JP2009123477A - Sample holder for ultraviolet-visible-near infrared absorption spectrum measurement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample holder for concurrently allowing easy and sure high-resolution observation of a sample as well as ultraviolet-visible-near infrared absorption spectrum measurement by, using an existing electron microscope. <P>SOLUTION: A sample holder 10 performs structural observation of a sample S by radiating electron beam E in a TEM1. The holder includes an incident side optical fiber 38 which is arranged along the axial direction X of the sample holder 10 for transferring the light in the region of ultraviolet-visible-near infrared from a light source 60 outside an electron microscope, an incident side condenser lens 42 which condenses incident light L<SB>1</SB>transmitted through the incident side optical fiber 38, a transmissive side condenser lens 43 which is arranged on the side counter to the incident side condenser lens 42 through the sample S and condenses light L<SB>2</SB>transmitted through the sample S, and a transmissive side optical fiber 39 which is arranged along the axial direction of the sample holder 10 and transmits the transmissive light L<SB>2</SB>condensed by the transmissive side condenser leans 43 to the outside of the electron microscope. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a sample holder capable of simultaneously performing excitation and absorption measurement with light and high-resolution observation of an electron microscope, particularly for ultraviolet, visible, and near-infrared absorption spectrum measurement that can be attached to an existing transmission electron microscope. It relates to the sample holder.

  UV-Vis-NIR (UV-Vis-NIR) measures light absorption in the ultraviolet (UV, UltraViolet), visible (Vis, Visible), and near infrared (NIR, Near InfraRed) regions. This is a spectroscopic method for analyzing the electronic transition energy peculiar to a substance. Usually, it measures about the wavelength range of about 200-1500 nm. Ultraviolet, visible, and near-infrared spectroscopy is easy to measure, the results are consistent with the naked eye and easy to understand, some molecules have very characteristic spectra, and the spectra are sensitive to the state of the material It is a measurement method widely used for research in fields such as dielectrics, ionic crystals, and semiconductors.

  In UV / visible / near-infrared absorption spectrum measurement, a transparent support substrate such as quartz glass is generally used. However, since electron beams do not pass through the glass substrate, structural analysis using an electron microscope and ultraviolet / visible / The near infrared absorption spectrum measurement was performed separately and independently. In order to observe an ultraviolet, visible, and near-infrared spectrum thin film with an electron microscope, the substrate is dissolved with a chemical such as hydrofluoric acid (HF), or the substrate is physically removed by mechanical polishing or ion polishing. Therefore, the sample is often remade. Sample preparation processes such as dissolution by chemicals such as hydrofluoric acid, mechanical polishing, and ion polishing cause destruction of the surface structure and crystal structure of the sample. For this reason, the sample structure in which the ultraviolet / visible / near-infrared absorption spectrum was measured and the structure of the sample observed by the electron microscope may be displaced. Therefore, it has been desired to simultaneously perform structural observation and measurement of ultraviolet, visible, and near-infrared absorption spectra in an electron microscope.

  On the other hand, Patent Document 1 is proposed as a sample holder capable of performing cathodoluminescence analysis for detecting and analyzing excitation light generated from an electron beam irradiated on a sample at the same time as observing the sample with an existing transmission electron microscope. ing. The sample holder of Patent Document 1 can be attached to an existing transmission electron microscope, and is arranged on the back side of the sample with respect to the optical fiber extending from the rear end portion to the vicinity of the sample fixing portion and the irradiation direction of the electron beam. And a reflecting plate that reflects the excitation light generated by the electron beam irradiation toward the optical fiber, and a condensing lens that collects the light from the reflecting plate. When the sample is irradiated with an electron beam, the direction of the excitation light generated by the electron beam passing through the sample is changed by the reflector, and the excitation light collected through the condenser lens is passed through the optical fiber through an electron microscope. It can be measured with a spectrophotometer provided outside.

  Further, there is Patent Document 2 by the present applicant as a sample holder that can be easily observed with a high-resolution electron microscope at a high temperature, although it is not for measuring optical characteristics. Patent Document 2 solves the problems in the conventional electron beam method and laser beam method for increasing the temperature of a sample, and includes an optical fiber extending to the vicinity of a sample fixing portion of a sample holder, and an optical fiber. A reflecting plate that reflects the Nd-YAG laser light emitted from the reflector, and a condenser lens that collects the laser light from the reflecting plate. This makes it possible to easily irradiate the sample with laser light even in the pole piece.

