JPH0293356A - Beam type surface analyser - Google Patents

Abstract

PURPOSE:To shorten an analytical time by dispensing with focus matching by vibrating a sample in the axial direction of exciting beam at amplitude larger than the depth of the surface unevenness of the sample and detecting the energy line of the sample through a spectroscope to store the intensity thereof. CONSTITUTION:A sample S is set to a sample mount stand 1 to be irradiated with electron beam B and minute vibration is given to said sample S in the axial direction of the electron beam B on the basis of the signal of an exciting circuit 5. By this method, the surface of the sample is excited by the electron beam B to generate fluorescent X-rays which are, in turn, incident to a detector 6 through a spectroscope 7 to be converted to an electric signal. From this, the focus of the spectroscope 7 is successively transferred from the front focus point of the sample to the rear focus point thereof and the output proportional to the matched focus to the spectroscope 7 of fluorescent X-rays is generated. Said X-rays are converted to an electric signal by the detector 6 to be inputted to a memory circuit 10 and surface properties are analyzed by a data analyser 11. By this method, focus matching is made unnecessary to make it possible to shorten an analytical time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a surface analysis bag using an electromagnetic beam or a particle beam.

(Prior art) For example, an electron beam microanalyzer that analyzes the types of elements forming the solid surface and the bonding state by exciting the solid surface with an electron beam and detecting various signals obtained from the surface. In other words, the distance between the area to be analyzed and the spectrometer depends on the signal intensity from the detector or the degree of focus of the fluorescent X-rays from the sample on the spectrometer, that is, on the detector. Focusing is performed through relative adjustment.

(Issues to be solved) For this reason, since the 100 sample units are moved not only in the scanning direction but also in the axial direction of the excitation beam, a precise movement mechanism is required, and each time the analysis area is changed. There is a problem in that the analysis requires a long time due to the need for focusing.

The present invention has been made in view of these problems, and its purpose is to provide a novel surface analysis device that does not require focusing, shortens analysis time, and simplifies the device. There is a particular thing.

(Means for Solving the Problems) In order to solve such problems, in the present invention, an excitation beam is provided in the excitation beam path from the excitation beam generating means with an i width that is at least larger than the depth of the irregularities on the sample surface. A sample mounting means that vibrates in the axial direction, a configuration means that receives energy rays emitted from the sample via a spectrometer and converts them into electrical signals, and a means that stores the intensity of the energy rays emitted from the sample. Prepared.

(Function) Because the focus of the detection beam from the area to be analyzed due to the vibration of the sample mounting means necessarily passes through the optical system of the detector, the unevenness of the sample is detected by integrating the signal. changes in signal strength caused by

(Example) Therefore, the details of the present invention will be explained below based on an illustrated example.

FIG. 1 shows an embodiment of the present invention, in which reference numerals in the figure denote a sample R mounting table, which is placed near the focal point of the detection optical path system, and generates an electron beam B from the electron beam generator 2. It is configured to receive a sample. This sample@j table 1 has a sample moving mechanism 3 that can be moved in three axial directions by a drive mechanism.
Then, the vibration table 4 vibrates in the axial direction of the electron beam by a piezoelectric element or the like provided on the surface of the vibration table 4, which vibrates in the axial direction of the electron beam. The beam B vibrates in the axial direction, and the spectrometer 7
The optical path length is also temporally changed in the axial direction of the detection optical path system connecting the sample stage 1 and the sample table 1.

10 is a storage circuit that stores signals from the detector 8 that convert fluorescent X-rays from the spectrometer 7 into electrical signals; It is configured to store output signals in correspondence with time, that is, displacement in the axial direction. A data analysis device 11 is configured to read data stored in the signal storage circuit 10 for each analysis region and analyze one shape of the sample S based on the integral value of the data for each time.

In this embodiment, when the sample S is set on the sample mounting table 1 and the apparatus M is operated, the vibration table 4 receives a signal from the excitation circuit 5 and moves in the axial direction of the electron beam B, in this embodiment up and down. The sample S is slightly vibrated in this direction.

As a result, the surface of the region to be analyzed of the sample is excited by the electron beam B and generates fluorescent X-rays representing the individual atoms and their bonding states. This fluorescent X-ray enters the detector 6 via the spectroscope 7 and is converted into an electrical signal.

