JPS628437A - Particle beam micro-analyzer - Google Patents

Abstract

PURPOSE:To facilitate focusing by arranging a marker member having light transmitting portion and blocking portion at the subject face position or optically equivalent position of objective lens. CONSTITUTION:When arranging a marker board 14 at the subject face of objective lens 11, cross image of markers 15a, 15b is focused on the image face S of objective lens 11. Upon matching of the surface of sample 4 and the image face S, the marker image is focused on the surface of sample under just focus state thus to enable observation of marker image and sample image. The imaging lens system comprising an objective lens 11 and an eye lens 12 is previously focused to the image face S of the objective lens 11, to move the sample 4 up and down along the optical axis while observing the marker image thus to most clarify the marker image on the sample and to arrange the sample at the position of the subject face S resulting in considerable facilitation of focusing.

Description

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

[Prior Art] In general, particle beam microanalyzers such as X-ray microanalyzers and ion microanalyzers analyze the surface of a sample by detecting X-rays and secondary ions generated when a sample is irradiated with electron beams or ions. At the same time, preliminary observation of the sample and alignment of the spectrometer are performed using an optical microscope using visible light.

[Problems to be Solved by the Invention] In such an optical microscope, focusing of an optical image of a sample is performed by moving the sample up and down.

On the other hand, since the analysis surface of the J3 sample used in such a particle beam microanalyzer is polished to a mirror surface, the contrast of the obtained optical image is often small. As a result, it is difficult to judge whether the subject is in focus or not.

In order to solve this problem, it is an object of the present invention to provide an apparatus that can easily focus an optical image of a sample.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes 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 for forming an image of reflected light from the sample that has passed through the objective lens, the object surface position of the objective lens or a position optically equivalent to the object surface position. It is characterized by disposing a marker member having a part that allows light to pass through and a part that blocks light.

[Example] Fig. 1 is a schematic diagram showing the configuration of an example in which the present invention is applied to an X-ray microanalyzer, and 1 is an electron gun. The electron beam E8 generated from the electron gun is focused by the focusing lenses 2 and 3, and irradiates the sample 4. The X-ray 1 reflected electrons and secondary electrons generated from the sample by this electron beam irradiation are detected by a detector not shown. 5
is an optical microscope installed between the focusing lenses 2 and 3, and the optical microscope includes a light source 6. Condensing lens 7, projection lens 8. Semi-transparent mirror 91 Reflection mirror 10. It is composed of reflective objective lenses 11a and 11b and an eyepiece 12. Holes are provided in the mirror body 9 and the reflective objective lenses 11a and 11b of this microscope so as not to obstruct the passage of the electron beam [B]. The light from the light source 6 passes through the condensing lens 7 and the projection lens 8, is reflected by the semi-transparent mirror 9 and the reflecting mirror 10, and is reflected by the objective lens 1.
The sample 4 is irradiated through 1a and 11b. The reflected light from the sample 4 is reflected by objective lenses 11a and 11b.

Reflection mirror 10. It is led out through the semitransparent mirror 9 and the eyepiece 12, and an optical image of the sample can be observed.

13 is an objective lens 11 in the optical path of the illumination system of the optical i'im mirror.
A field-limiting diaphragm is placed at the object plane position a and 11b, and a marker plate 14 is attached above the aperture hole 13a of the diaphragm, as shown in a plan view in FIG. The marker board 1
4 is made of a transparent material such as glass or plastic, and opaque cross-shaped markers 15a and 15b are drawn on the marker board. The markers 15a, 15b are formed by depositing a metal such as aluminum or chrome to a thickness of several thousand layers.

The operation of this embodiment will be explained below based on the optical diagram shown in FIG. 3, in which the semi-transparent mirror 9 and the reflective mirror 10 are omitted.

As is clear from the figure, if the marker plate 14 is placed on the object plane of the objective lens 11, images of cross-shaped markers 15a and 15b will be formed on the image plane S of the objective lens 11. Therefore, when the surface of the sample 4 coincides with the image plane S,
A marker image is formed on the sample surface in just focus.

This marker image can be observed together with the sample image.

Therefore, the focus of the imaging lens system consisting of the objective lens 11 and the eyepiece 12 is adjusted in advance to the image plane S of the objective lens 11, and the sample 4 is moved up and down along the optical axis while observing the marker image. By making the marker image projected on the sample the clearest, the sample can be placed at the object plane S, and the optical microscope will be in focus.

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, although the shape of the marker is shown as a cross, it may be of any shape as long as it can be recognized as an image. Further, in creating the marker, although the case where metal is vapor-deposited has been described, it is also possible to draw on a transparent plate using a suitable method 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 attached to the field-limiting aperture hole. Furthermore, the position at which the marker plate is placed is not necessarily limited to the position of the object plane of the objective lens, but rather the position of the projection lens where the object plane position of the objective lens is the imaging position in the optical path of the illumination system. It may be the object position.

[Effects of the Invention] With the above configuration, when focusing an optical microscope, focusing U can be performed extremely easily even in the case of a sample with very low contrast.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is a plan view of a marker plate used in the present invention, and FIG. 3 is an optical diagram between the light source of the optical microscope and the sample in the present invention. . 1: Electron gun 2.3-: Focusing lens 4: Sample
5: Optical microscope 6: Light source 7: Condensing lens 8: Projection lens 9: Semi-transparent mirror 10: Reflecting mirrors 11a, 11b: Objective lens 12: Eyepiece 13: Field-limiting diaphragm 14: Marker plate 15a, 15b: v- car

Claims (1)

[Claims] 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 lens for forming an image of the reflected light from the sample that has passed through the objective lens. In a device equipped with an optical microscope,
A particle beam microanalyzer characterized in that a marker member having a part that transmits light and a part that blocks light is disposed at the object surface position of the objective lens or at a position optically equivalent to the object surface position.