JPH06291022A - Positioning device - Google Patents

Abstract

PURPOSE:To prevent a change in the temperature of a movable stand and of a wafer held by it. CONSTITUTION:An aligner E1 is provided with a positioning device S1 which positions a wafer W1 with reference to a projection lens system 3. The positioning device S1 is composed of a Y-stage 4 which is moved on a base stand 2 in the Y-axis direction, of an X-stage 5 which is moved on it in the X-axis direction, of a ceiling plate 6 integrated with it and of a wafer chuck 6a installed on the ceiling plate 6. The ceiling plate 6 is provided with a mirror 8 which reflects a laser beam toward a laser interferometer 7a. A plurality of nozzle units 10b, 10c are installed integrally at prescribed intervals on the surface of the ceiling plate 6, and the nozzle units 10b, 10c blow the air for temperature regulation on the ceiling plate 6, the wafer chuck 6a and the wafer W1 held by it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device such as a semiconductor exposure device, a precision machine tool and a precision measuring instrument.

[0002]

2. Description of the Related Art A semiconductor exposure apparatus, a precision machine tool, a precision measuring instrument, and the like require a positioning device for positioning a substrate such as a wafer to be exposed, a workpiece, or a workpiece with high accuracy. FIG. 5 shows a conventional example of a positioning device used in an exposure apparatus. The exposure apparatus E0 includes a support frame 1 supported on a floor surface F0 via a vibration absorbing device 101a.
01, a base plate 102 fixed to the bottom plate 101b of the support frame 101, and a positioning device S0 supported on the base plate 102.
And the projection lens system 103 held by the top plate 101c of the support frame 101, and the positioning device S0 is located in a plane perpendicular to the optical axis of the projection lens system 103 (hereinafter referred to as the "Z axis"). One of the two axes orthogonal to (hereinafter, "Y-axis"
Say. ) A Y stage 104 that can freely reciprocate along
On the Y stage 104, an X stage 105 that is reciprocally movable along the other of the two axes (hereinafter, referred to as “X axis”), and a wafer chuck 106 supported by the X stage 105, The wafer chuck 106 can be finely moved in the Z axis direction with respect to the X stage 105, and can be finely rotated about the X axis, the Y axis, and the Z axis. The wafer chuck 106 sucks the wafer W0 on its surface by the vacuum suction force.

Further, on a pair of side edges of the X stage 105 which are adjacent to each other, first and second laser beams are respectively reflected toward the first and second laser interferometers 107a and 107b for length measurement. Mirrors 108a and 108b of the laser interferometers 107a and 107b are provided.
The position of the stage 105 in the X-axis and Y-axis directions is measured.
The respective driving devices of the Y stage 104 and the X stage 105 are driven based on the measurement values of the laser interferometers 107a and 107b, and position the wafer W0 with respect to the projection lens system 103. Positioned wafer W0
Is exposed by exposure light emitted from a light source (not shown) through a mask (not shown) and the projection lens system 103.

The wafer W 0, the wafer chuck 106, and the X stage 105 are heated by the irradiation energy of illumination light such as exposure light, and their dimensions may change due to thermal expansion. The change in the dimension of the wafer W0 is a direct cause of the transfer deviation in the fine pattern to be printed, and also the X stage 105 and the wafer chuck 10
The dimensional change of 6 depends on the wafer W0 and the respective mirrors 108a, 10a.
By changing the relative position of 8b, laser interferometer 107a,
The measurement error of 107b is caused, and the positioning accuracy of the wafer W0 is lowered. In order to prevent this, air whose temperature is adjusted is blown from the ducts 109a and 109b provided on the side of the positioning device S0, and as shown in FIG.
209b to the upper surface of the positioning device S0 and the wafer W0
It has been devised such as blowing air on. Further, in order to prevent the temperature rise due to heat generation of the motors of the above-mentioned drive devices, the motors are covered with a cover or the like to prevent heat from being transferred to the positioning device E0 and the wafer W0.

[0005]

However, according to the above-mentioned conventional techniques, in any case, since air is blown to the whole of the positioning device from the side or above of the positioning device to prevent the temperature change, a large amount of temperature is required. Is required, and it is difficult to remove the local uneven temperature generated on the surface of the wafer or the wafer chuck and the surface of the X stage. Further, since the air blown from the duct to the X stage becomes hotter on the downstream side, a temperature gradient is generated in the moving region of the X stage, and the temperature of the wafer or the X stage changes every time the X stage moves. There is a fear.

