JPS6244601A - Mobile mounting table device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Cliff 1 Upper Example ■ Rikunidan The present invention provides a device for reliably holding an original plate or a prototype, such as a master holding device for a semiconductor wafer exposure device or a hologram standard holding device for a holographic interferometer. , and relates to a movable mounting table device for precisely moving these into a microscopic space position.

Prior Art As a conventional movable mounting table device, for example, if we consider a four-axis movable mounting table, a movable stage that moves in the Y-axis direction is mounted on a base that moves in the Z-axis direction, and an X-axis Attach a stage that moves in the direction, and then
A rotation stage in the θ direction was mounted on the axis stage, the object to be placed was placed on this rotation stage, and a feed screw mechanism was built in to feed the object to each of the above stages. .

1 As described above, the conventional movable mounting table requires as many moving stages and feed screw mechanisms as the number of axes on which the object to be mounted is to be moved. In addition, a dovetail structure was used as a guide rail to improve the running accuracy of each stage.

Note that as an interferometer, for example, a Fizeau type interference needle shown in FIG. 22 is known. i.e. light source (laser)
The light from the LS is made into a parallel beam by a collimator lens C. After that, the imaging lens L.

A part of the light beam reflected by the beam splitter BS, which is a half mirror tilted between the diverging lens Lt and the diverging lens L2, is reflected by the reference sphere R after being diverged by the diverging lens L2. It passes through the same optical path as in (11), passes through the beam splitter BS and the hologram prototype H1 imaging lens L, becomes a 0th-order reference light, and passes through the aperture of the spatial filter SF.

On the other hand, the light that passes through the reference spherical surface R and is reflected by the optical element to be tested (aspherical concave mirror) T, that is, the object light, travels backwards and passes through the beam splinter BS. The 0th-order light that passes through the beam splitter BS and is not diffracted by the hologram prototype is canted by the spatial filter SF, while the -order diffracted light, for example, which is diffracted by the hologram prototype, passes through the aperture of the spatial filter SF and is then canted by the spatial filter SF. Interference fringes are formed on an interference screen or film with the zero-order reference light.

As mentioned above, the conventional movable mounting table requires stages for the number of moving axes, resulting in a complex structure, large size, high cost, and the accumulation of assembly errors. This has the disadvantage that it is difficult to obtain a highly accurate movable mounting table.

Further, when the above-mentioned dovetail groove structure is used to guide the moving stage in the running direction, there are drawbacks such as difficult machining and high parts and manufacturing costs.

The present invention has been made in view of the drawbacks of the conventional movable mounting table, and its purpose is to provide a new and useful movable iI3 that is simple in structure, can be manufactured at low cost, and has high precision! The purpose is to provide a stand.

The structural features of the movable mounting table device of the present invention for achieving the above object include: a movable stage on which an object is placed; a base stage that movably supports the base stage; at least one X-axis feed screw attached to the base stage for applying a moving force to the movable stage from one direction along the Y-axis;
an elastic means for applying a moving force to the moving stage from opposite directions along the axis; and at least two Y-axes for applying a moving force to the moving stage from one direction along at least two Y-axes. The present invention includes a feed screw and at least two resilient means for applying a moving force to the moving stage from opposite directions along each of the two Y axes.

According to the present invention, the movement stage supported on one base stage is capable of rotational movement in the Y-axis, Y-axis, and θ directions, and the number of parts for this is extremely small, and the entire device can be moved. It can be miniaturized and costs can be reduced.

On the other hand, since the direction in which the moving force of the feed screw acts on the moving stage and the direction in which the moving force acts on the moving stage of the elastic means are directly opposite, the backlash of the feed screw is canceled and the stage is moved with high precision, that is, the direction of the moving force acting on the moving stage is directly opposite. It can guarantee high movement accuracy of the placed items.

In addition, according to one of the more limited embodiments, although the movable stage is always attached to the base stage by a spring means via a steel ball, which is an extremely simple structure, Eliminates blurring in the Z-axis direction.

Embodiments of the present invention will be described in detail below using a hologram prototype holder for a holographic interferometer as an example, but the present invention is not limited thereto.

Embodiments of the holographic interferometer according to the present invention will be described in detail below.

FIG. 1 shows an overall diagram of the optical configuration of a holographic interferometer according to the present invention. Light from a laser 101 as a light source has its optical path changed by mirrors 102a and 102b, and then is condensed by a condenser lens 103. A pinhole reticle plate 104 having a pinhole 104a is arranged near this focal point. The diverging light passing through the pinhole 104a acts as if the pinhole 104a were a secondary light source. Note that a quarter wavelength plate 105 is disposed between the mirrors 102a and 102b.

A collimator lens 106 has a focal point at the pinhole 10.
4a.

