JPH0438249Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a sample holder for an electron beam length measuring machine, etc., and particularly to a sample holder for positioning a plate-shaped sample at a concentric position.

[Conventional technology]

An electron beam length measuring machine is a device that scans an electron beam in a fixed direction and measures distances such as minute line widths of IC patterns on plate-shaped samples such as wafers and masks from changes in secondary electrons. The XY coordinates of the multiple fiducial marks on the top are accurately measured, and the position of each pattern on the wafer etc. can be determined accurately from those values. By the way, the reference marks of samples such as silicon wafers are placed concentrically, so by setting the samples concentrically, the deviation in the position of the reference marks can be reduced, correction by the control circuit can be easily performed, and automatic measurement can be performed. There is.

Conventionally, as shown in FIG. 4, as shown in FIG. In order to hold the pinion with the chuck pins 2 arranged at equal intervals and the regulating plate 3 that abuts the orientation flat part 1a, three of the four racks that mesh with the pinion in a grid pattern are placed at the same distance from the center. By providing the chuck pin 2 and the regulating plate 3 on the other one, the rotation of the sample 1 is regulated and held concentrically.
A method has been proposed in which a single sample holder can be used for many types of samples with different shapes and sizes (Utility Model Application No. 16933/1983).

[Problem that the invention attempts to solve]

However, in the conventional sample holder as described above, when holding the sample 1 having a plurality of notches 1b as shown in FIG. 3, the center of the sample 1 and the center of the sample holder are shifted from each other. There was a problem that it could not be held concentrically.

This idea was developed to solve the above problems. Even for samples with multiple notches, the electron beam can be held concentrically by aligning the center of the sample with the center of the sample holder. The purpose is to provide sample holders for length measuring machines, etc.

[Means for solving problems]

This idea consists of a pinion provided on the base, and first and second pinions meshing in parallel with this pinion.
a rack, and first and second holders provided at the tips of the first and second racks extending on the opposite side from the pinion, and moving the same distance from the center to capture the circumferential shape of the sample from three sides. first and second holding parts provided on the first holder and a third holding part provided on the second holder so as to abut on the peripheral edge of the sample; a rotation regulating section provided at a position facing the first and second holding sections of the second holder so as to be in contact with each other; a pressing means for pressing the rotation regulating section against the orientation flat section of the sample; This sample holder is characterized by comprising: urging means for urging the first or second rack toward the center with a force greater than the pressing force of the pressing means.

[Effect]

In the sample holder of the present invention, the two racks reciprocate by the same distance in opposite directions due to the rotation of the pinion, the first to third holding parts abut against the periphery of the sample, and the rotation regulating part The specimen is held in contact with the specimen so as to restrict its rotation. At this time, the first
The position in the y-axis direction is determined by the second holding part and the rotation regulating part, and then the position in the x-axis direction is determined by the third holding part.
The axial position is determined and the sample is held so that its center coincides with the center of the sample holder.

〔Example〕

This invention will be explained below with reference to embodiments of the drawings.

Figures 1 to 3 show an embodiment of this invention, with Figure 1 being a plan view of the sample holder and Figure 2 -
It shows the state when looking at the surface, and the second figure is - in Figure 1.
The sectional view and FIG. 3 are plan views of the sample attached state.

In the drawing, 4 is a casing-like base;
The structure is such that an upper lid 4c covers the upper part of a lower case 4b extending in a rectangular shape around a center piece 4a. Two parallel insertion passages 5a and 5b are provided in the lower case 4b of the base 4 with the center piece 4a in between, and an opening is formed in the upper lid 4c corresponding to one end on the opposite side of each passage. 6
is provided. Further, a pinion 7 is rotatably attached to the center piece 4a via a bearing 8 at the center of the base 4.

Racks 9a and 9b are reciprocatably inserted through the insertion passages 5a and 5b, one end of each on the opposite side meshes with the pinion 7, and the other end extends in the opposite direction. Holders 11a and 11b extending on both sides are attached to the ends of the racks 9a and 9b extending on the opposite side from the pinion 7 through the opening 6 by screws 10a and 10b provided at the same distance from the engagement point with the pinion 7. , the holder 11a has first and second chuck pins 2 on both sides of the base 4.
a, 2b are attached, and a third chuck pin 2c is attached to one side of the base 4 of the holder 11b. These chuck pins 2a to 2c are arranged so as to move the same distance from the center, and the chuck pin 2c is the same as the chuck pin 2a.
Alternatively, it is placed at a position facing 2b. On one side of the holder 11b are chuck pins 2a, 2b.
A regulating plate 3 is attached by a pin 12 at a position opposite to the plate 3, and is pressed toward the center by a spring pressure 13.

A spring tension 16 is provided in the tension direction between the pin 14 provided on the lower case 4b and the pin 15 provided on the rack 9a.
a and 9b are biased toward the center. The spring tension 16 is given a tensile force greater than the pressing force of the spring pressure 13. 17 is a spacer attached to the base 4, and 18 is a jig.

In the sample holder constructed as described above, the racks 9a and 9b are engaged with the parallel pinion 7, so that the rotation of the pinion 7 reciprocates the same distance in opposite directions. and screw 1
Since the pins 0a and 10b are at the same distance from the point of engagement with the pinion 7, the chuck pins 2a to 2c move the same distance from the middle, and the regulating plate 3 also moves at almost the same position. Since the pin 15 of the rack 9a is pulled by the spring tension 16, the rack 9a9b is urged toward the center.

To attach the sample 1 to the sample holder, the jig 18 is pushed out and the rack 9a is pressed to spread the chuck pins 2a to 2c and the regulating plate 3 outward, and then the sample 1 is placed on the spacer 17, and the jig is When the pressure by 18 is released, the spring tension 1
6 pulls the rack 9a, causing the pinion 7 to rotate, and the other racks 9b also move toward the center, causing the chuck pins 2a to 2c to abut the circular periphery of the sample 1 from three sides, and the regulating plate 3 to release the spring plate. The shear 13 moves the sample 1 from the position facing the chuck pins 2a and 2b to the orientation flat portion 1.
Press a to restrict rotation. At this time, since the tensile force of the spring tension 16 is greater than the pressing force of the spring pressure 13, the position of the sample 1 in the y-axis direction is first determined by the chuck pins 2a, 2b and the regulating plate 3, and then the chuck pin 2c is Therefore, the position in the x-axis direction is determined.

The sample 1 held in the above manner is always set in a concentric position regardless of the error in external dimensions, and the center of the sample 1 is held in alignment with the center of the sample holder. Further, even if the shape and size of the sample 1 changes, the racks 9a and 9b are always biased toward the center, so that they can be used for many types of samples. When the thickness of the sample 1 is different, the spacer 17 is replaced and the sample 1 is attached in order to position the upper surface of the sample 1 at a fixed position.

In addition, although the chuck pins 2a to 2b were illustrated as the holding portions in the above description, other holding mechanisms may be used. Further, although the restriction plate 3 is illustrated as the rotation restriction part, other similar mechanisms may be used. Further, the structure of the base 4 and the means for attaching the pinion 7 are not limited to those shown in the drawings.

Although the present invention is suitable for the sample holder of an electron beam length measuring machine, it is also applicable to the sample holder of other devices that position a plate-shaped sample in a concentric position or a fixed position for the same purpose.

[Effect of idea]

According to this invention, one of the two racks meshing in parallel with the pinion is provided with the first and second sample holding parts at the same distance from the center, and the other rack is provided with the sample rotation regulating part. and a third sample holding part were provided, and the first or second rack was urged toward the center with a force greater than the pressing force of the rotation regulating part, so that the first and second holding parts and the rotation regulating part While the rotation of the sample is regulated, the sample can be positioned using the third holder so that the center of the sample coincides with the center of the sample holder.This allows the sample to be automatically placed in the correct position. Positioning can be performed. In addition, even for samples with multiple notches, the center of the sample and the center of the sample holder can be aligned and held concentrically, and one sample holder can be used for many types of samples with different shapes and sizes. It has the advantage of being able to attach and replace specimens with a simple structure and operation, and to position even specimens with errors in external shape in concentric positions.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of this invention, with Figure 1 being a plan view of the sample holder and Figure 2 -
Figure 2 shows the side viewed from the side, and Figure 2 shows - of Figure 1.
3 is a sectional view, FIG. 3 is a plan view showing a state in which a sample is attached, and FIG. 4 is a plan view showing a state in which a sample is attached to a conventional sample holder. In each figure, the same reference numerals indicate the same or corresponding parts.
1 is a sample, 2, 2a to 2c are chuck pins, 3 is a regulation plate, 4 is a base, 5a, 5b are insertion passages, 7 is a pinion, 9a, 9b are racks, 11a, 11b
13 is a spring pressure, 16 is a spring tension, and 17 is a spacer.

Claims (1)

[Claims for Utility Model Registration] (1) A pinion provided on the base, and first and second pinions meshing in parallel with this pinion.
a rack, and first and second holders provided at the tips of the first and second racks extending on the opposite side from the pinion, and moving the same distance from the center to capture the circumferential shape of the sample from three sides. first and second holding parts provided on the first holder and a third holding part provided on the second holder so as to come into contact with the peripheral edge of the sample; a rotation regulating section provided at a position facing the first and second holding sections of the second holder so as to come into contact with the second holder; and a pressing means for pressing the rotation regulating section against the orientation flat section of the sample. A sample holder comprising: a biasing means for biasing the first or second rack toward the center with a force greater than the pressing force of the pressing means. (2) The sample holder according to claim 1, wherein the holding portion is a chuck pin. (3) The sample holder according to claim 1 or 2, wherein the third holding part is located opposite the first or second holding part. (4) The sample holder according to any one of claims 1 to 3 of the utility model registration claim, in which the rotation regulating portion is a regulating plate pressed by a spring pressure. A sample holder according to any one of claims 1 to 4, which is adapted to be attached.