JPH09223477A - Scanning electron microscope - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To improve the vibration resistance of a sample moving stage to improve the resolution of a scanning electron microscope. A z moving member 71 that moves a sample 6 in the optical axis direction, a tilt table 82 that tilts the sample with respect to the optical axis, and a x table that moves the sample in an x direction orthogonal to the optical axis.
A table 94, a y-table 108 for moving the sample in the y direction orthogonal to both the optical axis and the x direction, and a rotation table 122 for rotating the sample around the optical axis.
Actuators 92, 103, 120, 130 that constitute a sample moving stage and drive each table
And position detection means 106, 118, 13 for each table
2 are all placed in the sample chamber 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning electron microscope equipped with a sample moving stage.

[0002]

2. Description of the Related Art FIG. 1 is a schematic sectional view of a conventional scanning electron microscope, FIG. 2 is a detailed view of a sample moving stage thereof, and FIG.
A cross-sectional view taken along the line A is shown in FIG. 3, and a view taken along the line BB of FIG. 2 is shown in FIG. The scanning electron microscope irradiates the electron beam generated by the electron gun 1 through the condenser lens 2 and the objective lens 3 while scanning the sample 6 mounted on the sample moving stage 5 in the sample chamber 4, and then exits from the sample. Coming 2
The secondary electron detector 7 captures the secondary electrons and observes the shape of the sample surface. Reference numerals 9 to 13 in FIG. 1 denote vacuum pumps for drawing a vacuum in the sample chamber 4, the electron gun chamber 8 and the like. The sample chamber 4 is placed on a load plate 69 fixed on a vibration isolation device (not shown) attached to a pedestal 68. The pedestal 68 is a cover 67
It is covered with a and 67b.

A stage case 14 is attached to the sample chamber 4, and a z moving member 15 is attached to the cross roller bearings 16a and 1a.
It is connected to the stage case 14 via 6b. z
The moving member 15 is pulled upward by the spring 17, and is moved in the z direction by being guided by the cross roller bearings 16a and 16b by rotating the knob 18 to move the z moving shaft 19 up and down, thereby moving the sample 6 in the z direction. To do.

A tilt shaft 21 is attached to one end of the L-shaped tilt table 20, and the tilt shaft 21 is a ball bearing 22, 2.
It is rotatably connected to the z moving member 15 via 3. The other end of the L-shaped tilt table 20 is pressed by a pressing pad 25 by an air cylinder 24 attached to the sample chamber 4. This is done especially when observing at high magnification. A worm wheel 26a is attached to the tilt shaft 21, and a worm gear 26b combined with the worm wheel 26a is supported by ball bearings 27 and 28, and z is supported by bearing housings 29 and 30.
It is attached to the moving member 15. Knob 31 for rotating the worm wheel 26a and the worm gear 26b
Are connected by spline shafts 32a, 32b, z
It is possible to follow the movement of the moving member 15 in the z direction. By rotating the knob 31, the tilt shaft 21 rotates and the sample 6
Tilt.

An x table 33 for moving the sample 6 in the x direction
Is attached to the L-shaped tilt table 20 via a cross roller bearing 34. The x table 33 is driven by the feeding action of the x drive female screw 35 and the x drive male screw 36.
The x drive female screw 35 is fixed to the x table 33.
Both ends of the x drive male screw 36 are supported by ball bearings 37 and 38, and the L-shaped tilt table 2 is supported by the bearing housings 39 and 40.
It is attached to 0. The x drive male screw 36 and the DC motor 41 that rotates the x drive male screw 36 are
Are connected by The x-stage joint 42 includes a pair of joint portions 42a and 42b for following an angle and a telescopic portion 42c for length adjustment in which a square rod is inserted into a square pipe. The x table 33 moves in the x direction by driving the DC motor 41 and rotating the x drive male screw 36 via the x stage joint 42 to transfer the x drive female screw 35, thereby moving the sample in the x direction.

The y table 43 is a cross roller bearing 44.
It is attached to the x-table 33 via a and 44b. The y table 43 is driven by the feeding action of the y drive female screw 45 and the y drive male screw 46. The y drive female screw 45 is fixed to the y table 43. Both ends of the y drive male screw 46 are supported by ball bearings 47 and 48, and a bearing housing 49,
It is attached to the x table 33 at 50. A bevel gear 51a is attached to one end of the y drive male screw 46, and a bevel gear 51b meshing with the bevel gear 51a is supported by a ball bearing 52 and fixed to the x table by a bearing housing 53. DC motor 54 for rotating bevel gear 51b and y-drive male screw 46
Are connected by a y stage joint 55. The y-stage joint 55 is composed of a pair of joint parts 55a and 55b for tracking the angle and a telescopic part 55c for length adjustment in which a square bar is inserted into a square pipe. y table 43 is DC
The motor 54 is driven to rotate the bevel gears 51a and 51b and the y-driving male screw 46 via the y-stage joint 55 to move the y-driving female screw 45, thereby moving in the y-direction and moving the sample in the y-direction.

A worm wheel 57a is attached to the rotation table 56, and a ball bearing 58 is used for y rotation.
It is rotatably connected to the table 43. Both ends of the worm gear 57b are supported by ball bearings 59 and 60, and mounted on the y table 43 by bearing housings 61 and 62. Worm gear 57b and knob 6 for rotating it
3 are connected by an R stage joint 64. The R stage joint 64 is composed of a pair of joint portions 64a and 64b for following the angle, and a telescopic portion 64c for length adjustment in which a square rod is inserted into a square pipe. For the rotation table 56, turn the knob 63 to rotate the R stage joint 6
4 through the worm gear 57b, worm wheel 57
By rotating a, the sample is rotated.
The sample 6 is adhered to the sample holder 65, and the sample holder 65 is inserted and fixed to the holder base 66 attached to the rotation table 56.

