JPH05273156A - X-ray analyzer - Google Patents

Abstract

PURPOSE:To perform an accurate element analysis on a sample via X-rays by providing the second detector detecting the signals other than X-rays, and selectively passing the detection signal of the first second detector. CONSTITUTION:When an electron beam is radiated to a sample 4, X-rays XR are emitted from the sample 4, and reflected electrons and secondary electrons are generated besides the X-rays XR. The X-rays XR from the sample 4 are detected by an X-ray detector 6, and the secondary electrons from the sample 4 are detected by a secondary electron detector 7. The secondary electron detection signal is fed to a switch circuit 9, and the circuit 9 passes the X-ray signal while the secondary electron detection signal is kept at a fixed level or above. The X-ray signal is fed to a signal processing circuit 11 only while the electron beam is radiated to the specific region of the sample 4. The element analysis of the specific region of the sample 4 can be accurately performed based on the X-ray signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray analyzer for irradiating a sample with an electron beam and detecting X-rays generated from the sample to analyze the sample.

[0002]

2. Description of the Related Art When a sample is irradiated with an electron beam, characteristic X-rays corresponding to the elements composing the sample are generated. By analyzing this X-ray, qualitative and quantitative analysis of the sample can be performed. FIG. 1A is a plan view of the sample S, and the shaded region (A) and the other region (B) have different kinds of contained elements. Now, the analysis line L shown by the dotted line in the figure
When the relative scanning of the electron beam and the sample is performed along, the detection signal of the characteristic X-ray as shown in FIG. 1B is obtained.

[0003]

By the way, when the sample is irradiated with the electron beam, the electron beam is scattered inside the sample. As a result, the electron beam incident on the B region near the boundary between the A region and the B region in FIG. 1A penetrates into the A region by scattering and generates characteristic X-rays from the constituent elements of the A region. As a result, the elemental analysis of each region of the feed cannot be performed accurately.

The present invention has been made in view of the above points, and an object thereof is to eliminate the influence of unnecessary X-rays due to the scattering of electron beams in a sample and to accurately perform elemental analysis of the sample by X-rays. It is to realize an X-ray analysis apparatus that can perform the above.

[0005]

An X-ray analyzer according to the present invention includes a first detector for detecting X-rays generated from a sample by irradiating the sample with an electron beam, and irradiation of the sample with the electron beam. A second detector for detecting signals other than X-rays obtained from the sample by means of means, and means for selectively passing the detection signal of the first detector according to the intensity level of the signal of the second detector. It is characterized by having.

[0006]

The X-ray analyzer according to the present invention accurately determines the irradiation position (analysis position) of the electron beam based on the detection signals of secondary electrons and reflected electrons.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 2 shows an embodiment of the present invention,
1 is an electron gun. The electron beam generated from the electron gun 1 is focused by the focusing lens 2 and the objective lens 3 and is irradiated onto the sample 4. The electron beam with which the sample 4 is irradiated is scanned according to the scanning signal supplied to the deflection coil 5. X generated by irradiating the sample 4 with the electron beam
The ray XR is detected by the energy dispersive X-ray detector 6. Secondary electrons SE generated by the irradiation of the sample 4 with the electron beam are detected by the secondary electron detector 7. The detection signal of the X-ray detector 6 is amplified by the amplifier 8 and then supplied to the switch circuit 9 (may be a gate circuit). The detection signal of the secondary electron detector 7 is amplified by the amplifier 9 and then supplied to the switch circuit 9. The X-ray detection signal that has passed through the switch circuit 9 is supplied to a signal processing circuit 11 including a wave height analyzer and the like. The result of signal processing is stored in the memory 12 or supplied to the cathode ray tube 13. The operation of such a configuration will be described below.

By irradiating the sample 4 with the electron beam, X-rays are generated from the sample 4, but other than that, reflected electrons, secondary electrons, etc. are also generated. The X-ray XR from the sample 4 is detected by the X-ray detector 6, and the secondary electron SE from the sample 4 is 2
It is detected by the secondary electron detector 7. Here, FIG.
When the electron beam is scanned along the analysis line L in (a), X
The line signal changes as shown in FIG. 1 (b), and the secondary electron signal changes as shown in FIG. 1 (c). In this case, the secondary electrons generated from the sample 4 are less affected by the scattering of the electron beam in the sample 4 than the X-rays, and the detected secondary electrons are almost the surface portion of the sample irradiated with the electron beam. Can be considered to have originated from. Therefore, FIG.
The signal shown in (c) makes it possible to accurately determine the irradiation area of the electron beam. The secondary electron detection signal of FIG. 1C is supplied to the switch circuit 9, but the switch circuit 9 allows the X-ray signal to pass while the secondary electron detection signal is at a certain level or higher. As a result, the X-ray signal is supplied to the signal processing circuit 11 only during the period when the electron beam is irradiated to the area A of the sample, and therefore, the X
Based on the line signal, it is possible to accurately perform elemental analysis of the area A.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to this embodiment. For example, the irradiation area of the electron beam is discriminated using the secondary electrons, but other information obtained from the sample such as reflected electrons may be used. Although the electron beam is deflected to move the analysis position, the sample may be moved.

[0010]

As described above, X based on the present invention
Since the line analyzer accurately determines the irradiation position (analysis position) of the electron beam based on the detection signals of secondary electrons and reflected electrons, unnecessary X-rays due to scattering of the electron beam in the sample are generated. The influence can be removed, and the elemental analysis of the sample by X-ray can be performed accurately.

[Brief description of drawings]

FIG. 1 is a plan view of a sample and a characteristic X-ray along an analysis line and 2
It is a figure which shows the detection signal waveform of a secondary electron.

FIG. 2 is a diagram showing an example of an X-ray analysis apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electron gun 2 Focusing lens 3 Objective lens 4 Sample 5 Deflection coil 6 X-ray detector 7 Secondary electron detector 8, 10 Amplifier 9 Switch circuit 11 Signal processing circuit 12 Cathode ray tube

Claims (1)

[Claims] 1. A first detector for detecting X-rays generated from a sample by irradiating the sample with an electron beam, and a signal other than X-rays obtained from the sample by irradiating the sample with an electron beam. An X-ray analysis apparatus comprising a second detector and means for selectively passing the detection signal of the first detector according to the intensity level of the signal of the second detector.