Sample stage and microscope

Abstract

The present invention provides a sample stage with a built-in pressure sensor compatible with attenuated total reflection (ATR) measurements, which allows for smooth attachment and detachment of the detachable plate. The sample stage includes a stage surface member 4 having an opening 2 and a detachable plate 6 held by the stage surface member 4 so as to cover the opening 2. Pressure sensors 8 are arranged on the stage surface member 4 at three locations along the edge of the opening 2. A sample is placed on the surface of the detachable plate 6, and three protrusions 18 are formed on the side or back of the plate at positions corresponding to the pressure sensors 8. Placing the protrusions 18 of the detachable plate 6 on the pressure sensors 8 of the stage surface member 4 places the pressure sensors 8 in a sensing state. Rotating the detachable plate 6 by a predetermined angle and placing the protrusions 18 on a portion 22A of the edge of the opening 2 other than the pressure sensors places the pressure sensors 8 in a non-sensing state.

Description

[Technical Field]

[0001] The present invention relates to an improvement in a specimen stage in a microscope. [Background technology]

[0002] For example, an infrared microscope is a device that irradiates a sample placed on a movable stage with infrared light, collects and detects the transmitted light, reflected light, or total reflected light from a small area on the sample, and obtains its infrared spectrum.

[0003] Attenuated Total Reflection (ATR) measurements using an infrared microscope are a technique in which a prism (crystal element) with a higher refractive index than the sample is placed in close contact with the sample, measurement light is incident from the prism side at an angle of incidence that causes total reflection at the boundary surface, and the spectrum of the total reflected light is detected to measure the absorption characteristics of the sample. Therefore, ATR measurements require that the sample and prism (crystal element) be in close contact with each other, and the XY stage on which the sample is placed is raised to press the sample against the prism placed above the XY stage. If the pressing force is too strong, there is a risk of damaging the prism, so a pressure sensor that measures the pressure on the sample is used to prevent excessive pressure from being applied.

[0004] There are two possible positions for incorporating the pressure sensor: on the prism side and on the sample stage side. If a pressure sensor is built into the prism, the pressure sensor on the prism side will deform when a sample is pressed against the prism, causing a slight change in the position of the prism in the prism holding structure. This means that the optical system will move, which may change the angle of incidence on the prism, cause the sample position to no longer match the focal position, or result in measurements not being performed with the optimal optical system.

[0005] On the other hand, if a pressure sensor is built into the stage, there is no need to worry about the optimal optical system being disrupted even if the sample is pressed against the prism. For example, Patent Document 1 provides a detailed explanation using Figure 5 of an ATR measurement method that uses a sample stage with a built-in pressure sensor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-147379 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, there has been a demand for a single infrared microscope that can switch between transmission, reflection, and ATR measurements, and some microscopes are designed with a replaceable sample placement plate for each measurement mode.The sample stage of such an infrared microscope typically consists of a stage surface member with a central opening and a detachable plate that is held by the stage surface member and covers the opening.

[0008] The inventors have used a detachable plate with a built-in pressure sensor as an ATR measurement plate. The electrical cable from the pressure sensor extends from the detachable plate and can be inserted and removed from the connection part of the infrared microscope body. When performing transmission measurements, the ATR measurement plate is replaced with a transmission measurement plate that has an opening that transmits infrared light. Each time such replacement is performed, the cable of the ATR measurement plate must be inserted and removed, which poses a problem of cumbersome installation and removal of the detachable plate.

[0009] Therefore, in developing a sample stage with a built-in pressure sensor compatible with ATR measurement, the inventors aimed to create a stage that would enable smooth attachment and detachment of the detachable plate. [Means for solving the problem]

[0010] That is, the specimen stage for a microscope of the present invention is a stage surface member having an opening; a detachable plate that is held by the stage surface member so as to close the opening, the stage surface member has pressure sensors arranged at a plurality of locations along the edge of the opening; The detachable plate is a plate surface on which the sample is placed; a plurality of protrusions formed on the side surface or rear surface of the plate at positions corresponding to the pressure sensors; The stage surface member is a sensing holding position in which the detachable plate is held by placing a protrusion on the pressure sensor, thereby putting the pressure sensor into a sensing state; The device is characterized by having a non-sensing holding position in which the detachable plate is rotated by a predetermined angle relative to the sensing holding position, and a convex portion is placed on the part of the edge of the opening other than the pressure sensor to hold the detachable plate and put the pressure sensor into a non-sensing state.