JP 2003-139703 A JP-A-8-31361

  In Patent Document 1, cathodoluminescence analysis can be performed together with structure observation using an existing electron microscope. However, Patent Document 1 has only an electron beam irradiation system and a fiber optical system that detects excitation light by electron beam irradiation, and has no ultraviolet, visible, or near infrared light incident system.・ Visible and near-infrared spectroscopy is also impossible. On the other hand, Patent Document 2 can easily irradiate Nd-YAG laser light with an existing electron microscope, but only irradiates laser light for making a sample into a high temperature condition. It is impossible to measure the absorption spectrum. That is, with these sample holders and heating devices, it is not possible to measure the excitation light or absorption spectrum of the sample even if the temperature measurement using the amount of thermal radiation (infrared rays) or the cathodoluminescence can be measured. In addition, a predetermined amount of the tip of the optical fiber disclosed in Patent Document 2 is exposed to the outside of the sample holder.

  Further, since Patent Document 1 and Patent Document 2 are fundamentally different from those for ultraviolet / visible / near infrared spectroscopy, they cannot be simply applied to ultraviolet / visible / near infrared spectroscopy. In other words, in order to realize spectroscopic measurement with a sample holder that is generally used for existing electron microscopes, complex modifications are required. It was difficult to construct a concrete means to measure by Therefore, in Patent Document 1 and Patent Document 2, the tilting mechanism of the sample required in high-resolution electron microscope observation is sacrificed. Moreover, in both Patent Document 1 and Patent Document 2, since the electron beam or laser light is directed to the sample only by the reflector, it is difficult to precisely adjust the relative angle between the light and the sample, and a reflector is provided. Space is also required, making it difficult to apply to a pole piece with a small sample installation space.

  Therefore, an object of the present invention is to realize electron excitation by light absorption by irradiating the sample with ultraviolet, visible, and near infrared light reliably at the same time as observing the sample with a high resolution electron microscope using an existing electron microscope. It is an object of the present invention to provide a sample holder that can easily and reliably perform ultraviolet, visible, and near infrared absorption spectrum measurement.

  The present invention is a sample holder for observing the structure of a sample by irradiating an electron beam in an electron microscope, and is arranged along the axial direction of the sample holder, and is irradiated with ultraviolet, visible and near light from a light source outside the electron microscope. An incident side optical fiber that transmits light in the infrared region into the lens barrel of the electron microscope, and an incident side condensing lens that condenses the incident light transmitted by the incident side optical fiber on the sample installed in the sample holder And arranged on the opposite side of the incident side condensing lens through the sample, arranged along the axial direction of the sample holder, and a transmission side condensing lens for condensing the light transmitted through the sample, A transmission-side optical fiber that transmits the transmitted light collected by the transmission-side condensing lens from the opposite side of the incident-side optical fiber to the outside of the electron microscope column through the sample; Discussion At the same time, characterized by the measurement of the excitation and emission spectra of the sample by light in the ultraviolet-visible-near-infrared region.

  Further, in the present invention, it is possible to provide a sample holder characterized in that the incident side optical fiber and the transmission side optical fiber are inserted through the entire inside of the sample holder.

  In the present invention, light from the condenser lens is reflected toward the sample between the incident-side condenser lens and the sample and between the transmission-side condenser lens and the sample. It is possible to provide a sample holder provided with an incident side reflection plate and a transmission side reflection plate.

  In the present invention, the sample holder includes a holder tilt mechanism that adjusts the tilt angle of the entire sample holder, and a tilt angle of a sample mounting base that is fixed to a sample fixing portion provided at the tip of the sample holder. The sample holder can be tilted biaxially within the pole piece for high resolution by the sample mounting table tilting mechanism that is adjusted in the axial direction orthogonal to the axial direction of the sample holder. .

  According to the present invention, there is provided a sample holder, wherein the incident side condensing lens and the transmission side condensing lens can adjust the distance from the incident side optical fiber and the transmission side condensing lens, respectively. be able to.

