JPH06309035A - Sample stage - Google Patents

Abstract

(57) [Summary] [Structure] A worm wheel fixed on the tilt stage, a worm for driving the worm wheel, a bearing for supporting the worm, and a tilt installed between the tilt guide member and the bearing. A sample stage provided with a wedge-shaped spacer that can slide only in the direction, and a Z-direction guide member that guides the bearing and the worm so that the bearing and the worm can slide only in the vertical direction. According to the present invention, it is possible to improve the assembly accuracy of the worm gear that drives the tilt stage in each direction.
The centers of curvature of both tilting stages and the observation point of the sample can be made to coincide, the movement of the observation point due to the inclination of the stage can be prevented, and the observation image can be minimized in the observation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample stage used in an optical microscope or an electron microscope, and the sample stage is tilted by a worm gear, which results from the processing accuracy and the assembly accuracy of the tilt stage generated when the sample stage is tilted. The present invention relates to a sample stage having an adjustment mechanism configured to prevent an observation image from escaping from the microscope visual field and always operate while maintaining the observation position at the center of the microscope visual field.

[0002]

2. Description of the Related Art In a conventional sample stage, as shown in FIG. 3, unidirectional tilting stages 12 and 14 each having an arcuate lower surface are superposed on each other and each tilting stage is tilted at an arbitrary angle so that an observation sample can be arbitrarily selected. It was possible to observe from the direction. The observation point coincides with the center of curvature of each tilt stage. Each tilt stage is driven by a worm gear. This sample stage is based on Japanese Patent Laid-Open No. 3-1.
Used in electron microscopes as described in 29653.

In addition, a wedge-shaped spacer is installed between both tilt stages, and the spacer is moved in the tilt direction of the wedge to finely move the height of the tilt stage located on the upper side. The shift is corrected and the tilt center is made to coincide with the observation point.

[0004]

SUMMARY OF THE INVENTION In the above prior art,
The accuracy of meshing of the worm gear that drives the Y-direction tilt stage is determined by the processing accuracy and the assembly accuracy. However, unlike the normal worm gear used in this sample stage, it is difficult to improve the machining accuracy because the worm wheel is fan-shaped. Moreover, since the worm wheel has no central axis, the assembly accuracy cannot be measured.

Further, it is possible to correct the error in the center distance of the worm gear that drives the X-direction tilt stage, which is caused by moving the wedge-shaped spacer installed between the Y-direction tilt stage and the X-direction tilt stage. could not.

If the accuracy of the worm gear that drives the tilting stage deteriorates due to the above reasons, the magnitude and direction of the force acting on the tooth surface deviates from the ideal state, and each tilting stage moves correctly on each tilting guide member. There is a problem that it becomes impossible to slide, the center of inclination shifts, and the observation image escapes from the visual field.

[0007]

In order to achieve the above object, a wedge-shaped first spacer is provided between a Y-direction tilt guide member and a bearing that supports a worm that drives a Y-direction tilt stage. The first spacer is made to slide in the inclination direction of the first spacer. Further, the worm for driving the Y-direction tilt stage and the bearing can be moved only in the vertical direction by the first guide member on the Y-direction tilt guide member.
The Z direction guide member is fixed.

Further, a wedge-shaped second spacer is provided between the X-direction tilt guide member and a bearing that supports a worm that drives the X-direction tilt stage, and the second spacer is provided in the tilt direction of the second spacer. It is made to slide. Further, a second Z-direction guide member is fixedly provided on the Y-direction tilt stage so that the worm and the bearing for driving the X-direction tilt stage can be moved only in the vertical direction.

[0009]

A wedge-shaped first spacer is provided between the Y-direction tilt guide member and a bearing that supports a worm that drives a worm wheel fixed to the Y-direction tilt stage.
First, a worm and a bearing for driving the Y-direction tilt stage
By supporting the Z-direction guide member so as to be movable only in the vertical direction, the worm that drives the Y-direction tilt stage and the bearing finely move in the vertical direction, and an error in the axial angle between the worm and the worm wheel occurs. It is possible to correct the error in the center-to-center distance between the pair of worm gears that drives the Y-direction tilt stage without increasing the deviation between the two central planes. Further, a wedge-shaped second spacer is installed between the X-direction tilt guide member and a bearing that supports a worm that drives a worm wheel fixed to the X-direction tilt stage, and drives the X-direction tilt stage. By supporting the worm and the bearing so as to be movable only in the vertical direction along the second Z-direction guide member, the worm and the bearing for driving the X-direction tilt stage finely move in the vertical direction, and the worm and the worm. It is possible to correct the error in the center-to-center distance between the pair of worm gears that drives the X-direction tilt stage without increasing the error in the axial angle with the wheel or the deviation between the center planes of the two.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the sample stage according to the present invention when viewed in X, and FIG. 2 is a partial cross-sectional side view when viewed in Y.

In FIGS. 1 and 2, a cylindrical Y-direction tilt stage 12 is an arc-shaped guide surface 1 having the same radius of curvature.
It is slidably supported by a Y-direction tilt guide member 11 having 1a. A wedge-shaped spacer 17 is mounted on the Y-direction tilt stage 12. The spacer 17 is formed by the guide surface 12 a on the Y-direction tilt stage 12.
Is slidably guided only in the inclination direction (X direction). The spacer 17 has an inclined surface 13b at the same angle as the inclination of the spacer 17 on the lower surface, and an arc-shaped guide surface 1 on the upper surface.
An X-direction tilt guide member 13 having 3a is mounted. X
The direction tilt guide member 13 is a Z direction guide member 18 fixed to the upper surface of the Y direction tilt stage 12 and is movable only in the vertical direction (Z direction). A sample holder 15 is mounted on the X-direction tilt stage 14. The sample holder 15 holds an observation sample 16.

The center of curvature of the X-direction tilt stage 14 and the center of curvature of the Y-direction tilt stage 12 coincide with each other on the observation sample 16 and are tilted about the observation point on the surface of the sample 16. When the spacer 17 slides in the X direction, the X-direction tilt guide member 13 and the X-direction tilt stage 14 move in the vertical direction along the Z-direction guide member 18, and the curvature of the X-direction tilt stage 14 due to a processing error or an assembly error. The deviation between the center and the center of curvature of the Y-direction tilt stage 12 is corrected.

A wedge-shaped spacer 24 is mounted on the Y-direction tilt guide member 11. The spacer 24 is formed by the guide surface 11 a on the Y-direction inclined guide member 11.
Is slidably guided only in the inclination direction (X direction). A bearing 23 having an inclined surface 23 a at the same angle as the inclination of the spacer 24 is mounted on the lower surface of the spacer 24.
The bearing 23 is movable only in the vertical direction along the Z-direction guide member 25 fixed to the upper surface of the Y-direction tilt guide member 11. The worm 21 is supported by the bearing 23, and the Y
Worm wheel 22 fixed to the direction inclination guide member 11
To drive. When the spacer 24 slides in the X direction, the worm 21 and the bearing 23 move in the vertical direction along the Z direction guide member 25, so that the meshing of the worm gear 20 due to a machining error or an assembly error can be corrected.

Further, a wedge-shaped spacer 34 is mounted on the Y-direction tilt stage 12. The spacer 34 is guided by the guide surface 12a on the Y-direction tilt stage 12 so as to be slidable only in the tilt direction of the spacer 34.
On the lower surface of the spacer 34, a bearing 33 having an inclined surface 33a at the same angle as the inclination of the spacer 34 is mounted. Bearing 33
Is movable only in the vertical direction along the Z-direction guide member 35 fixedly provided on the upper surface of the Y-direction tilt stage 12.
The worm 31 is supported by a bearing 33 and drives a worm wheel 32 fixed to the X-direction tilt stage 14. When the spacer 34 is slid in the Y direction, the worm 3
1 and the bearing 33 move in the vertical direction along the Z-direction guide member 35 to cause a machining error, an assembly error, or the spacer 17 to slide in the X-direction, so that the X-direction tilt guide member 13 and the X-direction tilt stage 14 are vertically moved. It is possible to correct the meshing of the worm gear 30 caused by the movement in the direction.