[0011] Using a sample stage with this configuration, the built-in pressure sensor enables detection of external forces, such as the pressure applied to the sample on the detachable plate. If the pressure sensor were built into the detachable plate, attaching or detaching the plate would require the attachment or detachment of a signal line connecting the pressure sensor to the control unit of the measurement device main body, making the process complicated. However, by incorporating the pressure sensor into the stage surface member as in the present invention, the detachable plate does not include a pressure sensor, eliminating the need to attach or detach the pressure sensor's signal line during attachment or detachment, making the detachable plate easier to attach or detach. Furthermore, the pressure sensor can be switched between sensing and non-sensing states simply by changing the holding position of the detachable plate. For measurements that do not require pressure sensor sensing, such as transmission or reflection measurements, the non-sensing state can be quickly switched to the non-sensing state, and this also protects the pressure sensor. A microscope according to the present invention is characterized by including the above-described sample stage. [Brief explanation of the drawings]

[0012] [Figure 1]FIG. 2A is a schematic three-dimensional view of the sample stage of the first embodiment, FIG. 2B is a plan view, and FIG. 2C is a longitudinal sectional view. [Figure 2] FIG. 2 is a stereoscopic view showing the configuration of the sample stage in more detail. [Figure 3] FIG. 3 is a plan view showing a characteristic part of the sample stage in FIG. 2. [Figure 4] FIG. 3 is a longitudinal sectional view showing a characteristic part of the sample stage of FIG. 2. [Figure 5] FIG. 3 is a vertical cross-sectional view showing the mounting state of the pressure sensor of FIG. 2. [Figure 6] 3 is a stereoscopic view showing an automated XY stage, which is a specific example of the sample stage of FIG. 2, and various plates that can be attached to it. FIG. [Figure 7] FIG. 3 is a plan view showing a state in which a transmission measurement plate is attached to the sample stage of FIG. 2. [Figure 8] FIG. 2 is a diagram showing the optical path when performing transmission measurement using a microscope equipped with the sample stage of FIG. 1. [Figure 9] FIG. 9 is a diagram showing the optical path when ATR measurement is performed using the microscope of FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a sample stage for a microscope according to the present invention will now be described with reference to the drawings. Figures 1(A) and 1(B) schematically show a sample stage 10 according to this embodiment.

[0014] The sample stage 10 comprises a stage surface member 4 having an opening 2 in the center, and a detachable plate 6 held by the stage surface member 4 so as to cover the opening 2. In this example, the opening 2 and the detachable plate 6 are circular and of approximately the same size. Figure 1(B) is a plan view of these components.

[0015] The stage surface member 4 has pressure sensors 8 evenly spaced at three positions along the edge of the opening 2. The plate surface 12 of the detachable plate 6 is the surface on which a sample is placed, and three protrusions 18 are formed on the plate side surface 14 or the plate back surface 16 at positions corresponding to the pressure sensors 8. Figure 1(C) is a longitudinal cross-sectional view of these.

[0016] When the detachable plate 6 is held by the stage surface member 4 with the protrusion 18 placed on the pressure sensor 8, the pressure sensor 8 enters a sensing state. This holding position is called the sensing holding position (left side of FIG. 1(C)). Furthermore, when the detachable plate 6 is rotated a predetermined angle relative to the sensing holding position and the protrusion 18 is placed on the portion 22 of the edge of the opening 2 other than the pressure sensor, the pressure sensor 8 enters a non-sensing state. This holding position is called the non-sensing holding position (the right side of Figure 1(C)).

[0017] Next, a specific example of the configuration of the sample stage 10 will be described with reference to Figures 2 to 4. Figure 2 is an enlarged view of the protrusion 18 of the detachable plate 6 and the opening 2 of the stage surface member 4.

[0018] The detachable plate 6 is circular, and the thickness around its entire periphery is thinner than the thickness at the center. However, the thickness of the periphery is not uniform; there are three slightly thicker portions formed at 120-degree intervals along the periphery, which are the protrusions 18.

[0019] Two steps are formed around the edge of the opening 2 of the stage surface member 4. The first step surface 22A is lower than the stage surface, and the second step surface 22B is even lower. These step surfaces 22A and 22B are not formed continuously around the entire edge, but are discontinuous at three locations spaced 120 degrees apart along the edge of the opening 2. At these three locations, there are openings to storage spaces for the pressure sensors 8, and each storage space is formed inside the stage surface member 4.

[0020] The outer diameter of the first-step step surface 22A is approximately the same as the outer diameter of the detachable plate 6, and the outer peripheral surface of the detachable plate 6 is detachably fitted inside the wall surface of the first-step step surface 22A. Furthermore, a step surface 22C of intermediate height between the first-step and second-step step surfaces 22A, 22B is formed in the portion of the first-step step surface 22A adjacent to the storage space. The formation range (dimension A) of the intermediate step surface 22C on the left and right sides, including the storage space, is slightly wider than the width (dimension B) of the protrusion 18.

[0021] The first step surface 22A or the second step surface 22B corresponds to the "portion 22 of the edge of the opening 2 other than the pressure sensor" shown in FIG. 1(C).

