JPS58204454A - Reflected electron diffraction microscopic device of scanning type - Google Patents

Abstract

PURPOSE:To easily perform observation of the surface form of a sample, while obtaining efficiently a reflected electron signal even in a state of heating, ion irradiation etc. of the sample, by focusing the whole luminance on a phosphor plate obtained by reflected electrons. by means of a half-mirror and a lens. CONSTITUTION:The whole luminance 11 on a phosphor plate 9 obtained by reflected electros is guided to an optical lens 13 by means of a half-mirror 12. Because of semictransparency of the half-mirror 12, a reflected diffraction image on the phosphor plate 9 can be easily observed without interrupting analysis of the crystal properties. When the interval between the optical lens 13 and the halr-mirror 12 is properly selected, a luminous region on the phosphor plate 9 can be sufficiently reduced to come into an detection aperture of a photoelectric conversion element while being able to convert the whole luminance 11 on the phosphor plate 9 into an electric signal. Said electric signal is converted into a brightness modulation signal of a CRT 16 in order to obtain a scanning electron microscope image of the sample 7 on the CRT 16 and select an analytic point on the sample 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scanning electron reflection diffraction microscope apparatus for analyzing the crystallinity of a sample surface.

Conventional scanning backscattered electron diffraction microscopy uses current signals absorbed in the sample or secondary
They used scanning electron microscopy images based on electron signals. However, it is difficult to obtain the sample absorption current signal when the sample is being heated or irradiated with ions. In addition, since the incident electrons are incident very close to the sample surface, the number of playions emitted from the sample is overwhelmingly large in the direction of incidence, and conventional secondary electron detection methods have the disadvantage of not being able to effectively detect secondary electrons. there were.

An object of the present invention is to provide a scanning type backscattered electron diffraction microscope that can efficiently acquire backscattered electron signals and easily observe the morphology of the sample surface even when the sample is being heated, ion irradiated, etc. It is in.

In order to achieve the above objects, 1 the scanning type backscattered electron diffraction microscope device according to the present invention focuses all the light emitted by backscattered electrons on a fluorescent plate using a half mirror and a lens, and transmits this optical signal to a photoelectric conversion element. It is characterized by obtaining a scanning electron microscope image instead of an air signal.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of a scanning type backscattered electron diffraction microscope according to the present invention. In the figure, a primary Ichiko beam 3 emitted from an electron gun 2 having a power source 1 of approximately 20 kV is focused by a converging lens 4 onto the surface of a sample 7 located within a vacuum volume 2;6. During scanning, the deflection coil group 5 is operated through the gap 17, and the primary beam s3 is scanned over the surface of the sample 7.

The absorbed current signal of the sample 7 obtained at this time is converted into a brightness modulation signal of a cathode ray tube (abbreviated as CR, T) 16 to obtain an absorbed current image of the sample 7 on the CRT 14. The location to be analyzed on the sample 7 is selected based on this absorbed current. is observed as a backscattered electron diffraction image through the peephole 10. By analyzing this diffraction image, the crystal state at any location on the surface of sample 7 (that is, the arrangement state of the elements constituting the surface portion of sample N7) ) can be analyzed.

In the present invention, a condensing means is provided to condense all the light emitted from the backscattered electrons on the fluorescent plate 9 in such a scanning-type reflected electron diffraction microscope. For example, a half mirror 12 and an optical lens 13 are used as the condensing means.

Conventionally, when selecting an analysis point on the surface of the sample 7, a scanning electron microscope image using a current signal absorbed by the sample 7 has been used. However, in this case, it is difficult to select an analysis point in a state where the sample 7 is heated by passing an electric current or irradiated with ions because it is difficult to separate the signal current from the heating current or the ion current. In order to eliminate this drawback, the present invention guides all the light emitted from the backscattered electrons 11 on the fluorescent plate 9 to the optical lens 13 by means of a half mirror 12. Since the half mirror 12 is semitransparent, the reflection diffraction image on the fluorescent plate 9 can be easily observed and does not interfere with the analysis of crystallinity. If the distance between the optical lens 13 and the half mirror 12 is appropriately selected, the light emitting area on the fluorescent plate 9 can be sufficiently reduced to enter the detection aperture of the photoelectric conversion element 15, and the entire light emitted 11 on the fluorescent plate 9 can be converted into an electrical signal. can be converted. This electric signal is converted into a brightness modulation signal of CR, T16 to obtain a scanning electron microscope image of the sample 7 on the CRT 16, and an analysis point on the sample 7 is selected. As a result, the signal is converted onto the optical fiber, and the sample 7 and the signal system are insulated, so the analysis point on the sample 7 can be easily selected even when the sample is heated by passing a current or irradiated with ions. . In addition, the optical lens 13
By appropriately selecting the distance between the mirror 12 and the nozzle mirror 12, a real image having the same size as the light emitting area on the fluorescent plate 9 can be created between the optical lens 13 and the photoelectric conversion element 15. By using the aperture 14 on this real image plane, it is also possible to select only the optical signal due to a specific reflection diffraction line and obtain a scanning electron microscope image, that is, a diffraction microscope image using this as a signal. The crystal distribution on the surface of sample 7 can be seen from this diffraction microscopic image.

As described above, the scanning backscattered electron diffraction microscopy apparatus according to the present invention allows the sample 7 to be placed in various physical states, such as heated states,
This method has extremely excellent advantages in that a scanning electron microscope image of the surface of the sample 7 can be easily and efficiently obtained even under ion irradiation conditions, and analysis points can be easily selected.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention.

Claims (1)

[Claims] A primary electron beam is extracted from an electron source in a vacuum and irradiated onto a predetermined area on the sample surface at a predetermined angle, and a backscattered electron diffraction image of the electrons reflected from the sample surface is formed on a fluorescent plate. In a scanning type backscattered electron diffraction microscope device that selectively extracts only light emitted from a specific position of a backscattered electron diffraction image on a light plate and converts it into an electrical signal, a condensing means for focusing all the light emitted on the fluorescent plate is provided. Converts the focused light into electrical signals,
A scanning electron diffraction microscope device that uses this signal to obtain a scanning electron microscope image;