JPH01122554A - Particle-ray microanalyzer - Google Patents

Abstract

PURPOSE:To confirm whether a sample is located on the over-focus side or under-focus side without moving the sample and improve the operability by slantly arranging a marker member with the portion allowing the light to perme ate and the portion shielding the light at the position of an objective lens to the face of an object or at the position optically equivalent to the position. CONSTITUTION:A marker plate 15 is slantly arranged at the object face of an objective lens as the visual field limiting orifice 14 of a particle-ray microanalyzer provided with an optical microscope. Since this marker plate is inclined, a marker 16V is dislocated upward and downward centering the object face of the limiting orifice 14, and points (a)-(e) on the marker 16V are image-formed as points (a')-(e') centering the image face of the lens. As a result, the marker image on the sample face is changed due to the positional relationship between the sample face and the image formation face, focused points are indicated as 4a-4e as the sample face is lowered to the points (a')-(e') and others are indicated as defocused points respectively, thereby the focus state can be judged without moving the sample.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides an apparatus that can easily perform focusing using an optical image of a sample in a particle beam microanalyzer equipped with an optical microscope.

[Prior art] Generally, in particle beam microanalyzers such as X-ray microanalyzers and ion microanalyzers,
The surface of the sample is analyzed by detecting the X-rays and secondary ions generated when the sample is irradiated with electron beams or ions. Preliminary observations and alignment to the spectrometer are being carried out.

In FIG. 4, reference numeral 1 denotes an electron gun, and an electron beam EB generated from this electron gun is focused by focusing lenses 2 and 3 and irradiated onto a sample 4. Then, X-ray 1 reflected electrons, secondary electrons, etc. generated from the sample by this electron beam irradiation are detected by a detector not shown. 5 is a vertical movement mechanism for vertically moving the sample 4 along the optical axis Z. 6
is an optical microscope installed between the focusing lenses 2 and 3, and this optical microscope has a light source 7. Condensing lens 8. Projection lens9. It is composed of a semi-transparent mirror 109, a reflective mirror 119, reflective objective lenses 12a and 12b, and an eyepiece 13. This reflection mirror 11 and reflection type objective lens 1
Holes are provided in each of 2a and 12b so as not to obstruct passage of the electron beam FB. The light from the light source 7 passes through the condensing lens 7 and the projection lens 8 to the semi-transparent mirror 101.
It is reflected by the reflecting mirror 11, and the objective lens 12a, 1
2b to illuminate the sample 4.

On the other hand, the light generated from the sample surface is transmitted through the objective lenses 12a and 1.
2b, reflective mirror 11. It is guided outside through the semi-transparent mirror 10 and the eyepiece 13, and an optical image of the sample can be observed.

14 is an objective lens 12a in the optical path of the illumination system of the optical microscope;
A field-limiting diaphragm placed on the object plane of 12b, and the hole 14 of this diaphragm. A marker plate 15 is attached on top a, as shown in a plan view in FIG.

This marker board is made of transparent glass or plastic, for example, and cross-shaped markers 16H and 16V are drawn on the marker board. This marker is formed by depositing a metal, such as aluminum or chrome, to a thickness of several thousand thicknesses.

Hereinafter, the operation of this device will be explained in detail based on the optical diagram shown in FIG. 6 in which the semi-transparent mirror 10 and the reflecting mirror 11 are omitted.

As is clear from the figure, if the marker plate 15 is placed at the object plane position of the objective lens 12, images of cross-shaped markers 16H and 16V are formed on the image plane S of the objective lens 12. Therefore, when the surface of the sample 4 coincides with the image plane S, a marker image is formed on the sample in a state of just focus, and this marker image can be observed together with the sample F31 image. Therefore, the pin 1 of the imaging lens system consisting of the objective lens 12 and the eyepiece 13 is aligned in advance with the image plane S of the objective lens 12, and the sample 4 is moved up and down along the optical axis Z while observing the marker image. By moving the
If the marker image projected onto the sample is made to be the clearest, the sample surface can be placed at the image plane S, and the optical microscope will be in focus. Furthermore, the alignment of the spectrometer, which is aimed at the position of the image plane S, is also completed.

[Problems to be Solved by the Invention] In such a configuration, when starting focusing, the sample surface and the image plane S of the objective lens are often out of alignment, and both the sample image and the marker image are blurred. At this time, it is unclear whether the blur is due to the sample surface shifting below or above the image plane S, in other words, whether it is due to overfocus or underfocus. . Therefore, the operator first moves the sample upward or downward, and if this causes the image to become less blurry, the operator moves the sample in the opposite direction, or the image becomes clearer. In such cases, the sample is further moved in the same direction. In this way, the direction of movement of the sample cannot be determined unless the sample is moved in either direction, which makes the operation extremely complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of this problem, and it is an object of the present invention to provide an apparatus that can determine the moving direction of a sample without actually moving the sample.