[0022] Here, pressure sensor 8 is provided in the storage space so that the tip of cantilever arm 8A that constitutes pressure sensor 8 protrudes into opening 2. Using Figures 3 and 4, the positional relationship between these pressure sensors 8, each of step surfaces 22A to 22C, and protrusion 18 will be explained. Figure 3 is a plan view of the periphery of pressure sensor 8, and the tip of pressure sensor 8 provided in the storage space of stage surface member 4 protrudes into opening 2, but only as far as first step surface 22A and intermediate step surface 22C, and does not protrude as far as second step surface 22B.

[0023] 4 shows a cross section along the edge of the opening shown in FIG. 3, and FIG. 5 shows a cross section along the longitudinal direction of the pressure sensor 8. As shown in FIG.

[0024] FIG. 4(A) shows the positional relationship with the pressure sensor 8 before the detachable plate 6 is attached to the sensing holding position, and FIG. 4(B) shows the positional relationship after attachment. The height of the upper surface of the pressure sensor 8 is equal to or slightly lower than the height of the first step surface 22A. When the detachable plate 6 is attached, the lower surface of the convex portion 18 of the detachable plate 6 comes into contact with the upper surface of the tip of the pressure sensor 8, and the weight of the detachable plate 6 is applied to the pressure sensor 8, causing the pressure sensor 8 to enter a sensing state. Even if the tip of the pressure sensor 8 bends downward, the convex portion 18 will not come into contact with the first step surface 22A because there are intermediate step surfaces 22C on the left and right of the pressure sensor 8.

[0025] Figure 4(C) shows the positional relationship after the detachable plate 6 has been attached to the non-sensing holding position. The detachable plate 6 in Figure 4(A) is rotated a certain angle around a central axis perpendicular to the plate surface, and then the detachable plate 6 is attached. In this state, the underside of the convex portion 18 of the detachable plate 6 contacts the first step surface 22A, so the part of the edge of the detachable plate 6 where the convex portion 18 is not formed does not come into contact with the pressure sensor 8. Therefore, the non-sensing state of the pressure sensor 8 is maintained.

[0026] Figure 5 is a longitudinal cross-sectional view of the pressure sensor 8. The pressure sensor 8 includes a cantilever arm 8A and a strain gauge 8B that detects bending of the cantilever arm 8A. The base end of the cantilever arm 8A is fixed to the back of the stage surface member 4 by a set screw 8C, located deep within the storage space of the stage surface member 4. The tip of the cantilever arm 8A protrudes into the opening 2 and is positioned to receive the protrusion 18 of the detachable plate 6. The strain gauge 8B attached to the surface of the cantilever arm 8A can detect the vertical displacement of the arm tip as arm deflection with high sensitivity. Furthermore, the sensor can be thinner than other pressure sensors, which is a significant advantage when used in a sample stage where a thin structure is preferred. For example, a thinner sample stage 10 can increase the range of movement of the sample stage 10 in the Z-axis direction (the optical axis direction of the microscope), thereby increasing the working distance.

[0027] FIG. 6 is an external view of an automated XY stage incorporating the sample stage of this embodiment. In addition to the detachable plate 6, a common plate 6A for ATR / transmission measurements is also shown. The surface of this common plate 6A includes an area for total reflection measurement that does not transmit measurement light and an area for transmission measurement (opening 6B) that transmits measurement light. The aperture 6B for transmission measurement does not necessarily need to be located in the center of the plate surface. Except for the presence or absence of this aperture, the common plate 6A has the same configuration as the ATR measurement plate 6. When attached to the sensing holding position of the aperture 2 of the stage surface member 4, the pressure sensor 8 can be put into a sensing state. Using the above-described common plate 6A allows a single plate to be used for both total reflection measurement and transmission measurement. This eliminates the need to replace the detachable plate when switching from total reflection measurement to transmission measurement in the microscope, reducing the workload and enabling seamless measurement changes. Furthermore, in total reflection measurements, by holding the detachable plate in the sensing position, the microscope can perform measurements using the detection information from the pressure sensor, and in transmission measurements, by holding the detachable plate in the non-sensing position, unnecessary load is not placed on the pressure sensor, thereby protecting the pressure sensor during transmission measurements.

[0028] 6 also shows a transmission measurement plate 32 and a common holder 34 as other detachable plates not intended for ATR measurement. The transmission measurement plate 32 has an opening 32A for transmission measurement. The common holder 34 is a holder that can be used in common between, for example, an infrared microscope and other microscopes (such as a laser Raman spectrophotometer or a microscopic ultraviolet-visible-near-infrared spectrophotometer), and the common holder 34 also has an opening 34A for transmission measurement. The outer diameters of the transmission measurement plate 32 and the common holder 34 are slightly smaller than those of the ATR measurement plate 6 and the common plate 6A, and no protrusions are formed on the side or back of the plates.

[0029] 7 is a plan view showing the state in which the transmission measurement plate 32 is attached to the stage surface member 4. The back surface of the transmission measurement plate 32 is placed on the second step surface 22B of the opening 2 of the stage surface member 4, and it can be seen that the transmission measurement plate 32 does not come into contact with the pressure sensor 8. Therefore, when attaching the transmission measurement plate 32, there is no need to specify a holding position such as a sensing holding position or a non-sensing holding position, and the transmission measurement plate 32 can be attached at any angle, and the pressure sensor 8 can be kept in a non-sensing state. The common holder 34 is also attached in the same way as the transmission measurement plate 32.