By the way, since the sample stage 1 vibrates in the direction of the beam B during this detection process, the relative distance between the sample S and the spectrometer 7 changes over time, and the focal point of the spectrometer 7 Move the focus sequentially from the top side of the figure (Fig. 2) to the rear side (II), then move to the front focus side of the sample S (■), then move downward to the back focus side, the bottom side of the figure. Move to the side (■).

As a result, fluorescent XS! Outputs proportional to the degree of focus for the spectroscope 7 are sequentially generated.

This fluorescent X-ray is converted into an electrical signal by the detector 6,
The memory circuit 10 stores the vibration direction. This stored signal is read out by the data analysis device 11 and integrated for each region to be analyzed, and the properties of the sample surface are analyzed using the same method as normal data analysis using this integrated value.

When the analysis for one analysis target area is completed in this way, the drive mechanism 3 is operated to move the sample S, the analysis target area is changed, and the focusing operation is performed in the same manner as in the above process. After that, repeat this process to analyze the necessary areas.

By the way, when the focus of the electron beam B moves away from the sample surface to a certain distance by more than 1,Δ1' (Figure 3), the level of the fluorescent X-rays emitted from the sample decreases to about the background level B.
Since the value decreases to 1, the integrated signal becomes only a signal representing the properties near the surface of the region of interest.

In this example, the analysis is performed using the integral value, but the same effect can be obtained by calculating the average value for the direction of the detection light path and performing the analysis based on this average value. That is clear.

FIG. 4 shows a second embodiment of the present invention, in which reference numeral 12 indicates that the signal from the detector 6 is transmitted to at least a vibration table 4.
Buffer 13 stores data for 1/2 period of
The sampling circuit extracts the signal with the maximum intensity from among the signals stored in the buffer 12, and the data analysis bag = 14.
It is configured to output to .

In this embodiment, when the sample S is vibrated in the axial direction of the electron beam B by the vibration table 4, the intensity of the fluorescent X-rays detected within 172 cycles is temporarily stored in the buffer 12. The sampling circuit 13 extracts the maximum signal from among the signals stored in the Balanor 12, that is, the signal when the detection beam is focused on the detector 7, and outputs it to the data analysis device 14.

Thereby, analysis is performed based on the signal at the time when the fluorescent X-rays from the sample are focused on the spectrometer 7.

In this embodiment, the signal from the detector is temporarily stored in the buffer, or if the response speed of the sampling circuit is fast, the signal from the detector is stored within the vibration period without passing through the buffer. It is also possible to extract the largest one in .

Although the above embodiments have been explained using electron beams as an excitation source, the present invention can also be applied to surface analysis microscopes and optical microscopes that use other excitation rays such as ions and X-rays. It is clear that the same effect can be achieved.

Further, in the above-described embodiments, it is clear that the same effect can be obtained even if the vibration table is driven by a piezoelectric element or other vibration elements such as an electrostrictive element are used.

(Nine results) As explained above, since the present invention has been adopted, a sample is mounted on the excitation beam path from the excitation beam generating means, and the sample is vibrated in the axial direction of the excitation beam with an amplitude larger than at least the depth of the irregularities on the sample surface. It is equipped with a detection means that receives the energy rays emitted from the sample via a spectrometer and converts them into electrical signals, and a means that stores the intensity of the energy rays emitted from the sample. The spectrometer can focus the energy rays from the area where the specimen is located, and receive a uniform detection beam within at least 1/2 oscillation period regardless of the irregularities of the sample. While aiming to improve analysis accuracy by offsetting changes in
Analysis speed can be improved by eliminating the need for sequential focusing operations.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams showing the operation of the upper cover, and FIG. 4 is a block diagram showing another embodiment of the present invention. 1... Sample mounting 2... Electron beam generator 100 B... Electron beam 4... Shaking table S... Sample

Claims (2)

[Claims] (1) In the excitation beam path from the excitation beam generation means, there is a sample mounting means that vibrates in the excitation beam axis direction with an amplitude greater than at least the depth of unevenness on the sample surface, and the energy rays emitted from the sample are passed through the spectrometer. A beam-type surface analysis device comprising a detection means for receiving energy rays and converting them into electrical signals, and a means for storing the intensity of energy rays emitted from a sample. (2) In the excitation beam path from the excitation beam generating means, a sample mounting means is provided that vibrates in the excitation beam axial direction with an amplitude larger than at least the depth of unevenness on the sample surface, and
A beam-type surface analysis comprising a detection means for receiving energy rays emitted from a sample via a spectroscope and converting them into electrical signals, and a means for extracting a signal of maximum intensity within one amplitude of the sample mounting means. Device.