KR19990039609A - Fine Pattern Formation Method of Semiconductor Device - Google Patents

Abstract

The present invention relates to a method of forming a fine contact in a semiconductor device, comprising applying a photoresist film on an upper surface of an interlayer insulating film having a non-uniform thickness on a semiconductor substrate, and then coating the upper anti-reflection coating on the photoresist film. (a) An interlayer insulating film is formed over the semiconductor substrate on which the lower structure of the semiconductor device is formed. (b) After the photosensitive film is coated on the interlayer insulating film, it is flowed. (c) a top anti-reflective layer (TAR layer) is coated on the photoresist. (d) The photosensitive film is exposed through the upper antireflection film. (e) After removing the upper antireflection film, the photoresist film is developed to form a photoresist pattern. (f) A contact hole is formed through the interlayer insulating layer to expose the upper surface of the semiconductor substrate by an etching process using the photoresist pattern as a mask.

Description

Fine Pattern Formation Method of Semiconductor Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fine pattern of a semiconductor device, and in detail, after applying a photoresist film to an upper portion of an interlayer insulating film having a non-uniform thickness, there is a flow, and a semiconductor comprising a step of coating an upper anti-reflection film on the photoresist film. A method of forming a fine pattern of an apparatus.

Due to the miniaturization of semiconductor devices, there is a need for a method of forming a fine pattern such as a contact having a higher resolution and forming a finer pattern. Currently, a photo light source commonly used is Krypton Floride (KrF), that is, a wavelength of 248 nm. It has a high resolution and is attracting attention as a light source for commercial facilities. Accordingly, various photoresists suitable for photo light sources have been developed and used, and further efforts are being made to improve the resolution by using modified illumination systems.

However, due to various limitations, contacts below 200 nm cannot be stably formed to date, so alternatively, contacts below 200 nm cannot be formed directly, but are formed using a modified illumination system or a phase inversion (PSM) mask. After forming a large pattern, a process of reducing critical dimension (CD) is selected by using a property of expanding a photoresist by performing a high temperature process. However, this method is extremely low in reliability for the formation of fine contacts, which is not a sufficient alternative. That is, there is a problem in that a contact having a large scattering of critical line widths is formed according to a change in a step or a thickness of a material layer formed on the semiconductor substrate. Scattering the critical line width is a serious problem when forming a fine pattern, that is, a fine pattern having a line width of 200 nm or less.

The technical problem to be achieved by the present invention is to provide a method of forming a fine pattern, for example, a fine pattern having a line width of 200 nm or less, to improve the dispersion of the critical line width and to form a fine pattern with high reproducibility.

1 to 3 are cross-sectional views illustrating one embodiment according to the present invention.

4 and 5 are cross-sectional views illustrating another embodiment according to the present invention.

6 is a perspective view of FIG. 5.

FIG. 7 is a perspective view illustrating a photosensitive film pattern formed in FIG. 6.

8 is a plan view of FIG. 7.

The first method of forming a fine pattern of a semiconductor device for achieving the above-described technical problem is as follows. (a) An interlayer insulating film is formed over the semiconductor substrate on which the lower structure of the semiconductor device is formed. (b) After the photosensitive film is coated on the interlayer insulating film, it is flowed. (c) a top anti-reflective layer (TAR layer) is coated on the photoresist. (d) The photosensitive film is exposed through the upper antireflection film. (e) After removing the upper antireflection film, the photoresist film is developed to form a photoresist pattern. (f) A contact hole is formed through the interlayer insulating layer to expose the upper surface of the semiconductor substrate by an etching process using the photoresist pattern as a mask. Then, the manufacture of the desired semiconductor device is completed through a conventionally known method.

At this time, the first method of forming a fine pattern of the semiconductor device is more preferably carried out by the following. It is more preferable to apply the interlayer insulating film of step (a) to the case where the thickness of the semiconductor substrate is formed to have an uneven thickness with respect to the upper surface of the semiconductor substrate. The upper antireflection film of step (c) is formed using a material having a refractive index different from that of the photoresist film. Step (d) is performed using deep ultra violet.

A second method of forming a fine pattern of a semiconductor device for achieving the above-described technical problem is as follows. (a) An interlayer insulating film is formed on the upper surface of the semiconductor substrate on which the lower structure of the semiconductor device is formed. (b) A stepped pattern is formed in the interlayer insulating film. (c) After the photosensitive film is coated on the interlayer insulating film on which the stepped pattern is formed, the flow is performed. (d) a photodevelopment process is performed on the flowed photoresist film to form a photoresist pattern exposing an upper surface of the stepped pattern formed on the interlayer insulating film. (e) A contact hole is formed through the interlayer insulating film to expose the upper surface of the semiconductor substrate by an etching process using the photosensitive film pattern as a mask. Then, the manufacture of the desired semiconductor device is completed using a conventionally well-known method.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art related to the present invention. In the drawings, the thicknesses of layers or regions are exaggerated for clarity. In the drawings like reference numerals refer to like elements. In addition, where a layer is described as being "on top" of another layer or substrate, the layer may be present directly on top of the other layer or substrate, with a third layer intervening therebetween.