[0030] It should be noted that reflection measurements can be performed by placing a sample on any of the various detachable holders shown in Figure 6. Reflection measurements are not limited to areas without an aperture, and can also be performed when a sample is positioned in an aperture. Furthermore, the outer diameter of the transmission measurement plate 32 may be the same as that of the ATR measurement plate 6 and the common plate 6A. Even if the outer diameter is changed, by not forming a convex portion 18 on the transmission measurement plate 32, the back surface of the transmission measurement plate 32 with an enlarged outer diameter is placed on the first step surface 22A of the opening 2 of the stage surface member 4, and it can be seen that in this case too, the transmission measurement plate 32 does not deflect the pressure sensor 8. Note that the outer diameter of the common holder 34 can also be expanded in the same way as the transmission measurement plate 32.

[0031] The sample stage 10 configured in this embodiment incorporates a pressure sensor 8, making it possible to detect external forces, such as the pressure applied to the sample on the detachable plate 6. If the pressure sensor 8 were incorporated into the detachable plate 6, attaching or detaching the detachable plate 6 would require the attachment or detachment of a signal line connecting the pressure sensor 8 to the control unit of the measurement device main body, making the process complicated. However, if the pressure sensor 8 is incorporated into the stage surface member 4 as in this embodiment, the detachable plate 6 does not include the pressure sensor 8. This eliminates the need to attach or detach the signal line for the pressure sensor 8, making the detachable plate 6 easier to attach or detach. Furthermore, the pressure sensor 8 can be switched between a sensing state and a non-sensing state simply by changing the holding position of the detachable plate 6. For example, in measurements that do not require sensing by the pressure sensor 8, such as transmission or reflection measurements, the pressure sensor 8 can be quickly switched to a non-sensing state, which also protects the pressure sensor 8. Furthermore, if the detachable plate 6 is left in the sensing holding position, the pressure sensor 8 can detect the presence or absence of a sample on the detachable plate 6. For example, a message can be automatically displayed on a monitor or the like to warn the user if a sample has been left on the detachable plate 6.

[0032] A microscope 500 to which the sample stage 10 shown in the first embodiment is applied will be described below with reference to Figures 8 and 9. The microscope 500 is an infrared microscope configured by connecting a Fourier transform infrared spectrophotometer (hereinafter referred to as FTIR) 520. The FTIR 520 has a built-in infrared light source and a Michelson interferometer, and serves to supply the microscope 500 with an interference wave of infrared light output from the interferometer, and corresponds to the light irradiation means of the present invention.

[0033] The microscope 500 is composed of a microscopic optical unit 530, an aperture 540, a single-element detector 550, and various reflecting mirrors. The microscopic optical unit 530 is a part that performs transmission, reflection, or total reflection measurement of a minute area of ​​a sample using infrared light. The detector is not limited to the single-element detector 550, and other detectors such as a linear array detector 560 can also be selected as appropriate.

[0034] <Transmission measurement> First, the transmission measurement will be described. A removable plate for transmission measurement, such as the common plate 6A, transmission measurement plate 32, or common holder 34 shown in Figure 6, is attached to the stage surface member 4 of the sample stage 10. In the case of the common plate 6A, it is attached in a non-sensing position. In the case of the transmission measurement plate 32 or common holder 34, the pressure sensor 8 of the sample stage 10 can remain in a non-sensing state regardless of the angle at which it is attached. The measurement target is then placed on the surface of these plates. For example, a rectangular plate carrying a sample can be placed in the opening 6B of the common plate 6A, or for samples larger than the opening 6B, the sample can be placed directly on the opening 6B to perform transmission measurements. For measurements using infrared light, the rectangular plate is made of an infrared-transmitting material such as potassium bromide or diamond.

[0035] Switchable mirror 512 in FIG. 8 guides infrared light from FTIR 520 to an optical path for transmission measurement (reflecting mirror 514, transmission measurement mirror 516, and lower Cassegrain mirror 518, in that order). Lower Cassegrain mirror 518 for sample (corresponding to the illumination-side Cassegrain mirror) focuses the infrared light reflected from transmission measurement mirror 516 and illuminates a predetermined area of ​​the sample placed on sample stage 10 from below. Light transmitted through the sample is extracted and focused by upper Cassegrain mirror 524 for sample (corresponding to the detection-side Cassegrain mirror) and reflected by detection-side scanning mirror 526 above. An aperture 540 is placed at the imaging position behind upper Cassegrain mirror 524 to cut out light (such as stray light) generated from areas other than the light-focusing area on the sample and detect only the light transmitted through the desired light-focusing area. Light passing through the opening of aperture 540 passes through a light-collecting element for the detector (not shown) and forms an image on single-element detector 550. An electrical signal corresponding to the amount of light received by single-element detector 550 is Fourier transformed by signal processing means to become infrared spectrum data.