  In the present invention, it is possible to provide a sample holder in which the incident-side reflecting plate and the transmissive-side reflecting plate are adjustable in angle with respect to the sample.

  Moreover, in this invention, an electron microscope provided with the sample holder which has one of the said structures can also be provided.

  The present invention has a simple configuration in which a sample holder conventionally used in an electron microscope is mainly provided with an incident side optical fiber and a transmission side optical fiber, and both optical fibers are provided in the sample holder. Therefore, it is not necessary to attach the optical fiber to the electron microscope separately from the sample holder. Therefore, the sample holder of the present invention can be mounted on an existing electron microscope as it is, and the excitation of the sample and measurement of the absorption spectrum by the light in the ultraviolet, visible, and near infrared region can be performed simultaneously with the conventional structure observation by the electron beam. Can be highly versatile. Moreover, if it is possible to measure the light absorption spectrum in the ultraviolet, visible, and near-infrared regions simultaneously with the structural observation by the electron beam, electron excitation by light absorption, which was impossible with the conventional transmission electron microscope, is possible. In-situ observation of the process with an electron microscope and the correlation between the structure and light absorption at the atomic level can be observed to a fine level. This saves the trouble of performing the measurement of the optical characteristics of the sample separately from the structural observation, and eliminates the need to modify the existing electron microscope into a complicated mechanism for measuring the optical characteristics. Further, since both optical fibers are arranged along the axial direction of the sample holder, it is possible to avoid an increase in the size of the sample holder. If an incident side condensing lens and a transmission side condensing lens are arranged between both optical fibers and the sample, light can be efficiently condensed on the sample and the transmission side optical fiber.

  If the incident-side optical fiber and the transmission-side optical fiber are inserted through the entire sample holder, the sample holder can be prevented from being enlarged, and can be as large as the sample holder used in conventional electron microscopes. . In addition, when the sample holder is mounted on the electron microscope, it is possible to prevent the optical fiber from getting in the way or being damaged by being caught on the lens barrel of the electron microscope.

  If an incident-side reflector and a transmission-side reflector are provided between the two condenser lenses and the sample, respectively, the angle of the light incident from the incident-side optical fiber in accordance with the fixed position or fixed angle of the sample, The sample and the transmission side optical fiber can be accurately adjusted, and precise sample excitation and absorption spectrum measurement can be performed.

  If the sample holder can be tilted in two axes, the position and angle of the sample with respect to the electron beam can be adjusted, and the angle with respect to light in the ultraviolet, visible, and near-infrared region that is incident from the optical fiber can also be adjusted. Observation and sample excitation and absorption spectra can be measured.

  In addition, if both the condensing lenses and the two reflecting plates are adjustable in angle, it is possible to measure the excitation spectrum and absorption spectrum of the sample with light in the ultraviolet, visible, and near infrared regions more precisely.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. However, the present invention is not limited thereto, and various modifications can be made without departing from the scope of the present invention. Since the sample holder of the present invention is attached to an existing electron microscope, first, an overview of sample structure observation using a well-known electron microscope that has been conventionally used will be described.

  FIG. 1 shows a schematic configuration diagram of an existing transmission electron microscope (TEM). FIG. 2 shows a schematic sectional view of the inside of the pole piece. FIG. 3 shows a cross-sectional plan view of an existing holder tilting mechanism. In addition, illustration of the holder tilting mechanism is omitted in FIG. In FIG. 1, a TEM 1 includes an electron gun (filament) 2, a first converging lens 3, a second converging lens 4, an objective lens 5, an intermediate lens 6, a projection lens 7, and a fluorescent plate 8 from above. A sample holder 10 that has a camera 9 and holds a sample S to be observed is disposed in a pole piece 16 between the second converging lens 4 and the objective lens 5. The sample holder 10 is a side entry type, and as shown in FIG. 2, the internal space of the pole piece 16 to which the sample holder 10 is actually mounted is narrow. The first converging lens 3 and the second converging lens 4 are an irradiation system, and the objective lens 5, the intermediate lens 6, and the projection lens 7 are an imaging system. The electron beam E irradiated from the electron gun 2 is converged in a spot shape by the first and second converging lenses 3 and 4 and passes through the sample S. When the electron beam E passes through the sample S, secondary electrons are emitted from the sample S. The electrons that have passed through the sample S are imaged by the objective lens 5, and the image is magnified by the projection lens 7 and projected onto the fluorescent screen 8. The transmitted electron image projected on the fluorescent screen 8 is displayed on a monitor (not shown) via the camera 9 when the fluorescent screen 8 is raised. Reference numeral 11 denotes a lens barrel of TEM1. The position and angle of the sample S can be changed and adjusted on the electron beam axis by a holder tilting mechanism 15 that adjusts the tilt angle of the entire sample holder 10, and the sample S can be adjusted from various angles while holding the sample S at the center of the field of view of the electron microscope. It is possible to observe a transmission electron image.

