KR20000055564A - An Exposure Apparatus - Google Patents

Abstract

PURPOSE: An exposing apparatus for manufacturing a semiconductor device is provided to reduce an energy loss of a laser beam and improve a control ability of a coherence and minimize a size of the apparatus. CONSTITUTION: An exposing apparatus for manufacturing a semiconductor device comprises a light source(10) for generating a first laser beam, an optical coherence lowering portion(101) which adapts the first laser beam to have a deferent optical passage and passing time to reduce a coherence, a lens portion(11) for controlling a magnification of the second laser beam to form a third laser beam, a reticle portion(12) for forming a pattern to be transferred through the third laser beam, and a reflecting portion(13) for reflecting the pattern formed by the reticle on a wafer(14). In the apparatus, the optical coherence lowering portion is comprised of a phase deforming circular plate(101a) of which both sides are irregularly deformed and which is formed of a transparent material, and a rotating portion for rotating the phase deforming circular plate at a high speed.

Description

Exposure apparatus for semiconductor manufacturing {An Exposure Apparatus}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for semiconductor manufacturing, and more particularly, to an exposure apparatus for semiconductor manufacturing which reduces coherence caused by laser beams during wafer patterning by using a laser beam as a light source to reduce defects of patterns caused by speckle.

Generally, a light source used in a semiconductor exposure process for forming a pattern on a wafer is used in consideration of characteristics such as wavelength, polarization, temporal and spatial coherence, monochromaticity, pulse duration, intensity, and uniformity. .

Halogen lamps, xenon lamps, or laser beams are mainly used for light sources used for semiconductor exposure. Among these light sources, semiconductor exposure using laser beam as a light source is characterized by excellent time and spatial coherence due to the characteristics of the laser beam. It is used a lot because it is possible.

However, in the semiconductor exposure process using the laser beam, when foreign matter such as dust is attached on the reticle due to the characteristics of the highly coherent laser beam, even a fine pattern defect is transferred onto the wafer as it is. It will cause a bad pattern.

Therefore, when exposing on a wafer using a laser beam, the coherence of the laser beam is adjusted to have a degree of coherence necessary for exposure.

1 is a simplified diagram of a semiconductor exposure apparatus using a laser beam as a light source. The conventional exposure apparatus includes a light source unit 10 for generating a first laser beam for forming a pattern on a wafer 14, and the first exposure apparatus. The optical interference reducing unit 15 which cuts the wavelength of the first laser beam finely to form a second laser beam having reduced coherence of light, and reduces or enlarges the magnification of the second laser beam to block or transmit the third laser beam. A projection for transferring a lens portion 11 forming a laser beam, a reticle portion 12 for forming a pattern to be transferred by the third laser beam, and a pattern formed in the reticle portion 12 to the wafer 14 It consists of a part (13).

The optical interference reducing unit 15 includes an optical cutting disc 15a having a plurality of through holes and a rotating unit 15b for rotating the optical cutting disc at high speed.

In the conventional exposure apparatus for manufacturing a semiconductor having such a configuration, a first laser beam having a wavelength of approximately 600 Hz is generated at the light source generator 10 and is incident on the optical interference reducing unit 15.

The first laser beam incident to the optical interference lowering portion becomes a second laser beam at the through hole of the optical cutting plate 15a, which is rotated at a high speed by the rotating part 15b while the through hole is shuttered. The second laser beam is shortened by cutting the wavelength of the first laser beam by temporarily blocking or transmitting the first laser beam in proportion to the rotational speed of the rotating unit 15b.

The second laser beam passes through the lens unit 11 and becomes a third laser beam whose magnification is adjusted, and the third laser beam enters the reticle unit 12 to form a pattern. Then, the focus alignment progresses through the projection unit 13, and then the pattern is transferred onto the wafer 14.

However, such a conventional exposure apparatus for semiconductor manufacturing has a large energy loss in the process of shortly cutting the wavelength of the first laser beam into the second laser beam by the optical cutting disc of the optical interference reducing portion.

That is, since the first laser beam can be transmitted only through the through hole of the optical cutting plate, the first laser beam not passing through the through hole is blocked and energy loss is generated by the amount of the laser beam blocked.

In addition, since the coherence control of the laser beam is only adjusted by the rotational speed of the rotating unit, the coherence adjustment is not free and there is a limit in the controllability.

Accordingly, an object of the present invention is to solve the problems of the conventional semiconductor manufacturing exposure apparatus, the laser beam exposure is low, the energy loss of the laser beam is improved, the coherence controllability is improved, and the device can be miniaturized exposure To provide a device.

Accordingly, in order to achieve the above object, the exposure apparatus for semiconductor manufacturing according to the present invention includes a light source unit for generating a first laser beam, and a first coherency having low coherence by allowing the first laser beam to have different light passage paths and light transmission time differences. A light interference reducing unit forming a second laser beam, a lens unit forming a third laser beam by adjusting a magnification of the second laser beam, and a reticle forming a pattern to be transferred to a wafer through the third laser beam Section and a projection section for projecting the pattern formed in the reticle section onto the wafer.