[0036] The magnification of the sample Cassegrain mirror may be selected from the range of 4 to 100 times. The opening size of the aperture 540 indicates the size of the light-collecting area on the sample. Even if the aperture is the same, the size of the measurement area on the sample varies depending on the magnification of the sample Cassegrain mirrors 518, 524 that are combined. Even if the magnification of the sample Cassegrain mirrors 518, 524 is fixed, it is preferable that the size and shape of the opening be changeable so that the measurement area on the sample can be adjusted. For example, multiple apertures with different shapes and opening sizes may be prepared, and an aperture with the desired shape and opening size may be selected and used depending on the measurement conditions. An aperture equipped with a mechanism that allows the shape and size of the opening to be changed may also be used.

[0037] <Switching to reflection measurement> Next, we will briefly explain how to switch from the optical configuration for transmission measurement to the optical configuration for reflection measurement in Fig. 8. For reflection measurement, switching mirror 512 is rotated 90 degrees so that infrared light from FTIR 520 is guided to the optical path for reflection measurement (reflecting mirror 532, reflection measurement mirror 534, upper Cassegrain mirror 524, in that order).

[0038] In reflection measurement, the upper Cassegrain mirror 524 for the sample (corresponding to the illumination-side Cassegrain mirror) focuses the infrared light reflected by the reflection-measuring mirror 534 and illuminates a predetermined area of ​​the sample placed on the sample stage 10 from above. The light reflected from the sample is again extracted and focused by the upper Cassegrain mirror 524 for the sample (which also serves as the detection-side Cassegrain mirror) and directed to the detection-side scanning mirror 526 located above. The components from the detection-side scanning mirror 526 onwards are the same as those for transmission measurement.

[0039] Here, the reflection measurement mirror 534 is arranged in a half region separated by a boundary line passing through the optical axis on a cross section perpendicular to the optical axis connecting the upper Cassegrain mirror 524 and the detection side scan mirror 526, and is not arranged in the remaining half region, so it is also called a half mirror. In reflection measurement, the infrared light from the mirror 532 is reflected by the reflection measurement mirror 534 and advances toward the upper Cassegrain mirror 524 to irradiate the sample. The reflected light from the sample is condensed by the upper Cassegrain mirror 524 and then advances to the detection side scan mirror 526 through the space where the reflection measurement mirror 534 is not arranged.

[0040] <ATR measurement> Next, the ATR measurement will be described. Also, the mapping measurement (high-speed imaging) in the ATR measurement will be described. By selecting a linear array detector 560 in which a plurality of detection elements are arranged in a row for the detector, the spectra of a plurality of measurement positions within the condensing region on the sample can be measured at once, so the time for the mapping measurement is shortened.

[0041] In the change from transmission measurement to ATR measurement, the measurer can quickly and smoothly replace the transmission measurement plate 32 of the sample stage 10 with the detachable plate 6 for ATR measurement. Just by mounting the detachable plate 6 at the sensing holding position, the pressure sensor 8 can be put into the sensing state. Also, when the common plate 6A is used in the transmission measurement, it is only necessary to rotate the common plate 6A by a predetermined angle and move it to the sensing holding position. In this way, the switching among ATR measurement, reflection measurement, and transmission measurement becomes smooth, and the measurement method can be seamlessly changed according to the measurement object.

[0042] Then, the measurement object is placed on the surfaces of these plates (in the case of the common plate 6A, the part without an opening). Also, the revolver above the sample stage 10 is rotated to select the Cassegrain mirror 523 with the ATR prism 522 as the upper Cassegrain mirror.

[0043] In the ATR measurement optical system shown in Figure 9, the reflective surface of switching mirror 512 is rotated 90 degrees so that switching mirror 512 guides infrared light to the reflection measurement optical path (reflecting mirror 532, reflection measurement mirror 534, and Cassegrain mirror 523 with ATR prism). Cassegrain mirror 523, which has ATR prism 522, a high-refractive-index crystal element, serves two functions: irradiating a predetermined focusing area within the contact surface between the sample and ATR prism 522 at an incident angle equal to or greater than the critical angle (function of the illumination-side Cassegrain mirror), and also focusing the total reflected light from the sample via the ATR prism again on the Cassegrain mirror (function of the detection-side Cassegrain mirror). Reflection measurement mirror 534 is located in one half of the area divided by the boundary line passing through the optical axis on a cross section perpendicular to the optical axis connecting Cassegrain mirror 523 with ATR prism and detection-side scan mirror 526, and is not located in the other half. Therefore, it is also called a half mirror. That is, in total reflection measurement, infrared light from reflecting mirror 532 is reflected by reflecting measurement mirror 534, travels toward Cassegrain mirror 523 with ATR prism, and irradiates the sample. Then, the total reflected light from the contact surface between the sample and ATR prism 522 is collected and travels toward detection-side scanning mirror 526 through the space where reflecting measurement mirror 534 is not located.

