JPH02284837A - Compensation of stage tare in vertical state - Google Patents

Abstract

PURPOSE:To perform the compensation of a tare with high reliability by forming the structure that the pressure offsetting the tare of a Y stage generates thrust in the state of the pressure offsetting the tares of both stages in the state of a jogging stage is bonded with the Y stage being released with its generation of a thrust on an air cylinder. CONSTITUTION:In the state of a jogging stage 8 being bonded with a Y stage 5 the pressure PH set by a 1st regulator 18 generates a thrust FH on an air cylinder 13 through the passages 25, 26 provided with the jogging stage 8 and a Y stage 5 and a shuttle valve 26. In the state of the jogging stage 8 being released from the Y stage 5 the jogging stage 8 and Y stage 5 are separated and so the pressure PH set by the 1st regulator 18 is released to the atmosphere and the pressure PL set by a 2nd regulator 19 generates a thrust FL on the air cylinder 13 through a shuttle valve 22. The state of the jogging state 8 is directly related to the pressure setting of the air cylinder 13 to perform the changeover of the thrust.

Description

[Detailed Description of the Invention] [Summary] Regarding a method of compensating for the dead weight of a stage in a vertical stage, the purpose of this invention is to compensate for the dead weight of the stage in the vertical direction with high reliability. When the Y-axis direction of the X stage of the XY stage matches the vertical direction, install the air cylinder on the X stage so that its sliding direction matches the Y-axis direction, and move the moving part of the air cylinder to the Y stage. This is a stage weight compensation method for a vertical stage, in which compressed air is injected into the vertical stage to generate a steady thrust force in the opposite direction and equal in magnitude to the weight of the Y stage and its mounting member, the fine movement stage. When the fine movement stage is connected to the Y stage, the pressure (PH) that offsets the weight of the Y stage and the fine movement stage set by the first regulator is applied to the flow channels 25 and 26 provided in the fine movement stage and the Y stage.
and thrust (FH) to the air cylinder through the shuttle valve.
is generated, and when the fine movement stage is separated from the Y stage, the pressure (PL) that offsets the self weight of the Y stage set by the second regulator is configured to generate thrust (FL) in the air cylinder through the shuttle valve. do.

[Industrial application field]

The present invention relates to a method for compensating for stage weight in a vertical stage.

2. Description of the Related Art As LSIs become smaller and more highly integrated, techniques for exposing and transferring circuit patterns on a mask onto a wafer are required to have higher precision.

The present invention is mainly applied to a stepper that exposes and transfers a circuit pattern on a mask onto a wafer, and makes it possible to position the mask and wafer with high precision by compensating for the weight of the stage. be.

[Prior Art] A vertical stage to which the present invention is applied, for example, uses synchrotron orbital radiation (hereinafter referred to as SOR) as a light source to expose and transfer a circuit pattern on a mask onto a wafer.
Because the SOR light is emitted horizontally and the wavelength of the SOR light is very short, it cannot be reflected by a mirror or the like to change the direction, so the mask and wafer are placed vertically and exposed. It is configured.

As shown in the explanatory diagram of FIG. 3, there is an X-axis guide 2 in front of the upright wafer stage base l of the vertical stage.
Above the X-axis guide 2 is a movable X stage 3.
Above the X stage 3 is a Y-axis guide 4, and above the Y-axis guide 4 is a movable X stage 5 equipped with a transfer section 27, using a linear ball screw or the like (not shown). It is equipped with a moving mechanism, and these two XY guides constitute a coarse movement stage 6 that roughly positions the wafer.

A fine movement stage 8 is movably mounted on the X stage 5 for holding the wafer 7 and performing precise positioning in the XY force directions using an electro-mechanical transducer such as a piezoelectric element.

Therefore, the wafer 7 can be freely moved in the XY force directions by the X stage 5 and the fine movement stage 8, and the area of the wafer 7 to be exposed can be moved by the step-and-repeat operation using the mask 10 held on the mask table 9. SOR light 11 is sequentially positioned at
exposed to light.

