JPH1010046A - Sample analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device by which damage of an electron beam of a sample can be reduced and a focus can be adjusted with high accuracy or an analysis using the electron beam and an analysis using the light can be attained with high accuracy and with simple constitution in a single device. SOLUTION: In a sample analyzer to detect a sample through a converging mirror 3 having a reflecting surface to condense fluorescence emitted from the sample by irradiating an electron beam to the sample 2, illuminating systems 7 and 31 to project the illuminating light on the sample and a light detecting system 22 to detect the reflected light of the illuminating light on the sample surface through the converging mirror, are provided, and an analysis of the sample is performed by properly switching them to/from each other by having both a sample analyzing function by the electron beam and a sample analyzing function using the light. Therefore, since there is no need to replace the sample and a focus can be aligned by an observing system, damage of the electron beam of the sample can be prevented without irradiating the electron beam more than necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample analyzer for irradiating a sample with an electron beam or light and analyzing the reflected light from the sample to analyze the sample.

[0002]

2. Description of the Related Art Conventionally, there has been known a sample analyzer utilizing cathodoluminescence, which irradiates an electron beam onto a sample surface and detects the fluorescence generated on the sample surface to analyze the sample. This apparatus uses a condensing mirror having a spheroid or a paraboloid of revolution (hereinafter, referred to as an ellipsoid or a paraboloid) in order to efficiently condense the fluorescence generated from the sample. A device has been devised to widen the solid angle of the emitted fluorescent light. However, as a result, the depth of focus of the detection system becomes shallow, and if the sample position is slightly deviated from the focal position of the condenser mirror, the intensity of the detected fluorescence is sharply reduced. For this reason, it was necessary to accurately adjust the sample to the focal position.
Further, since the sample surface generally has irregularities, it is necessary to adjust the focus of the sample position every time the detection site is changed.

In the conventional apparatus, in order to adjust the focus, the intensity of the detected fluorescence is detected, and the focus where the intensity is the strongest is set as the position where the focus is located. In such a conventional apparatus, since the focus is adjusted by the intensity of the fluorescent light, the electron beam irradiated while searching for the focus position causes damage to the electron beam of the sample, and the fluorescent light is discolored. Had. In addition, when the fluorescence is weak, the signal intensity varies, and it is difficult to find the signal peak value.

On the other hand, as described above, apart from a sample analyzer utilizing an electron beam, which irradiates a sample with an electron beam and analyzes the sample by fluorescence from the sample, the sample is irradiated with light, and the reflected light of the sample is reflected. 2. Description of the Related Art A sample analyzer using light for analyzing a sample by optical analysis or the like has been conventionally known.

[0005]

The above-described analyzer using an electron beam can obtain a much higher magnification than the sample analysis using light, and the electron beam has a high resolution and a high depth of focus. For this reason, the analysis region can be narrowed down to a small size, which is excellent in crystal analysis, elemental analysis, and the like, but has disadvantages such as damage to the sample, and is not suitable for analyzing the chemical bonding state of the sample and analysis of organic substances. Therefore, when analyzing an unknown sample, it is necessary to analyze with an electron beam-based analyzer and replace it with a light-based analyzer, and perform analysis separately for each device. However, there is a problem that dust is attached to the sample due to the replacement.

In view of the above circumstances, the present invention can reduce electron beam damage to a sample, perform focus adjustment with high accuracy, or analyze electron beam use and light use in one device. It is an object of the present invention to provide a device which can achieve the above with high accuracy and with a simple configuration.

[0007]

According to the present invention, there is provided a sample analyzer for irradiating a sample with an electron beam and detecting the same through a collector mirror having a reflecting surface for collecting fluorescence emitted from the sample. The present invention relates to a sample analyzer provided with an illumination system for projecting illumination light on a sample, and a light detection system for detecting reflected light of the illumination light on the sample surface via the converging mirror. The illumination system relates to a sample analyzer that illuminates the sample via the converging mirror, and has an observation system for observing the surface of the sample via the converging mirror. An optical path according to the analysis device, wherein a plurality of photodetectors are provided for a reflected light path of the focusing mirror, and an optical path for directing reflected light from the focusing mirror to any one of the plurality of photodetectors. The present invention relates to a sample analyzer in which switching means is provided on the reflected light path. The condensing mirror relates to a sample analyzer having a reflecting surface that is any one of a spherical surface, an elliptical curved surface, a parabolic curved surface, or a combination thereof, and further includes an optical path of the observation system or the illumination system. The present invention relates to a sample analyzer in which a stop for restricting an opening angle of a light beam is arranged in at least one of the above, and the light detection system is a Raman analysis means for spectrally analyzing and analyzing light from a sample, The present invention relates to a sample analyzer having at least one of external analysis means.