  Although a well-known mechanism can be used as the holder tilting mechanism 15, FIG. 3 shows an example of a cross-sectional plan view. In the following, the axial direction (left and right direction in FIG. 3) of the sample holder 10 is defined as the x direction, and the direction perpendicular to the x direction (vertical direction in FIG. 3) on the horizontal plane is defined as the y direction. A direction (a front and back direction in FIG. 3) that is orthogonal to the height direction of TEM1 is defined as the z direction. In FIG. 3, a sample holder 10 is a cylindrical member having a predetermined length, and a flat sample fixing portion 10a on which a sample is placed and fixed is integrally formed at the tip thereof. The sample holder 10 is inserted and fixed to a cylindrical sheath tube 17 that is open on both the left and right sides. The distal end of the sheath tube 17 has a spherical shape and is configured to be accommodated in the spherical seat 18. In order to control the sample S with high accuracy in the yz direction, a fine actuator 20 fixed from the yz2 direction is provided on the cylinder 19 provided in the outer layer of the sheath tube 17, and the fine actuator 20 and the opposing surface thereof are provided. The sheath tube 17 is sandwiched between the return spring 21 provided on the side. The fine movement actuator 20 can be moved into and out of the cylinder 19 by receiving an electrical pulse input, and can incline the sample holder 10 arbitrarily in the yz direction at a few nm level with the center C of the spherical seat 18 as a fixed point. The position restoring force is generated by the urging force of the return spring 21. As described above, the sample holder 10 can be tilted in the yz direction at an arbitrary angle with the center C of the spherical seat 18 as a fixed point, so that the sample S placed on the sample fixing portion 10a at the tip of the sample holder 10 is yz. Can move in any direction. Adjustment of the position of the sample in the x direction is realized by an insulator 27 fixed to the tip of the sample holder 10. That is, the sample S can be finely adjusted in the x direction by pushing up the handle 28 with the lever 27. Further, the cylinder adjusting mechanism 23 finely adjusts the position of the cylinder 19 in the yz direction, and the cylinder guide adjusting mechanism 26 adjusts the relative positional relationship between the lens barrel 11 and the cylinder guide 24. Note that the vacuum in the lens barrel 11 is maintained by fitting an O-ring or the like to the outer periphery of the sample holder 10 at any location between the outside of the TEM 1 and the lens barrel 11.

  Next, the sample fixing portion 10a at the tip of the sample holder 10 will be described in detail with reference to FIGS. FIG. 4 is an enlarged plan view of a main part of the sample fixing part 10a. FIG. 5 is a vertical side view of the sample fixing portion 10a. As shown in FIG. 4, the sample fixing portion 10 a has a flat rectangular shape, and a flat plate-like setting table 32 for setting the sample is disposed in an opening 31 formed near the tip. The sample S is installed in the center of the installation table 32 via a mesh (not shown) or the like. The installation base 32 is provided in the sample holder 10 via a torsion coil spring 33, and the inclination angle can be adjusted by an installation base inclination mechanism. That is, the installation table 32 is rotatable about a rotation axis Y in the y direction orthogonal to the axial direction X of the sample holder 10. Although a well-known mechanism can be adopted as the tilting mechanism of the installation table 32, for example, one of the support shafts 34 integrally formed on both side surfaces of the installation table 32 (downward in FIG. 4) A linear or belt-like traction member 35 is wound and fixed, and the other end extends through the inside of the sample holder 10 to the rear end side. Then, by pulling the pulling member 35 from the rear end side of the sample holder 10, the installation table 32 resists the biasing force of the torsion coil spring 33 and the axial direction X of the sample holder 10 as shown in FIG. It is rotatable (angle adjustable) about a rotation axis Y in the orthogonal y direction. Note that the biaxial tilting mechanism is merely an example, and other mechanisms such as those disclosed in Japanese Patent Laid-Open No. 6-68828 may be employed.