[0008]

The sample moving stage of the prior art described above does not give sufficient consideration to vibration resistance. That is, the x stage joint 42, the y stage joint 55, the R stage joint 64, and the spline shaft 32.
Since a and 32b have rattling and are hung in the air, and the z moving shaft 19 is also cantilevered, it is easily vibrated by vibrations from the floor. The z moving member 15 is supported by cross roller bearings 16a and 16b, and the system including the z moving member 15, the tilt shaft 21 and the L-shaped tilt table 20 has a cantilever structure, which is a structure weak against vibration. .

Further, the x-stage joint 42, the y-stage joint 55, and the R-stage joint 64 are provided with an expansion / contraction part 4 in order to follow the x, y, z movement and inclination of the sample.
2c, 55c, 64c become longer, the stage case 14
Has a long depth. The sample moving stage 5 needs to be replaceable with another stage such as a cryostage, its weight is limited in consideration of portability, and the wall pressure cannot be increased to sufficiently increase rigidity.

From these points, the conventional sample moving stage is easily vibrated by the vibration from the floor, and the vibration is transmitted to the sample 6 to cause an image defect, which hinders the improvement of the resolution of the scanning electron microscope. The present invention has been made in view of such problems of the conventional art, and an object of the present invention is to improve the vibration resistance of the sample moving stage and increase the resolution of the scanning electron microscope.

[0011]

According to the present invention, all the actuators for driving the respective tables of the sample moving stage are arranged in the sample chamber, the transmission system is simplified, and the respective tables are directly driven to achieve the above object. . Further, among the encoders that detect the position of each table, by mounting the encoders of x table, y table, and rotation table, which require particularly accuracy, to the drive output shaft, highly accurate position detection is realized.

That is, the present invention provides a scanning electron microscope which scans an electron beam on a sample placed on the sample moving stage and detects a signal generated from the sample to form a sample image. A z-table for moving the sample in the optical axis direction, a tilt table for tilting the sample with respect to the optical axis, an x-table for moving the sample in the x-direction orthogonal to the optical axis, and a sample for the optical-axis and the x-direction. And a rotation table for rotating the sample around the optical axis,
The actuator for driving each table and the position detecting means for each table are all arranged in the sample chamber.

In the sample moving stage, an x table for moving the sample in the x direction orthogonal to the optical axis is arranged on a z table for moving the sample in the optical axis direction, and the sample is placed on the x table with respect to the optical axis. Place a tilt table to tilt
A y table for moving the sample in a direction orthogonal to both the optical axis and the x direction is arranged on the tilt table, and a rotation table for rotating the sample around the optical axis is arranged on the y table. Or z
The tilt table may be arranged on the table, the x table may be arranged on the tilt table, the y table may be arranged on the x table, and the rotation table may be arranged on the y table.

The sample moving stage includes a z moving member that is engaged with a stage case attached to the side wall of the sample chamber to move the sample in the optical axis direction, and a tilt shaft that is rotatably engaged with the z moving member. A tilt table connected to the tilt axis to tilt the sample with respect to the optical axis; an x table arranged on the tilt table to move the sample in an x direction orthogonal to the optical axis; It can be composed of a y-table which is arranged to move the sample in the y-direction orthogonal to both the optical axis and the x-direction, and a rotation table which is arranged on the y-table and rotates the sample around the optical axis. .

The x-table is moved in the x-direction by transmitting the rotational driving force of the motor to the converting means for converting the rotary motion into the linear motion, and the rotary table for detecting the position of the x-table on the rotating shaft of the converting means. The encoder is connected. The y-table is moved in the y-direction by transmitting the rotational driving force of the motor to the converting means for converting the rotary motion into the linear motion, and the rotary encoder for detecting the position of the y-table is connected to the rotating shaft of the converting means. To be done. The rotation table is rotated by transmitting the rotational driving force of the motor to a conversion unit that converts the rotation operation of the rotation table, and a rotary encoder for detecting the rotation position of the rotation table is connected to the rotation shaft of the conversion unit. .
A DC motor or a pulse motor can be used as the motor.

The x-table, y-table or rotation table can be driven by a driving mechanism using a piezo element. That is, the x-table can be moved in the x direction by expanding and contracting the piezo element by pressing the driving mechanism using the piezo element attached to the z-table below the slider provided on the side surface, and the y-table can be moved to the side surface. A drive mechanism using a piezo element attached to a tilt table below the slider is pressed against the provided slider, and the piezoelectric element can be moved in the y direction by expansion and contraction. Further, the rotation table can be rotated by pressing the drive mechanism using the piezo element attached to the y table below the slider provided on the side surface and expanding and contracting the piezo element. Each table may be driven by one drive mechanism or a plurality of drive mechanisms. The sample moving stage may be arranged on a base fixed to the bottom of the sample chamber, or may be arranged on a base fixed to a base attachment member attached to the side surface of the sample chamber.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] The first embodiment of the present invention will be described with reference to FIGS.
An embodiment will be described. FIG. 5 is a schematic sectional view of the sample moving stage. FIG. 6 is a view taken along the line CC of FIG.
FIG. 7 is a view taken along the line DD of FIG.