The pinhole 104 uses the pinhole 104a as a secondary light source.
The light beam emitted from a is made into a parallel light beam by the collimator lens 106. A reference plane plate 107 is arranged behind the collimator lens 106. This reference plane plate 107 is arranged so that the front plane 107a is perpendicular to the apparatus optical axis (collimator optical axis) OI. Further, the rear plane 107b is inclined at a small angle with respect to the front plane 107a, so that interference light between the light reflected from the front plane 107a and the light reflected from the rear plane 107b does not affect the measurement. It has become.

When the test object T is a concave object such as an aspherical concave mirror, a reference lens 109 is provided behind the reference plane plate 107.
is attached and arranged on the device lens barrel 108. The parallel light beam transmitted through the reference plane plate 107 becomes a convergent light beam, and after converging once at a point P, it becomes a divergent light beam again and enters the object to be inspected, for example, an aspherical concave mirror T.

The object light reflected from the test object T and the reference light reflected from the front plane 107a of the reference plane plate 107 are arranged between the pinhole reticle plate 104 and the collimator lens 106 with the half mirror surface 110a as the optical axis. The beam enters a prism type beam splitter 110 which is tilted with respect to 01. Both the object beam and the reference beam are reflected by the half mirror surface 110a' and enter a hologram prototype 300 supported by a hologram prototype holder 200, which will be described later.

Laser 1.01. Mirrors 102a, 102b.

18 wavelength plate 105. Pinhole reticle 104° zoom splitter 110. Collimator lens 106° reference plane plate 107. Reference lens 109. The test object T and the hologram prototype holder 200 are installed on one common optical bench 100.

The light transmitted through the hologram prototype 300 passes through the imaging lens 11
1. Spatial filter 113 via half mirror 112
is imaged. This spatial filter 113 is for selectively extracting only one of the reference light and the object light that was diffracted by the hologram prototype 300 and the other light that was not diffracted by the hologram prototype 300. . To be more specific, as in the conventional Fizeau interferometer shown in FIG. Only the reference light and the primary object light diffracted by the hologram prototype 300 are extracted from the reference light and the object light from the test object T, and the diffracted light of the reference light and the object light are removed.
The second and higher order diffraction lights act to be cut.

The object light and reference light selected by the spatial filter 113 are
Zoom lens 114. An interference pattern between the reference light and the object light is formed on the imaging surface 117a of the TV camera 117 via the half mirror 115 and the imaging lens 116. The image captured by the TV camera 117 is captured by an interference pattern analysis device 119 consisting of a monitor television 118 and a personal computer.
sent to. Note that the reference light and object light transmitted through the half mirror 115 are transferred to the film 12 of the instant development type camera 120.
When the interference pattern is formed on the image plane 117a on the image plane 117a, a similar interference pattern is formed and recorded on the film 120a.

A part of the light passing through the imaging lens 111 is half 1
, U-1□28i3iML, Ya, □, Yo-U. The image is formed on a reticle plate 121 arranged at the same time.

The image on the reticle plate 121 is
The image is captured by the camera 123 and displayed on the monitor +118 via the switching circuit 124. These reticle plates 121. Photographing lens 122. TV camera 123. The monitor 118 forms an alignment optical system 125 for aligning the object T in the measurement optical path.

Imaging lenses 111, 116. Half mirror-112°11
5. Spatial filter 113. Zoom lens 114, photographic lens 122. TV camera 117°123 and camera 1
20 is placed i3I on the optical bench 130. This optical bench 130 has an arm that rotates by driving a known micro-feeding mechanism 131 around a point LC that is conjugate with the exit pupil EP of a composite optical system of a collimator lens 107 and a reference lens 109 in order to adjust the off-axis angle described later. It is fixedly installed at 131. Note that if the object to be inspected is a flat object, the reference lens 109 is not necessary, and in this case, the center of rotation LC is set at a position conjugate with the center of the exit pupil of the collimator lens 107.

As described above, since the present holographic interferometer is of the Fizeau type, the number of optical elements can be significantly reduced compared to the Twyman-Green type and Matsuhatsu-Ender type.

Also, unlike conventional Fizeau-type interferometers, this interferometer uses a beam splitter as a collimator lens and pinhole 1.
Since it is placed in the diverging beam between 04a and 04a, the area of the half mirror surface can be reduced to about 1/4 compared to a conventional beam splitter in which a beam splitter is provided in the parallel beam by the collimator lens.

Furthermore, by narrowing the half mirror surface, the beam splitter can be constructed in a prism type, and as will be described later, it is possible to reduce the calculation information and drawing information for drawing a hologram pattern. Furthermore, since the beam splitter has become smaller, its manufacturing accuracy can be significantly improved, and its manufacturing cost can also be reduced.