Here, the optical interference lowering portion is formed of a distorted surface of irregular shape on both sides, consisting of a phase distortion disc made of a transparent material, and a rotating portion for rotating the phase distortion disc at high speed, or the optical interference The thickness of the lower part of the lower part may be relatively thicker than the thickness of the lower part of the lower part, and an optical wedge disc made of a transparent material and a rotating part for rotating the optical wedge disc at high speed.

In another aspect, an exposure apparatus for manufacturing a semiconductor according to the present invention includes a light source unit for generating a first laser beam, and a high frequency optical switch for repeatedly blocking or transmitting the first laser beam to form a second laser beam having low coherence. And a lens unit for forming a third laser beam by adjusting a magnification of the second laser beam, a reticle unit for forming a pattern to be transferred to a wafer through the third laser beam, and a pattern formed in the reticle unit. A projection for projecting the light onto a wafer.

Here, the high frequency optical switch unit is composed of a nonlinear medium capable of generating polarization, and a high frequency voltage supply unit generating polarization by applying a high frequency voltage to the nonlinear medium to block or transmit the laser beam, and the nonlinear medium. Blowing It is characterized by a series of crystal media.

In addition, voltage conversion of the high frequency voltage applied to the nonlinear medium part is easily formed.

1 is a schematic diagram of a conventional exposure apparatus for manufacturing semiconductors,

2, 3, and 4 are schematic diagrams for illustrating various embodiments of an exposure apparatus for manufacturing a semiconductor according to the present invention.

<Brief description of the main parts of the drawings>

10: light source generator 11: lens unit

12: reticle portion 13: projection portion

14: wafer 15,101,102: optical interference reduction portion

103: high frequency optical switch unit

Hereinafter, an exposure apparatus for manufacturing a semiconductor of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a brief drawing of the exposure apparatus for semiconductor manufacturing according to the present invention, and a first embodiment of the exposure apparatus for semiconductor manufacturing according to the present invention will be described.

The exposure apparatus for semiconductor manufacturing according to the present invention includes a light source unit 10 for generating a first laser beam, and an optical interference reducing unit 101 for shortly cutting a wavelength of the first laser beam to form a second laser beam having low coherence. ), A lens unit 11 for forming a third laser beam by adjusting the magnification of the second laser beam, and a reticle unit 12 for forming a pattern to be transferred to the wafer 14 through the third laser beam. ) And a projection portion 13 for projecting the pattern formed on the reticle portion onto the wafer 14.

The optical interference lowering unit 101 includes a phase distortion disc 101a and a rotation unit 101b for rotating the phase distortion disc at high speed.

At this time, the phase distortion disc 101a is made of a transparent material so that both sides have a distorted surface irregularly distorted so that the thicknesses are different from each other according to positions, and all the laser beams generated by the light source generator 10 are passed through. It can be formed.

In the exposure apparatus for manufacturing a semiconductor according to the present invention having such a configuration, a first laser beam having a wavelength of approximately 600 Hz is generated in the light source generator 10 to pass through the phase distortion disk 101a of the optical interference reducing portion.

The first laser beam passing through the phase distortion disk 101a becomes a second laser beam whose wavelength is shortened to reduce coherence.

This is because the phase distortion original plate 101a is a distortion plane whose both surfaces are irregularly distorted, is made of a transparent material so as to pass the laser beam, and is rotated at high speed by the rotating unit 101b.

That is, the first laser beam not only has irregularly distorted distortion surfaces having different thicknesses, but also continuously changes in thickness due to rotation, and thus, different light passing paths and transit times at each moment passing through the phase distortion disk 101a. Since it is possible to obtain the effect of cutting the wavelength can be reduced the coherence of the laser beam.

The second laser beam having low coherence is adjusted while passing through the lens part 11 to become a third laser beam, and is incident on the reticle part 12 to form a pattern to pass through the projection part 13. The focus alignment is then transferred onto the wafer 14.

Another embodiment of a semiconductor exposure apparatus of the present invention will be described with reference to FIG. 3.

The second embodiment of the present invention has the same configuration and operation as the first embodiment described above, wherein the phase distortion disk 101a of the optical interference reducing portion is an optical wedge disk 102a.

That is, the optical wedge disc 102a is made of a transparent material that allows the thickness of the upper end to be relatively thicker than the thickness of the lower end and allows the laser beam to pass therethrough.

Therefore, when rotating at a high speed by the rotating unit 102b, the thickness continuously changes with rotation, and the wavelength of the first laser beam is shortly cut in the same way that the phase distortion disk 101a continuously changes in thickness by rotation. In this way, the effect of forming the second laser beam with low coherence can be obtained.

Next, a third embodiment of the semiconductor exposure apparatus of the present invention will be described with reference to FIG.

