JPH04179041A - sample stage - Google Patents

Abstract

PURPOSE:To correct the deviation in center of tilt between a Y tilt stage and an X tilt stage to cause the tilt center to coincide with a. center of observation, by moving a wedge-shaped spacer installed between the Y tilt stage and the X tilt stage. CONSTITUTION:A wedge-shaped spacer 7 is installed between a lower Y tilt stage 2 and an upper X tilt stage 4, and this spacer 7 is slided in an inclined direction thereof. Further, Z-directional guide members 9 are provided to an X tilt stage 4 guide member 3 so that the X tilt stage 4 may be moved only in a Z direction. Accordingly, when the spacer 7 is finely moved in the inclination or tilt direction of the wedge spacer, the X tilt stage 4 is finely moved in the Z direction, whereby a center of tilt of the X tilt stage 4 can be brought into coincidence with a center of tilt of the Y tilt stage 2. This enables obtaining a sample stage having an upper/lower stage tilt-center deviation correcting means, which sample stage is of a type observable from any given direction with the upper/ lower stages superposed one over the other.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sample stage used in an optical microscope or an electron microscope that can be observed tilted in all directions. The present invention relates to a sample stage having an adjustment mechanism that prevents an observation image from escaping from the microscope field of view due to accuracy or assembly precision, and keeps the observation position always at the center of the microscope field of view.

[Conventional technology]

As shown in Fig. 3, the conventional sample stage allows the observation sample to be observed from any direction by overlapping -axis tilt stages 2 and 4 and tilting each tilt stage at an arbitrary angle. It had become. A stage similar to this sample stage is described in Japanese Patent Application Laid-Open No. 60-39749.

[Problem to be solved by the invention]

In the above conventional technology, in order to always observe an image in the field of view of a microscope at any tilt, it is necessary to precisely match the center of tilt of each tilt stage with the observation point ○ on the sample surface. It is necessary to minimize machining dimensional errors and assembly errors of the tilt stage. However, for applications such as electron microscopes that require observation at high magnifications of 10,000 times or more, there is a limit to what can be achieved by processing and assembly accuracy alone.

For example, in order to observe fine structures of semiconductors, which are becoming increasingly dense, with high resolution, observation at high magnifications of tens of thousands to hundreds of thousands of times is required.

At this time, if the tilt centers of the upper and lower tilt stages are shifted by Δ2 and are tilted at an angle θ, the observed image on the microscope field of view is shifted by ΔZXsinO in the X or Y direction. For example, if ΔZ is 10 μm, the observed image will be shifted by several hundred degrees, so the M observed image will escape out of the field of view. In order to keep the observed image on the field of view, it is necessary to suppress the deviation Δ2 of the center of inclination to about 1 μm, but this is extremely difficult to achieve.

The object of the present invention is to provide a sample stage that can be stacked in two stages, upper and lower, and can be observed from any direction.

A sample stage is provided that has a mechanism for correcting a shift in the center of inclination of an upper and lower tilt stage.

[Means to solve the problem]

In order to achieve the above object, the present invention installs a wedge-shaped spacer between a lower X-tilt stage and an upper X-tilt stage, and slides the spacer in the direction of inclination of the spacer. Further, a Z-direction guide member was provided to the guide member of the X-tilt stage so that the X-tilt stage moved only in the Z direction.

Furthermore, in order to correct the deviation of the inclination centers of the upper and lower tilt stages, four X guide rollers are provided to support the X tilt stage. It is now possible to move in the tangential direction of the cylindrical surface.

[Effect]

A wedge-shaped spacer is provided between the upper X tilt stage and the lower X tilt stage, and the X guide member supporting the X tilt stage is movably supported in only two directions by the Z guide member. By making a slight movement in the inclination direction, the X-tilt stage is made to make a slight movement in the Z-direction, and the inclination center of the X-tilt stage can be made to coincide with the inclination center of the X-tilt stage.

In addition, four X guide rollers are provided to support the X tilt stage, and moving a pair of X guide rollers located in the circumferential direction of the X tilt stage in opposite directions means that the distance between the support points of the X tilt stage is This means that X
The tilt stage can be moved slightly in the Z direction to align the tilt center of the X tilt stage with the tilt center of the X tilt stage.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. An X tilt stage 2 whose lower surface is cylindrical with a radius of curvature R2 is supported by a Y guide member 1 having an arcuate guide surface 1a with a radius of curvature R2 so as to be freely tiltable in the Y direction. A wedge-shaped spacer 7 is provided on the upper surface of the X-tilt stage 2. The spacer 7 is guided by a guide surface 2a provided on the upper surface of the X tilt stage 2 so as to be movable only in the direction of inclination of the spacer 7 (X direction). A spacer cantering mechanism 8, which is fixed to a Y tilt stage and includes a ball screw and a motor, is connected to either end surface of the spacer 7 in the X direction. The upper surface of the spacer 7 has an inclined surface 3b having the same angle as the inclination angle of the spacer 7 on the lower surface, and an arc-shaped guide surface 3 with a radius of curvature R4 on the upper surface.
An X guide member 3 with a is installed. X guide member 3
is supported by a Z guide member 9 provided on the upper surface of the Y tilt stage 3 so as to have a degree of freedom only in the X direction. Further, the cylindrical X tilt stage whose lower surface has a radius of curvature R4 is supported by the X guide member 3 so as to be freely tiltable in the X direction.

A sample holding table 5 is provided on the upper surface of the X-tilt stage 4, and holds an observation sample 6.