Furthermore, since the hologram prototype is also placed within the convergence and reflection beam of the beam splitter, it is possible to downsize, reduce costs, and achieve high-precision drawing. This has made it possible to create a holographic interferometer that can measure with high precision even large-diameter test objects and non-shape test objects with a large degree of asphericity.

Figure 2 is a plan view showing the configuration of the hologram prototype. The hologram prototype 300 has a hologram pattern section 301 made of a computer-generated hologram in the center. Conventional interferometers use mirror-type beam splitters to separate and combine the reference beam and object beam.゛In the case of this mirror type beam splitter, if the mirror surface and mirror back surface (half mirror surface) are formed in parallel, the light reflected from each surface will interfere with each other and adversely affect the measurement. In the beam splinter, the mirror surface and back surface were not parallel, but tilted at a slight angle. As a result, the symmetry with respect to the optical axis is shifted, so even with an on-axis hologram prototype, the hologram pattern had to be calculated for all quadrants to obtain drawing data. In a holographic interferometer,
Since the beam splitter 110 is a prismatic beam splitter as described above, symmetry with respect to the optical axis is preserved, and the hologram pattern of the on-axis hologram prototype is a concentric pattern and point-symmetric.

Therefore, the pattern calculation and drawing data calculation are
As shown in Fig. 4, this is done only for the first quadrant of (x, y), and the other (-X,
Regarding the second, third, and fourth quadrants of -y), the data in the first quadrant may be simply subjected to coordinate transformation, and the calculation cost and calculation time can be shortened, and the amount of drawing data can be reduced. On the other hand, if the same amount of expense and time as in the past is spent on calculating hologram patterns and creating drawing data, those data can have higher precision.

A cross-shaped distortion test pattern 302 is formed around the hologram pattern section 301, which is drawn at the same time as the hologram pattern is drawn by electron beam scanning. This strain test Pa) 7. Yoai, nari, wa, ioi*z-ska, oh.

The amount of distortion in the hologram pattern can be inspected from the amount of mutual positional deviation.

Further, a black-white ratio test pattern 303 is formed at two locations outside the distortion test pattern. This black-and-white ratio test pattern includes, for example, a black part 304 and a white part 305 as shown in FIG.
A checkerboard pattern is used in which the same area is alternately arranged in a plane.

This black-and-white ratio test pattern 303 is drawn at the same time as the hologram pattern 301 is drawn with an electron beam, so if the black-and-white ratio of this black-and-white ratio test pattern 303 is measured with a densitometer, the black-and-white ratio of the hologram pattern itself can be indirectly determined. can be known in detail.

At the four corners of the hologram prototype 300, cross-hair-shaped alignment marks 306 are formed for positioning when the hologram prototype 300 is attached to the hologram prototype holder 200. An L-shaped upper/lower discrimination mark 307 is formed below the two alignment marks on the lower side of the figure.

C. Hologram prototype holder FIGS. 5 to 7 are diagrams showing the hologram prototype holder 200. Bearing 20 placed on optical bench 100
1, 202, a shaft 203 is supported so as to be slidable in parallel to the optical axis 02 (see FIG. 1). The shaft 203 is connected to the Z-axis direction (optical axis 0
2 directions) A moving stage 205 is fixed. Bearing 2
A cylinder 206 is attached to 01, and a spring 207 is inserted into the cylinder 206. On the other hand, a Z-axis feed screw 208 is screwed into the bearing 202 . This Z transport screw 208
cooperates with the spring 207 via the steel ball 209 to clamp the Z-axis direction moving stage 205, and by its feeding, the stage 2
05 back and forth along the Z-axis direction.

An X-Y direction movement stage 211 is placed on the stage surface 205a of the Z-axis direction movement stage 205 via a steel ball 210. As shown in FIG. 6, a screw 212 is installed on the back surface of this stage 211, and a spring is inserted between it and a rod 214 passed to the rear of an opening 213 formed in the Z-axis direction moving stage 205. It is multiplied by 215.

Due to the tensile force of this spring 215, the X-Y direction moving stage 211 moves to the stage surface 20 of the Z-axis direction moving stage 205.
It is attracted in the direction 5a, and the moving surface is stabilized.

Further, as shown in FIG. 5, two Y-axis feed screws 216 and 217 and one X-transport screw 218 are attached to the Z-axis direction movement stage 205. The side surface of the X-Y direction moving stage 211 has guides 220 via hair rings 219, and these guides 220 are connected to steel balls 22.
1 by feed screws 216, 217, and 218.

The X-Y direction moving stage 211 further has a notch 222 on the side opposite to the mounting position of the X-axis feed screw 218. Side surface of notch 222 and Z-axis direction movement stage 205
A resilient body 223 is inserted between the upright piece 224 and the upright piece 224 .