Since the sample analysis function using an electron beam and the sample analysis function using light are provided and the sample is analyzed by appropriately switching, there is no need to replace the sample, and the observation system can focus on the sample. Since the alignment can be performed, the electron beam is not irradiated more than necessary, so that the electron beam damage of the sample can be prevented.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

A sample 2 is placed on a sample support 1, and a condensing mirror 3 having an elliptical curved surface is provided on the sample 2. The sample supporter 1 is movable toward and away from the condensing mirror 3 and is movable in the horizontal direction. The surface of the sample 2 is moved by moving the sample supporter 1 toward and away from the surface. Can be accurately matched with the focal point of the condenser mirror 3, and by moving the sample support 1, an optimal analysis point can be selected. The sample 2 and the electron gun 4 are disposed on the same optical path with the converging mirror 3 interposed therebetween. The converging mirror 3 is formed with a through hole 3a so that an electron beam from the electron gun 4 can pass therethrough. ing. In addition to the electron gun, there are a focusing lens for focusing an electron beam, a deflection coil for scanning, and the like, but they are not shown. A perforated mirror 5 is provided on the optical path, and an illumination light source 6 for observation is disposed to face the perforated mirror 5. The illumination light source 6 and the perforated mirror 5 apply illumination light from the illumination light source 6 to the light source 6. A first illumination system 7 for projecting onto the sample 2 is configured.

The condensing mirror 3 condenses the fluorescence emitted from the sample 2 or the light reflected on the surface of the sample 2 and reflects it toward the magnifying lens 9. The image formed by passing through the magnifying lens 9 can be directly observed through an eyepiece 10, or can be observed by means of a television monitor or the like via photoelectric conversion means such as an imaging device. An observation optical system 11 is composed of the magnifying lens 9, the eyepiece 10, and the like that magnify and image the light reflected from the optical mirror 3.

A first movable reflection plate 13 is provided on a reflection optical path O of the condensing mirror 3, and a second movable reflection plate 14 and a third movable reflection plate 14 are provided on a reflection optical path P switched by the first movable reflection plate 13.
Movable reflector 15, fourth movable reflector 16, fixed reflector 17
Are disposed, a color separator 18 corresponding to the second movable reflector 14, and a spectroscope 1 corresponding to the third movable reflector 15.
9. Raman spectroscope 20 for the fourth movable reflector 16
Are provided, and infrared spectrometers 21 are provided respectively corresponding to the fixed reflection plates 17.

The first movable reflection plate 13 is capable of entering and retracting into the reflection optical path O of the condenser mirror 3, and is rotatable, for example, about the upper end as shown in FIG. or,
The second movable reflecting plate 14, the third movable reflecting plate 15, and the fourth movable reflecting plate 16 can also enter and retract with respect to the reflection optical path P of the first movable reflecting plate 13, for example, as shown in the drawing. It is rotatable around the upper end.

The second movable reflector 14, the third movable reflector 15, the fourth movable reflector 16, the fixed reflector 17,
A light detection system 22 includes the color separator 18, the spectroscope 19, the Raman spectroscope 20, the infrared spectroscope 21, and the like.

Condensing lens 27 with respect to half mirror 24
The excitation light source 25 is disposed on the transmission side via the light source, and the observation light source 26 is disposed on the reflection side via the condenser lens 28. The light from the excitation light source 25 and the observation light source , Through a mirror 29, to a half mirror 30 disposed on the reflection optical path O of the condenser mirror 3, and the half mirror 30 transfers the light from the excitation light source 25 and the observation light source 26 to the condenser mirror 3. It is designed to reflect toward. The excitation light source 25, the observation light source 26, the half mirror 24, the mirror 29, and the half mirror 30
The illumination system 31 is configured.

A stop 32 is disposed on the reflection optical path O of the condenser mirror 3 between the half mirror 30 and the condenser mirror 3, and the angle of opening of the light beam in the observation optical system 11 is determined by the stop 32. Can be restricted. The aperture 32 may be provided in the first illumination system 7 and the second illumination system 31.

Hereinafter, the operation will be described.

The reflected light path O of the first movable reflecting plate 13
The path of the reflected light from the converging mirror 3 is switched by entering and retreating to the optical path.

First, the sample 2 is irradiated by the illumination light source 6 and the observation light source 26, the first movable reflection plate 13 is retracted from the reflection optical path O of the condenser mirror 3, and the reflected light from the condenser mirror 3 is enlarged. It is guided to the lens 9. The reflected light can be observed by the operator via the magnifying lens 9 and the eyepiece 10. An operator observes the sample 2 with the observation optical system 11, moves the sample support 1 toward and away from the condenser mirror 3 (up and down in the figure) while performing observation, and performs focusing.

When the focusing is completed, the first
An electron beam is passed from the electron gun 4 through the condenser mirror 3 in a state where the movable reflector 13 enters the reflection optical path O of the condenser mirror 3 and the second movable reflector 14 enters the reflection optical path P. Is projected onto the sample 2.