1 to 8 are views for explaining an embodiment of a method for forming a fine pattern of a semiconductor device according to the present invention.

1 to 3 are cross-sectional views illustrating one embodiment according to the present invention.

Referring to FIG. 1, after forming interlayer insulating films having different thicknesses (116 and 117) according to positions on the semiconductor substrate 110, a photosensitive film 120 is coated on top of the semiconductor substrate 110, and upper reflection is formed on the top of the photosensitive film 120. The prevention film 125 is coated.

Referring to FIG. 2, when the exposure process is performed on the resultant substrate of FIG. 1, an upper surface of the semiconductor substrate 110 and an upper surface of the semiconductor substrate 110 are stacked by an interlayer insulating film 115 having an uneven thickness on the semiconductor substrate 110. The upper surface of the material layer (especially the upper antireflection film) cannot be formed in parallel. When the thickness of the material layer applied on the semiconductor substrate is uniformly formed, the size of the mask pattern 130a may be transferred to the semiconductor substrate 130c as it is, but in the region where the thickness is large, the size of the mask pattern ( The pattern 130d is smaller than 130b). Using the latter case, it can be seen that a fine pattern can be formed.

Referring to FIG. 3, contact holes 135a and 135b having different sizes may be formed on the interlayer insulating layers 115a and 115b on the semiconductor substrate 110 through the process of forming the pattern of FIG. 2. In this case, it can be seen that the actual exposed area of the contact hole exposing the semiconductor substrate is more finely formed when the thickness is formed unevenly.

4 and 5 are cross-sectional views illustrating another embodiment according to the present invention.

4 shows an interlayer insulating film 215 having a non-uniform thickness on the semiconductor substrate 210. FIG. 5 illustrates that the stepped pattern 220 is formed on the interlayer insulating film 215a on the resultant substrate of FIG. 4. 6 is a perspective view of FIG. 5. FIG. 7 is a perspective view illustrating a photosensitive film pattern 225 formed in FIG. 6. 8 is a plan view of FIG. 7. In this case, although the photoresist pattern 225 is illustrated in a circular shape, the photoresist pattern 225 may be deformed into an elliptical pattern extending in an arrow direction by a process of flowing the photoresist. Therefore, a pattern with a smaller critical line width can be formed.

Embodiments of the present invention described with reference to the accompanying drawings are optimal embodiments. Although specific terms have been used herein, they are used only for the purpose of describing the present invention in detail and are not used to limit the scope of the present invention as defined in the meaning or claims.

In the aforementioned method for forming a fine contact of a semiconductor device according to the present invention, after forming a pattern having a larger line width than a desired fine pattern, the micro pattern may be ultimately formed by reducing the size of the pattern using thermal characteristics. have. In addition, the present invention can be applied where the process margin or the process margin of the critical line width in one direction is insufficient.

Claims (5)

(a) forming an interlayer insulating film on the semiconductor substrate on which the lower structure of the semiconductor device is formed; (b) applying a photoresist film on the interlayer insulating film, and then flowing it; (c) coating a top anti-reflective layer (TAR layer) on the photoresist; (d) exposing the photosensitive film through the upper antireflection film; And (e) removing the upper anti-reflection film and developing the photoresist to form a photoresist pattern; (f) forming a contact hole through the interlayer insulating film to expose the upper surface of the semiconductor substrate by an etching process using the photosensitive film pattern as a mask; forming a fine pattern of a semiconductor device Way. The method of forming a fine pattern of a semiconductor device according to claim 1, wherein the interlayer insulating film of step (a) is formed to have an uneven thickness with respect to the upper surface of the semiconductor substrate. The method of forming a fine pattern of a semiconductor device according to claim 1, wherein the upper antireflection film of step (c) is formed using a material having a refractive index different from that of the photosensitive film. The method of forming a fine pattern of a semiconductor device according to claim 1, wherein the step (d) is performed using deep ultra violet. (a) forming an interlayer insulating film on the upper surface of the semiconductor substrate on which the lower structure of the semiconductor device is formed; (b) forming a stepped pattern on the interlayer insulating film; (c) applying a photoresist film on the interlayer insulating film on which the stepped pattern is formed, and then flowing; (d) forming a photoresist pattern that exposes an upper surface of the stepped pattern formed on the interlayer insulating layer by performing a photolithography process on the flowed photoresist; And (e) forming a contact hole through the interlayer insulating layer to expose the upper surface of the semiconductor substrate by an etching process using the photoresist pattern as a mask; forming a fine pattern of a semiconductor device Way.