JPS61142648A - Sample table for scan electron microscope - Google Patents

Abstract

PURPOSE:To identify a sample table and sample position depending on a symbol when the inage is observed by marking detectably through a microscope the symbol indicating the sample table position on the surface of the sample table for scan electron microscope. CONSTITUTION:On the surface on which a sample is mounted of the sample table for scan electron microscope, the spider's web shaped pattern consisting of the concentric circle and radial lines or the lattice shaped pattern consisting of the vertical and transverse lines is marked by etching or carving with the symbol such as numeral, etc. given to the radial line, vertical and transverse line. When observing the image by mounting the sample on the table, the position of the sample table and sample can be checked by providing slight parallel movement for the sample table. Therefore, when the distance from the object lens to the sample is changed, the rotary angle of the electron beam scanning coordinate, etc. can be easily checked and working efficiency can also be improved.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a sample stand for a scanning electron microscope that allows the observation position of the sample stand and the sample to be easily recognized during image observation using a scanning electron microscope (hereinafter referred to as 8EM). It is.

[Background of the invention]

In general, since the 8113M has a deep depth of focus, the sample is often observed from an oblique direction. For this reason, most of the conventional sample stands for 8EM have been made small in order to increase the degree of freedom so as not to collide with the objective lens etc. when the sample stand is tilted.

However, recently, the pattern width of semiconductors and other devices has become finer, and as a result, the conventionally widely used optical microscopes lack the resolving power, so SIBMs are used instead of optical microscopes. There is a tendency for this to increase. Therefore, in order to eliminate the need to cut the semiconductor wafer into small pieces, the 8gM, which is equipped with a large sample stage onto which the semiconductor wafer can be mounted as is, has been adopted.

On the other hand, in SIBM, an electron beam is irradiated onto a sample to be observed, and the resulting secondary electrons and reflections 1. In order to obtain image signals by collecting samples, it is necessary to place the sample in a vacuum sample chamber.

When detecting secondary electrons, many 8BMs use a combination of a scintillator and a photodetector such as a photomultiplier tube to convert the observed secondary electrons into -fluorescence and then obtain an electrical signal. It is necessary to prevent light from entering the room from outside.

Therefore, when observing a sample with 8EM,
It is impossible to directly view the sample from the outside.

Therefore, it has been difficult to easily determine where on the whole sample or on the sample stage the observation point is. 8BM also changes the electron beam scanning X by changing the distance from the objective lens to the sample, that is, the working distance.

Although the Y coordinate rotates, it is difficult to grasp this rotation angle.

[Purpose of the invention]

The present invention solves the difficulties of the prior art as described above, and
It is an object of the present invention to provide a sample stand for a scanning electron microscope that allows the observation position of the sample stand and the sample to be easily recognized during the image M festival by iM.

[Summary of the invention]

In order to achieve the above object, the present invention includes a mark indicating the position of the sample stand on the surface of a sample stand for a scanning electron microscope on which a sample is mounted, so that the position of the sample stand can be detected by the microscope. The feature is that the position of the table is recognized.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(a) and 1(b) are a plan view and a sectional view of a sample stage 1 applied to this embodiment, and the surface 1 of this sample stage 10 is
A pattern as shown in FIGS. 2(a) and 2(b) K is marked on A. That is, FIG. 2(a).

The pattern shown in (b) represents a spider web-like pattern consisting of concentric circles and radial lines, and a lattice-like pattern consisting of orthogonal vertical lines and horizontal lines, and the radial lines, vertical and horizontal lines, and A symbol, for example, a number, is written at each arbitrary number of intersections of the vertical and horizontal lines of the top.

The size of the above number is that the minimum magnification of SEEM is 20 to 10.
Since it is 0, it is less than tmm', so when a sample is attached, it is difficult to confirm the characters with the naked eye. Therefore, as shown in FIG. 2, large letters are written on parts that do not interfere with the pattern, for example, on the outermost part of each pattern.

The above patterns and symbols may be marked by carving or etching on the surface of the sample stand, or by marking the surface of the sample stand with a metal that has a different secondary electron emission rate from the material of the sample stand. Marked by vapor deposition or metallization on one person.

FIG. 3 is a plan view in which a complete semiconductor wafer 2 is mounted on the surface of the sample stage on which the spider web pattern is marked in FIG. 2(a). As is clear from this figure, although the patterns and symbols marked on the sample stage surface 1A cannot be seen inside the semiconductor wafer 2, by moving the sample stage 1 parallel to the periphery of the semiconductor wafer, , as shown in Figure 4, 8 gM observation CRT (Ca
(Thode Ray Tube) The observation position of the reflected sample stage 1 and the semiconductor wafer 2 reflected on the CRT can be easily recognized.

On the other hand, FIG. 5 is a plan view in which a plurality of semiconductor wafers 3 divided into small pieces are mounted on the sample stage surface 1A marked with the grid pattern shown in FIG. 2(b). Similarly, the observation positions of the sample stage 1 and the semiconductor wafer 5 can be easily recognized by the grid pattern and symbols marked on the sample stage 1, as shown in FIG.

Additionally, when the working distance is changed as described above, the scanning coordinates of the electron beam may rotate;
In this case, if you use the sample stage 1 marked with the grid pattern shown in Fig. 2(b), 8BM as shown in Fig.
The semiconductor wafer 3 is displayed on the observation CRT, and the rotation angle with respect to the coordinates of the sample stage 1 can be easily recognized.
[Effects of the Invention] As explained above, according to the present invention, the observation position of the sample stage and the sample can be easily recognized, and the rotation angle of the electron beam scanning coordinate when changing the working distance can be easily adjusted. can be recognized. Therefore, according to the present invention, it is possible to improve work efficiency at 11 tvt.

[Brief explanation of drawings]

Figures 1(a) and (b) are a plan view and a sectional view of a sample stage applied to the present invention, and Figures 2(a) and (b) are each pattern marked on the sample stage in Figure 1. FIGS. 3 and 5 are plan views of each embodiment of the sample stage according to the present invention when the sample is mounted, and FIGS. 4, 6, and 7 are the sample stage and mounting of the present embodiment. FIG. 3 is a diagram showing an example of a display on an observation CRT when a sample is observed using an SEM. 1.1'...Sample stand, 1 person...Sample stand surface, 2.3...Sample, enter...Spiderweb pattern, B・・・・・・Lattice pattern.

Claims (1)

[Claims] 1. In a sample stage for a scanning electron microscope on which a sample is mounted,
A sample stand for a scanning electron microscope, characterized in that a symbol indicating the position of the sample stand is marked on the sample mounting surface so that it can be detected by the microscope, and the position of the sample stand is recognized by the symbol during image observation. . 2. The above symbol shall be marked on each radial line of the spider web pattern or each vertical/horizontal line of the lattice pattern, any number of intersections of these vertical/horizontal lines, and on the outermost part of both patterns. A sample stage for a scanning electron microscope according to claim 1, characterized in that: