JPH0765768A - Sample chuck mechanism of scanning type electron microscope - Google Patents

Abstract

PURPOSE:To fix a sample on a sample mount by chucking the sample stably and securely without using an adhesive, by providing two sets of chuck members which consists of chuck claws moving by regulation screws, at the upper and the lower sides of a center pillar fixed to the sample mount. CONSTITUTION:A center pillar 41 is fixed to a disconnection plate 142 with a screw 411, and chucks 4A and 4B are installed to the center pillar 41. Then, a fixing screw 43 is loosened, and both center blocks 42 are moved z so as to fit the interval z to the height size of a chip 2'. Then, both screw rods 44a and 44b are rotated to move x both cubic blocks 45a and 45b, and the interval x of both chuck claws 47a and 47b is fitted to the width driction of the chip 2'. Furthermore, both chuck claws are moved y by both regulation screws 46a and 46b, the chip 2' is inserted to the gap, and the both chuck claws are moved y in the reverse directions so as to chuck the chip 2'. Consequently, a random form of sample can be chucked securely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample chuck mechanism for mounting a sample on a sample stage of a scanning electron microscope.

[0002]

2. Description of the Related Art As is well known, a scanning electron microscope (SEM) has a high magnification of 100,000 times or more and is used for observing the fine structure of various substances. Also, the crystal structure is observed and analyzed by SEM. FIG. 3 shows a schematic configuration of a main part of the SEM. The SEM 1 has a microscope main body 11 and a vacuum chamber 12 provided below the microscope main body 11. Inside the SEM 1, a drive mechanism 13 in the 6-axis direction and above it are provided. A sample table 14 is provided in the. An opening / closing door 121 is provided on one side surface of the vacuum chamber 12, and a sample table 14 is pulled out from the vacuum chamber 12 to mount the sample 2. The sample table is inserted again into the chamber 12 and air is evacuated to form a vacuum. The sample table 14 is moved in the X, Y, Z directions by the drive mechanism 13 or is rotated around the X, Y, Z axes, and the microscope main body 11
On the other hand, the observation points of the sample 2 are aligned and observed.

FIG. 4 shows the appearance of the sample table 14. The sample table 14 is provided on the 6-axis drive mechanism 13 and has two guide grooves 141a, 1a.
Guide plate 141 with 41b and each guide groove 141a, 1 on the bottom.
Attachment / detachment plate 142 having guide rods 142a and 142b fitted to 41b
, And a mounting plate 143 provided on the detachable plate 142. The mounting plate 143 has a central shaft 143a fixed to the lower surface thereof screwed into the vicinity of the center of the detachable plate 141 to be detachably fixed, and has a hand hole H with respect to a screw hole 144 provided on its side surface.
The mounting plate 143 is pulled out or inserted by screwing in and moving it along the guide grooves 141a and 141b.

There are various kinds of samples 2, but in the case of a chip 2'of a silicon wafer, when observing the surface 21, the chip 2'faces the surface 21 upward and mounts it by a suitable jig (not shown). It is fixed to 143. On the other hand, when observing either side 22 of the chip 2 ', the mounting plate
The L-shaped fixture 3 shown in FIG. 4 is screwed to an appropriate position of 143, and the surface 21 of the chip 2 ′ is adhered to its vertical surface by an appropriate adhesive agent for observation. In the SEM 1, the sample 2 needs to be completely grounded, and is not grounded by an insulating adhesive, so a conductive adhesive is used.

[0005]

As described above, the fixture 3
The method of adhering the chip 2 ′ to the vertical surface of No. 2 with a conductive adhesive requires a considerably long time, and therefore its workability is not good. That is, this adhesive contains volatile components, and when the chip 2'is inserted into the chamber 12 and a vacuum is drawn while the volatile components are not sufficiently dried, the volatile components evaporate and the required degree of vacuum is obtained. I can't. A minimum of 30 minutes is required to fully dry the adhesive. Also,
Since the fixture 3 and the mounting plate 143 are contaminated by the adhesive, it is necessary to clean them in a timely manner, and the conductive adhesive has various drawbacks such as being considerably expensive. The present invention has been made in view of the above, and an object thereof is to provide a chuck mechanism that mechanically chucks a sample 2 such as a chip 2 ′ and mounts it on a sample base 14 without using an adhesive.

[0006]

The present invention is a SEM sample chuck mechanism in which a central column is detachably fixed to an appropriate position of the sample table. The center column penetrates the center part, moves in the z direction by hand, and is fixed at an arbitrary position by a fixing screw, and two screw rods rotatably supported on both sides of the center block. , A cubic block screwed to each screw rod and moved in the X direction by each rotation, and attached to each cubic block,
One set of chuck portions, which is composed of chuck claws that move in the Y direction by respective adjusting screws, is arranged above and below the central column.

[0007]

In the above-mentioned chuck mechanism, the two columns of chuck portions arranged above and below the central column which is detachably fixed to an appropriate position on the sample table have z intervals of respective central blocks. , Is set to fit the height of the sample. A cubic block is screwed to each of the two threaded rods rotatably supported on both sides of the central block, and these are moved in the X direction by the rotation of each threaded rod.
Each x-spacing is set to fit the width of the sample. In this setting, when the chuck claws are moved in the Y direction with respect to the sample inserted between each cubic block and each chuck claw, the four positions around the sample are pressed by the chuck claws. It is chucked stably and surely. In this case, since the upper and lower cubic blocks can independently set the x-interval, it is possible to reliably chuck a sample having an almost arbitrary shape. The setting of the z-interval of each central block and the x-interval of each cubic block and the chuck operation of the chuck claws described above are manual operations, but can be easily performed in a short time.

