JPH04109253A - Exposure device - Google Patents

Abstract

PURPOSE:To realize high superposition accuracy, high productivity, and high flexibility by providing a means which eliminate the heat generation of an actuator. CONSTITUTION:A cover 18 is fitted to a pulse motor 10 as the driving actuator and air whose temperature is controlled is supplied into the cover 18 from a nipple 19 on one side of the cover 18 and discharged by evacuation from a nipple 20 on the opposite side at all times or upon occasion. Dust produced when the motor 10 can be discharged by this forcible evacuation together with the heat. Therefore, positioning operation is accurately performed without being affected by temperature variation of respective parts such as the wafer and a wafer chuck, air temperature variation at the periphery of the wafer and a laser interferometer, etc. Consequently, exposure transfer can be carried out with the extremely high superposition accuracy, high productivity, and high flexibility.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exposure apparatus for forming a pattern on a flat object such as a semiconductor wafer or a liquid crystal display panel, and particularly relates to an exposure apparatus for forming a pattern on a flat object such as a semiconductor wafer or a liquid crystal display panel. The present invention relates to an exposure apparatus that can perform highly accurate exposure by properly holding the posture of an exposed object such as a wafer on which a circuit pattern is to be printed during the manufacture of integrated circuit chips.

[Prior Art] In conventional devices of this type, for example, exposure devices such as steppers that project a pattern drawn on a reticle onto a wafer,
A function is provided to align the reticle and the wafer, and exposure is performed after alignment.

Such alignment is accomplished by measuring the amount of misalignment between an original plate such as a reticle on which a pattern to be projected is drawn and an exposed object such as a wafer, and adjusting the position of the exposed object based on the result. This is done by moving the original plate and the object to be exposed.

[Problem to be solved by the invention] However, in such an exposure apparatus, during processing,
Thermal deformation due to temperature changes in the mechanism that drives the reticle and wafer up and down, left and right, and in the rotational direction, thermal contraction of the mirror and wafer mounting surface, thermal deformation of the position measuring mirror and the sea urchin, and furthermore, 6 air due to temperature changes. Due to changes in density, etc., measurement errors may occur in laser length measurement, and the aligned reticle and wafer may become misaligned. More specifically, for example, during step movement in the XY direction in a stepper, temperature changes due to heat generated by the motor inside the XY wafer stage and the wafer up/down/rotation mechanism mounted thereon may cause the wafer up/down/rotation mechanism to mechanical deviation due to thermal expansion of the wafer, deviation due to thermal contraction of the wafer chuck and wafer, thermal deformation of the length measurement mirror, sag due to thermal contraction between the wafer chuck and mirror, and changes in air density on the laser measurement optical path. There is a problem in that the position of the wafer may shift due to measurement errors or the like. That is, there are difficulties in the accuracy of overlapping the reticle and wafer and in flexibility with other devices.

In view of the problems of the conventional method described above, the present invention provides extremely high overlay accuracy, high productivity, and high flexibility without causing positional shift of the exposed object such as a wafer during operations such as step operations. An object of the present invention is to provide an exposure apparatus having the following features.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a measuring means for measuring the position of an original plate having a pattern to be transferred to an exposed object and/or an exposed object, and an actuator that drives an actuator. and a positioning means for holding the original plate and/or the exposed object and positioning the original plate and/or the exposed object based on the measurement results by the measuring means, and positioning the original plate and the exposed object by these means. An exposure apparatus for exposing and transferring a pattern on an exposed object is equipped with heat exhaust means for removing heat generated by an actuator of a positioning means via a coolant.

The actuator is, for example, a motor, and the heat exhausting means includes, for example, a member surrounding the motor, and means for forcibly supplying and/or forcibly exhausting refrigerant air between the member and the motor.

The refrigerant may be, for example, air, gaseous gas, liquid, or a combination thereof.

Preferably, the heat exhausting means is sealed to prevent refrigerant from leaking in the heat generating portion of the actuator, and dust generated by the actuator is prevented from diffusing outside the heat exhausting means.

The member for sealing the heat generating portion may be made of either a thermally conductive material or a heat insulating material.

[Function] In this configuration, during exposure transfer, the original plate and/or
Alternatively, the exposed object is held by a positioning means, the amount of deviation between the original and the exposed object is measured by a measuring means, and the original and/or the exposed object is positioned according to the results. When the actuator is driven for this purpose, the actuator generates heat. However, since this heat is exhausted by the heat exhausting means, positioning is affected by heat, such as temperature changes in various parts such as the wafer and wafer chuck, and even temperature changes in the air around the wafer and laser interferometer. It is done accurately. Therefore, exposure transfer is performed with extremely high overlay accuracy, high productivity, and high flexibility.

[Example] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a cross-sectional view of a wafer stage portion of an exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a portion related to a motor cooling mechanism.

