KR19990002911U - Lighting device of photo etching process - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

Modified lighting device of semiconductor device

2. The technical problem to be solved by the invention

The present invention relates to a lighting apparatus of an exposure apparatus that is applied to a photolithography process in a semiconductor device manufacturing process, and to improve the pattern forming ability by improving the uniformity of the exposure amount.

3. Summary of solution of design

In order to increase the uniformity and exposure of light by adding a fly-eye lens and a condenser lens, respectively, under the condenser lens collecting light.

4. Important uses of the devise

Used in photolithography during semiconductor device manufacturing.

Description

Lighting device of photo etching process

The present invention relates to an exposure apparatus of an exposure process belonging to a photolithography process step of a semiconductor device manufacturing process.

In general, a photolithography process is a technique for implementing a pattern laid out on an exposure mask on a wafer under process control standards. To this end, a photochemical reaction occurs in the photoresist when the light having a specific wavelength is exposed on the photoresist-coated wafer through an exposure mask in which a pattern is formed. Using to form a pattern. The formed photoresist pattern serves as a barrier during subsequent etching or ion implantation siege and is finally removed by oxygen plasma.

As the pattern to be realized on the wafer is becoming more and more refined, the shortening of the exposure light and the increase in the numerical aperture of the transparent lens are further accelerated in the case of the optical photo etching, and also the phase which uses the interference phenomenon of the light reversely. Research into extending the optical photolithography process capability by using a phase shift mask and off-axis illumination is being actively conducted. Although studies using X-rays and electron beams (E-beams) have been conducted as means of overcoming the limitations of the optical photolithography process, many technical problems need to be solved in the future.

The process procedure of the photolithography process is roughly shown after the application of the photoresist, followed by a soft bake process, exposure, post-exposure bake, development and etching.

1 schematically shows a modified illumination device used in the exposure step of a conventional photolithography process.

As shown in Fig. 1, reference numeral 1 denotes a source of wavelength, reference numeral 2 denotes a reverberator, 3 denotes a fly's eye lens, 4 denotes a condenser lens, 7 denotes a reticle, 8 denotes a projection lens, and 9 denotes a wafer. It is made and shown in turn.

The prior art is equipped with a fly's eye lens 3 under a high-pressure mercury light source to improve the uniformity of the exposure dose. However, when the modified illumination method is applied, the uniformity of the exposure amount decreases with one fly-eye lens 3. Therefore, the uniformity of the pattern formed on a wafer falls, and the ability to form an insulating pattern falls.

The present invention devised to solve the above problems is to improve the uniformity of the light to improve the pattern forming ability during exposure of the photoresist.

1 is a schematic diagram of an illumination device for exposure in a conventional photolithography process;

2 is a schematic diagram of an illumination device for exposure of a photolithography process according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

1: discharge lamp

2: reverber

3: first fly's eye lens

4: first condensing lens

5: second fly's eye lens

6: second condensing lens

7: reticle

8: projection lens

9: wafer

The present invention to achieve the above object, the lighting unit for providing a light source;

A reverber unit positioned under the illumination unit to select a numerical aperture of a lens according to a use; A first transmission unit including a first fly-eye lens for improving the uniformity of the light source sequentially connected to the reverberation unit and a first condenser lens for collecting light sources incident from the first fly-eye lens; Second delivery consisting of a second fly's eye lens for improving the uniformity of the light source incident from the first transfer unit and a second condensing lens for collecting light sources incident from the second fly's eye lens part; And a reticle portion capable of moving the patterned mask connected to the second transfer portion, a reduced projection lens portion which reduces the image transmitted through the mask and transfers the image onto the wafer, and positions the wafer on which the image is to be formed at a predetermined position. It comprises a wafer stage for driving.

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

2 is a schematic view of an illumination device for exposure of a photolithography process according to an embodiment of the present invention.

First, as shown in FIG. 2, reference numeral 1 denotes a high-pressure mercury lamp, reference numeral 2 denotes a reverber capable of selecting an illumination numerical aperture (Numerical Aperature) according to a use, and 3 and 4 respectively indicate a first fly's eye. The lens and the condenser lens are shown. Reference numerals 5 and 6 added in the present invention represent the second fly-eye lens and the condenser lens, respectively. Below, reference numeral 7 denotes a reticle, 8 a projection lens, and 9 denotes a wafer.

As shown in the drawings will be described in detail the role of the second fly eye lens and the condenser lens added in the present invention.

By mounting a second fly-eye lens that improves the uniformity of light under the first condenser lens, the uniformity of the amount of transmission of the annular illumination system in which the light is transmitted obliquely can be doubled. In addition, the second condensing lens increases the coherence of light, thereby contributing to the uniformity of the light properties and the amount of light. In addition, by reducing the time error of light reaching the surface of the projection lens, the interference effect of light appears uniformly.

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 within the scope of the present invention without departing from the technical idea. It will be evident to those who have knowledge of.

The present invention made as described above can improve the uniformity of power density of high pressure mercury lamp by adding the fly eye lens and the condenser lens pair accordingly, and improve the uniformity of light to apply the modified manicure method more efficiently. Can be.

Claims (1)

An illumination unit providing a light source; A reverber unit positioned under the illumination unit to select a numerical aperture of a lens according to a use; A first transmission unit including a first fly-eye lens for improving the uniformity of the light source sequentially connected to the reverberation unit and a first condenser lens for collecting light sources incident from the first fly-eye lens; Second delivery consisting of a second fly's eye lens for improving the uniformity of the light source incident from the first transfer unit and a second condensing lens for collecting light sources incident from the second fly's eye lens part; And A reticle unit capable of moving the patterned mask connected to the secondary transfer unit, a reduced projection lens unit which reduces the image transmitted through the mask and transfers the image onto the wafer, and drives the wafer to be positioned by positioning the wafer on which the image is to be formed. A modified illumination device of a semiconductor device comprising a wafer end to be made.