KR20000003358A - Fine pattern forming of semiconductor - Google Patents

Abstract

PURPOSE: A fine pattern forming method of a semiconductor is provided to form a fine pattern over the resolution limit of an exposing source. CONSTITUTION: A fine pattern forming method comprises the steps of: spreading the photoresist(22) on a certain lower layer; coating the wet anti-reflective(23) on the photoresist; baking the wet anti-reflective and hardening the interfacial part between the photoresist and the anti-reflective; exposing and developing the photoresist and the anti-reflective; and selectively etching the lower layer using the photoresist pattern and the anti-reflective as an etching mask.

Description

Fine Pattern Formation Method of Semiconductor Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor technology, and more particularly, to a method of forming a fine pattern of a semiconductor device.

An i-line is a light source that is currently used mainly in lithography processes. However, in a lithography process using an i-line, it is difficult to realize a contact hole having a line width of 0.3 μm or less. In other words, in order to form a small contact hole, it is necessary to design a small line width of a photo mask or reduce exposure energy. When using a light source having a large wavelength (368 nm) such as an i-line, the resolution is limited. Due to the contact hole pattern of 0.3㎛ or less is not well defined.

Therefore, in order to realize a contact hole of 0.3 μm or less, deep ultraviolet rays (deep UV, 246 μm) having a wavelength shorter than that of an i-line should be used as a light source. Since the reticle, etc. must be replaced, the production cost increases. In addition, maintenance costs also increase, resulting in a reduction in international competitiveness and sales margins.

1 is a view illustrating a photoresist pattern for forming a contact hole formed according to the prior art, by applying a photoresist on a lower layer 10 on which a contact hole is to be formed, and forming a contact hole reticle 12. The used i-line exposure is performed, and the image development process is performed and the state in which the photoresist pattern 11 was formed is shown.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a fine pattern of a semiconductor device, which forms a fine pattern above a resolution limit of an exposure source.

1 is a cross-sectional view of a photoresist pattern for forming a contact hole formed according to the prior art.

2A to 2E are cross-sectional views illustrating a process of forming a fine contact hole in a semiconductor device according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

20 silicon substrate 21 interlayer insulating film

22: photoresist for i-line 23: wet ARC

24: reticle

In order to achieve the above object, there is provided a method of forming a fine pattern of a semiconductor device, the method comprising: applying a photoresist on a predetermined lower layer; Coating a wet antireflective layer on the photoresist; Baking the wet antireflective layer to cure an interface portion with the photoresist; Exposing and developing the photoresist and the wet antireflective layer; And selectively etching the lower layer using the wet anti-reflection layer and the photoresist pattern as an etching mask.

That is, the present invention utilizes a tail phenomenon due to curing at the interface with the photoresist and a development rate difference between the ARC and the photoresist by controlling the baking temperature and time of the wet ARC (Wet type Anti-Reflective Coating). Therefore, it is a technology for implementing an intaglio pattern having a line width below the resolution limit of the exposure source.

Hereinafter, the embodiment is introduced in order to attain the preferable and easy implementation of this invention.

2A through 2E illustrate a process of forming a fine contact hole in a semiconductor device according to an embodiment of the present invention, and the process will be described below with reference to the drawings.

First, as shown in FIG. 2A, an interlayer insulating film 21 is deposited on a silicon substrate 20 having a predetermined lower layer process, and an i-line photoresist 22 is applied thereon.

Next, the wet ARC 23 is coated on the applied photoresist 22 as shown in FIG. 2B to a thickness of 1200 to 1600 kPa, and baked at 180 to 195 ° C. for 60 to 100 seconds. At this time, the wet ARC 23 is hardened at the interface portion with the photoresist 22, and a product of BROWER Corporation may be used as the wet ARC.

Subsequently, i-line exposure is performed using the reticle 24 for forming a contact hole as shown in FIG. 2C.

Subsequently, the developing process is performed as shown in FIG. 2D. At this time, the developing process is performed for 40 to 60 seconds, and the wet process is performed by the curing phenomenon of the wet ARC 23 at the interface portion with the photoresist 22 and the development rate difference between the photoresist 22 and the wet ARC 23. The tail phenomenon A is caused in the ARC 23, and the photoresist 22 is developed less than the actual exposed area.

Next, as shown in FIG. 2E, the interlayer insulating layer 21 is dry-etched using the patterns of the wet ARC 23 and the photoresist 22 as an etching mask to form contact holes having a line width of 0.3 μm or less. The remaining wet ARC 23 and photoresist 22 are removed.

In the above-described embodiment, the formation of the contact hole pattern has been described as an example, but the present invention can be applied to all lithography processes for forming a fine intaglio pattern. It is also applicable to the case of using a light source other than an i-line as the exposure source.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention can form a fine pattern beyond the resolution limit of the exposure source without changing equipment and chemicals, thereby improving the productivity of the semiconductor device.

Claims (4)

Applying a photoresist on a predetermined underlying layer; Coating a wet antireflective layer on the photoresist; Baking the wet antireflective layer to cure an interface portion with the photoresist; Exposing and developing the photoresist and the wet antireflective layer; And Selectively etching the lower layer using the wet antireflection layer and the photoresist as a etch mask Method of forming a fine pattern of a semiconductor device comprising a. The method of claim 1, And the exposure is performed using i-line, and the photoresist is a photoresist for i-line. The method according to claim 1 or 2, The method of forming a fine pattern of a semiconductor device, wherein the baking is performed at a temperature of 180 to 195 ° C. The method of claim 3, wherein The method of forming a fine pattern of a semiconductor device wherein the baking is performed for 60 to 100 seconds.