Example 1
Next, a member configuration for ultraviolet / visible / near infrared spectroscopy, which is a characteristic configuration of the present invention, will be described. 4 and 5, the sample holder 10 receives the incident side optical fiber 38 that transmits the light L ₁ in the ultraviolet, visible, and near infrared region from the light source 60 toward the sample S, and the light L ₂ that has passed through the sample S. A transmission-side optical fiber 39 that transmits to the spectroscopic measuring instrument 61. Both the optical fibers 38 and 39 are inserted and disposed along the axial direction X inside the sample holder 10 over almost the whole of the optical fibers 38 and 39. Specifically, the other end of the incident-side optical fiber 38 is connected to a light source 60 outside the TEM 1 (see FIG. 1), and wraps around the side of the installation base 32 so that the inner periphery on the tip side of the opening 31 of the sample holder 10. It reaches the surface and is inserted to the vicinity of the tip edge of the installation base 32. The transmission-side optical fiber 39 is also connected to the spectroscopic measuring instrument 61 outside the TEM 1 (see FIG. 1), reaches the rear end side inner peripheral surface of the opening of the sample holder 10, and is inserted to the vicinity of the rear end edge of the installation base 32. ing. That is, both optical fibers 38 and 39 are arranged in a facing state with the sample S interposed therebetween. The tip portions of both optical fibers 38 and 39 are pressed and held by a screw 40 screwed into the sample holder 10, and the position in the xy direction can be finely adjusted by the screwing amount of the screw 40. The optical fibers 38 and 39 are composed of a combination of a dielectric line capable of transmitting light in the ultraviolet, visible, and near infrared regions and reflecting means.

  Thus, both optical fibers 38 and 39 are inserted into and fixed to the sample holder 10 so that they can be introduced into the pole piece 16 of the TEM 1 together with the sample holder 10 and handled together. Moreover, since both optical fibers 38 and 39 are penetrated into the sample holder 10, it can be easily introduced into the pole piece 16 using the port for the sample holder 10 (installation space in the pole piece 16). There is no need for a separate port for optical fibers 38 and 39. Therefore, the sample holder 10 can be easily applied to the existing TEM1. Since the ultraviolet / visible / near-infrared light source 60 and the ultraviolet / visible / near-infrared spectroscopic measuring instrument 61 are installed outside the TEM 1 via the optical fibers 38 and 39, the semiconductor detector is provided. It is possible to select an optimal light source 60 and measuring instrument 61 in accordance with improvements such as a monochromator.

A heat-resistant incident-side condensing lens 42 and transmission-side condensing lens 43 are welded and fixed to the tips of the incident-side optical fiber 38 and the transmissive-side optical fiber 39, respectively. The incident side condensing lens 42 condenses incident light L ₁ diffusing from the tip of the incident side optical fiber 38 and directs it toward the sample S on the sample holder 10, and the welding surface with the optical fiber 38 has a welded surface. The surface on the sample S side is a spherical surface that is convexly curved. Permeate side condenser lens 43 is for introducing light L ₂ transmitted through the sample S by the reciprocity theorem the incident-side optical system 38, 42 to the permeate side optical fiber 39, the plane welding face of the optical fiber 39, The surface on the sample S side is a spherical surface curved in a convex shape.

  As shown in FIG. 4, after the height positions of the optical fibers 38 and 39 and the installation base 32 are made different from each other, the tips of the optical fibers 38 and 39 (and the condensing lenses 42 and 43) are respectively placed on the sample. In the axial direction X of the holder 10, the holder 10 is brought close to a position where it overlaps with the leading edge and the trailing edge of the installation base 32. The incident-side optical fiber 38 is located above the installation base 32, and the tip surface thereof is inclined downward. Thereby, the incident side condensing lens 42 welded to the front end surface of the incident side optical fiber 38 is also inclined downward at a predetermined angle. On the other hand, the transmission-side optical fiber 39 is located below the installation base 32, and its tip surface is inclined upward. Thereby, the transmission side condensing lens 43 welded to the front end surface of the transmission side optical fiber 39 is also inclined upward at a predetermined angle. Note that the opposing relationship between the incident-side optical fiber 38 and the transmission-side optical fiber 39 and the vertical position relationship may be the reverse of the configuration of the first embodiment.