As shown in FIG.
, a piston 226 inserted into the cylinder, and a spring 227 fitted into the cylinder 225 to constantly apply a pressing force to the piston 226.Similarly, the stage 211 has a notch 228, 229 are formed to face the Y transport line screws 216 and 217, and elastic bodies 232 and 233 are interposed between the upright pieces 230 and 231 of the stage 205 and the sides of these notches.

The configuration of the elastic bodies 232 and 233 is similar to that of the elastic body 223 described above.

In the configuration of the hologram prototype holder described above, by feeding the feed screws 216 and 217 in the same direction and by the same amount, the stage 211 obtains a movement amount Y as shown in FIG. 10B. Also, by feeding the feed screw 218, the stage 2
'l l obtains the amount of movement X as shown in FIG. 10A.

Furthermore, fix the feed screws 216 and 218, and
By sending only the rotation angle 17, the stage 211 is rotated by the rotation angle θ, as shown in FIG. 10C.

The X-Y direction moving stage 211 has a substantially rectangular opening 235 at its center, and an opening 235 at the upper left corner and the lower right corner.
Circular openings 236, 237 are formed. These circular openings 236 and 237 correspond to an opening 238 formed in the Z-axis direction movement stage 205.

A microscope objective lens 240 is provided in the opening 238 for observing the alignment mark 304 on the Borochram prototype 300.
is inserted.

Further, a circular groove 241 is formed around the opening 235 of the stage 211, and a nozzle 242 of a vacuum pump (not shown) is connected to this groove via a pipe 243. Furthermore, a guide piece 244 is provided on the outer surface of the stage 211.
is fixed.

Thereby, the hologram prototype 300 is placed on the stage 211 along the guide piece, and is brought into close contact with the stage 211 at atmospheric pressure by absorbing the air in the groove 241 with a vacuum pump.

Arms 246° 247 are attached to the tip of the shaft 203 and the tip of the pole 245 installed on the stage 205, and a light emitting diode 248 and a heat ray absorption filter 249 are housed at the tips of the arms 246° 247, respectively. It is used to illuminate the alignment mark 304 of the hologram prototype placed on the stage 211.

FIG. 8 shows the hologram prototype holder 2 having the above-mentioned configuration.
00 is a perspective view schematically showing a hologram prototype alignment optical system 250 attached to the hologram prototype alignment optical system 250. The alignment optical system 250 includes the above-mentioned light emitting diode 248. Heat ray absorption filter 249° Objective lens 240. mirror 25
1 and a beam splitter 252.
and a light emitting diode 248. Heat ray absorption filter 249
．． Objective lens 240. It is composed of a second optical path 255 consisting of a mirror 254 and a beam splitter 252, and an eyepiece optical path 256 which is composed of the first optical path 253 and the second optical path 255 by the beam splitter 252.

This eyepiece optical path 256 has a reticle plate 257.258 and an eyepiece lens 259 that move in a plane perpendicular to the optical axis 03 (xy plane) by a known moving means (not shown). is a circular index 2 as shown in Figure 9.
60,2f31 are formed.

As described above, according to the present hologram prototype holder, it is possible to move these X, Y, and θ-related stages without using a triple stage structure of an X-direction moving stage, a Y-direction moving stage, and a θ rotation stage as in the past. can be performed in one stage. Further, the configuration thereof is extremely simple, and has the advantage of allowing highly accurate movement control and positioning.

D. Off-axis measurement Measurement methods using device interferometers generally include on-axis measurement methods and off-axis measurement methods.

The on-axis type refers to a measurement type in which the object light from the test object and the reference light from the reference plane are coaxial, and because the spatial frequency of the hologram prototype used for measurement can be lowered, it can also be used for test objects with a large degree of asphericity. It has measurable benefits. But on the other hand,
The diffracted light from the 0th order to the higher order by the hologram prototype is all superimposed on the optical axis, although their focal lengths are different.
For example, even if a spatial filter is placed at the focal point to extract the -order diffracted light, the 0th and 2nd order
A portion of the higher order diffracted light is also passed through this spatial filter. Therefore, there is a drawback that the central part including the optical axis becomes an unmeasurable part.

On the other hand, with the off-axis type, unlike the on-axis type mentioned above, unmeasurable parts do not occur, but because the spatial frequency of the hologram prototype is higher than that with the on-axis type, it is difficult to manufacture and align the hologram prototype. Due to limitations, for example, only aspherical objects with small degrees of asphericity can be measured.

Furthermore, since the off-axis angle varies depending on the type of object and the amount of asphericity, when creating a hologram prototype, the optimal off-axis angle is determined in advance. Therefore, the holographic interferometer of this embodiment is configured as an interferometer that is capable of both on-axis and off-axis measurements and has a variable off-axis angle.