A stage case 70 is attached to the sample chamber 4, and a z moving member 71 is provided with cross roller bearings 72a, 7a.
It is connected to the stage case 70 via 2b. z
The moving member 71 is transferred in the z direction by the z ball screw 73 and the nut 74. The z nut 74 is fixed to the z moving member 71, and the z ball screw 73 has ball bearings 75 and 76 at both ends.
And is mounted on the stage case 70 by bearing housings 77 and 78. A DC motor 80 is connected to one end of the z ball screw 74 via a coupling 79.
It is attached to 0. A speed reducer is incorporated in the front part of the DC motor 80, and a rotary encoder is incorporated in the rear part. The z moving member 71 is driven by the DC motor 80 and the z ball screw 73 is rotated to be guided by the cross roller bearings 72a and 72b to move in the z direction.
The sample 6 is moved in the z direction.

A tilt shaft 83 is attached to one end of the L-shaped tilt table 82, and the tilt shaft 83 has ball bearings 84, 8.
It is rotatably connected to the z moving member 71 via 5. The other end of the L-shaped tilt table 82 is pressed by the pressing pad 25 by the air cylinder 24 attached to the sample chamber 4. This is done especially when observing at high magnification. A worm wheel 86a is attached to the tilt shaft 83, a worm gear 86b combined with the worm wheel 86a is supported by ball bearings 87 and 88, and z is supported by bearing housings 89 and 90.
It is attached to the moving member 71. Worm gear 86
DC motor 92 is connected to one end of b through coupling 91.
, And the DC motor 92 is attached to the z moving member 71 by a motor base 93. A speed reducer is incorporated in the front part of the DC motor 92, and a rotary encoder is incorporated in the rear part.

By driving the DC motor 92 and rotating the worm wheel 86a and the worm gear 86b, the tilt shaft 83 rotates and the sample 6 is tilted. The axis center of the tilt shaft 83 is set so as to pass through the intersection of the surface of the sample 6 and the electron beam, and has a eucentric structure in which the field of view of the electron microscope does not move when the sample 6 is tilted.

An x table 94 for moving the sample 6 in the x direction
Is attached to the L-shaped tilt table 82 via a cross roller bearing 95. The x table 94 is transferred by the feeding action of the x ball screw 96 and the x nut 97. x
The nut 97 is fixed to the x table 94. Both ends of the x ball screw 96 are supported by ball bearings 98 and 99, and are attached to the L-shaped tilt table 82 by bearing housings 100 and 101. The DC motor 103 is attached to one end of the x ball screw 96 via the coupling 102, and the rotary encoder 106 is attached to the other end via the coupling 105.
Are connected. The DC motor 103 is a motor base 104
The rotary encoder 106 is attached to the L-shaped table 82 by the encoder base 107. DC motor 1
A speed reducer is incorporated in the front part of 03. By driving the DC motor 103 and rotating the x ball screw 96, the x table 94 is guided by the cross roller bearing 95 to move in the x direction, and moves the sample in the x direction.

The y table 108 is a cross roller bearing 1
It is attached to the x-table 94 via 09a and 109b. The y table 108 is transferred by the feeding action of the y ball screw 110 and the y nut 111. y nut 11
1 is fixed to the y table 108. Both ends of the y ball screw 110 are supported by ball bearings 112 and 113, and are attached to the x table 94 by bearing housings 114 and 115. The bevel gear 11 is attached to one end of the y ball screw 110.
6a is attached, and the rotary encoder 118 is connected to the other end via a coupling 117. The rotary encoder 118 is attached to the x table 94 with an encoder base 119. The bevel gear 116b meshing with the bevel gear 116a is connected to the DC motor 120, and D
The C motor 120 is fixed to the x table 94 by a motor base 121. A speed reducer is incorporated in the front portion of the DC motor 120. The y table 108 drives the DC motor 120 and rotates the y ball screw 110,
The sample is moved in the y direction by being guided by the cross roller bearings 109a and 109b and moving in the y direction.

A worm wheel 123a is attached to the rotation table 122, and the rotation table 122 is rotatably connected to the y table 108 by a ball bearing 124. Both ends of the worm gear 123b are supported by ball bearings 125 and 126, and the bearing housings 127 and 128 support the y table 1.
08. The DC motor 130 is connected to one end of the worm gear 123b via a coupling 129, and the rotary encoder 132 is connected to the other end thereof via a coupling 131. DC motor 13
Reference numeral 0 is a motor stand 133, and rotary encoder 132 is attached to the y table 108 by an encoder stand 134. The rotation table 122 is the DC motor 1
30 is driven to rotate the worm gear 123b and the worm wheel 123a, thereby rotating the sample.

The sample 6 is adhered to the sample holder 64, and the sample holder 64 is inserted and fixed to the holder base 65 attached to the rotation table 122. The rotary encoder is attached to detect and move the position, rotation angle, and tilt angle of the sample in the x, y, and z directions with respect to the electron beam. A rotary encoder for detecting the position and rotation angle of the sample in the x and y directions drives an x ball screw 96 and a y ball screw 1 respectively.
10. The one attached to one end of the worm gear 123b is
This is because the detection accuracy of the position and rotation angle of the sample in the x and y directions is increased and the sample is moved to a target position with high accuracy.

According to this embodiment, x table, y
DC that is an actuator that moves the table, the z moving member, the L-shaped tilt table, and the rotation table.
Since all the motors are arranged in the sample chamber, the x-stage joint 42, the y-stage joint 55, the R-stage joint 63, and the spline shaft 32a that are easily excited by the vibration from the floor used in the conventional scanning electron microscope are used. , 32b and the z-movement axis 19 are unnecessary. Also, since the stage joint is unnecessary, the stage case 14
The depth of can be shortened and sufficient rigidity can be provided. Therefore, the vibration resistance is improved and the resolution of the scanning electron microscope can be improved.