  Next, a measurement method using ultraviolet / visible / near-infrared spectroscopy will be described. First, the observation sample S is set on the setting base 32 of the sample holder 10, and the sample holder 10 of the first embodiment is side-entry into the pole piece 16 of the existing TEM 1 together with both optical fibers 38 and 39. Once the sample holder 10 can be mounted on the pole piece 16, a well-known method using the high spatial resolution by electron beam E transmission by adjusting the angle of the sample holder 10 by the holder tilting mechanism 15 so that the sample S is at the center of the field of view of the TEM1. To observe the structure of the sample S. At the same time, measurement by ultraviolet, visible, and near infrared spectroscopy using the light source 60 and the spectroscopic measuring instrument 61 can be performed.

A light source 60 provided outside the TEM ₁ emits light L _{1 in the} ultraviolet, visible, and near infrared regions that can be transmitted by an optical fiber and does not adversely affect the high-resolution observation of the sample S. Further, the ultraviolet / visible / near-infrared light source 60 is preferably one that can be condensed to a small diameter. This is because a high power density can be obtained and the minute sample S can be excited effectively. In addition, in order to easily detect a very small amount of light absorption, it is desirable to be able to stably output a high output. Further, those capable of continuous oscillation are preferable. As such a light source 60, for example, deuterium / tungsten (lamp D2 / W) can be used. Such ultraviolet, visible, and near-infrared light can oscillate in the air. In addition, the incident-side optical systems 38 and 42 and the transmission-side optical systems 39 and 43 are provided integrally with the sample holder 10 that is taken in and out of the lens barrel 11 without breaking the vacuum. Thereby, before setting the sample holder 10 in the pole piece 16 of TEM1, the axis | shaft adjustment of the sample S can be previously performed outside the lens barrel 11. FIG. The ultraviolet / visible / near-infrared spectrometer 61 can measure light in a wide range of wavelengths from the ultraviolet region to the near-infrared region (about 185 to 3300 nm), and can realize high sensitivity and low stray light. Is desirable.

First, before mounting the sample holder 10 in the pole piece 16, by pulling the pulling member 35 from the rear end of the sample holder 10, as shown in FIG. Adjustment is made so as to be perpendicular to the optical path from the incident side optical fiber 38 to the transmission side optical fiber 39. After that, the sample holder 10 is mounted on the TEM 1 and measurement by ultraviolet / visible / near infrared spectroscopy is performed together with high-resolution observation by electron beam transmission. The incident light L ₁ in the ultraviolet / visible / near infrared region transmitted from the light source 60 via the incident side optical fiber 38 is irradiated onto the sample S while being collected by the incident side condensing lens 42. Then, the sample S is excited by the transmission of the incident light L _1, and the transmitted light L _{2 that} has been absorbed is condensed by the transmission side condensing lens 43 and then dispersed through the transmission side optical fiber 39. It is transmitted to the measuring instrument 61 and the absorption spectrum of light can be measured. As a result, it has become possible to measure by ultraviolet / visible / near-infrared spectroscopy while concentrating light in the ultraviolet / visible / near-infrared region simultaneously with structural observation by conventional transmission electron microscopes. It is possible to observe the structure of the minimum region below nm and the optical properties at the same time. Therefore, it is possible to observe composition fluctuations, lattice distortion, and crystal grain boundaries with higher accuracy than in the past. In addition, if the sample holder is simply configured with an optical fiber and a condensing lens, it can be attached to a pole piece with a narrow gap, and is suitable for an electron microscope with high spatial resolution. it can.

