JPS6353457A - 2-d scan type state analyzer - Google Patents

Abstract

PURPOSE:To enable state analysis of a sample, by scanning over the surface of the sample with soft X rays or an X ray beam to obtain a 2-D distribution of chemical shift, coordination number and bond distance between atoms from an EXAFS spectrum gained. CONSTITUTION:Monochromic light emitted from a monochrometer 1 passes through an I0 monitor 2 to converge on a sample stage 5 with a Fresnel zone plate 3. A position on the (z) axis of the plate 3 is controlled to ensure that a convergent light of the same size is always irradiated on the surface of a sample. A collimator 4 removes a stray light and high-order light. The stage 5 is driven with a control measuring device 8 so that a spot of the convergent light scans over a x-y surface two-dimensionally. A detector 6 detects a signal from a sample allowed to detect the intensity of transmission light and a detector 7 detects reflected light, fluorescence and secondary electron. A measuring device determines an EXAFS spectrum from data obtained at points on the sample to obtain chemical shift, coordination number and distance between atoms and a 2-D distribution image is displayed thereby enabling the analyzing of the sample.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to new measurement techniques for evaluating thin film materials and analyzing basic surface physical properties, particularly chemical shifts, coordination numbers, and interatomic bond distances. The present invention relates to a two-dimensional scanning state analyzer suitable for obtaining a two-dimensional distribution of information.

[Conventional technology]

Conventionally, soft X-rays of 1200
The sample is irradiated with a focused beam of 0 to 3000 A, and the intensity of the transmitted light is measured while traveling across the sample two-dimensionally.
Obtain two-dimensional images of ~3,000 people, measure the transmitted light intensity of the sample at wavelengths around the absorption edge of the elements contained in the sample, and calculate the difference in intensity between the two to obtain a two-dimensional image of a specific element. The method is published in Physics Towadei Volume 38 (1985
) pages 22-32 (Physics roday 3
8 (1985) 22-32) K is discussed.

[Problem that the invention seeks to solve]

Since the above-mentioned conventional techniques mainly aim to obtain two-dimensional element distribution images or enlarged images, information for analyzing the state of the sample cannot be obtained, and because they measure the intensity of light transmitted through the sample,
Due to self-retention, it was not possible to measure thin films.

The purpose of the invention is to first irradiate the sample C with light in the soft X-ray to X-ray region that is narrowed using a Fresnel zone plate or reflective optical system, and scan the wavelength point by point to perform the EX
The goal is to obtain an AFS spectrum and thereby obtain a two-dimensional distribution of chemical shifts, coordination numbers, and interatomic distances N&.

[Means for solving problems]

The above purpose is to first use a Fresnel zone plate or a converging reflector (aberrations can be reduced by forming a multilayer film on the surface) to converge light in the soft X-ray to X-ray region;
This is made incident on a sample on a sample stage equipped with a two-dimensional scanning mechanism. If you measure the transmitted light, reflected light, fluorescence, and secondary electrons from the sample to obtain an EXAFS spectrum, then store the data at each point in a recording device and process the data. The purpose can be achieved by obtaining a two-dimensional distribution image of the order and interatomic distance.Also, thin films that cannot be self-retained are formed on the substrate, and the intensity is measured by reflecting the narrow beam. EX, , 1. Fs spectra can be obtained from the sample surface.A similar EXAFS spectrum can also be obtained by measuring fluorescent X-rays and secondary electrons emitted from the sample surface.

[Effect]

A Fresnel zone plate or a converging reflector is used to converge monochromatic light in the soft X-ray to X-ray region to submicron dimensions. The light incident on the sample is transmitted light, reflected light, fluorescent light,
Alternatively, secondary electrons are generated, and the intensity is measured using a corresponding detector. At this time, by scanning the wavelength, an EXAFS spectrum is finally obtained. Using software to analyze this, we obtain values for the chemical shift, coordination number, and interatomic distance of the constituent elements at each point in the sample. By measuring this at each point on the sample and storing it in a data memory, it is possible to obtain a two-dimensional distribution image.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. The overall configuration shown in Figure 1 consists of 1 monochromator (which emits monochromatic light in the soft (capable of converging human soft X-rays and light with a longer wavelength) and a drive mechanism on the Z axis, a two-dimensional scanning sample stage in the xy plane with a collimator 55 (4), a detector (6) (for measuring transmitted light intensity), It consists of 7 detectors (reflected light, fluorescence, or secondary electron intensity measurement), 8 control/measuring instruments, and a sword).

The monochromatic light emitted from monochromator 1 is.

(2) Passes through the 0 monitor 2 and is focused onto the sample stage 5 by the Fresnel zone plate 3. Since the focal length of the Fresnel zone plate 3 changes when the wavelength of the monochromatic light changes, the position of the Fresnel zone plate 3 on the Z axis is controlled so that convergent light of the same size is always irradiated onto the sample surface. do. Collimator 4 removes stray light and higher order light. Stage 5 has submicron positioning accuracy,
Signal 8 so that the spot of convergent light scans two-dimensionally on the xy screen
The detector 6 driven by the detector 6 is a device for detecting a signal from a sample whose thickness is less than aAm and whose intensity of transmitted light can be detected, and includes an electron multiplier tube, a proportional counter tube, etc. On the other hand, signals from samples where the sample is too thick to detect transmitted light (including samples where a film so thin that it cannot self-retain is formed on the substrate) are transmitted to the detector 7 as reflected light, fluorescence, and secondary rays.
Detected by The reflected light is detected using an electron multiplier, the fluorescent light is detected using a semiconductor detector, and the secondary electrons are detected using an electron energy analyzer. Whether to detect reflected light, fluorescence, or secondary electrons is determined by which element contained in the sample is of interest.

The control/measuring device 8 scans the wavelength at each point on the sample, measures and accumulates the signal from the detector, scans the sample two-dimensionally, accumulates data at each point, and measures and accumulates the signal from the detector at each point. EX from the data of
It has the function of determining the AFS spectrum, obtaining the chemical shift, coordination number, and interatomic distance, and displaying the two-dimensional distribution image.

Next, in order to converge light in the X-ray region (wavelength shorter than several amps), which is currently difficult to converge using Fresnel zone plates, a converging reflector 9 is used as shown in Figure 2. (The convergent reflector can also be used in the soft X-ray region). This convergent reflector has Walter, t'&
ii Sehwalzschild
) type, it is possible to obtain convergent light on the order of submicrons on the sample surface. Since this converging reflector has a constant focal length even if the wavelength is changed, there is no need to move it on the Z axis like a 7-Renel zone plate. Light incident on the sample generates reflected light, fluorescent light, transmitted light, or secondary electrons. The data acquisition by the detector, the data accumulation by the control/measuring instrument, and the two-dimensional distribution image forming method are exactly the same as in the case of FIG.

〔Effect of the invention〕

According to the present invention, (a) it is possible to obtain a two-dimensional distribution image of chemical shifts, coordination numbers, and interatomic distances of elements contained in a sample with submicron resolution, thereby fP)
The effect is that materials containing elements ranging from light to heavy elements can be evaluated quickly and precisely.

[Brief explanation of drawings]

FIG. 1 is an overall view showing a first arrangement as an embodiment of the present invention, and FIG. 2 is an overall view showing a second arrangement. 1... Monochromator, 2... Work 0 monitor, 3...
・Fresnel zone plate, 4...collimator, 5・
... Two-dimensional sample scanning stage, 6... Detector, 7...
- Detector, 8... Control/Measurement instrument, 9... Convergent reflector.

Claims (1)

[Claims] 1. An input optical system consisting of a Fresnel zone plate or a convergent reflector for irradiating a soft X-ray or submicron focused beam in the X-ray region onto the sample surface, and for scanning the beam on the sample surface. The sample scanning system detects the intensity of reflected light, fluorescence, secondary electrons, or transmitted light from the sample, obtains the EXAFS spectrum from its wavelength dependence, and calculates the chemical shift, coordination number, and interatomic bond distance. A two-dimensional scanning state analysis device comprising a detector and a data processing system for obtaining a dimensional distribution.