrode 1 and the metal electrode 9 is eliminated. Therefore, the margin between the gate electrode 1 and the contact hole 8 and the margin between the contact hole 8 and the gate electrode 2 can be reduced, which has the effect of miniaturization.

[Brief description of the drawings]

FIGS. 1A to 1C are main cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device of the present invention.

FIGS. 2A to 2D are main cross-sectional views illustrating a conventional method for manufacturing a semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Polycrystalline silicon gate 3 ... Insulating film 4 ... 2nd conductivity type impurity layer 5 ... 1st conductivity type semiconductor substrate 6, 7 ... Silicon oxide film 8 ... Contact Hall 9: Metal electrode 10: Side wall

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[Procedure amendment]

[Submission date] April 21, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Patent application title: Method of manufacturing semiconductor device

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

The present invention relates to a method for manufacturing a semiconductor device having an insulated gate transistor. Especially,
The present invention relates to a method for manufacturing a semiconductor device having a contact structure between a substrate and a conductive film.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0002

[Correction method] Change

[Correction contents]

SUMMARY OF THE INVENTION According to the present invention, in a method of manufacturing a semiconductor device having an insulated gate transistor, a contact hole is formed between a first gate electrode and a second gate electrode, and a semiconductor substrate is formed through the contact hole. When connecting the conductive film and the conductive film, a first insulating film is formed over the first gate electrode and the second gate electrode, and a second insulating film is formed thereover, so that the contact in the mask alignment step is performed. Even if misalignment occurs between the hole and the gate electrode, a short circuit between the conductive film connected to the contact hole and the gate electrode can be prevented.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

A method of manufacturing a semiconductor device according to the present invention comprises the steps of: forming a first insulating film on a semiconductor substrate;
Forming a first gate electrode and a second gate electrode on the first insulating film spaced apart from each other and having a second insulating film thereon; the first and second gates; Forming an impurity layer in the semiconductor substrate sandwiched between electrodes; forming a third insulating film on the first and second gate electrodes; and forming sidewalls on side surfaces of the first and second gate electrodes. Forming the third step;
Forming a third conductive film extending over the insulating film and the sidewall and connected to the impurity layer.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

As described above, according to the present invention, even if the gate electrode and the contact hole approach each other due to misalignment of the mask, the second insulating film on the gate electrode and the side surface of the gate electrode can be used. Insulation is maintained by the sidewall, and a short circuit between the gate electrode and the conductive film is eliminated. Therefore, the margin between the first gate electrode and the contact hole and the margin between the second gate electrode and the contact hole can be reduced, and the effect of miniaturization can be obtained.

Claims (1)

[Claims] A first insulating film provided on a semiconductor substrate; a first conductive film and a second conductive film provided on the first insulating film so as to be separated from each other; An impurity diffusion layer provided in the semiconductor substrate sandwiched between a conductive film,
A second insulating film having the same width as the first conductive film and the second conductive film, a third insulating film provided over the entire surface on the first insulating film, and at least directly on the second insulating film; A third conductive film extending over the insulating film; and a contact provided on the third insulating film on the impurity diffusion layer for electrically connecting the third conductive film to the impurity diffusion layer. A semiconductor device, comprising: