JP2000277047A - Visual field movement correcting device for scanning electron microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of axial displacement at any position of an X-ray detecting unit by providing a magnetic field generating source for offset as a means for detecting position of a detecting unit and for correcting position thereof in relation to the generation of visual field movement, and reducing the visual field movement. SOLUTION: Positional displacement of the electron beam for scanning a sample is generated by the influence of the leaked magnetic field, which is generated between a sample 9 and an objective lens 5 by putting in/out of an X-ray analyzing detecting unit 1, and the magnetic field of an electron trap assembled at a tip of an X-ray detecting unit 2. This positional displacement is changed by the quantity of insertion of the X-ray detecting unit 2 and the quantity of the leaked magnetic field of the objective lens 5. In order to correct the positional displacement, a position detecting unit 12 for correcting positional displacement to be generated by the insertion of the X-ray detecting unit and an object current detecting unit 13 for correcting influence due to the leakage magnetic field to be generated between the objective lens and the sample are provided, and the correcting signal 15 for feedback to a correcting function 14 so as to correct position of a positional displacement 8 is generated, and positional displacement is thereby corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual field movement for reducing a movement of an analysis position and a movement of an observation visual field caused by inserting and removing a detector such as a non-dispersive X-ray analyzer used for a scanning electron microscope. The present invention relates to a correction device.

[0002]

2. Description of the Related Art In a scanning electron microscope or the like, an analyzer such as a non-dispersive X-ray analyzer is widely used for analyzing components in a sample. In a non-dispersive X-ray analyzer, it is important to set a detector near the source of X-rays in order to improve the analysis sensitivity. However, problems such as damage to the detector due to reflected electrons generated from the sample may occur. Will happen.

As a means for avoiding this problem, a general X-ray detector is provided with a magnet at the tip of the detector so as to deflect reflected electrons so as not to enter the detector surface. However, if the detector is brought close to the sample with the magnet attached to the tip of the detector, the scanning electron microscope will deflect the electron beam under the influence of the magnetic field of the magnet, resulting in a change in the analysis location and the field of view. The problem of the movement of an object arises.

Specifically, when performing X-ray analysis such as a non-dispersive X-ray analyzer mounted on a Hitachi SEM, S-4700 type SEM, a detector for X-ray analysis is set in advance at an analysis position. After setting, the analysis position had to be reset.

[0005]

That is, in the conventional structure, it is necessary to reset the analysis position and adjust the axis of the electron optical system every time the detector for X-ray analysis is moved in and out.

It is an object of the present invention to provide a function for detecting the position of the detector and correcting the occurrence of the displacement of the electron beam at any position of the X-ray detector as means for solving the above-mentioned problems. Another object of the present invention is to provide a function that does not cause axis misalignment.

[0007]

In order to attain the above object, according to the present invention, a displacement of an electron beam caused by taking an X-ray detector in and out of an electron beam deflection system is detected by a position sensor in an X-ray detector section. Is provided to correct the shift of the analysis position and the observation position.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS SE as an example of an embodiment of the present invention
The M schematic diagram will be described with reference to FIG. FIG. 1 shows a configuration in which an X-ray analyzer is mounted on an SEM, and an X-ray analyzer for observing an SEM image and analyzing components in a sample in an observation region is mounted.

By taking the detector 1 for X-ray analysis in and out,
Leakage magnetic field generated between the sample 9 and the objective lens 5 and X
The electron beam scanning on the sample under the influence of the magnetic field of the electron trap incorporated in the tip of the X-ray detector 2 causes a position shift 8, resulting in a position shift in the observation region and the X-ray analysis position. . This displacement is caused by the X-ray detector 2
And the amount of leakage magnetic field of the objective lens 5.

In order to correct the positional deviation, a position detector 12 for correcting the position generated by inserting the X-ray detector unit, and a position detector 12 for correcting the influence of the leakage magnetic field generated between the objective lens and the sample. An objective current detection 13 is provided and a correction signal 15 for correcting the position of the position shift 8 by feeding back the correction function 14 is used to correct the position shift.

As described above, according to this embodiment, at any position of the X-ray detector, the occurrence of displacement on the sample surface can be prevented without being deflected by the electron trap of the X-ray detector. It becomes possible and the problem can be avoided.

[0012]

According to the present invention, X used in SEM
In the system equipped with the X-ray analyzer, the displacement of the electron beam due to the magnetic field generated from the electron trap incorporated in the X-ray analyzer can be corrected, and the effect is remarkable.

[Brief description of the drawings]

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Detector for X-ray analysis, 2 ... X-ray detector, 3 ... Electron beam,
4: Deflection coil, 5: Objective lens, 6: Objective current signal,
7 Deflection signal, 8 Position shift, 9 Sample, 10 Objective power supply, 11 Deflection power supply, 12 Position detector, 13
Object current detection, 14 correction function, 15 correction signal.

Claims (1)

[Claims] 1. A scanning electron microscope or the like, characterized in that a means for detecting a position of a detector and correcting the occurrence of a visual field movement is provided with a canceling magnetic field source to reduce the visual field movement. View movement correction device.