[0044] In order to cut out light (stray light, etc.) generated from areas other than the designated light-collecting area and detect only the total reflected light from the desired light-collecting area, an aperture 540 is placed at the imaging position behind the Cassegrain mirror 523 with an ATR prism. Light that passes through the opening of aperture 540 forms an image on a linear array detector 560 via a light-collecting element for the detector (not shown). An electrical signal corresponding to the amount of light received by each detecting element of the linear array detector 560 is Fourier transformed by a signal processing means to become infrared spectrum data.

[0045] The total magnification of the ATR prism-equipped Cassegrain mirror 523 may be selected from the range of 4 to 100 times. The opening size of the aperture 540 corresponds to the size of the contact area where the total reflected light is to be collected. Even if the aperture is the same, the size of the contact area where the total reflected light is to be collected varies depending on the magnification of the ATR prism-equipped Cassegrain mirror 523 to be combined. Even if the magnification of the ATR prism-equipped Cassegrain mirror 523 is fixed, it is preferable that the size and shape of the opening be changeable so that the desired contact area can be adjusted. For example, multiple apertures with different shapes and opening sizes may be prepared, and an aperture with the desired shape and opening size may be selected and used depending on the measurement conditions. An aperture equipped with a mechanism that allows the shape and size of the opening to be changed may also be used.

[0046] Here, the measurement function at a constant contact pressure in ATR measurement will be explained. 9 is further provided with a driving means 610 that can drive the sample stage 10 in the X-, Y-, and Z-axis directions relative to the ATR prism 522, a control means 612 that controls the operation of the driving means 610, an operation means 614 that controls the relative drive of the sample stage 10 and the ATR prism 522, and a storage means 616. A detection signal from the pressure sensor 8 built into the sample stage 10 is sent to the control means 612 through a signal cable.

[0047] The infrared microscope 500 can determine whether the ATR prism 522 is in contact with the sample based on the detection signal from the pressure sensor 8 read by the control means 612. Furthermore, the pressure between the sample and the ATR prism 522 has a significant effect on the results of the ATR measurement. For this reason, once an actual total reflection absorption spectrum has been measured, the data on the contact pressure between the sample and the ATR prism 522 at the time of the first measurement is stored in the storage means 616. When further measurements are to be performed on the same sample, when the operator determines another measurement location, the control means 612 automatically operates the stage so that the sample and the ATR prism 522 come into contact with each other at the same contact pressure data as the stored data.

[0048] In this way, when performing ATR measurements at multiple points on a sample, the control means 612 monitors the contact pressure measured by the pressure sensor at each measurement point, drives the sample stage 10 relative to the ATR prism 522 in the Z-axis direction using the driving means 610, and stops the driving means 610 when the contact pressure reaches a specific pressure, thereby measuring the total reflection spectrum at each measurement point at a constant contact pressure.

[0049] In this way, even when multiple measurements are performed on the same sample, it is possible to reduce variations in the contact state between the sample and the ATR prism 522 at each measurement point, making it possible to obtain highly reliable data even when performing linear measurements and mapping measurements.

[0050] A detailed description will be given of mapping measurement of a predetermined area on a sample using the infrared microscope 500 configured as described above. The infrared microscope 500 enables spectrum measurement at high magnification, but when it is desired to capture the entire sample to be measured, mapping measurement is performed to capture the entire sample or a specific area in a unified manner.

[0051] The first method is mapping measurement involving the operation of the sample stage 10, which has an electronically controlled automatic stage. In this method, a sample is placed on the automatic stage of the sample stage 10, and the light-collecting region on the sample is changed sequentially by moving the automatic stage. Here, a single-element detector 550 may be selected as the detector, and an aperture 540 corresponding to the single-element detector 550 may be used to perform spectral measurement for each light-collecting region. Alternatively, a linear array detector 560 may be selected, and an aperture 540 corresponding to the linear array detector 560 may be used to perform spectral measurement at multiple points within the light-collecting region all at once. These methods can be used to obtain spectral data for the light-collecting region and create mapping data for a specified range of the sample.

[0052] In the second method, the sample stage 10 is fixed, and the detection-side scanning mirror 526 is operated to sequentially change the light-focusing area on the sample, acquire spectral data for the light-focusing area, and create mapping data for a specified range of the sample. In this case, either the single-element detector 550 or the linear array detector 560 can be used. In this embodiment, the switching mirror 512, which switches between transmission and reflection measurements (including total reflection measurements), also serves as the illumination-side scanning mirror. In other words, the switching mirror 512 has two functions: a function to switch between transmission and reflection measurements by rotating the reflective surface 90 degrees, and a scanning function to sequentially move the illumination area on the sample by minutely controlling the orientation of the reflective surface with a controller at each 90-degree rotation (both transmission and reflection measurements).

