JP2876672B2 - Surface analyzer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surface analyzer such as an electron beam micro analyzer (EPMA).

[Prior art] An electron beam microanalyzer scans a sample with an electron beam focused to several tens of angstroms in diameter and, when the beam passes, electrically detects various information generated from each sample point and synchronizes with the scanning. Then, it is taken out as an image on a cathode ray tube, and qualitative and quantitative analysis can be performed.

Various signals are generated from the sample part irradiated with the electron beam, and depending on which of them is taken out and used for imaging, a secondary electron image, a reflected electron image, an absorption electron image, a super power image,
A luminescence image, an X-ray image, an Auger electron image, and the like can be observed.

When collecting analysis data using this electron beam microanalyzer, when analyzing a very small area, line data and surface data are collected by sweeping the electron beam,
When analyzing a wide range of mm, the analysis data is collected by moving the sample stage. The data collection operation S by the conventional sample stage scan will be described with reference to FIG. 4. In FIG. 4, the output pulse of the driving pulse generation circuit 1 is input to the pulse motor driving circuit 2,
The motor 3 is driven to move the sample stage. On the other hand, at the same time, the sample is irradiated with an electron beam, X-rays from the sample are detected by the X-ray detector 4, and the detection signal becomes X-ray.
It is input to the line data counting circuit 5. Then, the detection data of the X-ray data counting circuit 5 is input to the CPU 6 by the pulse for driving the pulse motor, and is displayed on the display device 7 as a map and stored in the image memory. At this time, the X-ray data counting circuit 5 is automatically reset at the same time as the detection data is taken in by the CPU 6.

[Problem to be Solved by the Invention] In the above-described surface analyzer, when the pulse motor is driven at a high speed, an acceleration / deceleration region is necessary. In this range, the pulse interval of the motor drive pulse is not constant.
Data could not be collected.

In addition, when the time interval of the pulse for driving the pulse motor is not accurate, or when the pulse interval is not constant such as when the pulse motor is driven by the pulse from the manual encoder, accurate data can be collected. could not.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and a surface analysis capable of collecting accurate analysis data even when the time interval of a pulse motor driving pulse is not constant. It is intended to provide a device.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides at least one of a sample stage or a spectroscope driven by using a pulse motor and means for counting a detection signal from a sample. A pulse motor driving pulse generating means for driving the pulse motor; a pulse generating means for driving the pulse motor; and a pulse generating means for collecting the output data from the detection signal counting means while driving the sample stage or the spectroscope. Means for measuring the pulse interval of the output pulse of the means, and an arithmetic processing circuit to which the output of the pulse interval measuring means and the output of the detection signal counting means are inputted, and correcting the detection signal count output by the pulse interval. Features.

[Operation] In the surface analyzer configured as described above, each time a pulse for driving the pulse motor is generated, the measurement output of the pulse interval measurement unit and the output of the detection signal counting unit are input to the arithmetic processing circuit. The detection signal count output is corrected by the pulse interval and output as analysis data.

[Embodiment] An embodiment of the present invention will be described with reference to FIG. 1 showing a block diagram of a surface analysis apparatus for driving a sample stage, and FIG. 2 showing a waveform diagram of a pulse motor driving pulse.
In FIG. 1, a motor 3 is connected to a sample stage of an electron beam microanalyzer, and an X-ray detector 4 detects an X-ray signal from the sample. On the other hand, the driving pulse generation circuit 1
Are input to the pulse motor driving circuit 2 and the pulse interval measuring circuit 8 and the X-ray data counting circuit 5
Is also entered.

The operation of this surface analyzer will be described with reference to the waveform diagram of the pulse motor drive pulse shown in FIG. The motor 3 is driven by inputting a pulse from the driving pulse generation circuit 1 to the pulse motor driving circuit 2 to irradiate the sample surface with a finely focused electron beam while moving the sample stage. Then, the X-ray signal obtained from the sample surface is detected by the X-ray detector 4 and input to the X-ray data counting circuit 5. On the other hand, the output of the pulse generation circuit 1 is also input to the pulse interval measurement circuit 8 and the X-ray data counting circuit 5, and the pulse generation circuit 1
The measured value from the pulse interval measuring circuit 8 and the output of the X-ray data counting circuit 5 are taken into the CPU 6 for each pulse from the CPU. Then, the CPU 6 counts the count number Ni of the X-ray data counting circuit 5.
From the output Ti pulse interval measuring circuit 8, is calculated by the reference pulse interval _{T o · N i / T i} , with the display image on the display device 7 and stored in the image memory.

FIG. 3 shows another embodiment of the present invention, in which the motor 3 is connected to the spectral crystal 12. To explain the operation of this embodiment, X-rays are generated from the sample 11 by irradiating the sample 11 with an electron beam, and the X-rays are incident on the spectral crystal 12. Only the X-rays of a specific wavelength are selected by the spectral crystal 12 and reach the X-ray detector 4, and the output of the detector 4 is counted by a counting circuit. Then, by rotating the spectral crystal 12 by the motor 3, the wavelength of the detected X-ray is swept, and the X-ray spectrum can be detected. Applying this to the block diagram shown in FIG. 1, the motor 3 drives the spectral crystal 12 instead of the sample stage, and the other components are the same as those in the embodiment of FIG. By measuring the pulse interval of the pulse and correcting the count data of the X-ray counting circuit with the pulse interval, the X-ray spectrum can be accurately obtained even if the pulse interval varies.

In the first embodiment, the case where X-ray detection data is collected has been described. However, a data collection device such as a secondary electron image, a reflected electron image, a luminescence image, and an Auger electron image can be applied. Further, the present invention can be applied not only to a surface analyzer using an electron beam but also to a surface analyzer using an ion beam.

[Effects of the Invention] As described above, according to the present invention, analysis data can be accurately collected even if the pulse interval of the motor driving pulse is not constant, and data can be collected even when the motor is accelerated or decelerated. Because it can be collected, a wide range of data can be collected. Further, even when the user of the analyzer performs a peak search or the like manually, analysis data can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the surface analyzer of the present invention, FIG. 2 is a waveform diagram of a pulse motor driving pulse, and FIG.
FIG. 4 is a block diagram showing another embodiment of the surface analyzing apparatus of the present invention, and FIG. 4 is a block diagram showing a conventional analyzing data collecting apparatus. DESCRIPTION OF SYMBOLS 1 ... Pulse generation circuit for drive, 2 ... Pulse motor drive circuit, 3 ... Motor, 4 ... X-ray detector, 5 ... X-ray data counting circuit, 6 ... CPU, 7 ... Display device, 8… Pulse interval measurement circuit, 11… Sample, 12… Spectral crystal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 23/00-23/227

Claims (1)

(57) [Claims] 1. A sample stage or a spectroscope driven by using a pulse motor, and means for counting a detection signal from a sample, wherein the detection signal is generated while driving the sample stage or the spectroscope. In the surface analyzer for collecting output data from the counting means, a pulse motor driving pulse generating means for driving the pulse motor, a means for measuring a pulse interval of an output pulse of the pulse generating means, and the pulse interval A surface analyzer comprising: a measuring means; and an arithmetic processing circuit to which an output of the detection signal counting means is input, wherein the detection signal counting output is corrected at a pulse interval.