Further, in the prior art, the knob and the DC motor, which are outside the sample chamber, that is, outside the vacuum, and drive each table, are connected to the z drive shaft, the spline shaft, and the stage joint, which are arranged in the vacuum, and are not shown in the drawing. A ring was used to isolate the atmosphere from the vacuum. Therefore, in the conventional technology, O
The ring may be worn to cause a leak, and the degree of vacuum in the sample chamber may be lowered to make it unobservable. Further, since the friction loss torque is generated by the O-ring, the knob is heavy and the operability is poor. Furthermore, since the friction loss torque at the time of startup changes depending on the stop time and is unstable, the DC motor O
It was difficult to finely adjust the movement of each table by N / OFF, that is, fine movement of the sample. In contrast,
According to this embodiment, since all the DC motors are arranged in the sample chamber, O-rings are not required, the risk of leakage is eliminated, reliability is improved, and fine movement of the sample by the DC motor is facilitated. Operability is improved.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS. 8 is a schematic sectional view of the sample moving stage, FIG. 9 is a view taken along the line EE in FIG. 8, FIG. 10 is a view taken along the line FF, and FIG. 11 is a view taken along the line GG in FIG. is there.

A stage plate 141 is attached to the sample chamber 140, an L-shaped base 142 is fixed to the stage plate 141, and a z base 143 is attached on the L-shaped base 142. Roller mounting portion 143 of z base 143
a, 143b and the roller mounting portion 14 of the z table 144
4a is connected by cross roller bearings 145a and 145b. The z table 144 is transported by the feeding action of the z ball screw 146 and the z nut 147. The z ball screw 146 has one end supported by a ball bearing 148 attached to the z table 144, and the other end combined with a z nut 147 attached to the z base 143.

A bevel gear 149a is attached to the z ball screw 146, and a bevel gear 149b meshing with the bevel gear 149a is connected to a DC motor 151 attached to a motor base 150 fixed to the z table 144. DC motor 15
A speed reducer is incorporated in the front part of No. 1 and a rotary encoder is incorporated in the rear part. z table 144 is D
By driving the C motor 151 and rotating the z ball screw 146 via the bevel gears 149a and 149b, the sample 6 is moved in the z direction while being guided by the cross roller bearings 145a and 145b.

The x table 152 is a cross roller bearing 1
It is attached to the z table 144 via 53a and 153b. x table 152 is x ball screw 154
And x nut 155 is fed by the feeding action. x nut 1
55 is fixed to the x table 152. Both ends of the x ball screw 154 are supported by ball bearings 156 and 157, and are attached to the z table 144 by bearing housings 158 and 159. A DC motor 161 is connected to one end of the x ball screw 154 via a coupling 160, and a rotary encoder 163 is connected to the other end via a coupling 162. The DC motor 161 is a motor base 164.
The rotary encoder 163 is attached to the z table 144 by the encoder base 165. DC motor 1
A speed reducer is incorporated in the front portion of 61. The x table 152 drives the DC motor 161 to drive the x ball screw 1
By rotating 54, the cross roller bearing 153
a, 153b is guided in the x direction and the sample is transferred to the x direction.
Move in the direction.

V-shaped arc guides 167 and flat arc guides 168 are mounted on both sides of the tilt table 166.
The V-shaped arc guide 167 is placed on the V-groove rollers 169 and 170, and the flat arc guide 168 is placed on the roller follower 171. The V groove roller 169 is supported by a ball bearing 172, and is fixed to the x table 152 by a bearing housing 173. The V groove roller 170 is also supported by a ball bearing, and is fixed to the x table 152 by a bearing housing 174. The roller follower 171 is fixed to the x table 152 via a roller base 175.

Arc holding guides 176 and 177 are attached to the lower portion of the tilt table 166. Ball bearings 178 and 179 attached to both ends of the connecting shaft 180 are arranged on the inner circumferences of the arc holding guides 176 and 177,
The connecting shaft 180 is connected via the leaf spring 181 and the spring base 182 to x
It is attached to the table 152. The tilt table 166 is pulled downward by the leaf spring 181. A flat arc guide 168 has an arc worm wheel 18
The worm gear 184, to which 3 is attached, is supported by ball bearings 185 and 186, and is attached to the x table 152 by bearing housings 187 and 188. A screw gear 189 is provided at one end of the worm gear 184.
a is attached, and the screw gear 189b meshing with this is connected to the DC motor 190, and the DC motor 190 is attached to the x table by the motor base 191. A speed reducer is incorporated in the front part of the DC motor 190, and a rotary encoder is incorporated in the rear part.

The DC gear 190 is driven to drive the screw gear 18
By rotating the worm gear 184 and the worm wheel 183 via 9a and 189b, the tilt table 166 rotates and the sample 6 is tilted. The rotation centers of the V-shaped circular arc guide 167 and the flat circular arc guide 168 are set so as to pass through the intersection of the surface of the sample 6 and the electron beam.
It has a eucentric structure in which the field of view of the electron microscope does not move when tilted.

The y table 192 is a cross roller bearing 1
It is attached to the tilt table 166 via 93a and 193b. y table 192 is y ball screw 1
It is transferred by the feeding action of 93 and y nut 194. The y-nut 194 is fixed to the y-table 192. Both ends of the y ball screw 193 are supported by ball bearings 195 and 196, and the tilt table 1 is supported by the bearing housings 197 and 198.
It is attached to 66. A spur gear 198a is attached to one end of the y ball screw 193, and the rotary encoder 200 is connected to the other end via a coupling 199. The rotary encoder 200 is attached to the tilt table 166 by the encoder base 201.