[0053] The orientation of the reflective surface of the detection-side scanning mirror 526 is adjusted so that only light from a specific light-collecting region on the sample is directed toward the opening of the aperture 540. By controlling the orientation of the reflective surface of this detection-side scanning mirror 526 with a controller, the light-collecting region on the sample can be moved to match the opening of the aperture 540. The orientation of the reflective surface of the switchable mirror (illumination-side scanning mirror) 512 is changed to move the illumination region on the sample, and at the same time, the orientation of the reflective surface of the detection-side scanning mirror 526 is also changed so that the light-collecting region moves in the same direction as the illumination region. Repeated spectral measurements of the light-collecting region for all of these moving positions of the light-collecting region and illumination region using either the single-element detector 550 or the linear array detector 560 enable two-dimensional mapping measurements of a certain area on the sample.

[0054] As described above, by synchronizing the operation of the switching mirror (illumination-side scanning mirror) 512 with the operation of the detection-side scanning mirror 526, when a wider XY plane range (here, the mounting surface of the sample stage is referred to as the XY plane) is set as the mapping measurement range, it is possible to acquire spectral data with high energy values ​​throughout the entire mapping measurement range. In other words, two-dimensional mapping measurement based on high-quality spectral data acquired over a wider XY plane range becomes possible.

[0055] Even if the switching mirror (illumination side scanning mirror) 512 is fixed and only the detection side scanning mirror 526 is operated, spectral data with a relatively high energy value can be acquired within a certain range of the XY plane near the center of the illumination light, making it possible to perform two-dimensional mapping measurement.

[0056] Even when using the ATR prism-equipped Cassegrain mirror 523 instead of the upper Cassegrain mirror 524 to measure the total reflection of a sample, two-dimensional mapping measurement can be performed without moving the sample stage 10 by using the detection-side scanning mirror 526 or by using both the detection-side scanning mirror 526 and the switching mirror (illumination-side scanning mirror) 512. That is, in total reflection measurement, the light-collecting area within the contact surface between the ATR prism and the sample is sequentially changed by the operation of the detection-side scanning mirror 526. Furthermore, by adding the operation of the switching mirror (illumination-side scanning mirror) 512, the irradiation area within the contact surface between the ATR prism and the sample is sequentially changed to match the light-collecting area.

[0057] By using the linear array detector 560 to simultaneously acquire spectral data from multiple points within the light collection area and repeating this process for each moving light collection area, two-dimensional mapping measurement can be performed at high speed. This type of mapping measurement is particularly called "imaging measurement." [Explanation of symbols]

[0058] 2 aperture 4 Stage surface member 6 Detachable plate (ATR measurement plate) 6A Detachable plate (common plate) 6B, 32A, 34A Apertures for transmission measurement 8. Pressure Sensor 8A Cantilever Arm 8B strain gauge 10 Sample stage 18 Convex part 22 The edge of the opening other than the pressure sensor 22A First step surface 22B 2nd step surface 22C Intermediate step surface 32 Plate for transmission measurement 34 Common Holder 500 Infrared microscope (microscope) 512 Switchable mirror that also serves as the irradiation side scanning mirror 516 Transmission measurement mirror 518 Lower Cassegrain mirror (illumination side Cassegrain mirror) 520 FTIR (light irradiation means) 522 ATR prism (total reflection crystal element) 523 Cassegrain mirror with ATR prism (serves as both the illumination and detection Cassegrain mirrors) 524 Upper Cassegrain mirror (serves as both the illumination and detection Cassegrain mirrors) 526 Detector side scanning mirror 534 Reflection measurement mirror 540 aperture 550 Single-element detector (light detection means) 560 Linear array detector (light detection means) 610 Driving means 612 Control means

Claims

1. a stage surface member having an opening; a detachable plate held by the stage surface member so as to cover the opening; A sample stage for a microscope, comprising: the stage surface member has pressure sensors arranged at a plurality of locations along the edge of the opening; The detachable plate is a plate surface on which the sample is placed; a plurality of protrusions formed on the side surface or rear surface of the plate at positions corresponding to the pressure sensors; The stage surface member is a sensing holding position in which the detachable plate is held by placing the protrusion on the pressure sensor, and the pressure sensor is put into a sensing state; a non-sensing holding position in which the detachable plate is held in an attitude in which the detachable plate is rotated by a predetermined angle relative to the sensing holding position, and the convex portion is placed on a part of the edge of the opening other than the pressure sensor, thereby placing the detachable plate in a non-sensing state.

2. The plate surface of the detachable plate includes an area for total reflection measurement that does not transmit measurement light and an area for transmission measurement that transmits measurement light.

2. The sample stage according to claim 1.

3. a separate detachable plate that does not have the protrusion, The other detachable plate is Instead of the detachable plate having the protrusion, it is configured to be held at the sensing and non-sensing holding positions, and Since the plate does not have the protrusion, the portion along the edge of the rear surface of the plate rests on the portion of the edge of the opening other than the pressure sensor at any of the holding positions, thereby keeping the pressure sensor in a non-sensing state.