FIG. 11 is an optical layout diagram schematically showing on-axis measurement and off-axis measurement. In the case of on-axis measurements, the reference plane plate 107 is arranged perpendicular to the optical axis 01 of the collimator lens 106.

An observation optical system, ie, a spatial filter 113, for observing the interference pattern between the object light and the reference light. zoom lens 11
4. The imaging lens 116 and the first image tube 117 have an optical axis O3.
They are arranged on the optical axis 0□, which intersects perpendicularly to .

A spatial filter 113 is arranged at the focal position of the first-order diffracted light of the diffracted light by the hologram prototype 300 of each of the object light and reference light, and interference fringes between the first-order diffracted light of the object light and reference light are formed. This will be imaged with a picture tube or photographed.

On the other hand, in the case of off-axis measurement, the reference plane 107 is rotated by an angle α (this angle α is referred to as an off-axis angle) as shown by a broken line. The observation optical system is rotated by an angle β together with the optical bench 130 about the rotation center LC. Here, the turning angle β is defined as (where r is the focal length of the collimator lens).

As a result, only the first-order diffracted light of the object light by the hologram prototype 300 and the O-th-order diffracted light of the reference light are passed through the spatial filter 11.
3' (referring to the spatial filter 113 during off-axis), and is configured so that both interference fringes can be observed and photographed.

The off-axis angle α is the half mirror surface 110a of the beam splitter 110 in the reflected light (reference light) from the reference plane.
can be determined from the imaging position of the image S formed on the pinhole reticle 104. That is, the imaging position and optical axis 0. The amount of deviation from the small off-axis angle α is proportional to the small off-axis angle α.

FIG. 12 is a plan view showing the structure of the pinhole reticle 104. A pinhole 104 is provided at one end of the reticle 104.
a is formed, and a scale 401 is formed along the longitudinal direction from there to the other end side. The scale 401 is graduated according to the amount of deviation of the spot S corresponding to the off-axis angle α from the optical axis 01 (center 2 of the pinhole 104a).
02 is printed.

FIG. 13 is a diagram showing the optical arrangement of the off-axis angle 1[J microscope 410 used when setting the off-axis angle α. The microscope 410 has an objective lens 411 that converts the light from the scale 401 and off-axis angle scale numbers 402 on the reticle 104 into parallel light, and converts the light from the scale 401 on the reticle 104 into parallel light.
After being reflected by the lens 2, an image is formed on the aperture 414 by the imaging lens. A scale image and an off-axis scale numeral image are observed through the eyepiece 415.

FIG. 14 shows the optical arrangement of the on-axis adjustment microscope 420. The above-mentioned off-axis angle adjustment lens 9J boundary 4
The difference in configuration from No. 10 is that the mirror 412 is a half mirror.
421, and there is no objective lens 411, and the condensing lens 103 of the interferometer cooperates with the imaging lens 413 to form an image.

If the running direction of the scale 401 of the pinhole reticle 104 is made parallel to the rotating direction of the reference plane plate 107, and the spot S is projected with a vertical deviation from the scale 401, the surface of the reference plane plate 107 may be tilted or , optical axis 0
Since it can be determined that one rotation has occurred, these chaesok can also be done.

(On-axis arrangement of measurement optical system) a-1= The on-axis adjustment microscope 420 is set on the optical axis 01 of the collimator lens 106, as shown by the two-dot chain line in FIG.

a-2: Whether or not the reflected spot image S by the reference plane plate 107 of the light beam transmitted through the half mirror 421 of the microscope 420 and condensed onto the pinhole 104a by the condensing lens 103 is focused on the pinhole 104a again. is observed through the eyepiece 415.

The spot light is observed through the eyepiece lens 415 only when the spot S coincides with the pinhole 104a. The reference flat plate 107 is adjusted so that the sub-S can be observed through the eyepiece 415. When the spot S is observed, the reference plane plate 107 is perpendicular to the optical axis OI, and the interferometer is in an on-axis arrangement.

(Setting the adjustment lens) a-3 = Switch the changeover switch 124 so that the image from the TV camera 123 of the alignment optical system 125 is displayed on the monitor television 118.

