JPS6182150A - X-ray spectrochemical analysis device - Google Patents

Abstract

PURPOSE:To improve sensitivity and to obtain the result of analysis without the influence of the ruggedness of a sample by disposing plural units of x-ray spectroscopes approximately symmetrically around the irradiating point of an electron beam, driving wavelength driving mechanisms by a common driving control circuit, adding the outputs of the X-ray detectors and displaying the same. CONSTITUTION:The X-ray spectroscopes M1, M2 are disposed approximately symmetrically around the point for irradiating the electron beam to the sample S and stepping motors P1, P2 are driven by a driving control circuit 1 to rotate feed screws T1, T2 and to drive cooperatively spectral crystals C1, C2 and X-ray detectors D1, D2. The outputs from the detectors D1, D2 which detect the diffracted X-rays from the sample S are added in an adder 3 via pulse amplifiers 21, 22 and are displayed on a display device 4. Since the outputs of the plural X-ray spectroscopes M1, M2 are added, the sensitivity is improved and the result of the analysis which is not influenced by the ruggedness of the sample S is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an X-ray microanalyzer that analyzes a minute area on a sample surface.

B. Conventional technology An X-ray microanalyzer focuses an electron beam on the sample surface and performs spectroscopic analysis of the X-rays emitted from the electron beam irradiation point on the sample surface. Usually, multiple X-ray spectrometers are installed around the sample. are installed, but one X is used for the analysis of one element.
A line spectrometer is now used.

C. Problem to be solved by the invention X-rays are emitted in all directions from the electron beam irradiation point on the sample surface, but since the solid angle at which one spectroscopic crystal views the X-ray emission point is small, Conventional X-ray microanalyzers that only use a standalone X-ray spectrometer have a problem in that one measurement takes a long time. In addition, with an X-ray microanalyzer, the electron beam irradiation area of the sample is small, so if the sample has thin irregularities and the electron beam irradiation point is exactly on the convex or concave part and there is a part that is shaded when viewed from the spectrometer crystal, the The X-rays emitted from the area cannot enter the spectrometer, and the element to be measured appears to be present at the electron beam irradiation point (micro area), or even if it is detected, the amount is observed to be smaller than it actually is. There was a problem that it would happen.

The present invention seeks to solve these two problems.

2. Means to solve the problem In the present invention, multiple X-ray spectrometers around the sample are set at the same wavelength position, and X-ray spectroscopic analysis is performed from different directions with multiple X-ray spectrometers for each element. .

E. Detection sensitivity in action X-ray spectrometry is proportional to the square root of the measurement time.If n X-ray spectrometers are used for the same wavelength, the sensitivity will be six times as high as the measurement time multiplied by n. If they are made the same, the time required for measurement will be reduced to 1/n. In addition, since the electron beam irradiation point on the sample is viewed from different directions, even if the sample has unevenness, there will be no shadows when viewed from the spectrometer, and analysis results that are unaffected by the unevenness can be obtained.

Embodiment FIG. 1 shows an embodiment of the present invention. E is electron beam, S
is the sample. C1 and C2 are spectroscopic crystals, DI and D2 are X
17) X-ray spectrometer M1
C2 and D2 constitute another X-ray spectrometer M2 having the same specifications as Ml. These two X-ray spectrometers are placed around the sample S at a distance of 180 degrees, and both aim at the electron beam irradiation point on the sample. The spectroscopic crystals c1 and C2 are driven in the direction of the arrow by feed screws Tl and T2, respectively, and the set wavelength is determined by the position on the line along the direction of the arrow. The X-ray detectors DI and D2 are mechanically connected to the spectroscopic crystals C1 and C2, respectively, and move as the crystals C1 and C2 move. Each feed screw Tl, T2 is driven by a stepping motor PI, P2, respectively, both stepping motors are driven by a common drive control circuit 1,
The two X-ray spectrometers Ml and M2 are set at the same wavelength position in conjunction. The outputs of the X-ray detectors DI and D2 are amplified by pulse amplifiers 21 and 22, and then summed by an adder circuit 3.
It is displayed on a display device 4 such as a recorder or CRT.

It is desirable that the X-ray spectrometers placed around the sample be placed as symmetrically as possible with the sample as the center.

This is because if the arrangement of the X-ray spectrometer is uneven, the influence of the irregularities on a sample with irregularities will not be symmetrical, and the influence of the irregularities will not be completely canceled.

FIG. 2 shows X-ray spectrometers Ml, M2, and M2 with the same specifications placed around the sample S at 120° intervals. This is where M3 is placed.

8 Effects According to the present invention, even though measurement is performed with a single spectrometer, a large amount of X-rays emitted from the sample is used for measurement, so detection sensitivity improves and analysis takes the same amount of time as before. Accuracy is improved and analysis time is reduced for the same sensitivity accuracy. In addition, a sample having a convex portion as shown in Fig. 3A was
When performing analysis along the line in the X direction on the sample surface while moving in the direction, the area B on the sample surface is in shadow when viewed from the spectroscopic crystal C, and the area F on the side face of the convex part is hidden from the area G. X-rays are emitted due to excitation by backscattered electrons and X-rays, and since these are detected during scanning in the G range, the X-ray detection intensity is
The directional distribution is as shown in Figure 3B, but the X-direction distribution of the X-ray intensity by the spectroscopic crystal C' is as shown in Figure 3C.
Since the shape is exactly opposite to that in Figure B, the influence of unevenness is eliminated when the results of both measurements are combined, allowing accurate analysis even for samples with unevenness.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of one embodiment of the invention, FIG. 2 is a plan view of another embodiment, and FIG. 3 is a diagram illustrating the invention in detail.

Claims (1)

[Claims] Multiple X units are installed approximately symmetrically around the electron beam irradiation point of the sample.
X-ray spectrometers are arranged, and the wavelength drive mechanisms of these X-ray spectrometers are driven by a common drive control circuit to set each of the X-ray spectrometers to the same wavelength. An X-ray spectrometer characterized in that the outputs of the ray detectors are summed up and displayed or recorded.