Spur gear 198b meshing with spur gear 198a
Is connected to the DC motor 202, and the DC motor 202 is fixed to the tilt table 166 by the motor base 203.
A speed reducer is incorporated in the front part of the DC motor 202. The y table 192 drives the DC motor 202,
By rotating the y ball screw 193, the y ball screw 193 is guided by the cross roller bearings 193a and 193b to be transferred in the y direction, and the sample is moved in the y direction.

A worm wheel 205a is attached to the rotation table 204, and is rotatably connected to the y table 192 by a ball bearing 206. Both ends of the worm gear 205b are supported by ball bearings 207 and 208, and the bearing housings 209 and 210 support the y table 1.
It is attached to 92. A bevel gear 211a is attached to one end of the worm gear 205b, and a rotary encoder 213 is connected to the other end via a coupling 212. The rotary encoder 213 is fixed to the y table 192 by an encoder base 214.

A bevel gear 211b meshing with the bevel gear 211a.
Are connected to a DC motor 215, and the DC motor 215 is attached to the y table 192 by a motor base 216. A speed reducer is incorporated in the front portion of the DC motor 215. The rotation table 204 is the DC motor 2
15 is driven to rotate the worm gear 122b and the worm wheel 122a, thereby rotating the sample.

As shown in FIG. 11 which is a view taken along the line GG in FIG. 9, the z base 143 has a piezo pressing member 217.
Is attached. One end of the piezo element 218 is bonded to the piezo pressing body 217, and the other end of the piezo element 218 is pressed by the adjusting screw 219. When a voltage is applied to the piezo element 218, the piezo element 218 expands and the deformed portion 217a of the piezo pressing body 217 contracts laterally, and the pressing surface 2
17b moves away from the roller mounting portion 144a of the z table 144, and the z table 144 becomes movable. When the voltage is turned off, the piezo element 218 contracts, the deformable portion 217a extends laterally, and the pressing surface 217b presses the roller mounting portion 144a of the z table 144. When observing the sample, the voltage is cut off, the pressing surface 217b is pressed against the roller mounting portion 144a, and the z table 144 is locked to form a both-end supporting structure that is resistant to vibration.

The sample 6 is adhered to the sample holder 64, and the sample holder 64 is inserted and fixed to the holder base 65 attached to the rotation table 204. The rotary encoder is attached to detect and move the position, rotation angle, and tilt angle of the sample in the x, y, and z directions with respect to the electron beam. A rotary encoder for detecting the position and rotation angle of the sample in the x and y directions was attached to one end of the x ball screw 154, the y ball screw 193, and the worm gear 205b for driving the respective tables. This is because the detection accuracy of the position and the rotation angle is increased and the position is accurately moved to the target position.

According to this second embodiment, the first
Z moving member 7 serving as a cantilever support in the embodiment of
1, the cantilever portion of the L-shaped base 142 is shorter than that of the system including the tilt shaft 83 and the L-shaped tilt table 82.
Further, since the L-shaped base 142 is directly fixed to the stage plate 141 and has higher rigidity and excellent earthquake resistance, the resolution of the scanning electron microscope can be further improved.

The structure of the second embodiment is smaller and lighter than the structure of the first embodiment, and z
Since the load for driving the table 144 and the tilt table 166 is small, the DC motor, the ball screw and the like can be made small and lightweight, so that the natural frequency is increased and the vibration resistance is further improved. Since the inertial load of the z table and tilt table is small, the z table and tilt table can be easily moved minutely by turning the motor on and off, further improving the operability. Further, since the weight of the entire stage including the stage plate is lighter than that of the prior art or the first embodiment, replacement work with another stage such as a cryostage becomes easy.

[Third Embodiment] The third embodiment of the present invention will be described with reference to the schematic sectional view of the sample moving stage shown in FIG. 12, the same components as in FIG. 8 are assigned the same reference numerals as those in FIG. 8 and detailed description thereof is omitted. In the second embodiment, the z base is arranged on the L-shaped base attached to the stage plate. On the other hand, in the third embodiment, the z base 143 is
Circular base 230 attached to the bottom of the sample chamber 140
It is fixed to. The other structure is the same as that of the second embodiment.

According to this embodiment, the cantilever portion required in the second embodiment is eliminated, the rigidity is high and the earthquake resistance is excellent, so that the resolution of the scanning electron microscope can be further improved. Further, since there is no L-shaped base and L-shaped tilt table, the symmetry is excellent as compared with the prior art and the first and second embodiments, and the temperature drift is reduced, especially when observing at high magnification. Image shift and distortion are reduced. Further, since the stage is attached to the bottom of the sample chamber and the bottom of the sample chamber is covered with the pedestal and the cover, it is difficult for sound to enter, and there is no fear that the sound is transmitted from the bottom of the sample chamber to the sample through the stage and deteriorates the resolution. Further, since the stage plate and the stage are separated from each other, the weight is further reduced, so that the replacement work with another stage such as a cryostage becomes easier.

[Fourth Embodiment] Referring to FIG. 13, a fourth embodiment of the present invention will be described. In the second and third embodiments, when the tilt angle of the tilt table becomes large and the stroke of the y table becomes long, the y table comes into contact with the roller mounting portion of the z table. This is because the cross table bearing cannot be arranged in the moving direction of the x table because the x table is on the z table.

In this embodiment, y is used together with the x table.
It is suitable for long table strokes. The z table 241 is connected to the z base 240 via cross roller bearings 242a and 242b, and the tilt table 243 is mounted on the z table 241 to form the V groove roller 24.
4, 245 and the flat roller 246, and x
The table 247 is connected on the tilt table 243 via cross roller bearings 248a and 248b, the y table 249 is connected on the x table 247 via cross roller bearing 250, and the y table 249 is rotated on the y table 249. Are arranged. According to this embodiment, in addition to the operation and effect described in the third embodiment, it is possible to achieve the operation and effect that the stroke of the x, y table can be increased without lowering the vibration resistance. .

[Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to FIGS. 14 and 15. Although the actuator of each table is a DC motor in the above-described embodiments, other types of motors such as a pulse motor, an ultrasonic motor, and an AC motor can be used. FIG. 14 shows an example in which a piezo drive mechanism is used instead of a motor as an actuator. FIG. 15 is a plan view of FIG.

The y table 250 is the tilt table 251.
To cross roller bearings 252a and 252b. The piezo drive mechanisms 253 and 254 are fixed to the tilt table 251. Piezo element 253a, 253
b has one end on the base 253c and the other end on the drive pad 253d
And the drive pad 253d is pressed against the slider 254 attached to the y table 250 with an appropriate force. The piezo drive mechanism 254 is also pressed against the slider 255 with an appropriate force.

This piezo drive mechanism is a type of inchworm type drive mechanism, and includes piezo elements 253a and 253b.
The sliders 254 and 255 are moved in the y direction by appropriately setting the expansion / contraction timing of the y table 25.
0 is moved in the y direction by being guided by the cross roller bearings 252a and 252b. The x-table can be moved in the same manner, and the rotation table can be rotated by a piezo drive mechanism. The position of the x-table and y-table when using the piezo drive mechanism is detected by a linear scale,
The rotation encoder detects the rotation angle of the rotation table.

According to this embodiment, the ball screws and nuts for moving the x and y tables used in the first to fourth embodiments can be omitted, and the x and y tables can be directly driven and further driven. Since the pad and the slider are in contact with each other with an appropriate force, a damping action occurs between the z-table and the x-table, the tilt table and the x-table, or the x-table and the y-table, and the vibration resistance is further improved. The resolution can be further improved.

As described above, when the piezo drive mechanism is used as the actuator, the table is directly driven, so that a ball screw and a ball bearing for supporting the table are not necessary, and since the drive pad and the slider are in sliding frictional contact with each other, a damping action is obtained. Occurs, vibration resistance is improved, and resolution is further improved. Further, the piezo drive mechanism directly drives the table, so that the piezo drive mechanism is more efficient than the drive method using the motor and the speed reduction mechanism, and the amount of heat generated is small, so that the temperature drift can be reduced.

[0051]

According to the present invention, since the vibration resistance of the sample moving stage is improved and the vibration trouble can be prevented at the time of observing the sample, it is possible to provide a scanning electron microscope having a high resolution.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a conventional scanning electron microscope.

FIG. 2 is a diagram showing an example of a conventional sample moving stage.

FIG. 3 is a view taken along the line AA of FIG. 2;

FIG. 4 is a view taken in the direction of arrows BB in FIG. 2;

FIG. 5 is a diagram showing a sample moving stage according to the first embodiment of the present invention.

FIG. 6 is a view taken along the line CC of FIG.

FIG. 7 is a view taken along the line DD of FIG.

FIG. 8 is a diagram showing a sample moving stage according to a second embodiment of the present invention.

9 is a view taken along the line EE of FIG.

FIG. 10 is a view on arrow FF in FIG.

FIG. 11 is a view taken along the line GG in FIG.

FIG. 12 is a diagram showing a sample moving stage according to a third embodiment of the present invention.

FIG. 13 is a diagram showing a sample moving stage according to a fourth embodiment of the present invention.

FIG. 14 is a diagram showing a fifth embodiment of the present invention.

FIG. 15 is a plan view of FIG. 14;

[Explanation of symbols]

4 ... sample chamber, 6 ... sample, 14 ... stage case, 15 ...
z moving member, 19 ... z moving shaft, 18 ... knob, 20 ... L
Shape tilt table, 21 ... Tilt shaft, 32a, 32b ...
Spline shaft, 33 ... x table, 41 ... DC motor,
42 ... x stage joint, 43 ... y table, 54
... DC motor, 55 ... y stage joint, 56 ... rotation table, 63 ... knob, 64 ... R stage joint, 70 ... stage case, 71 ... z moving member, 73 ... z ball screw, 74 ... nut, 80 ... DC motor, 82 ... L-shaped tilt table, 83 ... Tilt shaft, 8
6a ... worm wheel, 86b ... worm gear, 92
... DC motor, 94 ... x table, 96 ... x ball screw, 97 ... x nut, 103 ... DC motor, 106 ... rotary encoder, 108 ... y table, 110 ... y ball screw, 111 ... y nut, 116a, 116b ... bevel gear , 118 ... Rotary encoder, 120 ... DC motor, 122 ... Rotation table, 123a ... Worm wheel, 123b ... Worm gear, 130 ... DC
Motor, 132 ... Rotary encoder, 140 ... Sample chamber, 141 ... Stage plate, 142 ... L-shaped base, 143
... z base, 144 ... z table, 146 ... z ball screw, 147 ... nut, 149a, 149b ... bevel gear, 1
51 ... DC motor, 152 ... x table, 154 ... x ball screw, 155 ... x nut, 161, ... DC motor, 1
63 ... Rotary encoder, 166 ... Tilt table,
167 ... V-shaped arc guide, 168 ... Flat arc guide, 1
69, 170 ... V-groove roller, 171 ... Roller follower,
183 ... Arc worm wheel, 184 ... Worm gear, 189a, 189b ... Screw gear, 190 ... DC motor, 192 ... Y table, 193 ... Y ball screw, 19
4 ... y nut, 198a, 198b ... spur gear, 200 ...
Rotary encoder, 202 ... DC motor, 204 ... rotation table, 205a ... worm wheel,
205b ... Worm gear, 211a, 211b ... Bevel gear, 213 ... Rotary encoder, 215 ... DC motor, 230 ... Circular base, 240 ... Z base, 241 ...
z table, 243 ... tilt table, 247 ... x table, 249 ... y table, 251 ... rotation table