On the monitor television 118, a spot image conjugate to the pinhole 104a from the reference plane plate 107 is shown on the reticle plate 12.
The situation matching the intersection of the crosshairs 1 is displayed.

a-4= Reference lens 10 in the device lens barrel 108 of the interferometer
A reference lens holder 109a having a reference lens holder 9 is attached using a known holding means (not shown).

a-5: Holder 50 with adjustment mirror 501
so that the reference surface 502 of the reference lens holder 109a contacts the reference surface 109b (see FIG. 15A) of the reference lens holder 109a.
The holder 500 is attached to the reference lens holder 109a with screws 503.

a-6: Place the autocollimator 510 on the optical bench 100, and adjust the autocollimator 510 so that the crosshair target 511 matches the circle indication 512a of the reticle 512, as shown in FIG. 15B. Directly face the mirror 501. Thereafter, this autocollimator 510 is fixed on the optical bench 100 so that it does not move.

a-7: Remove the adjustment mirror 501 along with the holder 500 from the reference lens holder 1093.

a-8 = known 5-axis holder (not shown) (X% y,
An adjustment lens 520 held along five axes of 2, φ4, and φ; φ4 and φ8 indicate horizontal and vertical inclination directions) is placed between the reference lens 109 and the autocollimator 510. At this time, the adjustment lens 520
As shown in the figure, the spherical wave 520a of the adjustment lens 520
The center of curvature Q of the spherical surface 521 for generating , coincides with the focal point F of the reference lens 109, and
22 is the optical axis 0. of the autocollimator. is placed perpendicular to.

The adjustment lens 520 is configured so that the reference light from the reference plane plate 107 projected on the monitor television 118 and the object light (
Rough positioning is performed by making the interference fringes with a spherical wave one color, and then precise positioning is performed by matching the target image 511 and the reticle image 512a using the ocular observation image of the autocollimator. .

(Setting the adjustment hologram prototype) a-9; When the aspheric surface 523 for generating the aspheric wave 523a of the adjustment lens 520 is located at the above-mentioned setting completion position, the object from this aspheric surface 523 Light and reference plane plate 10
An adjustment hologram prototype consisting of an interference pattern generated by interference with the reference light from 7, or a computer-generated hologram created by calculating such an interference pattern with a computer and using the electron beam writing method based on the calculation results. The hologram prototype for adjustment is vacuum-adsorbed onto the stage 211 for moving in the X-Y direction of the hologram prototype holder 200 described above.

a40: Switch the changeover switch 124 to display the image from the TV camera 117 of the interference fringe observation optical system on the monitor TV 118.
so that it is displayed on the screen.

a-11: Feed screws 208, 216, 217 and 218
By adjusting, for example, the first-order diffracted light of the object light (aspherical wave) from the aspherical surface 523 of the adjustment lens 520 by the adjustment hologram prototype, and the O-th-order diffracted light of the reference light from the reference plane plate 107, for example. The interference fringes in the spatial filter 113 are made to be one color. As a result, the adjustment hologram prototype was adjusted in the X, Y, Z, and θ directions, and positioning was completed.

(Setting the hologram prototype for measurement) a-12: Adjust the reticle movement knob (not shown) and
The eyepiece lens 259 shown in FIG.
As shown in the observation field example, the circular indicators 260 and 261 of the reticle plates 257 and 258 are aligned.

a-13: Just to be sure, look through the autocollimator 510 and check whether the target image 511 and the reticle index 512a match, that is, whether the adjustment lens 520 is correctly positioned. Check again.

If the positioning is correct, it is determined that the settings from steps (a-9) to (a-12) have been performed correctly, and after this, the autocollimator 51
0 and adjustment lens 520 are unnecessary, so remove them.

a-14: Remove the adjustment hologram prototype from the stage 211, place the measurement hydrogram prototype 300 on the stage 211 instead, and vacuum adsorb it.

a-15: Hologram prototype holder eyepiece 25
9, look at the circular indicators 260, 2 of the reticle 257, 258 positioned in step (a-12).
61 and the alignment mark 306 of the measurement hologram prototype 300 placed in step (a-14), adjust the feed screws 216, 217° 218, and move the hologram prototype together with the stage 211. Position.

(Setting the test object) a-16: Place the test object T in a known 6-axis holder (x, y, z
1 Set 6 axes: φ1, φ8, and θ (θ is the rotation of the optical axis).

a-17: Switch the changeover switch 124 so that the image from the television camera 123 of the alignment optical system 125 is displayed on the monitor television 118. The object T is held so that the first-order diffracted spot light (usually brighter than the O-th order diffracted light) from the test surface matches the crosshair image of the reticle plate 121 on the screen of the monitor television 118 and becomes the smallest spot. Adjust the holder.

a-18: Next, the changeover switch 124 is switched to send the image of the television camera 117 of the interference fringe observation optical system to the monitor television 118. This allows monitor TV 1
The interference fringes are projected onto 18, and the holder is finely adjusted so that the direction and pitch of the interference fringes are suitable for measurement.

b) Set amplifier for off-axis measurement type In the case of off-axis measurement type, the work of adjusting the inclination of the reference flat plate 107 is simply added to the above-mentioned on-axis measurement. This tilting operation of the reference plane plate 107 is performed between step (a-15) and step (a-16) of the on-axis setup step described above, that is, after the setting of the measurement hologram prototype is completed. This work of tilting the reference flat plate is performed in the following steps.