The exposure apparatus for semiconductor manufacturing according to the present invention comprises a high frequency light source unit 10 for generating a first laser beam, and a high frequency wave forming the first laser beam as a coherent second laser beam by blocking or transmitting the first laser beam. An optical switch unit 103, a lens unit 11 for forming a third laser beam by adjusting the magnification of the second laser beam, and a reticle unit 12 for forming a pattern on the wafer through the third laser beam. And a projection part 13 for projecting the pattern formed in the reticle part 12 onto the wafer 14.

At this time, the high frequency optical switch 103 is a non-linear medium 103a, but the non-linear medium to be polarized Formed with a series of crystal media.

In addition, the high frequency optical switch unit 103 is provided with a high frequency voltage supply unit 103b which is capable of applying a high frequency voltage to the nonlinear medium unit 103a, and capable of converting the high frequency voltage.

In the exposure apparatus for manufacturing a semiconductor of the present invention having such a configuration, a first laser beam having a period and an amplitude of approximately 600 Hz is generated in the light source generator 10 to pass through the high frequency optical switch unit 103.

The first laser beam passing through the high frequency optical switch unit 103 becomes a second laser beam whose wavelength is shortened to reduce coherence.

This allows the nonlinear medium to be polarized. This is because polarization occurs according to the high frequency power applied by the high frequency voltage supply unit 103b, and the electrooptic effect is generated by the generated polarization.

That is, the nonlinear medium 103a maintains the arrangement of the medium to form a kind of shielding film to block the laser beam because no polarization occurs in the state where no high frequency voltage is applied, but when the high frequency voltage is applied, the laser is polarized. The arrangement of the medium is changed to form a passage through which the beam passes.

Therefore, when the high frequency voltage is alternately applied by the high frequency voltage supply unit 103b, the electro-optic effect is repeatedly performed to obtain the effect of cutting the wavelength of the laser beam while blocking or passing the laser beam. It forms a laser beam.

The second laser beam passing through the high frequency optical switch unit 103 passes through the lens unit 11, and the magnification is adjusted to become the third laser beam, and is incident on the reticle unit 12 to form a pattern. The focus alignment proceeds via 13) and is then transferred onto the wafer 14.

As described in the above first and second embodiments, all of the phase distortion discs and the optical wedge discs of the semiconductor exposure apparatus of the present invention are formed transparently, have different thicknesses, and are rotated at high speed to generate all of the light sources. Since the coherence of the laser beam can be reduced, the energy loss of the laser beam can be reduced.

In addition, in order to control the coherence of the laser beam, the thickness of the phase distortion disc and the optical wedge disc can be easily changed to easily adjust the coherence of the laser beam, and the cutting ability of the laser beam is improved to control the coherence. Is made more efficient.

In addition, as described in the third embodiment of the present invention, the semiconductor exposure apparatus of the present invention adjusts the coherence of the laser beam according to the voltage conversion of the high frequency voltage supplied from the high frequency voltage supply unit to the nonlinear medium portion, thereby causing the laser beam to rotate. It is easier to adjust the coherence than to cut the shape, and a separate rotating part is not required, thereby miniaturizing the exposure apparatus.

Claims (7)

In the exposure apparatus for semiconductor manufacturing, A light source unit generating a first laser beam, A light source interference reduction unit for forming the second laser beam having low coherence by allowing the first laser beam to have a different light passage path and light passage time; A lens unit forming a third laser beam by adjusting a magnification of the second laser beam; A reticle portion forming a pattern to be transferred to a wafer through the third laser beam; And a projection portion for projecting a pattern formed in the reticle portion onto a wafer. The method according to claim 1, wherein the optical interference lowering portion is formed of a distorted surface of a distorted shape of irregular shape on both sides, a phase distortion disc made of a transparent material, And a rotating part for rotating the phase distortion disc at high speed. The optical wedge disc of claim 1, wherein the optical interference reducing part has a thickness of an upper end relatively thicker than a thickness of a lower end, and an optical wedge disc made of a transparent material. Exposure device for manufacturing a semiconductor, characterized in that consisting of a rotating portion for rotating the optical wedge disc at high speed. In the exposure apparatus for semiconductor manufacturing, A light source unit generating a first laser beam, A high frequency optical switch unit for repeatedly blocking or transmitting the first laser beam to form a second laser beam having low coherence; A lens unit forming a third laser beam by adjusting a magnification of the second laser beam; A reticle portion for forming a pattern to be transferred to a wafer through the third laser beam; An exposure apparatus for manufacturing a semiconductor comprising a projection unit for projecting a pattern formed in the reticle unit on a wafer. The method according to claim 4, The high frequency optical switch unit and a non-linear medium capable of generating polarization; And a high frequency voltage supply unit configured to generate polarization by applying a high frequency voltage to the nonlinear medium to block or transmit the laser beam. The method of claim 5, wherein the non-linear medium portion Exposure apparatus for manufacturing a semiconductor, characterized in that formed of a series of crystal media. The exposure apparatus for manufacturing a semiconductor according to claim 5, wherein the high frequency voltage supply unit easily converts a high frequency voltage applied to the nonlinear medium unit.