The sample 2 is irradiated with the electron beam.
More fluorescence is emitted, and the fluorescence is condensed and reflected by the converging mirror 3. This reflected light beam is restricted to a desired light beam opening angle by passing through the stop 32, is further reflected by the first movable reflector 13, and is further reflected by the second movable reflector 14.
And is incident on the color separator 18.

The color separator 18 separates the fluorescent light into RGB and displays a color fluorescent image.
If the scanning movement is performed in a two-dimensional manner, a two-dimensional color fluorescent image of the sample 2 can be displayed on a television monitor or the like based on a signal from the color separator 18.

Further, the second movable reflection plate 14 is connected to the reflection optical path P
By retracting further, the third movable reflection plate 15 enters the reflection optical path P, whereby the reflected light from the first movable reflection plate 13 can enter the spectroscope 19. Spectroscopy of the light emitted from is performed in a wide wavelength range from ultraviolet to visible range.

When the analysis is performed by light irradiation, the first movable reflecting plate 13 enters the reflecting optical path O, and the second movable reflecting plate 14 and the third movable reflecting plate 15 are retracted from the reflecting optical path P. Then, the fourth movable reflection plate 16 is caused to enter the reflection optical path P. The irradiation of the electron beam from the electron gun 4 is stopped, and the excitation light source 25 is turned on to emit the excitation light to the half mirror 2.
The sample 2 is radiated through the mirror 29, the half mirror 30, and the condenser mirror 3. The excitation light emitted from the excitation light source 25 is light from visible light to near infrared light. The light irradiated with the excitation light and reflected from the sample 2 is condensed by the condensing mirror 3, transmitted through the half mirror 30, reflected by the first movable reflecting plate 13 and the fourth movable reflecting plate 16, and Light enters the Raman spectroscope 20. The Raman spectrometer 20 analyzes the sample by detecting the absorption wavelength of the sample by separating the sample reflected light.

Further, the fourth movable reflection plate 16 is retracted from the reflection optical path P, the infrared light is emitted from the excitation light source 25, and the infrared light passes through the mirror 29, the half mirror 30, and the condensing mirror 3 to the infrared light. The sample 2 is illuminated, and the reflected light from the sample 2 is reflected by the first movable reflector 13,
7 further reflects toward the infrared spectroscope 21. The infrared spectroscope 21 detects the absorption wavelength and performs sample analysis.

Either the illumination light source 6 or the observation light source 26 can be omitted, and the condensing mirror 3 is replaced by an elliptic curved surface instead of a parabolic curved surface, a spherical surface, or a combination of these curved surfaces. The surface may be composed of

[0027]

As described above, according to the present invention, a sample analysis function using an electron beam and a sample analysis function using light are provided, and the analysis using the electron beam and the analysis using the light can be performed by appropriately switching. Since two analyzes are performed, there is no need to replace the sample, it is possible to prevent contamination due to dust and the like accompanying the replacement of the sample, and it is possible to perform focusing with the observation system, so that the electron beam is not irradiated more than necessary. The electron beam damage to the sample can be reduced, the focus can be adjusted with high accuracy, and the analysis using electron beam and the analysis using light can be performed with high accuracy and simpleness in one apparatus. It has an excellent effect that it can be realized with a configuration.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sample support part 2 Sample 3 Condensing mirror 4 Electron gun 6 Illumination light source 7 1st illumination system 11 Observation optical system 13 1st movable reflection plate 14 2nd movable reflection plate 15 3rd movable reflection plate 16 4th movable reflection plate 17 Fixed reflector 18 Color separator 19 Spectroscope 20 Raman spectrometer 21 Infrared spectrometer 22 Photodetection system 25 Light source for excitation 26 Light source for observation 32 Aperture

Claims (7)

[Claims] 1. A sample analyzer for irradiating an electron beam on a sample and detecting the same through a converging mirror having a reflecting surface for condensing fluorescence emitted from the sample. And a light detection system for detecting reflected light of the illumination light on the sample surface via the condenser mirror. 2. The sample analyzer according to claim 1, wherein the illumination system illuminates the sample via the condenser mirror. 3. The sample analyzer according to claim 1, further comprising an observation system for observing the surface of the sample via a condenser mirror. 4. A light path switching means for providing a plurality of photodetectors to a reflected light path of the converging mirror and directing reflected light from the converging mirror to any one of the plurality of photodetectors. 2. The sample analyzer according to claim 1, which is provided on a reflected light path. 5. The sample analyzer according to claim 1, wherein the focusing mirror has a reflecting surface which is any one of a spherical surface, an elliptical curved surface, a parabolic curved surface, or a combination thereof. 6. The sample analyzer according to claim 3, wherein a stop for restricting an opening angle of a light beam is disposed in at least one of the optical paths of the observation system or the illumination system. 7. The sample analyzer according to claim 1, wherein the light detection system has at least one of a Raman analysis unit and an infrared analysis unit for spectrally analyzing and analyzing light from the sample.