KR19980084297A - Self-aligned contact formation method of semiconductor device - Google Patents

Abstract

A self-aligned contact forming method of a semiconductor device of the present invention comprises the steps of forming a gate oxide film, a conductive film, a first nitride film and a first boron nitride (BN) film on a semiconductor substrate, and a photoresist film on the first BN film. Forming a pattern, sequentially etching the first BN film, the first nitride film, and the conductive film using the photoresist pattern as a mask to form a first BN film pattern, a first nitride film pattern, and a gate electrode; Forming a second nitride film and a second BN film on an entire surface of the substrate on which the first BN film pattern, the first nitride film pattern, and the gate electrode are formed, and anisotropically etching the second BN film and the second nitride film to form the gate electrode, Forming a spacer including a BN film and a nitride film on both sidewalls of the first nitride film pattern and the first BN film pattern, forming an oxide film on the entire surface of the resultant product on which the spacer is formed, and then patterning the gate By etching and the step of exposing the gate oxide film between the poles, the gate oxide exposed by the oxide film by a self-alignment method comprises the steps of forming the contact hole.

Description

Self-aligned contact formation method of semiconductor device

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for forming a self-aligned contact of a semiconductor device.

As semiconductor devices are highly integrated, it is difficult to form contacts on the active regions between the gate electrodes, and thus self-aligned contacts are employed. As shown in FIG. 1, the self-aligned contact forms a gate oxide film 3 and a gate electrode 5 on the semiconductor substrate 1, and then the nitride film 7 is formed on the gate electrode 5 and the sidewalls. SiN) is formed. Subsequently, after forming the oxide film 9 exposing between the gate electrodes 5, a contact is formed by using a high selectivity between the oxide film 9 and the nitride film 7.

However, in the conventional self-aligned contact forming method using a high selectivity ratio between the oxide film 9 and the nitride film 7, the shoulder portion 10 of the nitride film has an angle of 30 to 60 degrees when ion is incident in the plasma. There is a disadvantage that it is damaged by sputtering.

Accordingly, an object of the present invention is to provide a method for forming a self-aligned contact of a semiconductor device which can solve the above-mentioned disadvantages.

1 is a cross-sectional view illustrating a self-aligned contact of a semiconductor device according to the prior art.

2 to 6 are cross-sectional views illustrating a method for forming a self-aligned contact of a semiconductor device according to the present invention.

In order to achieve the above technical problem, the present invention is to form a gate oxide film, a conductive film, a first nitride film and a first boron nitride (BN) film on a semiconductor substrate, and a photoresist film pattern on the first BN film Forming a first BN layer pattern, a first nitride layer pattern, and a gate electrode by sequentially etching the first BN layer, the first nitride layer, and the conductive layer using the photoresist layer pattern as a mask; Forming a second nitride film and a second BN film on an entire surface of the substrate on which the first BN film pattern, the first nitride film pattern, and the gate electrode are formed; and anisotropically etching the second BN film and the second nitride film to form the gate electrode and the first film. Forming a spacer including a BN film and a nitride film on both sidewalls of the nitride film pattern and the first BN film pattern, and forming an oxide film on the entire surface of the resultant product on which the spacer is formed and patterning the gate electrode. And forming a contact hole by etching the gate oxide film exposed by the oxide film by a self-align method, and forming a contact hole in the semiconductor device. do.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 to 6 are cross-sectional views illustrating a method for forming a self-aligned contact of a semiconductor device according to the present invention.

In FIG. 2, a gate oxide film 13, a gate electrode conductive film 15, a first nitride film 17, and a first boron nitride (BN) film 19 are formed on the semiconductor substrate 11. Subsequently, a photoresist film is formed on the first BN film 19 and then patterned to form a photoresist film pattern 21.

In FIG. 3, the first BN film 19, the first nitride film 17, and the conductive film 15 are sequentially etched using the photoresist film pattern 21 as a mask to form the first BN film pattern 19a, The first nitride film pattern 17a and the gate electrode 15a are formed.

In FIG. 4, a second nitride film 23 and a second BN film 25 are formed on the entire surface of the substrate on which the first BN film pattern 19a, the first nitride film pattern 17a, and the gate electrode 15a are formed. .

In FIG. 5, the second BN film 25 and the second nitride film 23 are anisotropically etched on both sidewalls of the gate electrode 15a, the first nitride film pattern 17a, and the first BN film pattern 19a. A spacer composed of the BN film 29 and the nitride film 27 is formed. In this case, a spacer formed of the nitride film 27 and the BN film 29 surrounds the gate electrode 15a to protect the device. In this case, the nitride film 27 is used as a diffusion barrier layer for the BN film 29.

In particular, the BN film 29 has a cubic or hexagonal structure. In particular, the cubic BN film has a hardness close to diamond. It is a chemically and thermally stable material, has a low dielectric constant and is excellent as a dielectric material. Therefore, it is possible to prevent damage to the shoulder portion which has conventionally occurred in the subsequent self-aligned contact formation.

In FIG. 6, the oxide layer 31 is formed on the entire surface of the resultant product on which the spacers are formed, and then patterned to expose the gate oxide layer 13 between the gate electrodes 15a. Subsequently, the gate oxide layer 13 exposed by the oxide layer 31 is etched to form a contact hole. In this case, the loss occurring in the shoulder portion of the conventional nitride film can be prevented due to the BN film 29.

The self-aligned contact forming method of the semiconductor device of the present invention can prevent damage occurring in the conventional shoulder area by using a mechanically strong material, a boron nitride (BN) film instead of the nitride film spacer type self-aligned contact structure.

Claims (1)

Forming a gate oxide film, a conductive film, a first nitride film and a first boron nitride (BN) film on a semiconductor substrate; Forming a photoresist film pattern on the first BN film; Sequentially etching the first BN layer, the first nitride layer, and the conductive layer using the photoresist layer pattern as a mask to form a first BN layer pattern, a first nitride layer pattern, and a gate electrode; Forming a second nitride film and a second BN film on an entire surface of the substrate on which the first BN film pattern, the first nitride film pattern, and the gate electrode are formed; Anisotropically etching the second BN film and the second nitride film to form a spacer including a BN film and a nitride film on both sidewalls of the gate electrode, the first nitride film pattern, and the first BN film pattern; Forming an oxide film over the entire surface of the resultant product on which the spacers are formed, and then patterning the oxide film to expose a gate oxide film between the gate electrodes; And Forming a contact hole by etching the gate oxide film exposed by the oxide film by a self-align method.