Claims (11)

[Claims] 1. A scanning electron microscope which scans an electron beam on a sample mounted on the sample moving stage and detects a signal generated from the sample to form a sample image, wherein the sample moving stage comprises a sample For moving the sample in the optical axis direction, a tilt table for tilting the sample with respect to the optical axis, and a table for moving the sample in the x direction orthogonal to the optical axis.
A table, a y-table for moving the sample in a y-direction orthogonal to both the optical axis and the x-direction, and a rotation table for rotating the sample around the optical axis. A scanning electron microscope characterized in that all position detecting means of each table are arranged in a sample chamber. 2. The x table is arranged on the z table, the tilt table is arranged on the x table, the y table is arranged on the tilt table, and the y table is arranged on the y table. The rotation table is arranged, and the z table is moved in the z direction by transmitting the rotational driving force of a first motor having a first rotary encoder to a first conversion means for converting a rotary motion into a linear motion. The x table is moved in the x direction by transmitting the rotational driving force of the second motor to the second converting means for converting the rotary motion into the linear motion, and the x table is attached to the rotary shaft of the second converting means. A second rotary encoder for detecting the position of the tilt table, and the tilt table transmits the rotational driving force of a third motor having a third rotary encoder to the tilt table. The y-table is transmitted to the third converting means for converting into a tilting motion of the bull, and the y-table is transmitted to the fourth converting means for converting the rotary driving force of the fourth motor into the linear motion to y. Direction, and a fourth rotary encoder for detecting the position of the y table is connected to the rotation shaft of the fourth converting means, and the rotation table applies a rotational driving force of a fifth motor to the rotation table. And a fifth rotary encoder for detecting the rotational position of the rotation table is connected to the rotation shaft of the fifth converting means. The scanning electron microscope according to claim 1. 3. A scanning electron microscope which scans an electron beam on a sample mounted on the sample moving stage and detects a signal generated from the sample to form a sample image, wherein the sample moving stage comprises a sample A z-moving member that is engaged with a stage case attached to the chamber side wall to move the sample in the optical axis direction, a tilt shaft rotatably engaged with the z-moving member, and a sample that is connected to the tilt shaft. Tilt table for inclining the sample with respect to the optical axis, an x table arranged on the tilt table for moving the sample in an x direction orthogonal to the optical axis, and a sample arranged on the x table for the optical axis of the sample. And a rotation table arranged on the y table for rotating in the y direction orthogonal to both the x direction and the sample for rotating the sample around the optical axis. The member transmits the rotational driving force of the first motor provided with the first rotary encoder to the first conversion means for converting the rotational motion into the linear motion and is moved in the z direction, and the tilt table has the second rotary table. The rotation driving force of the second motor having an encoder is transmitted to the second conversion means for converting the rotation driving force of the tilt shaft to be tilted, and the x-table rotates the rotation driving force of the third motor to rotate. A third rotary encoder for converting the linear motion to a third converting means, which is moved in the x direction, and a rotary shaft of the third converting means is connected to a third rotary encoder for detecting the position of the x table; The y-table is moved in the y-direction by transmitting the rotational driving force of the fourth motor to the fourth converting means for converting the rotational movement into the linear movement, and the position of the y-table on the rotation axis of the fourth converting means. Detect A fourth rotary encoder for connecting the rotation table to the fifth conversion means for converting the rotation driving force of the fifth motor into the rotation operation of the rotation table, and rotating the rotation table. A fifth rotary encoder for detecting the rotation position of the rotation table is connected to the rotation shaft of the means, and the first, second, third, fourth and fifth motors are arranged in the sample chamber. A scanning electron microscope characterized in that 4. A scanning electron microscope which scans an electron beam on a sample placed on the sample moving stage and detects a signal generated from the sample to form a sample image, wherein the sample moving stage comprises a sample For moving in the optical axis direction, a tilt table arranged on the z table for inclining the sample with respect to the optical axis, and a z table arranged on the tilt table for orthogonally intersecting the optical axis with the sample. The x-table which moves in the direction, the y-table which is arranged on the x-table and moves the sample in the y-direction which is orthogonal to both the optical axis and the x-direction, and the sample which is arranged on the y-table to move the sample A rotation table that rotates about an optical axis, and the z table converts the rotational driving force of a first motor having a first rotary encoder into a linear movement. The tilt table is converted to a second conversion means for converting the rotational driving force of the second motor having the second rotary encoder into the tilt motion of the tilt table. The x-table is transmitted and tilted, and the x-table is moved in the x-direction by transmitting the rotational driving force of the third motor to the third converting means for converting the rotary motion into the linear motion, thereby rotating the third converting means. A third rotary encoder for detecting the position of the x-table is connected to the shaft, and the y-table transmits the rotational driving force of the fourth motor to the fourth conversion means for converting the rotary motion into the linear motion. And a fourth rotary encoder for detecting the position of the y table is connected to the rotation shaft of the fourth converting means, and the rotation table drives the fifth motor to rotate. A fifth rotary encoder for transmitting the force to the fifth converting means for converting the rotary motion of the rotation table and being rotated, and a fifth rotary encoder for detecting a rotational position of the rotation table is provided on a rotation shaft of the fifth converting means. A scanning electron microscope, wherein the scanning electron microscope is connected and the first, second, third, fourth and fifth motors are arranged in a sample chamber. 