JPS6235056B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron probe device such as an X-ray microanalyzer, and more particularly to a device that can accurately irradiate a desired position on a sample surface with an electron beam.

When performing a compositional analysis of a specific minute region on a sample surface using an X-ray microanalyzer, the following steps are taken, for example. That is, as shown in FIG. 1, first, a scanning signal generated from a scanning circuit 1 is sent to a deflection coil 4 via a switching circuit 2 and an amplifier 3 to scan an electron beam 5 two-dimensionally on a sample 6. Information generated from the sample by scanning is detected by a detector 7, and the obtained detection signal is sent as a luminance signal via an amplifier 8 to a display device 9 driven in synchronization with the electron beam scanning to obtain a sample image. Then, the sample image is observed, an analysis point is selected, and the position of the analysis point is specified by the position designator 10. After that, the switching circuit 2 is switched to send the position signal from the position designator to the deflection coil 4, and the electronic Make the beam stationary at the specified position. At this time, the position signal is also sent to the display device 9, so that the position of the analysis point is displayed as a bright spot.

However, in the past, when the electron beam was switched from a scanning state to a stationary state, the position of the irradiation point (analysis point) of the electron beam on the sample surface was displayed on a display device due to the magnetic hysteresis of the material placed around the deflection coil. This causes the inconvenience that development occurs that does not match the desired point, resulting in analysis of a location other than the desired point. The present invention has been made in view of the above-mentioned conventional problems, and the present invention will be explained in detail below with reference to the drawings.

FIG. 2 shows the configuration of one embodiment of the present invention, and the first
Components that are the same as those in the figures are given the same numbers and their explanations will be omitted. In FIG. 2, reference numeral 11 denotes a comparison circuit that compares the scanning signal from the scanning circuit 1 and the position signal from the position designator 10, and the matching signal obtained from the comparison circuit 11 causes the switching circuit 2 to switch to the position designator. Switched to the side. Furthermore, the switching circuit 2 is configured to perform the above switching operation only during a period when a command signal is supplied from the switching command circuit 12.

After observing the sample image and specifying the position of the selected analysis point using the position designator 10, a switching command signal is sent from the circuit 12 to the switching circuit 2 at time _t1 as shown in FIG. Circuit 2 operates at time t ₂ when the scanning signal and position signal first match after t ₁ (Figure 3b).
The matching signal (FIG. 3c) generated from the comparator circuit 11 causes switching to the position designator side. Therefore, a deflection signal as shown in FIG. 3d is ultimately sent to the deflection coil 4. Therefore, the magnetic flux in the material surrounding the deflection coil, which was changing along a certain hysteresis loop in the scanning state before t ₂ , does not change after t ₂ while maintaining the value at t ₂ on that loop. In this way, whether the electron beam is stationary or scanning, the above magnetic flux is always on a constant hysteresis loop, so if a position signal is created based on the position of the analysis point on the image obtained in the scanning state, , there is no difference between the analysis point on the image and the actual analysis point on the sample.

It goes without saying that when starting scanning after analysis, the switching circuit 2 should be switched to the scanning circuit side at the moment when the scanning signal and the position signal first match after the switching command signal disappears.

As described in detail above, according to the present invention, it is possible to eliminate deviations in the irradiation position of the electron beam on the sample surface due to hysteresis.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a conventional example, FIG. 2 is a diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is a waveform diagram for explaining the operation of the embodiment. 1: Scanning circuit, 2: Switching circuit, 4: Deflection coil, 9: Display device, 10: Position designator, 11: Comparison circuit, 12: Switching command circuit.

Claims (1)

[Claims] 1. A deflection means for deflecting and scanning an electron beam on a sample, a scanning circuit for generating a scanning signal to be supplied to the deflection means, a means for generating a position signal for specifying a position on the sample, and a scanning circuit for generating a scanning signal for specifying a position on the sample. switching means for selectively supplying the position signal to the deflection means, means for generating a switching command signal for switching the switching means, and means for comparing the scanning signal and the position signal. , characterized in that scanning of the electron beam is stopped or started when the scanning signal and the position signal match by switching the switching means based on the switching command signal and the output signal of the comparing means. Electronic probe equipment.