(Example 2)
Next, Embodiment 2 of the sample holder 10 according to the present invention will be described with reference to FIGS. FIG. 6 is an enlarged plan view of a main part of the sample fixing portion 10a of the sample holder 10 according to the second embodiment. FIG. 7 shows a vertical side view of the sample fixing portion 10a of the sample holder 10 according to the second embodiment. The second embodiment is characterized in that the position of the condenser lens can be adjusted, and that a reflecting plate is provided between the condenser lens and the sample S. Therefore, the following description will focus on the features of the second embodiment that are different from the first embodiment.

  As shown in FIGS. 6 and 7, in the sample holder 10 of the second embodiment, the support frame 50 provided in an opposed manner with the optical path in between is provided in front of the distal ends of the optical fibers 38 and 39, respectively. It is formed so as to protrude integrally from the inner peripheral surface of the opening 31. The incident-side condensing lens 42 and the transmissive-side condensing lens 43 are provided by the holding member 51 from both the left and right side surfaces, so that they are provided independently of the incident-side optical fiber 38 and the transmissive-side optical fiber 39, respectively. Yes. The inner end portions of both holding members 51 are substantially U-shaped in a plan view, and the condenser lenses 42 and 43 are inserted and held in a clip shape therebetween, so that the condenser lenses 42 and 43 are held by the holding member 51. It is detachable from. As shown well in FIG. 7, a slide groove 52 having a predetermined length in the axial direction X of the sample holder 10 is formed in the support frame 50, and the outer end of the holding member 51 is formed in the slide groove 52. The parts are slidably fitted. As a result, the distance between the optical fibers 38 and 39 and the condenser lenses 42 and 43 can be adjusted. Further, an incident-side reflection plate 53 and a transmission-side reflection plate 54 are provided at the front end portion of the support frame 50 and between the condenser lenses 42 and 43 and the sample S. Both reflecting plates 53 and 54 are rotatably fixed to the support frame 50 via pins 55. The reflecting plates 53 and 54 are not particularly limited as long as they can be reflected without transmitting light. Typically, a reflecting mirror can be used. The shape is also generally a flat plate shape, but can also be formed in a concave curved surface shape in order to direct light efficiently.

When observing the sample S, light in the ultraviolet / visible / near infrared region is transmitted from the light source 60 outside the TEM 1 through the incident side optical fiber 38, and the incident light L ₁ from the incident side optical fiber 38 is incident on the incident side. While being condensed by the condenser lens 42, the light is reflected and directed toward the sample S by the incident-side reflecting plate 53, and the sample S is irradiated. The sample S is excited by passing the incident light L ₁ in the ultraviolet / visible / near infrared region through the sample S, and the transmitted light L ₂ transmitted through the sample S is reflected and directed toward the transmission side reflector 54 side. Then, the light is collected by the transmission side condensing lens 43 and transmitted to the spectroscopic measuring instrument 61 through the transmission side optical fiber 39, and the absorption spectrum of the light is measured.

At this time, by appropriately adjusting the positions of the condenser lenses 42 and 43, the inclination angles of the reflecting plates 53 and 54, and the inclination angle of the sample S, the degree of condensing of the incident light L _{1 on} the sample S, the incidence The relative angle between the light L ₁ and the sample S can be adjusted with high accuracy. Specifically, the holding member 51 is slid in the axial direction X of the sample holder 10 in the slide groove 52, and the position of the incident side condensing lens 42, that is, the distance between the incident side condensing lens 42 and the sample S is determined. By adjusting, the incident light L ₁ transmitted through the incident side optical fiber 38 can be most condensed in the sample S portion. Then, with respect to the sample S tilted to some extent about the axis Y, the tilt angles of the reflecting plates 53 and 54 are adjusted appropriately by rotating about the pin 55, and the sample S and the incident light L ₁ The relative angle can be adjusted precisely. The position of the transmission-side condensing lens 43 by adjusting the sliding operation of the holding member 51, since the transmitted light L ₂ transmitted through the sample S can be efficiently transmitted condenser while the permeate-side optical fiber 39, the absorption spectrum Measurement accuracy is also improved. As described above, the relative angle between the light L and the sample S can be determined by adjusting the inclination angles of the reflecting plates 53 and 54 and the sample S. The two condensing lenses 42 and 43 arranged in front are not inclined and face the horizontal direction.