When configuring such a vertical stage so that the Y axis coincides with the vertical direction, as shown in the explanatory diagram of FIG. 4(a),
A constant output is required to counter the load 12 of the X stage 5 and fine movement stage 8 moving on the axis guide 4.

As a means to compensate for this load 12, as shown in the figure, an air cylinder 13 such as a rodless cylinder is attached to the X stage 3 so that its sliding direction coincides with the Y axis, and the piston yoke 14, which is the moving part of the air cylinder 13, There is a method of connecting the X stage 5 and injecting an appropriate amount of compressed air into the air cylinder 13 via the regulator 1G to generate a steady thrust 15 of the same magnitude and in the opposite direction to the load 12.

In the case of the above self-weight compensation method, as shown in the explanatory diagram of FIG. , a steady thrust 17 is generated vertically upward against the X stage 5 by the amount that the output of the air cylinder 13 exceeds.
occurs, and in order for the drive system of the X stage 5 to face the suddenly generated excessive external force, it is necessary to generate a thrust in the air cylinder 13 in the opposite direction to and equal to the external force.

For this purpose, there is a method of increasing the size and performance of the drive actuator and power amplifier, but this cannot be realized for boat fishing due to the need to reduce the cost, size, and energy saving of equipment.

Therefore, as shown in FIG. 5, a method of switching the thrust of the air cylinder 13 is used.

In other words, when the fine movement stage 8 is separated from the Y stage 5, the thrust generated by the air cylinder 13 is set so as to oppose only the weight of the Y stage 5.

In the figure, 18 is a first regulator that sets a pressure PH equal to the weight of the Y stage 5 and fine movement stage 8;
19 is a second regulator that sets a pressure PL equal to the weight of the Y stage 5; 20 is a first three-boat solenoid valve connected to the first regulator 18; and 21 is a second regulator connected to the second regulator 19. 2, a 3-port solenoid valve; 22, a shuttle valve interposed between the first and second 3-boat solenoid valves 20, 21 and the air cylinder 13; 23, detecting the coupling state of the fine movement stage 8 and Y stage 5; The detection means 24 is, for example, an optical sensor, and the control means 24 is a control means, for example, a relay, which switches the first and second three-boat electromagnetic valves 20, 21 based on the information from the detection means 23.

The operation will be explained below.

As shown in the same figure (a), the fine movement stage 8 is the Y stage 5.
In the state where the air cylinder 13 is connected to the air cylinder 13, the pressure PH set by the first regulator 18 causes the air cylinder 13 to generate a thrust force FH through the first three-boat solenoid valve 20 and the shuttle valve 22.

On the other hand, as shown in FIG. 2(b), when the fine movement stage 8 is detached from the Y stage 5, the pressure PL set by the second regulator 19 is applied to the second 3-port solenoid valve 2.
A thrust force FL is generated in the air cylinder 13 through the air cylinder 1 and the shuttle valve 22.

[Problem to be solved by the invention]

In the configuration shown in FIG. 5, in addition to the detection means 23 and the control means 24, the detection means 23 and the control means 24 are
．． The following problems occur due to failure of the three boat solenoid valves 20, 21, etc.

(1) When the fine movement stage 8 is coupled to the Y stage 5, the pressure within the air cylinder cannot counteract the weight of the Y stage 5 and the fine movement stage 8, and the stage descends.

(2) When the fine movement stage 8 is separated from the Y stage 5, the pressure inside the air cylinder exceeds the weight of the Y stage 5, and the stage rises.

The object of the present invention is to ensure that compensation for dead weight is carried out with high reliability.

[Means to solve the problem]

In order to achieve the above object, in the present invention, FIG.
), the fine movement stage 8 is the Y stage 5.
When the Y stage 5 and the fine movement stage 8 are connected to each other, the pressure (PH) set by the first regulator 18 that offsets the weight of the Y stage 5 and the fine movement stage 8 is applied to the flow paths 25 and 26 provided in the fine movement stage 8 and the Y stage 5, and the shuttle. A thrust (FH) is generated in the air cylinder 13 through the valve 22, and when the fine movement stage 8 is detached from the Y stage 5, the pressure (PL) set by the second regulator 19 that offsets the weight of the Y stage 5 is applied to the shuttle. Air cylinder 1 through valve 22
3 to generate thrust (FL).