2. The sample stage according to claim 1.

4. the pressure sensor has a cantilever arm and a strain gauge that detects bending of the cantilever arm; the cantilever arm is disposed so that a base end thereof is fixed to the rear side of the stage surface member and a tip end thereof projects into the opening and receives the protrusion of the detachable plate; 2. The sample stage according to claim 1.

5. a total internal reflection crystal element; a sample stage according to any one of claims 1 to 4; a driving means for driving the sample stage relative to the total reflection crystal element in XY axis directions parallel to the stage surface and in a Z axis direction perpendicular to the stage surface; a control means for controlling the operation of the driving means; A microscope capable of measuring total internal reflection, comprising: the pressure sensor detects a contact pressure between the sample on the detachable plate and the total reflection crystal element; The microscope is characterized in that, when total reflection measurements are performed at multiple points on a sample, the control means drives the sample stage relative to the total reflection crystal element in the Z-axis direction using the driving means while monitoring the contact pressure measured by the pressure sensor at each measurement point, and stops the driving means when the contact pressure reaches a specific pressure, thereby measuring the total reflection spectrum at each measurement point at a constant contact pressure.

6. A microscope for measuring a spectrum of a small area of ​​a sample, a sample stage according to any one of claims 1 to 4; a light irradiation means for irradiating the sample with light; an aperture for transmitting transmitted light, reflected light, or totally reflected light from the sample; a light detection means for detecting transmitted light, reflected light, or totally reflected light from the sample via the aperture; A microscope characterized in that it is configured to perform measurements by passing transmitted light, reflected light, or totally reflected light from a sample through the aperture, thereby limiting the light detected by the light detection means to only light from a predetermined light-focusing area of ​​the sample.

7. a detection-side Cassegrain mirror is provided between the sample and the aperture to collect transmitted light, reflected light, or total reflected light from the sample; the sample stage is configured to be movable in a direction perpendicular to a central axis of the detection-side Cassegrain mirror, the microscope sequentially changes the light-collecting region of the sample by moving the sample stage, detects transmitted light, reflected light, or total reflected light from the light-collecting region, and acquires spectral data of the light-collecting region, thereby performing mapping measurement of a predetermined measurement region of the sample.

7. The microscope according to claim 6.

8. a detection-side Cassegrain mirror that collects transmitted light or reflected light from the sample, and a detection-side scanning mirror that reflects light from the detection-side Cassegrain mirror toward the aperture are provided between the sample and the aperture; the detection-side scanning mirror is capable of changing the orientation of a reflecting surface with respect to the incident direction from the detection-side Cassegrain mirror, thereby enabling the light-collecting region of the sample detected by the light detecting means to be changed; the microscope detects transmitted light or reflected light from the light-collecting area, which is sequentially changed by the detection-side scanning mirror, and acquires spectral data of the light-collecting area, thereby performing mapping measurement of a predetermined measurement area of ​​the sample.

7. The microscope according to claim 6.

9. an irradiation-side scanning mirror for guiding light from the light irradiation means to a sample; an illumination-side Cassegrain mirror for collecting light from the illumination-side scan mirror and illuminating a predetermined illumination area on a sample, 9. The microscope according to claim 8, wherein the illumination-side scanning mirror has a reflecting surface whose orientation is variable relative to the incident direction from the light illumination means, thereby enabling the illumination area to be sequentially changed in accordance with the light collection area.

10. a detection-side Cassegrain mirror that collects the light totally reflected from the sample, and a detection-side scanning mirror that reflects the light totally reflected from the detection-side Cassegrain mirror toward the aperture are provided between the sample and the aperture; the detection-side Cassegrain mirror has a high-refractive index total reflection crystal element to be brought into contact with the sample, and light from the light irradiation means that is supplied to the detection-side Cassegrain mirror, which also serves as the irradiation-side Cassegrain mirror, is condensed on the total reflection crystal element to irradiate a predetermined irradiation area within the contact surface with the sample at an incident angle equal to or greater than a critical angle; the detection-side scanning mirror is capable of changing the orientation of a reflecting surface with respect to the incident direction from the detection-side Cassegrain mirror, thereby changing the light-collecting area within the contact surface detected by the light detecting means; the microscope detects the total reflected light from the light-collecting area that is sequentially changed by the detection-side scanning mirror, and acquires spectral data of the light-collecting area, thereby performing mapping measurement of a minute area within the contact surface.

7. The microscope according to claim 6.

11. an illumination-side scanning mirror for guiding light from the light illumination means to the detection-side Cassegrain mirror; the irradiation-side scanning mirror is capable of varying the orientation of the reflecting surface relative to the incident direction from the light irradiation means, thereby enabling the light irradiation area in a minute portion within the contact surface to be sequentially changed in accordance with the light collection area; 11. The microscope according to claim 10.