KR960006341B1 - Removing method of small pocket - Google Patents

Abstract

forming a conduction film pattern of a predetermined size on an insulation film, and forming a second insulation film being the same material as the first insulation film over the resulting structure; and forming the remnant second insulation film, for preventing generation of under-cut in cleaning process, on side wall of the conduction film pattern by anisotropic etching of the second insulation film. The anisotropic etching process is easily applicable to manufacture of high integration element, and prevention of element demage by etching the remnant increases reliability of semiconductor device.

Description

Small desorption method of semiconductor device

1 is a semiconductor device manufacturing process chart according to the prior art,

2 is a semiconductor device manufacturing process diagram according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

l, 3,8 oxide film 2,4 polysilicon film

5: photosensitive film 4a: residual polysilicon film

7: residual oxide film 8a: residual oxide film.

The present invention is a small cloth formed by the difference in the stepped phase using the etch-back technology The method relates to the removal method, in particular, a small cloth produced by the occurrence of under cut generated during the cleaning process performed before the etching process. It is about a removal method.

In general, it is already known that the higher the integration level, the finer the design rules become, and that the technology is a major challenge for fine line width processing. According to the fabrication of the device, a polysilicon film is deposited, a pattern is formed, the next cleaning is performed, and an oxide film is formed for the purpose of etching obstacles or bit line formation with an oxide film on the surface exposed after a certain process. The process of depositing a polysilicon film again is performed.

The semiconductor device manufacturing process according to the prior art will be described in detail with reference to the accompanying drawings of FIG. 1, where FIG. 1 is a conventional etching process diagram, 1,3 is an oxide film, 2,4 is a polysilicon film, 5 is a photoresist film, and 4a. Denotes a dietary residue, respectively.

First, in FIG. 1A, the polysilicon film 2 is patterned to a predetermined size on the oxide film 1.

Subsequently, FIG. 1B illustrates a wet cleaning process in order to remove impurities generated during a process (mask and etching process) for polysilicon film patterning, and as shown in FIG. Small etch is incidentally performed and the oxide film is etched and penetrated under the sidewall of the polysilicon film pattern 2 (small pocket) occurs.

The small In the cleaning process, the oxide film 1 at the lower end portion of the sidewall of the polysilicon film 2 patterned by the chemical is etched. This is because isotropic etching occurs by the chemical during the wet cleaning process.

Subsequently, as shown in FIG. 1C, the oxide film 3 and the polysilicon film 4 are again deposited on the entire structure, the photosensitive film 5 is applied, and the polysilicon film 4 is patterned. Small foam formed during the process Residual polysilicon film 4a that is not etched is generated.

In the conventional method, the small When the anisotropic etching is required when forming a fine pattern, there is a problem in that the presence of the residue causes a defect of a device such as a bridge generation.

The present invention devised to solve the above problems is a small foam generated during the cleaning process Small semiconductor device that prevents residue formation during anisotropic etching required for high density device fabrication The purpose is to provide a removal method.

In order to achieve the above object, the present invention provides a method of manufacturing a semiconductor device in which a conductive film pattern having a predetermined size is formed on a first insulating film, and then a cleaning process is performed, wherein a conductive film pattern having a predetermined size is formed on the first insulating film. Forming a second insulating film of the same material as the first insulating film; A second insulating film is anisotropically etched to form a residual second insulating film on the sidewalls of the conductive film pattern to prevent undercuts in the subsequent cleaning process, and the remaining second insulating film is formed to the same amount as the etching amount expected in the subsequent cleaning process. And forming a washing step.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to FIG. 2, FIG. 2 is an etching process diagram according to the present invention, in which 1, 3, and 8 are oxide films and 2 and 4 are polysilicon. Film 5 is a photosensitive film and 8a a residual oxide film, respectively.

First, as shown in FIG. 2A, a polysilicon film 2 is deposited on the oxide film 1, and impurities are injected into the polysilicon film 2, and then the polysilicon film 2 is left as planned. Pattern to the size of.

Next, an oxide film 8 is deposited on the entire structure as shown in FIG.

Subsequently, as shown in FIG. 2C, the oxide layer 8 is etched back by anisotropic front etching to form a residual oxide layer 8a on the sidewall of the polysilicon layer pattern 2.

Next, FIG. 2D is a cross-sectional view of the cleaning state, which is formed by the residual oxide film 8a formed on the sidewall of the polysilicon film pattern 2. This will not happen.

Finally, the oxide film 3 and the polysilicon film 4 are sequentially deposited and impurities are injected into the deposited polysilicon film 4 to form a photosensitive film 5 pattern to form the polysilicon film 4. When selective etching, as shown in the drawing small For this reason, no residual polysilicon film is formed.

Looking at the operation of the embodiment of the present invention in detail as follows.

Small problem that is a conventional problem The occurrence occurs because of the isotropic etching characteristic due to the characteristics of the chemicals used in the cleaning process, and the conventional problem is suppressed by adding a two-step process before the cleaning process.

That is, the residual oxide film 8a is formed on the sidewalls of the polysilicon film by the amount of undercut etching generated during the cleaning process. And, for example, in the general cleaning process, it is common to etch an industrial film of about 200 mm thickness or less, in this case, the small cloth Small deposit during cleaning by forming 200 잔류 residual oxide film 8a in the expected area To prevent the occurrence of.

The present invention made as described above is a small cloth by the washing step Since it is possible to prevent the anisotropic etching required for high-density device fabrication, there is an effect that can increase the reliability of the device by preventing damage to the device by the etching residue.

Claims (2)

A method of manufacturing a semiconductor device in which a conductive film pattern having a predetermined size is formed on a first insulating film, and then a cleaning process is performed. A conductive film pattern having a predetermined size is formed on a first insulating film, and then the first insulating film is formed over the entire structure. Forming a second insulating film of the same material; A second insulating film is anisotropically etched to form a second insulating film on the sidewalls of the conductive film pattern to prevent undercuts in the subsequent cleaning process, and the remaining second insulating film is about the same amount as the etching amount expected in the subsequent cleaning process. Forming a; And performing a cleaning process. How to remove. The small size of the semiconductor device according to claim 1, wherein the semiconductor device has a thickness of 200 잔류 or less of the residual second insulating film. How to remove.