[Effect]

(1) When the fine movement stage 8 is connected to the Y stage 5, the pressure P set by the first regulator 18)
(The flow path 25 provided in the fine movement stage 8 and Y stage 5
, 26 , and the shuttle valve 22 to generate thrust FH in the air cylinder 13 .

In the shuttle valve 22, the pressure PH set by the first regulator 18 is equal to the pressure P set by the second regulator 19.
Since the pressure is higher than L, pressure PH has priority.

(2) When the fine movement stage 8 is separated from the Y stage 5, the fine movement stage 8 and the Y stage 5 are separated, so the pressure PH set by the first regulator 18 is released to the atmosphere, and the pressure PH set by the first regulator 18 is released to the atmosphere. Pressure P set by regulator 19
L is a thrust force F to the air cylinder 13 through the shuttle valve 22.
Generate L.

In this way, the state of the fine movement stage 8 directly affects the pressure setting of the air cylinder 13 and switches the thrust.

〔Example〕

1 and 2 show one embodiment of the present invention.

Identical parts are designated by the same reference numerals throughout the figures.

In the present invention, as shown in the explanatory diagram of FIG. 1(a),
When the fine movement stage 8 is coupled to the coarse movement stage 6,
X including the transfer section 27 set by the first regulator 18
The pressure PH that offsets the weight of the stage 5 and the fine movement stage 8 causes the air cylinder 13 to generate a thrust force F [-( As shown in FIG. 5B, when the fine movement stage 8 is separated from the coarse movement stage 6, the pressure PL set by the second regulator 19 to offset the weight of the X stage 5 is applied to the air cylinder 13 through the shuttle valve 22. It is designed to generate thrust FL.

In other words, as shown in FIG.
When connected to the X stage 5, the pressure PH set by the first regulator 18 applies thrust to the air cylinder 13 through the flow channels 25 and 26 and the shuttle valve 22 provided in the fine movement stage 8 and the X stage 5. Generate FH.

At this time, in the shuttle valve 22, the first regulator 18
Since the pressure PH set in is higher than the pressure PL set by the second regulator 19, the pressure PH takes priority.

On the other hand, as shown in the same figure, the fine movement stage 8 and the coarse movement stage 6
When the fine movement stage 8 and the X stage 5 are separated from each other, the pressure PH set by the first regulator 18 is released to the atmosphere and
The pressure PL set in step 9 causes the air cylinder 13 to generate thrust FL through the shuttle valve 22.

In this way, the state of the fine movement stage 8 directly affects the pressure setting of the air cylinder 13 and switches the thrust.
The problems of the prior art are solved.

The exposure operation of the vertical stage to which the present invention is applied will be explained with reference to FIG.

(1) As shown in FIG. 4A, the fine movement stage 8 on which the wafer 7 is mounted is held by the transfer section 27 of the X stage 5 and the X stage 3.

The wafer 7 is positioned with respect to the mask 10 on the mask table 9 by the movement of the XY stage. At this time, compensation for the weight of the X stage 5 and fine movement stage 8 is performed in the state shown in FIG. 1(a). .

(2) As shown in FIG. 4B, the fine movement stage 8 on which the wafer 7 is mounted is transferred to the mask table (scanning stage) 9 by the sliding movement of the transfer section 27.

At this time, compensation for the weight of the X stage 5 and fine movement stage 8 is performed in the state shown in FIG. 1(a).

(3) As shown in FIG. 2C, the fine movement stage 8 on which the wafer 7 is mounted is held by the mask table 9, and the X stage 5 returns to its original position by the sliding movement of the transfer section 27.

At this time, compensation for the own weight of the X stage 5 is shown in Figure 1 (
1))).

