JPH03246862A - X-ray analyzer for electron microscope or the like - Google Patents

Abstract

PURPOSE:To improve detection sensitivity by concurrently measuring X-rays with all detectors, and adding obtained signals for all detectors per each energy of X-rays. CONSTITUTION:An electron beam emitted from an electron gun passes a radiation lens system 2 along the optical axis and is radiated to a sample 3. The characteristic X-rays emitted from the sample 3 are detected by EDX detectors 5, 5' arranged around the optional axis, detected signals are amplified by preamplifier 6, 6' and amplifiers 7, 7' and sorted per each energy of X-rays by pulse processors 8, 8' and fed to the memory of a computer 9. The signals fed to the computer 9 from the pulse processors 8, 8' are fed at the same measurement time, and both signals are added per each energy of X-rays and displayed on a display 10. X-rays can be detected with the sensitivity twice that of a single detector. The detection sensitivity of X-rays can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to non-dispersive X-ray E
Regarding a DX analyzer.

[Conventional technology]

Conventionally, two EDX detectors have been attached to an electron microscope. The purpose of this method is to use different detectors depending on the purpose of detection, and both detectors are different from each other. Second
The figure shows a conventional example, and 5 is B with a detection element area of 50m++2.
EDX detector with e-film window, 5' is an ultra-thin film window with 10YrIr
This is an example of an EDX detector with 12 detection elements. 5′
Although it is possible to detect light elements, the detection sensitivity is insufficient.

5 cannot detect light elements, but the detection sensitivity is good.

In elemental analysis, it is not necessarily necessary to detect light elements, but when high detection sensitivity is desired, the detector 5 is used. The switch 12 selects which detector to use.

The signals detected by detectors 5 and 5' are not acquired simultaneously, and therefore the detection sensitivity is determined by each detector.

[Problem to be solved by the invention]

In an electron microscope, etc., a non-dispersive X-ray (EDX) detector detects characteristic X-rays unique to the constituent elements of the sample generated by an electron beam that is locally irradiated onto the sample to be examined. Although it is possible to identify the constituent elements of a sample by detecting them using this technique, there is an inherent drawback in sensitivity in that only a small portion of the X-rays emitted from the sample are detected. In order to improve detection sensitivity, efforts have been made to bring the detection element as close as possible to the sample or to increase the area of the detection element. If the area of the detection element is made too large, there is a problem of deterioration of detection resolution, and currently the area of the element is limited to 50 mm2. Furthermore, there is a limit to the distance between the element and the sample.

For this reason, the current X-ray intake angle is 0, 1st
It is around r. One way to solve this problem is to install a large number of detectors. If you install two, you can double the sensitivity compared to one, and if you install three, you can triple the sensitivity. The object of the present invention is to simultaneously acquire signals from a plurality of detectors and perform X-ray analysis with high sensitivity.

[Means to solve the problem]

In order to achieve the above objective, each of the plurality of detectors is provided with the necessary hardware for signal acquisition.

[Effect]

The signals detected by each detector in the same counting time are amplified,
A pulse processor separates the X-ray energy and stores it in memory, and a computer adds the stored signals for each X-ray energy and displays or outputs data on a display.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1 is the optical axis of the electron microscope, 2 is an irradiation lens system, and 4 is an imaging lens system. An electron beam emitted from an electron gun (not shown) passes through an irradiation lens system 2 along the optical axis and is irradiated onto a sample 3. Characteristic X-rays emitted from the sample are detected by EDX detectors 5, 5' arranged around the optical axis. The detected signal is amplified by a preamplifier 6.6' and an amplifier 7.7', and a pulse processor 8.8'.
', the signals are sorted by X-ray energy and sent to the memory of the computer 9. The signals sent from 8 and 8' to 9 are sent at the same measurement time. Add the signals of both for each X-ray energy,
When displayed on the display 10, X-rays can be detected with twice the sensitivity of a single detector, which is effective when the amount of signal is small in X-ray analysis of a minute part of a sample. 11 is data output, and a plotter, printer, etc. are used. In this embodiment, the computer 9 includes a memory, but the same effect can be achieved even if the computer 8, 8' includes a memory.

In Figure 1, only two sets of detection and signal processing systems from 5 to 8, including the EDX detector, are shown, but as long as space allows, the more there are, the better the detection sensitivity will be. Therefore, the effect can be expected.

Since the performance of a detector is determined by its resolution, it is desirable that the resolution of 5° 5' be the same.

〔Effect of the invention〕

According to the present invention, it is effective to improve X-ray detection sensitivity.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the present invention, Fig. 2 is a block diagram of an embodiment of the present invention; The figure is a block diagram of a conventional example.

Claims (1)

[Claims] 1. A plurality of non-dispersed Xs around the sample of an electron microscope, etc.
In an X-ray analyzer equipped with ray detectors, all detectors simultaneously measure X-rays, and the obtained signals are added up for all detectors according to the energy of the X-ray. X-ray analysis equipment such as electron microscopes. 2. The X-ray analysis of an electron microscope, etc. according to claim 1, wherein all the resolutions of the plurality of non-dispersive X-ray detectors arranged around the sample of the electron microscope, etc. are substantially the same. Device.