KR19980030405A - Contact hole formation method of semiconductor device - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

Semiconductor device manufacturing method.

2. The technical problem to be solved by the invention

An object of the present invention is to provide a method for forming a contact hole in a semiconductor device for forming a wine glass-shaped contact hole having good step coverage characteristics.

3. Summary of Solution to Invention

A method for forming a contact hole in a semiconductor device for locally exposing the conductive film by selectively etching the interlayer insulating film on the conductive film, the method comprising: a first size having a predetermined size larger than a size of a portion to expose the conductive film on the interlayer insulating film; Forming a photoresist; etching a predetermined thickness of the interlayer insulating layer using the first photoresist as an etch barrier; forming a groove; removing the first photoresist; After applying the second photoresist over the entire structure, patterning the second photoresist to the size of the portion to expose the conductive film and the second photoresist exposed to the etching barrier to the conductive film To provide a method for forming a contact hole in a semiconductor device comprising the step of etching the remaining interlayer insulating film until.

4. Important uses of the invention

Used in the process of forming contact holes in semiconductor device manufacturing processes.

Description

Contact hole formation method of semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a contact hole in a semiconductor device for electrical connection between upper and lower conductive films, and in particular, a contact of a semiconductor device for forming a wine glass type contact hole capable of achieving good step coverage characteristics. It relates to a hole forming method.

In general, a predetermined contact is required for electrical connection between upper and lower layers such as a connection line such as a bit line or a word line, a charge storage electrode, and a metal wiring during a semiconductor manufacturing process.

Conventionally, in the case of such a contact hole forming process, in particular, when the characteristic of the step coverage line is poor during the deposition of the subsequent film, the contact hole entrance is widened by isotropic etching by wet etching first, and then dry etching is performed to dry the wine glass type contact hole. Formed. In this case, the isotropic etching by the wet etching is preferably larger in a given device structure.

However, as the degree of integration of semiconductor devices increases, process margins become smaller when forming contact holes, and thus, process margins by wet etching also become smaller, thereby making it impossible to sufficiently compensate for step coverage.

An object of the present invention is to provide a method for forming a contact hole in a semiconductor device for forming a wine glass type contact hole having good step coverage characteristics.

1A to 1C are cross-sectional views illustrating a process of forming a contact hole in a semiconductor device according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10 substrate 20 BPSG film

30, 40: photoresist

In order to achieve the above object, the present invention provides a method of forming a contact hole in a semiconductor device for selectively exposing an insulating film on a conductive film to locally expose the conductive film. Forming a first photoresist having a predetermined size larger than the size; Etching a predetermined thickness of the interlayer insulating layer using the first photoresist as an etch barrier to form a groove; Removing the first photoresist, applying a second photoresist on the entire structure, and then patterning the second photoresist to a size equal to a size of a portion to expose the conductive film and the second photoresist. Etching the remaining interlayer insulating film until the conductive film is exposed to the resist as an etch barrier.

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

1A to 1C are cross-sectional views of a contact hole forming process of a semiconductor device according to an embodiment of the present invention.

First, FIG. 1A shows a BPSG film 20 as an interlayer insulating film formed on a semiconductor substrate 10 having a predetermined pattern formed thereon, flowed at a high temperature, and planarized, and then the FICD of the finally formed contact hole formed by conventional wet etching. The first photoresist 30 is formed on the BPSG film 20 so as to be patterned in the same size as Final Inspection Critical Demension.

Subsequently, in FIG. 1B, after the BPSG film 20 having a predetermined thickness is removed by a dry etching process using the first photoresist 30 as an etch barrier, the first photoresist 30 is removed and the entire structure The second photoresist 40 is coated on the top, and is etched and patterned.

Finally, FIG. 1C shows that the BPSG film 20 is etched until the lower silicon substrate 10 is exposed by dry etching using the second photoresist 40 as an etch barrier.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

According to the present invention made as described above, by forming isotropic dry etching instead of conventional wet etching when forming a wine glass type contact hole, a contact hole having a larger area than a conventional contact hole formed by conventional wet etching in a limited area can be formed. It is possible to achieve step coverage characteristics, thereby improving the yield of the device.

Claims (2)

A method for forming a contact hole in a semiconductor device for locally exposing the conductive film by selectively etching the interlayer insulating film on the conductive film, the method comprising: a first size having a predetermined size larger than a size of a portion to expose the conductive film on the interlayer insulating film; Forming a photoresist; forming a groove by etching a predetermined thickness of the interlayer insulating layer using the first photoresist as an etch barrier; removing the first photoresist; applying a second photoresist over the entire structure Patterning the second photoresist to a size as large as a portion of the portion to which the conductive film is to be exposed; and etching the remaining interlayer insulating film until the conductive film is exposed to the second photoresist as an etch barrier. A method for forming a contact hole in a semiconductor device. The method of claim 1, wherein the interlayer insulating film is a BPSG film.