The present invention has been made in view of the problems of the above-mentioned conventional techniques, in which temperature nonuniformity occurs on a movable table such as an X stage or a wafer held on the table,
An object of the present invention is to provide a positioning device capable of preventing the temperature of the movable table, the wafer, etc. from changing with the movement of the movable table.

[0007]

In order to achieve the above object, a positioning device of the present invention comprises a movable base having a mirror, a driving means for moving the movable base, and a length measuring means for receiving the reflected light of the mirror. And a gas jetting means for jetting the temperature-adjusted gas toward the movable table, and the gas jetting means is provided integrally with the movable table.

[0008]

Since the gas jetting means is provided integrally with the movable table, the gas discharge port can be provided close to the movable table. Therefore, without consuming a large amount of gas, the temperature of the movable table and the object held by the movable table can be adjusted entirely or locally, and these temperatures can be kept uniform. Further, even if the movable table moves, there is no possibility that the temperature of the movable table or an object held by the movable table changes.

[0009]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an elevational view showing an embodiment,
The exposure apparatus E1 of the present embodiment is supported by the support frame 1 supported on the floor surface F1 via the vibration absorber 1a, the base 2 fixed to the bottom plate 1b of the support frame 1, and the base 2. The positioning device S1 and the projection lens system 3 held by the top plate 1c of the supporting frame 1 are orthogonal to each other in a plane perpendicular to the optical axis (Z axis) of the projection lens system 3. A Y stage 4 that can reciprocate along one of the two axes (Y axis)
A driving device (not shown) for driving the same, an X stage 5 reciprocally movable on the Y stage 4 along the other of the two axes (X axis), and a driving device (not shown) for driving the X stage 5. , X stage 5 is Z
A top plate 6 that is a movable table that is slightly movable in the axial direction and is also capable of slightly rotating around each of the X axis, the Y axis, and the Z axis.
The top plate 6 has a wafer chuck 6a which is a holding means for holding the wafer W1 by a vacuum suction force.

Laser interferometers 7a and 7b (a laser interferometer 7b is not shown) which are a pair of length measuring means hung from a top plate 1c of the support frame 1 on a pair of side edges of the top plate 6 which are adjacent to each other. ) Mirrors 8a that respectively reflect the laser light toward
8b is provided, and each laser interferometer 7a, 7b measures the position of the top plate 6 in each of the X-axis and Y-axis directions by the reflected light from the mirrors 8a, 8b. The above-mentioned two driving devices, which are driving means, are respectively laser interferometers 7a and 7b.
The wafer W1 is positioned with respect to the projection lens system 3 by being driven based on the measured value of

Outside the pair of side edges of the positioning device S1 which are orthogonal to each other, ducts 9a and 9b (duct 9b is not shown) serving as second gas ejection means are provided, respectively, and these are used for temperature control. The air thus blown is blown from the outside of the positioning device S1 onto the entire positioning device S1 so that the temperature of the positioning device S1 rises due to the irradiation energy of the illumination light applied to the wafer W1 and the heat generated by the motor of the driving device. prevent. The top plate 6 of the X stage 5 has four nozzle units 10a to 10d that are integrally provided on the upper surface thereof and are gas ejecting means.
As shown in FIG. 2, d are arranged at equal intervals around the wafer chuck 6a. Each nozzle unit 10a-10
d is composed of a T-shaped support member 11 and three nozzles 12a to 12c supported by the support member 11, and the first nozzle 12a among them is from the outer peripheral portion of the top plate 6 to the center thereof as shown in FIG. Of the second and third nozzles 12b,
The outlet 12c has outlets 13b and 13c for ejecting air toward the surface of the top plate 6 (the outlet 13c is not shown). From each air supply pipe (not shown), each nozzle unit 10a-1
A part of the air supplied to 0d is blown toward the wafer chuck 6a and the wafer W1 held by the first nozzle 12a in the horizontal direction in the drawing,
Part of it flows along the surface of the wafer W1. The rest of the air is the second and third nozzles 12b, 12
After being blown onto the top surface of the top plate 6 by c, it is bent in the horizontal direction in the drawing so that a part thereof flows toward the edge of the wafer chuck 6a and the rest flows toward the edge of the top plate 6.
Part of the air flowing toward the edge of the top plate 6 is a mirror 8.
It is sprayed on a and 8b.