(4) As shown in FIG. 4(d), exposure is performed by the scanning movement of the mask table 9 and the SOR light 11.

At this time, compensation for the own weight of the X stage 5 is shown in Figure 1 (
b).

(5) As shown in FIG. 4(e), after the scanning movement of the mask table 9 is completed, the fine movement stage 8 returns to the scanning origin.

At this time, compensation for the own weight of the X stage 5 is shown in Figure 1 (b
).

(6) As shown in FIG. 4(f), the X stage 5 slides in the direction of the mask table 9 and is coupled to the fine movement stage 8.

Next, the fine movement stage 8 and the X stage 5 return to their original positions by the sliding operation of the transfer section 27.

At this time, compensation for the weight of the X stage 5 and fine movement stage 8 is performed in the state shown in FIG. 1(a).

[Effects of the Invention] According to the present invention, the detection means, 3-boat electromagnetic valve, and 3-port valve control means of the prior art are no longer necessary, and in addition to achieving cost reduction, the state of the fine movement stage can be directly detected. Because the configuration involves changing the air cylinder pressure and switching the thrust, self-weight compensation is performed with high reliability, etc.
It has great economic and industrial effects.

[Brief explanation of drawings]

Figure 1 (a) is an explanatory diagram of the stage weight compensation method in a vertical stage of the present invention, and Figure 1 (a) shows the state in which the fine movement stage is separated from the coarse movement stage. 2(a) to 2(f) are explanatory diagrams of the operation of the stage self-weight compensation method in a vertical stage of the present invention; FIG. 3 is an explanatory diagram of a contracted stage to which the present invention is applied; Figures 4 (a) and (b) are explanatory diagrams of a conventional stage self-weight compensation method for a vertical stage, and Figures 5 (a) and (b) are illustrations of a conventional technique that solves the problems in Figure 4. FIG. 3 is an explanatory diagram of a stage dead weight compensation method. In the figure, 1 is a wafer stage, 3 is an X stage, 5 is a Y stage, 7 is a wafer, 9 is a mask table, 11 is an SOR light, 13 is an air cylinder, 14 is a moving part (piston yoke), 15. 17 is steady thrust, 16 is regulator, 18
19 is a first regulator; 20 is a first 3-boat solenoid valve; 21 is a second 3-boat solenoid valve; 22 is a shuttle valve; 23 is a detection means; 24 is a control means; 25. 26 is the flow path, 2 is the X-axis guide, 4 is the Y-axis guide, 6 is the coarse movement stage, 8 is the fine movement stage, 10 is the mask, 12 is the load, Stage self-respect god redemption method yu dog /)! Ming map diagram (de- same I! l (ko) accommodation stage deer ζ 澤且moving stage, η
Is it like you left? Figure 1 (F) 2) The board stage of the present invention (2nd Stage White 1) Movement of the Divine Atonement Method

Claims (1)

[Claims] Y stage (5) of the XY stage in the vertical stage
When the Y-axis direction of matches the vertical direction, the X stage (
Attach the air cylinder (13) to the air cylinder (13) so that its sliding direction coincides with the Y-axis direction, and
) is coupled to the Y stage (5) and compressed air is injected so that the weights of the Y stage (5) and the fine movement stage (8), which is its mounting member, are opposite and equal to each other. A stage self-weight compensation method in a vertical stage that generates a steady thrust of a magnitude, wherein when the fine movement stage (8) is coupled to the Y stage (5), the first regulator (18) sets the The pressure (PH) that offsets the weight of the Y stage (5) and the fine movement stage (8) caused by the fine movement stage (8) and the Y stage (8)
Thrust (FH) is generated in the air cylinder (13) through flow channels 25 and 26 provided in the stage (5) and the shuttle valve (22), and the fine movement stage (8) is separated from the Y stage (5). In this state, the pressure (PL) set by the second regulator (19) that offsets the weight of the Y stage (5) generates a thrust force (FL) in the air cylinder (13) through the shuttle valve (22). A stage weight compensation method for a vertical stage, characterized in that the stage weight is compensated for in a vertical stage.