5. An x table for moving the sample in a direction orthogonal to the optical axis is arranged on a z table for moving the sample in the optical axis direction, and the sample is tilted on the x table with respect to the optical axis. A tilt table is arranged, a y table is arranged on the tilt table for moving the sample in ay direction orthogonal to both the optical axis and the x direction, and the sample is rotated around the optical axis on the y table. In the scanning electron microscope, which comprises a sample moving stage on which a rotation table is arranged, scans the sample with an electron beam and detects a signal generated from the sample to form a sample image, wherein the z table is a first rotary table. The rotational driving force of the first motor provided with an encoder is transmitted to the first conversion means for converting rotational motion into linear motion and moved in the z direction, and the x table is installed on the side surface. A first drive mechanism using a piezo element attached to the z-table is pressed against the slider provided, and is moved in the x direction by expansion and contraction of the piezo element, and the tilt table is provided with a second rotary encoder having a second rotary encoder. Of the motor is transmitted to the second conversion means for converting the tilting motion of the tilt table to be tilted, and the y table uses a piezo element attached to the tilt table for the slider provided on the side surface. The second drive mechanism is pressed and moved in the y direction by the expansion and contraction of the piezo element, and the rotation table transfers the rotational driving force of the third motor to the third conversion means for converting the rotation operation of the rotation table. And is rotated to detect the rotation position of the rotation table on the rotation shaft of the third conversion means. 3 of the rotary encoder is coupled, the first, scanning electron microscope the second and third motor is characterized in that it is arranged in a sample chamber. 6. A z moving member for moving the sample in the optical axis direction is engaged with a stage case attached to a side wall of the sample chamber, and a tilt shaft is rotatably engaged with the z moving member,
A tilt table for tilting the sample with respect to the optical axis is connected to the tilt axis, an x table for moving the sample in an x direction orthogonal to the optical axis is arranged on the tilt table, and the sample is placed on the x table. A y-table is arranged for moving in a y-direction orthogonal to both the optical axis and the x-direction, and a sample moving stage is provided on which a rotation table for rotating the sample around the optical axis is arranged. In a scanning electron microscope that scans a sample with an electron beam and detects a signal generated from the sample to form a sample image, the z moving member has a rotational driving force of a first motor including a first rotary encoder. Is transmitted in the z-direction by transmitting it to the first conversion means for converting the rotary motion into the linear motion, and the tilt axis is the second rotary encoder provided with the second rotary encoder.
Of the motor is transmitted to the second conversion means for converting the tilting motion of the tilt table to be tilted, and the x table uses a piezo element attached to the tilt table for the slider provided on the side surface. The first drive mechanism is pressed and moved in the x direction by expansion and contraction of the piezo element, and the y table presses a second drive mechanism using a piezo element attached to the x table on a slider provided on the side surface. Then, the rotation table is moved in the y direction by the expansion and contraction of the piezo element, and the rotation table is rotated by transmitting the rotation driving force of the third motor to the third conversion means for converting the rotation driving force of the rotation table. A third rotary encoder for detecting the rotation position of the rotation table is connected to the rotation shaft of the third conversion means. Is, the first, scanning electron microscope the second and third motor is characterized in that it is arranged in a sample chamber. 7. A scanning electron microscope which scans an electron beam on a sample mounted on the sample moving stage and detects a signal generated from the sample to form a sample image, wherein the sample moving stage comprises a sample For moving in the optical axis direction, a tilt table arranged on the z table for inclining the sample with respect to the optical axis, and a z table arranged on the tilt table for orthogonally intersecting the optical axis with the sample. The x-table which moves in the direction, the y-table which is arranged on the x-table and moves the sample in the y-direction which is orthogonal to both the optical axis and the x-direction, and the sample which is arranged on the y-table to move the sample. A rotation table that rotates about an optical axis, and the z table converts the rotational driving force of a first motor having a first rotary encoder into a linear movement. The tilt table is converted to a second conversion means for converting the rotational driving force of the second motor having the second rotary encoder into the tilt motion of the tilt table. The x-table is transmitted and tilted, and the x-table presses a first drive mechanism using a piezo element attached to the tilt table against a slider provided on a side surface, and the x-table is moved in the x direction by expansion and contraction of the piezo element, The y table presses a second drive mechanism using a piezo element attached to the x table against a slider provided on a side surface, and is moved in the y direction by expansion and contraction of the piezo element, and the rotation table is a third motor. Is transmitted to the third conversion means for converting the rotation driving force of the rotation table into the rotation operation of the rotation table, and is rotated. A scanning characterized in that a third rotary encoder for detecting the rotational position of the rotation table is connected to the rotation shaft of the stage, and the first, second and third motors are arranged in the sample chamber. Electron microscope. 8. The rotation table according to claim 3, wherein a piezo element attached to the y table is used in place of the third conversion means for converting the rotational driving force of the third motor into the rotation operation of the rotation table. 8. The drive mechanism according to claim 5, wherein the third drive mechanism is pressed against a slider provided on the side surface of the rotation table, and is rotated by expansion and contraction of the piezo element. Scanning electron microscope. 9. The sample moving stage according to claim 1, wherein the sample moving stage is arranged on a base fixed to the bottom of the sample chamber. Scanning electron microscope. 10. The sample moving stage is arranged on a base fixed to a base mounting member mounted on the side surface of the sample chamber.
The scanning electron microscope according to any one of 4, 5, 7, or 8. 11. The scanning electron microscope according to claim 2, wherein the motor is a DC motor or a pulse motor.