b~lE The off-axis adjustment microscope 4-10 is
As shown by the two-dot chain line in the figure, it is placed in front of the scale 401 of the pinhole reticle 104 near a position corresponding to the scale number of the desired off-axis angle. Next, eyepiece 4
15, position the microscope so that the scale line of the desired off-axis angle, for example, 2.5°, is in the center of the field of view.

b-2= Tilt the reference plane plate 107 so that the resulting reflection groove 7) S coincides with the intersection of a desired scale line (for example, a 2.5° scale line). When the tilt adjustment of the reference plane plate 107 is completed, the microscope 410 is removed.

b-3: Switch the changeover switch 124 so that the image of the television camera 123 of the alignment optical system 125 is displayed on the monitor television 118. Then, the micro mechanism 130 is operated so that the reflected spot image from the reference plane plate 107 coincides with the intersection of the crosshairs of the reticle 121 displayed on the monitor television 118, and the optical bench 130 is rotated around the rotation center LD. Rotate it.

Inu Rattan Masu ■ Ju Plate (1) Instead of the reference plane plate 107, the reference lens 10
You may use the rearmost surface of 9. In this case, this reference lens can be tilted or decentered to perform off-axis measurements.

(2) Instead of the scale 401 of the pinhole reticle 104 for checking the off-axis angle, as shown in FIG. The off-axis angle may be detected and adjusted.

(3) There are many possible variations of the alignment mark 306 and alignment optical system 250 for setting the hologram prototype 300, some of which will be briefly described below.

(3-1) In the example shown in FIG. 17, the alignment mark 306
The image from the objective lens 240 is directly transmitted to the area sensor 60.
2, the position is stored as element address information, and adjustment is made so that the alignment mark of the measurement hologram prototype is located at the same element address.

(3-2) In the example shown in FIG. 18, the hologram prototype 300
Using the hollow circular mark 606 as an alignment mark, the reticle side 257 of the alignment optical system 250,
258, a black circle mark 607 having a negative-positive relationship with this circular mark 606 is arranged, and then a light receiving element 608
The structure is such that the

As a result, the circular mark 606 of the hologram prototype 300 and the black circle mark 607 of the reticles 257, 258 are aligned, and the adjustment hologram prototype is set so that the output from the light receiving element 608 is zero, and then the reticle 257.2 is set.
Move 58. The subsequent setting of the measurement hologram prototype is similarly adjusted so that the output from the light receiving element 608 becomes zero.

(3-3) In FIG. 19A, a fine first concentric circle mark 609 is provided in place of the alignment mark 306 of the hologram prototype 300, and a second concentric circle mark having the same shape as this first concentric circle mark 609 is provided. 610, for example, on the Z-axis moving stage 205 in front of the objective lens 240.
An objective lens 240 is located very close to the directional movement stage 211.
This shows a configuration in which the device is movable in a plane perpendicular to the optical axis of the device.

The reference plate 608 having this second concentric circle mark 610 is
Moiré fringes 611 (
19B) is moved so that it disappears. Using the adjusted position of the reference plate 608 at this time as a reference, the measurement hologram prototype is positioned so that moire fringes between the first concentric circle mark on the measurement hologram prototype and the second concentric circle mark on the reference plate do not appear. do.

(3-4) The example shown in FIG. 20 is a hologram prototype 300
In place of the alignment mark of the Fresnel lens 62
Consists of 0. That is, the light from the light source is received by the four-split detector 621, and the detector 621 is arranged so that the output from each split element surface is equal, that is, the center of the detector 621 and the optical axis of the Fresnel lens 620 coincide.
The hologram prototype for measurement is set using the moved position as the reference position.

Note that if the Fresnel lens 620 has astigmatism, the deviation of the hologram prototype in the Z-axis, that is, the optical axis direction can also be adjusted by the output difference from each divided element surface of the detector 621.

(4) In setting the hologram prototype for adjustment,
Adjustment lens 52 having a spherical surface 521 and an aspherical surface 523
Instead of using 0, an adjustment lens 650 having only a spherical surface 521 is used, as shown in FIGS. 121A and 21B.

First, step (a-3) to step (a = 8) described above are performed to align the center of curvature Q of the spherical surface 521 and the focal point F of the reference lens 109, and to ensure that the plane 522 is free from collisions. Adjustment lens 650 is set so that it is perpendicular to meter optical axis OS. Next, the adjustment lens 650 is moved backward (or advanced) by a predetermined distance as shown in FIG. 21B. As a result, the spherical surface 52
The reflected wavefront from 2 is not a perfect spherical wave but has an aberration, in other words, it is emitted as an aspherical wave. If the hologram prototype for adjustment is created as an interference pattern between this aspherical wave and the reference light from the reference plane plate, the 21st B.
After moving the adjustment lens 650 as shown in the figure, by performing the above-mentioned steps (a-9) to (a-11) using the adjustment hologram prototype,
The hologram prototype for adjustment can be set correctly,
Furthermore, step (a-12) or step (a-1
5) allows the hologram prototype for measurement to be set correctly.