  In addition, since the condensing lenses 42 and 43 in Example 2 are detachable, the material, shape, characteristics, and the like can be appropriately selected as necessary. For example, the difference in the refractive index of the lens is usually not a problem in the wavelength range of about 200 to 1500 nm, but if necessary, it can be changed to a condenser lens without chromatic aberration or a condenser lens specialized for each wavelength region. It is. In addition, fine irradiation axis adjustment can be performed accurately and easily, and excitation and absorption spectrum measurement of the sample S can be reliably performed. Others are the same as those in the first embodiment, and the same members are denoted by the same reference numerals and description thereof is omitted.

It is a schematic block diagram of a transmission electron microscope. It is a schematic sectional drawing of a pole piece part. It is a cross-sectional top view of a sample holder inclination mechanism. 3 is an enlarged plan view of a main part of the sample holder of Example 1. FIG. 3 is an enlarged side cross-sectional view of a main part of a sample holder of Example 1. FIG. 6 is an enlarged plan view of a main part of a sample holder of Example 2. FIG. 6 is an enlarged side cross-sectional view of a main part of a sample holder of Example 2. FIG.

Explanation of symbols

1 Transmission electron microscope (TEM)
2 Electron gun (filament)
3.4 Converging lens 5 Objective lens 6 Intermediate lens 7 Projection lens 10 Sample holder 10a Sample fixing part 11 Lens barrel 15 Holder tilting mechanism 16 Pole piece 18 Spherical seat 19 Cylinder 20 Fine movement actuator 21 Return spring 23 Cylinder adjustment mechanism 24 Cylinder guide 26 Cylinder guide adjustment mechanism 27 Insulator 28 Handle 31 Opening 32 Sample mounting base 35 Pulling member 38 Incident side optical fiber 39 Transmission side optical fiber 42 Incident side condensing lens 43 Transmission side condensing lens 50 Support frame 51 Holding member 52 Slide groove 53 Incident side Reflector 54 Transmission side reflector 60 Light source 61 Spectrometer E Electron beam L ₁ Incident light L ₂ Transmitted light S Sample

Claims (7)

A sample holder for observing the structure of a sample by irradiating an electron beam in an electron microscope,
An incident-side optical fiber that is arranged along the axial direction of the sample holder and transmits light in the ultraviolet, visible, and near-infrared region from a light source outside the electron microscope into the lens barrel of the electron microscope,
An incident-side condensing lens that condenses incident light transmitted by the incident-side optical fiber on a sample installed in the sample holder;
A transmission-side condensing lens that is arranged on the opposite side of the incident-side condensing lens through the sample and collects light transmitted through the sample;
Transmission that is arranged along the axial direction of the sample holder and transmits the transmitted light collected by the transmission-side condensing lens from the opposite side of the incident-side optical fiber to the outside of the electron microscope barrel through the sample. Side optical fiber,
A sample holder that performs excitation and absorption spectrum measurement of samples by light in the ultraviolet, visible, and near-infrared regions simultaneously with structural observation by electron beams. The sample holder according to claim 1,
The sample holder, wherein the incident side optical fiber and the transmission side optical fiber are inserted into the sample holder over the whole. In the sample holder according to claim 1 or 2,
Between the incident side condensing lens and the sample, and between the transmission side condensing lens and the sample, an incident side reflecting plate and a transmission side for reflecting light from the condensing lens toward the sample, respectively. A sample holder provided with a reflector. In the sample holder according to any one of claims 1 to 3,
The sample holder includes a holder tilt mechanism that adjusts the tilt angle of the entire sample holder, and the tilt angle of the sample mounting base that is fixed to the sample fixing portion provided at the tip of the sample holder in the axial direction of the sample holder. A specimen holder characterized by being capable of two-axis tilting in a high-resolution pole piece by means of a specimen mounting table tilting mechanism that adjusts in an axial direction perpendicular to the axis. In the sample holder according to any one of claims 1 to 4,
The sample holder, wherein the incident side condensing lens and the transmission side condensing lens are capable of adjusting the distances between the incident side optical fiber and the transmission side condensing lens, respectively. In the sample holder in any one of Claims 1 thru | or 5,
The sample holder, wherein the incident side reflection plate and the transmission side reflection plate are adjustable in angle with respect to the sample. An electron microscope comprising the sample holder according to claim 1.

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