[0015]

According to the present invention, the wedge-shaped spacer installed on the Y-direction tilt guide member is slid to improve the assembly accuracy of the worm gear that drives the Y-direction tilt stage. Therefore, the deviation of the center of curvature of the Y-direction tilt stage can be prevented.

Further, by sliding a wedge-shaped spacer installed on the X-direction tilt guide member, the assembly accuracy of the worm gear for driving the X-direction tilt stage can be improved. Therefore, the deviation of the center of curvature of the X-direction tilt stage can be prevented.

From the above, by making the center of curvature of both tilt stages coincide with the observation point of the sample, the movement of the observation point due to the inclination of the sample stage can be prevented with respect to the omnidirectional inclination, and the observation image escapes. This has the effect of enabling observation with a minimum of.

[Brief description of drawings]

FIG. 1 is a side view of a sample stage viewed from X, showing an embodiment of the present invention.

FIG. 2 is a side view showing a partial cross section of the sample stage in the Y direction according to an embodiment of the present invention.

FIG. 3 is a perspective view of a sample stage showing a conventional technique.

[Explanation of symbols]

11 ... Y-direction tilt guide member, 12 ... Y-direction tilt stage, 13 ... X-direction tilt guide member, 14 ... X-direction tilt stage, 15 ... Sample holder, 16 ... Observation sample, 17, 2
4, 34 ... Spacer, 18, 25, 35 ... Z direction guide member, 20, 30 ... Worm gear, 21, 31 ... Worm, 22, 32 ... Worm wheel, 23, 33 ... Bearing.

Claims (2)

[Claims] 1. A unidirectionally tiltable sample stage comprising an inclined guide member having an arcuate upper surface and an arcuate inclined stage having a lower surface slidably mounted on the inclined guide member. A worm wheel fixed on the tilt stage, a worm that drives the worm wheel, a bearing that supports the worm, and a wedge that is slidable only in the tilt direction installed between the tilt guide member and the bearing. -Shaped spacer, and a Z-direction guide member that guides the bearing and the worm so that the bearing and the worm are slidable only in the vertical direction. 2. A Y-direction tilt guide member having an arcuate upper surface, a Y-direction tilt stage having a arc-shaped lower surface slidably mounted on the Y-direction tilt guide member, and fixed on the Y-direction tilt stage. An X-direction tilt guide member having an arcuate upper surface,
An X-direction tilt stage having a lower surface which is slidably supported by the X-direction tilt guide member and which is mounted and supported so as to have the same radius of curvature as the Y-direction tilt stage, and an X-direction tilt stage having an arcuate lower surface. A biaxial tilted sample stage including a sample holder mounted so that a sample surface is aligned with the center of curvature of the Y-direction tilted stage and the center of curvature of the X-direction tilted stage, wherein A first worm wheel fixed to the first worm wheel, a first worm driving the first worm wheel, and a first worm wheel
Bearing for supporting the worm, a wedge-shaped first spacer installed between the Y-direction tilt guide member and the first bearing and slidable only in the tilt direction, and the first bearing And a first Z-direction guide member for guiding the first worm so as to be slidable only in the vertical direction, a second worm wheel fixed to the X-direction tilt stage, and a second worm wheel.
Second worm that drives the worm wheel of No. 2, a second bearing that supports the second worm, and only in the inclination direction of the wedge installed between the X-direction inclination guide member and the second bearing. Sample provided with a slidable wedge-shaped second spacer, and a second Z-direction guide member that slidably guides the second bearing and the second worm only in the vertical direction. stage.