By the air thus flowing, the wafer chuck 6a, the wafer W1 attracted to the wafer chuck 6a, X
Since the top plate 6 of the stage 5 and the respective mirrors 8a and 8b are efficiently cooled, the energy of illumination light such as exposure light is transferred to the wafer W1, the wafer chuck 6a, the top plate 6 or the mirror 8 and the like.
Even if absorbed by a and 8b, heat is immediately radiated and there is no risk of dimensional change due to thermal expansion.

Before the wafer chuck 6a attracts the wafer W1, the surface of the wafer chuck 6a is uniformly and sufficiently cooled by the air blown from the first nozzle 12a. There is no possibility that the wafer W1 will be distorted due to the temperature difference between the two when it is adsorbed by 6a.

Furthermore, each nozzle unit 10a-10d
It is also possible to locally adjust the temperature of the top plate 6 and the surface of the wafer W1 by individually changing the flow rate and temperature of the air supplied to.

FIG. 4 shows a modification of this embodiment. This modification is the same as the above-mentioned nozzle units 10a to 10d.
In addition to the nozzle unit 20 similar to the above, a nozzle unit 24 similar to this is added to the lower surface of the top plate 26. A total of four nozzle units 24 are provided adjacent to each corner of the top plate 26, and air is blown to the side surfaces of the X stage 25 and the bottom surface of the top plate 26 to cool them.
Since the other points are the same as those shown in FIG. 3, they are represented by the same reference numerals, and the description thereof will be omitted.

[0017]

Since the present invention is configured as described above, it has the following effects.

It is possible to prevent the temperature of the movable table and the wafer held on the movable table from becoming non-uniform and to prevent the temperature of the movable table and the wafer from changing each time the movable table moves.
As a result, when the wafer or the like of the exposure apparatus is positioned, the displacement of the mirror occurs due to the thermal strain of the movable table, an error occurs in the measurement value of the laser interferometer, and the transfer displacement occurs due to the thermal strain of the wafer itself. Can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic elevational view showing an embodiment.

FIG. 2 is a plan view of the top plate of the X stage of the apparatus of FIG. 1 seen from the line AA.

FIG. 3 is a partially enlarged elevation view taken along the line BB of FIG.

FIG. 4 is a partially enlarged elevational view similar to FIG. 3 showing a modified example.

5A and 5B show a conventional example, in which FIG. 5A is a schematic elevation view thereof, and FIG. 5B is a schematic plan view seen from the line CC of FIG.

FIG. 6 is a schematic elevational view showing another conventional example.

[Explanation of symbols]

 W1 Wafer S1 Positioning device 1 Support frame 2 Platform 3 Projection lens system 4 Y stage 5,25 X stage 6,26 Top plate 6a Wafer chuck 7a, 7b Laser interferometer 8a, 8b Mirror 9a Duct 10a-10d, 20, 24 Nozzle unit 11 Support member 12a, 12b, 12c Nozzle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G03F 9/00 H 7316-2H H01L 21/68 G 8418-4M

Claims (5)

[Claims] 1. A movable base having a mirror, a drive means for moving the movable base, a length measuring means for receiving the reflected light of the mirror, and a gas ejection means for ejecting a temperature-adjusted gas toward the movable base. And a gas jetting means provided integrally with the movable table. 2. The positioning device according to claim 1, wherein the gas jetting means has at least one nozzle for jetting gas toward the surface of the movable table. 3. The positioning device according to claim 1, wherein the gas jetting means has at least one nozzle for jetting gas toward the back surface of the movable table. 4. The gas ejecting means has a plurality of nozzles, at least one of which ejects gas toward the surface of the movable table, and at least one of the remaining nozzles is provided on the movable table. The positioning device according to claim 1 or 2, wherein the positioning device is configured to eject gas toward the holding means and the object held by the holding means. 5. The positioning device according to claim 1, further comprising a second gas ejection unit provided at a position apart from the movable table.