In these figures, 1 is a wafer, 2 is a wafer transport hunt, 3 is a wafer chuck, 4 is a vacuum exhaust groove for wafer suction formed on the top surface of the wafer chuck, 5 is a through hole formed in the wafer chuck 3, and 6 is a through hole formed in the wafer chuck 3. The wafer holder is a support, 7 is a vacuum exhaust path formed in the wafer support 6, 8 is a chuck support base for fixedly supporting the wafer chuck 3, and 9 is a mounting board for fixing the entire wafer stage to an XY stage (not shown). , 10 is a motor which is a driving source for vertical movement of the sea urchin station, 11 is a gear, 12 is a pol screw, 13 is a lever, 14 is a ball bush, 15 is a ball, and 16 is a motor that moves the hole bush 14 in the vertical direction via the hole 15. This is a ball bush kite that will guide you. The lever 13 is rotatable around a central swing axis, and its tip end is connected to the lower end of the pole bush 14, and its opposite end is connected to the hole screw 12. The hall screw 12 is connected to the motor 10 via the gear 11.
is connected to. Therefore, the rotation of the motor 10 causes the ball screw 12 to move up and down, and in conjunction with this, the lever 1
3 is oscillated to move the hole bushing 14 up and down.

A Hall bushing guide 16 is fixed to the mounting board 9, and the wafer support support 6 is fixed to this Hall bushing guide 16. Further, a vacuum exhaust path 17 is formed in the ball bush guide 16, and the tubular wafer holder communicates with the vacuum exhaust path 7 inside the support column 6.

On the other hand, the wafer chuck 3 is fixed to the hole bush 14 via the chuck support base 8, and when the motor 10 is driven, the gear 11, the ball screw 12, and the lever 1 are activated as described above.
3. Force is transmitted in this order to the pole bush 14, allowing vertical movement.

As shown in FIG. 2, pulse motors 8 to 18 are attached to the pulse motor 1o, which is a driving actuator, and temperature-controlled air is supplied into the cover 18 from a nipple 19 on one side of the cover 18. From the nipple 2° on the opposite side, forced evacuation is performed by vacuum at all times or as needed.

Due to this forced exhaust, dust generated when the motor 1o is driven is also discharged together with heat.

In this configuration, when the wafer transfer hand 2 transfers the wafer 1 onto the wafer chuck 3, the evacuation groove 4 and the evacuation path 7 are vacuum-suctioned, and the wafer chuck 3 is raised by the drive of the motor 10. As a result, the wafer 1 is attracted and held by the wafer chuck 3.

During this time, the space between the motor 10 and the cover 18 is forcibly evacuated, whereby the heat and dust generated by driving the motor 10 are discharged outside the apparatus without being transmitted and diffused to each part of the apparatus.

In the above embodiment, the motor is cooled by forced air supply and exhaust, but instead of this, a liquid such as water or Fluorinert, or a gas such as fluorocarbon or ammonia gas may be used as a refrigerant for exhaust heat. For example, a tube for passing these refrigerants may be wrapped around the motor and the motor may be cooled by forced circulation using a refrigerator. Further, in the above embodiments, the case where the wafer is held has been described, but the same applies to the case where the reticle side is driven or the detailed positioning (alignment) of the wafer or reticle is performed using an XY stage.

[Effects of the Invention] As explained above, according to the present invention, the exposure apparatus is equipped with a means for eliminating heat generated by the actuator when moving and holding the original plate and/or the exposed object. During exposure transfer operations such as
The problem of positional deviation caused by changes in the Y and θ directions can be solved, and since there is no change in the temperature or density of the air, measurement errors caused by the measuring means can also be eliminated. Therefore, it is possible to provide an exposure apparatus having extremely high overlay accuracy, high productivity, and high flexibility.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a wafer stage according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a motor section in FIG. 1. Hook, Smopul, Wafer, 2 Transfer J hand, 3 Wafer cha 4: Vacuum exhaust groove, 5 Through hole, 10: Bulk, 18. Motor cover, 19: Air supply chive 20 Exhaust nipple.

Claims (5)

[Claims] (1) Measuring means for measuring the position of the original plate having a pattern to be transferred to the exposed object and/or the exposed object, and a measuring means that drives an actuator to hold the original plate and/or the exposed object and uses the measurement result by the measuring means. Based on the master plate and/or
or positioning means for positioning the exposed object, and in an exposure apparatus that positions the original plate and/or the exposed object by these means and transfers the pattern of the original plate to the exposed object by exposure, the actuator of the positioning means emits the An exposure apparatus characterized by comprising a heat exhaust means for eliminating heat via a coolant. (2) The actuator is a motor, and the heat exhausting means includes a member surrounding the motor, and means for forcibly supplying and/or forcibly exhausting refrigerant air between the member and the motor. The exposure apparatus according to claim 1, characterized in that: (3) The exposure apparatus according to claim 1, wherein the coolant is air, an evaporative gas, a liquid, or a combination thereof. (4) The exposure apparatus according to claim 1, wherein the heat exhausting means is sealed to prevent coolant from leaking at a heat generating portion of the actuator. (5) The exposure apparatus according to claim 1, wherein the member that seals the heat generating portion is made of a material with good thermal conductivity or a material with heat insulation properties.