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a light source, a focusing lens for irradiating a sample with light from the light source, an objective lens having a hole in the center, and a focusing lens for irradiating a sample with light from the light source. In an apparatus equipped with an optical microscope comprising an eyepiece lens through which light from the sample that has passed through the objective lens is guided, a marker member having a light transmitting part and a light blocking part is positioned at the object plane position of the objective lens or at the object surface position of the objective lens. It is characterized by being arranged at an angle at a position optically equivalent to the surface position.

Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

[Embodiment] FIG. 1(a) is an enlarged cross-sectional view of essential parts showing an embodiment of the present invention, and FIG. 1(b) is a side view thereof, and the same reference numerals as in FIGS. It indicates an element.

This embodiment is characterized in that the marker plate 15 placed at the position □ of the field limiting diaphragm 14, that is, the object plane of the objective lens 12, is tilted. Here, marker board 1
The center of inclination (inclination axis) of 5 is one of the two markers shown in FIG. 5, for example 16H, and this inclination axis is orthogonal to the optical axis R of the optical lens system.

By tilting the marker plate 15 in this way, the marker 1
6V are placed with the object plane of the objective lens as the center and are continuously shifted upward and downward.Therefore, points a to e on the marker 16V are centered on the image plane S of the objective lens. As a result, due to the positional relationship between the sample surface and the imaging surface S, the marker images formed on the sample surface are The image changes as shown in Figure 3. Figure 3 (a> is the marker image on the sample surface when the sample surface is at position 4a in Figure 2 above the image plane S; Only the image a- of point a is focused and the other points are defocused, so only point a' appears as an image.The sample surface is 4b, 4.c, 4d.
,4. The point that is focused according to e and the descending slope is b'
, c-, d-, and e', the positional relationship between the sample surface and the image surface S can be immediately determined based on the marker image.

That is, when the sample is located above the image plane S of the objective lens 12 (on the overfocus side), the marker image is located at any position between FIG. 3(a) and FIG. 3(C). , and conversely, when the sample is located below the image plane S of the objective lens (on the underfocus side), it appears somewhere between Figure 3(C) and Figure 3(e). It hangs in position. Therefore, when focusing, the position of the sample is on the overfocus side if the marker image is on the left side of the center of the viewing area F (indicated by C- in Figure 3 (C)), and on the underfocus side if it is on the right side. This makes it possible to easily determine whether the sample should be moved upward or downward.

In addition, especially when the sample surface is at 4C, that is, when it coincides with the image plane S and is in focus from 1 to 1, the marker image 16H-
Since it is imaged as a line, it is possible to easily determine the Jas 1, A, and Cas positions.

It should be noted that the above description is an example of the present invention, and many modifications can be made in implementing the present invention. For example, we used a crosshair-like marker as a marker, but you can also use a scale line if it is displayed along the slope, or a line of numbers or figures. It can be of any shape.

Moreover, although the marker was formed by vapor-depositing metal, it may also be drawn on a transparent plate with a paint such as black that does not transmit light.

Furthermore, instead of using a transparent plate, a wire bent into an appropriate shape may be directly tilted over a large part of the field-limiting diaphragm.

Further, the position where the marker plate is placed is not necessarily limited to the position of the object plane of the objective lens, but may be any position that is optically equivalent thereto. For example, the object surface position of the objective lens may be the object surface position of the projection lens, which becomes the image forming position.

[Effects] As detailed above, according to the present invention, when performing focusing, it is possible to check whether the position of the sample is on the overfocus side or the underfocus side without moving the sample. The moving direction of the sample can be immediately determined, and operability can be improved.

[Brief explanation of the drawing]

FIG. 1(a) is an enlarged cross-sectional view of a main part showing one embodiment of the present invention, FIG. 1(b) is a side view thereof, and FIGS. 2 and 3(a)
7(e) are diagrams for explaining the present invention in detail, and FIGS. 4 to 6 are diagrams for explaining a conventional example. 1: Electron gun 2.3; Focusing lens 4: Sample
5: Vertical movement mechanism 6: Optical microscope
7: Light source 8: Condenser lens 9: Projection lens 10: Semi-transparent mirror 11: Reflective mirrors 12a, 12b: Reflective objective lens 13: Eyepiece lens 14: Field-limiting aperture 15: Marker plates 16H, 16V: Marker

Claims (1)

[Claims] An optical microscope consisting of a light source, a focusing lens for irradiating the sample with light from the light source, an objective lens having a hole in the center, and an eyepiece through which the light from the sample that has passed through the objective lens is guided. In the apparatus, a marker member having a light-transmitting part and a light-blocking part is tilted and arranged at the object plane position of the objective lens or at a position optically equivalent to the object plane position. line microanalyzer.