[0008]

1 is a plan view of a chuck mechanism 4, and FIG. 1 (b) is an elevation view from the front side. 2A and 2B are perspective external views for explaining a method of chucking the sample 2 by the chuck mechanism 4. FIG. 2A is a square chip 2'of a silicon wafer, and FIG. 2B is a disk chip 2 ". 1 (a) and 1 (b), the chuck portions 4A and 4B have the same structure, as shown in (b), with respect to the screw holes of the detachable plate 142 described above. screw
A central column 41 is provided, which is screwed into and fixed with 412 so as to be detachably attached. The flange 411 is for stabilization. Each chuck part 4A, 4B has a central column 41 penetrating through the central part thereof and is manually moved z (up and down), and is fixed to an arbitrary position by a fixing screw 43, and freely rotatable on both side surfaces thereof. Two supported screw rods 44a and 44b, and cubic blocks 45a and 45 that are screwed into each screw rod and move x by each rotation.
b, and chuck claws 47a, 47 attached to each cubic block and moving in y by the respective adjusting screws 46a, 46b.
As shown in (b), both chuck parts 4A and 4B are arranged above and below the central column 41.

Referring to FIG. 2A, a method of chucking the rectangular tip 2'to the chuck mechanism 4 will be described by taking the square tip 2'as an example. First, the attachment / detachment plate 142 is pulled out from the chamber 12, and the central column 41 is fixed to the above-mentioned screw hole by the screw 412 to mount the chuck mechanism 4. Then, each fixing screw 43,4
3 is loosened and each central block 42, 42 is z-moved, and its z-interval is set so as to match the height dimension of the chip 2 '.
In addition, each screw rod 44a, 44a, 44b, 44b is rotated to move each cubic block 45a, 45a, 45b, 45b x, and each chuck claw 47a,
The x-spacing of 47a, 47b, 47b is set to match the width dimension of the chip 2 '. Further, the chuck claws are moved in the y direction by the adjusting screws 46a, 46a, 46b, 46b, and stopped at positions where appropriate gaps are formed between the surfaces of the cubic blocks. When the tip 2'is inserted into this gap and each chuck claw is moved in the opposite direction by y, the tip 2'is pressed by these and contacted with the surface of each cubic block to be chucked. The chuck mechanism 4 that chucks the chip 2'is inserted into the chamber 12, and air is exhausted to create a vacuum.
The axis drive mechanism 13 moves in the X, Y, Z directions, or
It is rotated around the Y and Z axes, and the observation point of the chip 2 ′ is aligned with the microscope body 11 for observation. Figure 2
In the case of the circular chip 2 ″ shown in (b), the same as above, 4
The part is chucked by each chuck claw 47a, 47a, 47b, 47b, and the side surface of the upper part is observed. In the above,
As the sample 2, a square chip 2'and a circular chip 2 "are taken as an example, but other irregular shapes can also be used.
Since the distances a and 47b can be set independently of each other, it is possible to securely chuck.

[0010]

As described above, in the chuck mechanism of the present invention, the sample of arbitrary shape is securely and stably chucked at four points by the mechanical method, which is expensive in the conventional adhesive method. All the drawbacks such as the use of conductive adhesive, its long drying work, and the contamination of the sample stand are eliminated, and the sample can be easily mounted in a short time, improving its workability and SEM operation efficiency. There are great effects that contribute to the.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, (a) is a plan view of a chuck mechanism 4, and (b) is an elevation view from the front side.

FIG. 2 is a perspective external view of a chuck mechanism 4 that chucks a sample 2, where (a) is a rectangular chip 2 ′ and (b) is a sample.
Indicates the case of the disk chip 2 ".

FIG. 3 shows a schematic configuration diagram of a main part of a scanning electron microscope (SEM).

FIG. 4 shows an external view of the sample table 14.

[Explanation of symbols]

1 ... Scanning electron microscope (SEM), 11 ... Microscope body, 12
… Vacuum chamber, 13… 6-axis drive mechanism, 14… Sample stand, 14
1 ... Guide plate, 142 ... Removable plate, 143 ... Mounting plate, 144 ... Screw hole, 2 ... Sample, 2 '... Square tip, 2 "... Circular tip, 3 ... Fixing tool, 4 ... Chuck mechanism, 4A, 4B … Chuck part, 41… Center pillar, 411… Screw, 412… Flange, 42
… Central block 43… Fixing screws, 44a, 44b… Screw rods, 45
a, 45b ... cubic block, 47a, 47b ... chuck jaws.

Claims (1)

[Claims] 1. In a scanning electron microscope having a sample stage for mounting a sample inside a vacuum chamber, a central column is detachably fixed to an appropriate position of the sample stage, and the central column penetrates the central part. Then, the center block is manually moved in the z direction and fixed at an arbitrary position by a fixing screw, two screw rods rotatably supported on both side surfaces of the center block, and each of the screw rods. Two cubic blocks that are screwed together and move in the X direction by each rotation, and are attached to each of the cubic blocks, and Y is adjusted by each adjustment screw.
2. A sample chuck mechanism for a scanning electron microscope, characterized in that two sets of chuck parts each composed of a chuck claw that moves in a predetermined direction are arranged above and below the central column.