KR20040059255A - Photoresist Deposition Apparatus with Vibrator - Google Patents

Abstract

PURPOSE: A photoresist coating apparatus is provided to improve remarkably uniformity of a photoresist layer by using ultrasonic vibrations in a photoresist coating process. CONSTITUTION: A spraying nozzle(12) supplies photoresist(15) on a wafer(13). A wafer chuck(14) for supporting the wafer spins with a desired speed. When the photoresist is supplied on the wafer through the spraying nozzle, an ultrasonic generator(31) as a vibration generator supplies fine vibrations to the wafer chuck.

Description

Photoresist coating apparatus having a vibration generating device {Photoresist Deposition Apparatus with Vibrator}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist coating apparatus, and more particularly, to an apparatus for applying a photoresist on a wafer with uniform thickness.

In general, in order to manufacture integrated circuit semiconductor devices, liquid crystal displays, plasma displays, and the like, it is necessary to form a predetermined material film pattern on a semiconductor substrate (wafer) or a glass substrate. For this purpose, a photoresist is applied onto a material film on a semiconductor substrate or a glass substrate and then exposed to form a photoresist pattern. Subsequently, the material film pattern is formed by etching the material film using the photoresist pattern as an etching mask.

Fig. 1 schematically shows a photoresist coating apparatus used when applying photoresist in a semiconductor manufacturing process. As shown in FIG. 1, the photoresist coating apparatus includes a wafer chuck 14 capable of holding a wafer in a bath in a bath and a motor connected to the wafer chuck 14 through an arm to rotate the wafer (not shown). ), A nozzle 12 for spraying the photoresist 15 on the wafer 13 from the top, a nozzle support 11 for supporting the nozzle 12, and the like.

The photoresist coating apparatus is a spin coating method for applying the photoresist 15 to the surface of the wafer 13 while rotating the wafer 13 mounted on the wafer chuck 14 at a predetermined speed using a motor and an arm. It is mainly used, and by using the centrifugal force by such rotation, it is possible to apply the photoresist 15 uniformly to the wafer 13 to some extent.

On the other hand, since photoresist occupies a part of the optical system, precise thickness control is required. The thickness of the photoresist applied is usually several hundred nm to one thousand nm. The photoresist thickness is controlled by controlling the rotational speed of the wafer in consideration of the viscosity of the photoresist after supplying the photoresist on the wafer which rotates at a stationary state or at a slow speed. At this time, the uniformity of the photoresist to be applied should be maintained within 0.5%, the uniformity and thickness are changed by factors such as the amount, temperature and viscosity of the sprayed photoresist, the temperature and rotation speed of the wafer chuck, exhaust pressure, humidity.

2 is a cross-sectional view of the surface profile of a photoresist layer applied on a wafer. When the wafer is rotated in consideration of the viscosity of the photoresist while supplying the photoresist on the wafer 13 which is stopped or rotated at a slow speed, as shown in FIG. 2, the time taken to spread from the center to the edge and the photo The photoresist 15 applied on the wafer is not uniform in thickness, for example, because the resist 15 is in direct contact with the surface of the wafer 13. In this state, when the soft bake is performed, the light bake is exposed as it is, causing a bad pattern profile.

An object of the present invention is to solve such a problem, and an object thereof is to improve the surface uniformity of a photoresist layer applied by a spin coating method and to prevent a pattern profile defect after pattern exposure in advance.

1 is a schematic diagram of a photoresist coating apparatus used when applying photoresist in a semiconductor manufacturing process;

2 is a cross-sectional view of the surface profile of a photoresist layer applied on a wafer;

3 is a block diagram of a photoresist coating apparatus including an ultrasonic wave generating apparatus according to the present invention, and

4 is a cross-sectional view of the surface profile when applying the photoresist layer on the wafer while applying ultrasonic vibration.

-Explanation of symbols for the main parts of the drawings-

11: nozzle support 12: nozzle

13: wafer 14: wafer chuck

15: photoresist 31: ultrasonic generator

In order to achieve the above object, the present invention is provided with an ultrasonic generator capable of applying a fine vibration to the wafer chuck, by generating an ultrasonic wave at the same time as supplying the photoresist to fine vibration of the wafer, the surface of the photoresist applied on the wafer Provided is a photoresist coating apparatus capable of improving uniformity.

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

3 is a block diagram of a photoresist coating apparatus including an ultrasonic wave generating apparatus according to the present invention. As shown in Fig. 3, the photoresist coating apparatus of the present invention includes a wafer chuck 14 for holding a wafer, a nozzle 12 for spraying the photoresist 15 onto the wafer 13 from above, and a nozzle 12 ), And an ultrasonic generator 31 connected to the wafer chuck 14 to apply vibration to the wafer chuck 14.

The ultrasonic generator 31 may use a rod-shaped ultrasonic motor described in US Patent Application No. 340,469. This example is composed of a vibrator, a sliding part, a moving object, etc., in which an alternating voltage is applied to the piezoelectric element, causing the vibrator to vibrate, and the surface particles of the sliding part perform an elliptic motion. Delivers fine vibrations This vibration is transmitted to the wafer 13, and the vibration is applied to the photoresist applied on the wafer 13.

The wafer chuck 14 is rotated at a predetermined speed using a motor and an arm, and a wafer 13 is mounted on the wafer chuck 14 to rotate at the same speed as the wafer chuck 14. With the rotation of the wafer 13, photoresist supplied from the top to the surface of the wafer 13 is applied while spreading from the center to the edge by centrifugal force.

With the supply and application of the photoresist, the microscopic vibration applied to the wafer chuck 14 from the ultrasonic generator 31 causes the wafer chuck 14 and the wafer 13 to vibrate. Application is made while vibrating. When vibration is applied to the flowable photoresist having a predetermined viscosity, the flatness of the upper surface of the photoresist is improved.

4 is a cross-sectional view of the surface profile when applying the photoresist layer on the wafer while applying ultrasonic vibration. When the photoresist is supplied to the wafer 13 and the micro vibration is applied to the wafer by an ultrasonic generator, and the wafer is rotated at a rotational speed considering the viscosity of the photoresist, as shown in FIG. The flatness of the surface appearing over is greatly improved. This result makes it possible to sufficiently overcome the nonuniformity of the photoresist thickness due to the time taken for the photoresist to spread and the photoresist 21 to be in direct contact with the surface of the wafer 13. Therefore, even after soft bake and exposure, which are subsequent processes, defects in the pattern profile are significantly reduced.

As such, when ultrasonic vibration is used in the photoresist coating using the spin coating method, the surface uniformity of the photoresist layer to be applied is greatly improved, so that the pattern profile defect is significantly reduced even after the pattern exposure, which is a subsequent process.

Claims (2)

An apparatus for applying a photoresist on a wafer, A spray nozzle for supplying a photoresist on the wafer; A wafer chuck which supports the wafer and rotates at a predetermined speed; And And a vibration generator for applying fine vibration to the wafer chuck when the photoresist is supplied through the injection nozzle. According to claim 1, wherein the vibration generating device A photoresist coating device having a vibration generating device, characterized in that the ultrasonic generator.