The radius of curvature R4 of the X tilt stage 4 is set so that the center of curvature coincides with that of the Y tilt stage 2, and the Y tilt stage 2 and the X tilt stage 4 are tilted around the observation point O on the surface of the sample 6. become. However, due to processing errors, assembly errors, etc., it is difficult to accurately match the center of curvature of the Y tilt stage 2 and the center of curvature of the X tilt stage 4, and they usually deviate by Δ2. At this time,
By moving the spacer 7 in the X direction by the spacer cantering mechanism 8, the X guide member 3 and the X tilt stage 4 are moved in the X direction, and the deviation ΔZ between the centers of curvature of both tilt stages can be corrected. Further, since the X guide member 3 is restrained from moving in the XX direction by the Z guide member 9, the observation point ◯ does not move in the XX direction. Therefore, according to this embodiment, even if the Y tilt stage 2 and the X tilt stage 4 are tilted at any angle, the shift of the IS point ○ can be minimized, and the observation point 0 can be set at any arbitrary angle within the field of view of the microscope. It becomes possible to observe from the direction of

Another embodiment of the present invention will be described with reference to FIGS. 3 and 4. A Y tilt stage 2 having a cylindrical lower surface with a radius of curvature R2 is supported by a Y guide member 1 having an arcuate guide surface 1a with a radius of curvature R2 so as to be freely tiltable in the X direction. Four X guide rollers 10 are provided on the upper surface of the Y tilt stage 2 and are arranged in the axial direction and the circumferential direction of the X tilt stage 4.

The X tilt stage, whose lower surface has a cylindrical surface with a radius of curvature R4, is supported by an X guide roller 10 to freely tilt in the X direction, and is restrained in the X direction by a thrust bearing 14 provided on the Y tilt stage 2.

The X guide roller 10 is attached to a guide member 13 installed on the upper surface of the Y tilt stage 2 in the X direction. Furthermore, two X guide rollers 10a are located in the axial direction (X direction) of the X tilt stage 4.

10a', 10b, and 10b' are connected to each other by a connecting member 13. A roller drive mechanism 11 is connected to the connecting member 13, and X guide rollers 10a face each other as shown by the two-dot chain line in FIG.

10b, 10a'', and 10b' are driven in opposite directions.

A sample holding table 5 is provided on the upper surface of the X-tilt stage 4 and holds an observation sample 6.

Similar to the above embodiment, the center of curvature of the X tilt stage 4 and the center of curvature of the Y tilt stage are arranged to match. Here, as shown by the two-dot chain line in FIG. 3, when the roller drive mechanism 11 drives the X guide rollers 10 closer to each other, the distance between the support points of the X tilt stage 4 is shortened to Ll, and the X The tilt stage 4 moves in the 2+ direction. Conversely, if the X guide roller 10 is released, the X tilt stage 4 can be moved in two directions. Therefore, the deviation between the centers of curvature of the X tilt stage 4 and the Y tilt stage 2 can be corrected, and observation point 0 can be observed from any direction within the field of view of the microscope.

〔Effect of the invention〕

According to the present invention, the X-direction position of the X-tilt stage can be changed by moving the wedge-shaped spacer installed between the Y-tilt stage and the X-tilt stage. Correct the l! It can be matched with the observation point. Therefore, movement of the observation point due to the tilting of the tilt stage is prevented, and observation can be performed while minimizing escape of the i-sacred image.

Furthermore, by moving the X guide roller that supports the X tilt stage, the position of the X tilt stage in two directions can be changed, and the shift in the center of curvature can be corrected. Therefore, observation can be performed with minimal deviation of the observation image.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
Figure 3 is an explanatory view showing another embodiment of the present invention, Figure 4 is a view viewed from the ■ arrow in Figure 3, and Figure S is a perspective view showing a conventional sample stage. . 1...Y guide member, 2...tilt stage, 3...
-X guide member, 4...X tilt stage, 7...spacer, 8...spacer drive mechanism, 9...2 guide member,
10...X guide roller, 11...roller drive mechanism, 1
3... Guide member, 14... Thrust bearing. Agent: Patent attorney, J\Kawayo Otobun'nee No. 2m, Figure 3, Collection 4,

Claims (1)

[Scope of Claims] 1. A Y tilt stage whose lower surface is a cylindrical surface and which is supported by an arc-shaped Y guide member so as to be tilted freely in the Y direction, and an arc-shaped X guide member installed on the Y tilt stage. an X-tilt stage whose lower surface is a cylindrical surface and which is supported freely tilting in the X direction and installed so that the center of curvature roughly coincides with the Y-tilt stage; and a Y-tilt stage with the sample surface on the X-tilt stage in front. and a sample holder installed to approximately coincide with the center of curvature of the X tilt stage, in which a wedge-shaped spacer is installed between the Y tilt stage and the X guide member in the direction of inclination of the wedge. A spacer drive mechanism is provided on the end face of one of the spacers facing the moving direction of the spacer, and a Z guide member is provided to guide the X guide member so as to be movable only in the Z direction. A sample stage characterized by: 2. A Y tilt stage with a cylindrical lower surface supported by an arc-shaped Y guide member so as to be freely tilted in the Y direction, and four Xs installed symmetrically with respect to the Y and X axes on the Y tilt stage.
a guide roller; an X tilt stage which is supported by the X guide roller so as to be freely tilted in the X direction and whose lower surface is cylindrical and is installed so that the center of curvature approximately coincides with the Y tilt stage; and on the X tilt stage; In the sample stage, the sample holding table is installed such that the sample surface approximately coincides with the center of curvature of the Y tilt stage and the X tilt stage.
A guide member that supports the guide roller movably in the tangential direction of the cylindrical surface of the X tilt stage is provided, a connecting member that connects the two X guide rollers located symmetrically to the X axis, and a connecting member that is symmetrically located to the Y axis. A sample stage characterized by being provided with a roller drive mechanism that drives two positioned X guide rollers in opposite directions.