(5) Although the hologram pattern 301 of the hologram prototype 300 described in detail based on FIGS. 2 and 4 is an amplitude-type hologram pattern, the present invention is not limited to this, and the hologram pattern is a phase-type hologram pattern. You may also use

[Brief explanation of the drawing]

Fig. 1 is an optical layout diagram showing the entire holographic interferometer according to the present invention, Fig. 2 is a plan view showing the configuration of the hologram prototype, and Fig. 3 is a black-white ratio inspection pattern applied to the hologram prototype. FIG. 4 is a diagram showing an example of the hologram pattern in its first quadrant, FIG. 5 is a front view showing the hologram prototype holder, and FIG. 6 is the Vl-■ plane of FIG. 5. 7 is a cross-sectional view taken along ■--■ in FIG. 5; FIG. 8 is a perspective optical layout diagram showing the alignment optical system of the hologram prototype holder; and FIG. 9 is an eyepiece of the alignment optical system of the hologram prototype holder. A diagram showing an example of the field of view,
Figures 10A to 10C are schematic diagrams showing the function of the hologram prototype holder, Figure 11 is a partial diagram showing the optical arrangement relationship for on-axis measurement and off-axis measurement, and Figure 12 is an example of a pinhole reticle. 13 is an optical layout diagram showing the configuration of the microscope for off-axis adjustment, and FIG.
The figure is an optical layout diagram showing the configuration of a microscope for on-axis adjustment, and Figure 15A shows a reference lens, an adjustment mirror, an adjustment lens, and an autocollimator to explain the setting adjustment of the holographic interferometer of the present invention. Figure 15B is a diagram showing an example of the eyepiece observation field of the autocollimator, Figure 16 is an optical layout diagram showing a modified example of the pinhole reticle, and Figures 17 to 20 are diagrams showing the arrangement relationship of the four parts. Figures 21A and 21B are diagrams showing modified examples of the alignment mark and alignment optical system of the hologram prototype, respectively.
This figure shows another method of setting the hologram prototype for adjustment, and FIG. 22 is an optical layout diagram of a conventional Fizeau type interferometer. 101...Laser 104...Binhole reticle 106...
... Collimator lens 107 ... Reference plane plate 109 ... Reference lens T ... Test object 110 ... Beam splinter 113 ... Spatial filter 117.123...TV camera 200...
... Hologram prototype holder 205 ... Z-axis direction movement stage 211 ... X-Y direction movement stage 208, 216, 217, 218 ... ... Feed screw 223, 232 , 233...Elastic body 21
5... Spring 240... Objective lens 300... Hologram prototype 301... Hologram pattern 302...
... Distortion test pattern 306 ... Alignment mark 303 ... Black-white ratio test pattern 410 ...
...Microscope 420 for off-axis adjustment...W4a for on-axis adjustment Mirror 501...Adjustment mirror 520.650...Adjustment lens 510...
...Autocollimator Fig. 2 Fig. 3 Fig. 4 (Fig. 5 Fig. 12 Fig. 13 Fig. 14 Fig. 20

Claims (5)

[Claims] (1) A movable stage on which an object is placed, a base stage that supports the movable stage movably in the X-axis direction and the Y-axis direction, and a base stage that is attached to the base stage and is attached to the movable stage in the X-axis direction. at least one X-axis feed screw for applying a moving force from one direction along the X-axis; a resilient means for applying a moving force to the moving stage from an opposite direction along the X-axis; at least two Y-axis feed screws for applying a moving force from one direction along at least two Y-axes; and applying a moving force to the moving stage from opposite directions along each of the two Y-axes. A movable mounting table device characterized in that it has at least two springing means for. (2) Claims characterized in that the moving stage is provided with a guide rail that includes a bearing on its side surface, and the guide rail is brought into contact with the feed screw via a steel ball. The movable mounting table device according to item 1. (3) The movable stage and the base stage are always connected by a spring member with a steel ball interposed between them, and the movable stage has one end fixed to the movable stage and the other end fixed to the base stage. 3. The movable stage device according to claim 1, wherein the movable stage device is attracted toward the base stage. (4) The movable mounting table according to any one of claims 1 to 3, wherein the base stage is attached to support means that supports the base stage so as to be movable in the Z-axis direction. Device. (5) The movable stage device according to any one of claims 1 to 4, wherein the movable stage is provided with suction means for vacuum suctioning the object.