JPS62154542A - X-ray analyzer - Google Patents

Abstract

PURPOSE:To improve an S/N ratio as well as to display an X-ray profine image, by displaying the count value of the counter X-ray pulse as one point of an X-ray detecting signal in an artificial manner, while electron beams in the specified width are scanned in an X direction. CONSTITUTION:A characteristic X-ray (x) out of an sample by scanning of electron beams 2 is detected by an X-ray detector 8, and X-rays of the specified wavelength are selected by a pulse height analyzer 9 and outputted to an integrator 10 which starts integration of X-rays of the set window W when a timing pulse signal comes to be higher than that at an (a) point, and when it is scanned up to a (b) point, an output signal is converted into an analog signal by a digital-to-analog converter 11, and fed to a deflecting coil 7X of a cathode-ray tube 7, therefore a luminescent spot is displayed on the cathode-ray tube 7. Accordingly, during one scanning, X-rays are counted, and with this, it is set down to a one point output signal artificially so that an S/N ratio is improved and displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to an X-ray analyzer that displays an X-ray profile image on a display device and performs analysis.

[Prior Art] Generally, in an X-ray analyzer such as an analytical electron microscope, a precipitate A in a sample is displayed on a display device as shown in FIG. B, and X-ray analysis is performed by displaying an X-ray profile image C of characteristic X-rays detected from the sample by the electron beam scanning.

Many objects that are subject to X-ray analysis using such an X-ray analyzer include grain boundaries and interfaces, and in this case, line analysis analyzes changes in the concentration of specific elements as a function of distance from the interface. It is.

[Problems to be Solved by the Invention] In the above-mentioned conventional X-ray analyzer, characteristic If the precipitates inside are clear and the difference in the concentration of the target element is large, this will not be much of a problem. However, when the concentration difference is small, or when the diameter of the electron beam probe is narrowed down to several tens of people, the characteristic X-ray detection signal may be obscured by noise, etc.
/N ratio was lowered, so it was not possible to obtain an X-ray profile image with a good S/N ratio.

The present invention was made in view of the above points, and even when the a-degree difference between the opposing elements is small or when the probe diameter of the electron beam is narrowed down, the X-ray profile can be improved without improving the S/N ratio. The object of the present invention is to provide an X-ray analysis device that enables image-based X-ray analysis.

[Means for Solving the Problems] The present invention for achieving the present purpose is to
a scanning means for scanning in the axial and Y-axis directions; an X-ray detector for detecting X-rays generated by irradiation of the sample with an electron beam; and a wave height to which a detection pulse signal from the X-ray detector is supplied. an analyzer, an integrator that integrates the signal selected by the pulse height analyzer every predetermined period of electron beam scanning in the X-axis direction, and an integrated value from the integrator is supplied as a deflection signal in the X-axis direction. It is characterized by comprising a display means.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

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

Reference numeral 1 denotes an electron beam generation source that emits an electron beam 2. The electron beam 2 from the electron beam generation source 1 is narrowed down by a focusing lens 3 and irradiated onto a sample 4. 5X and 5Y are electron beam 2 and sample 4.
A scanning coil that scans two-dimensionally on the top, 6 is a scanning power supply,
A horizontal (X-axis) scanning signal and a vertical (Y-axis) scanning signal from the scanning power source 6 are supplied to the scanning coils 5X, 5Y, and also to the deflection coils 7X, 7Y of the cathode ray tube 7. 8 is X generated by irradiation of sample 4 with electron beam 2
9 is a pulse height analyzer to which a detection pulse signal from the X-ray detector 8 is supplied; 10 is an X-ray detector for scanning the signal selected by the pulse height analyzer 9 with an electron beam in the X-axis direction; An integrator 11 is a D/to converter that converts the digital signal from the integrator 10 into an analog signal.

Reference numeral 12 denotes a changeover switch that switches between the signal from the D/A converter 11 and the X-axis scanning signal from the scanning power supply 6 and supplies the signal to the deflection coil 7x. 13 is a secondary electron detector, and 14 is an amplifier for amplifying a detection signal from the secondary electron detector 13. 15 is a luminance signal generation circuit; 16 is a selection switch for switching and supplying the luminance modulation signal from the secondary electron detector 13 or the luminance signal generation circuit 15 to the grid 7G of the cathode ray tube 7; 17 is a scanning power supply 6. integrator 10,
A control circuit 18 controls the changeover switch 121, selection switch 16, etc., and a keyboard 18 is connected to the control circuit 17.

A case will be described in which an X-ray profile image is displayed and X-ray analysis is performed using the apparatus configured as described above. First, when the start signal S is input from the keyboard 18, the scanning signal shown in FIG. 2 (a) and the scanning signal shown in FIG.
Since the retrace signal (only the signal in the X-axis direction shown in FIG. The electron beam of tube 7 is scanned. Secondary electrons e generated from the sample 4 by this electron beam scanning
is detected by the secondary electron detector 13, amplified by the amplifier 14, and sent to the grid 7G via the selection switch 16.
supplied to Therefore, the cathode ray tube 7 displays an interface K as a secondary electron image of the sample 4 as shown in FIG.

Here, if the interface K of the sample 4 to be analyzed is not displayed horizontally on the cathode ray tube 7 as shown in FIG. 3, the sample 4 is rotated using, for example, a sample rotation device (not shown). This allows the X-axis scanning direction of the electron beam 2 that scans the sample 4 to be parallel to the interface of the sample 4 in the horizontal direction. Next, depending on the state of the interface of the sample 4 displayed on the cathode ray tube 7, the interface K is a relatively smooth box surface.
In addition, the width of the region to be analyzed by X-rays is determined. Furthermore, as shown in FIG. 4, a window W of the energy width of the element of interest, for example iron (Fe), is input from the keyboard 18.

When the analysis conditions are set in this way, the control circuit 17 switches the selector switch 12 and the R switch 16 to the state shown by the dotted line, and sends the signal from the D/A converter 11 to the deflection coil 7X to generate a luminance signal. a'il+1 to supply the luminance signals of the circuits 15 to the grids 7G, respectively;
Do 10. Furthermore, since the scanning power supply 6 is controlled by the control circuit 17, the scanning of the sample 4 with the electron beam 2 starts from point a shown in FIG. The timing signal shown is output. The characteristic XmX from the sample 4 resulting from the scanning of the electron beam 2 is detected by the X-ray detector 8, and the X-ray of a specific wavelength is selected by the pulse height analyzer 9 and output to the integrator 10. The integrator 10 starts counting (integrating) the X-rays in the set window W when the timing pulse signal becomes a high (h) signal. Then, when scanning is completed to point b, the timing pulse signal becomes a low (inclusive) signal, and the integrator 10 stops counting the X-rays. Next, when the timing pulse signal becomes a low signal, the integrator 10 changes the count (integrated value) of Xa to D.
/A converter 11 and clears the X-ray count of integrator 10. Here, the output signal from the integrator 10 is converted into an analog signal by the D/A converter 10, and is supplied to the deflection coil 7X of the cathode ray tube 7 as a deflection signal for electron beam scanning from point a to point b. On this occasion,
Since the selection switch 16 is controlled by the control circuit 17 to the state shown by the dotted line, the luminance signal from the luminance signal generation circuit 15 is supplied to the grid 7G only when the timing pulse signal is a low signal, and therefore the cathode ray tube 7 A bright spot is displayed. Since such an operation is repeated for one screen, when the Y axis of the cathode ray tube 7 is displayed as the electron beam scanning direction and the X axis is displayed as the count number, a characteristic X-ray profile image as shown in Fig. 5 is formed. .

Therefore, in X-ray analysis using such an X-ray profile image, X-rays are counted during one scan from point a to point b, and one point is output in a pseudo manner for this one scan (X-axis). Since the signal is used as a signal, it is possible to display the signal with an improved S/N ratio compared to the conventional case where a detection signal obtained by one scan is displayed. Therefore, S/
An X-ray profile with a good N ratio can be displayed and analyzed.

Note that the above embodiments are merely illustrative and can be implemented in other ways. In the above embodiment, the window W is made of iron (F
For example, as shown in Fig. 6, window W1 is made of chromium (Cr), window W2 is made of iron (Fe), and the X-ray profile shown in Fig. 7 is displayed and analyzed. Alternatively, the concentration ratios of these elements may be displayed and analyzed simultaneously.

Further, in the above embodiment, a secondary electron image is displayed on the cathode ray tube, and then an X-ray profile image is separately displayed in place of this secondary electron image.
It is also possible to display the secondary electron image and the X-ray profile image simultaneously. In that case, the sample 4 is scanned with the scanning signal shown in Fig. 2 (a), while the secondary electron detection signal is supplied as the brightness signal of the cathode ray tube, while the timing pulse signal shown in Fig. 2 (d) is A high signal starts counting (integration) of X-rays, and a low signal stops counting. This X-ray count value (integrated value) is output to the D/A converter 11 in synchronization with the blanking period shown in FIG. What is necessary is to switch to the state shown by the dotted line and control to display the X-ray profile image.

C Effects of the Invention 1 As detailed above, according to the present invention, for example, while scanning an electron beam with a predetermined width in the X direction, X-ray detection pulses are counted, and this count value is calculated as Because it is displayed as a beam detection signal, the S
By improving the /N ratio, it is possible to display an X-ray profile image and perform X-ray analysis.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a schematic diagram of an embodiment of the present invention. Figure 3 is an explanatory diagram of the interface of the sample, etc. Figure 4 is a diagram for making the window d2 brighter, Figure 5 is a diagram for explaining an example of display, Figure 6 is a diagram for displaying multiple windows. Explanatory diagram of the case, M7
9 and gi18 are display examples of other embodiments, and FIG. 9 is a diagram for explaining a display example of a conventional device. 1: Electron beam source, 2: Electron beam, 3: Focusing lens, 4:
Sample, 5X, 5Y: scanning coil, 6: scanning power supply, 7: cathode ray tube, 8: X-ray detector, 9: pulse height analyzer, 10: integrator, 11: D/A converter, 12: changeover switch, 13: Secondary electron detector, 14: Amplifier, 15: Luminance signal generation circuit, 16: Selection switch, 17: Control circuit, 1
8: Keyboard.

Claims (1)

[Claims] A scanning means for scanning an electron beam on a sample in the X-axis and Y-axis directions, an X-ray detector for detecting X-rays generated by irradiation of the sample with the electron beam, and detection by the X-ray detector. A pulse height analyzer to which a pulse signal is supplied, an integrator that integrates the signal selected by the pulse height analyzer at every predetermined period of electron beam scanning in the X-axis direction, and an integrated value from the integrator in the X-axis direction. X
Line analyzer.