JP2016118464A - Planar spectroscopic interferometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a device of a simple configuration to quickly acquire an observation result by an interferometer and an observation result by a spectrometer in the same observation area.SOLUTION: A planar spectroscopic interferometer 100 is configured to arrange an interference measurement unit 20A and a spectroscopic measurement unit 20B on an irradiation optical axis O of a measured object S. The interference measurement unit 20A and the spectroscopic measurement unit 20B are configured to simultaneously observe the measured object S. Surface shape information processing means 31 is configured to acquire a three-dimensional distribution image 55 by an image from an interference detector 5, and spectroscopic information processing means 32 is configured to acquire a spectroscopic information image 56 by an image from a spectroscopic detector 13. Display control means 34 is configured to comprise three-dimensional information storage means 35, spectroscopic information storage means 36, three-dimensional display means 37, and spectroscopic information display means 38. Only specification of one point of the three-dimensional distribution image 55 displayed on display means 40 by input means 50 allows the spectroscopic information image 56 at a coordinate to be quickly and simply acquired and displayed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a planar spectroscopic interferometer that performs observation inspection of the surface of an object to be measured.

  2. Description of the Related Art Conventionally, an apparatus provided with an interferometer is known as an apparatus for performing observation and inspection of an object to be measured such as a silicon wafer. FIG. 10A is a schematic diagram showing the configuration of the interferometer. The interferometer 60 divides the light incident from the light source 61 into two irradiation light paths by the beam splitter 62, irradiates one irradiation light to the object S to be measured, and irradiates the reference mirror 63 with the other irradiation light. The reflected light reflected from the sample and the reference reflected light are caused to interfere with each other, and the formed interference fringes are observed by the detector 64. Reference numeral 65 denotes a collimator lens, and 66 and 67 denote imaging lenses. Thereby, the surface of the object to be measured S and the internal state are observed and inspected. By using such an interferometer 60, it is possible to inspect the three-dimensional structure of the measurement object S, for example, the height dimension of the convex portion.

  In Patent Document 1, for a simple configuration, a reference optical path for guiding light between the beam splitter and the reference mirror is provided, and a measurement optical path for guiding light is provided between the beam splitter and the sample. There is described a method in which an optical optical path difference is provided between the reference optical path and the measurement optical path, and an interference fringe is formed on the detection means by tilting the reference mirror by a minute amount.

  In addition, when performing an observation inspection of an object to be measured, there is a case in which spectroscopy for analyzing a wavelength distribution of reflected light in an observation region of the object to be measured is performed. FIG. 10B is a schematic diagram showing a spectroscope. The spectroscope 70 splits the irradiation light from the object S to be measured with a spectroscopic element 71 such as a diffraction grating or a prism, and observes the split light with a detector 72. In the figure, reference numeral 74 denotes a collimating lens, and 75 denotes an imaging lens. Thus, by performing spectroscopy with the spectroscope 70, the surface composition, surface structure, etc. of the object S to be measured can be observed and inspected.

JP 2011-38829 A

  In the observation inspection of the object to be measured, there is a demand to obtain the observation result by the interferometer and the observation result by the spectrometer for the same region, and to perform the observation inspection of the object to be measured comprehensively from these. However, the same object to be measured must be individually observed with an interferometer and a spectrometer. Further, in order to obtain two observation results for a minute observation region of the object to be measured, it takes time to adjust the position of the sample. Moreover, when the observation result by the spectrometer in a specific location is acquired based on the observation result by the interferometer and the observation result is acquired for the same region, it takes time and effort.

  Therefore, the present invention makes it possible to simultaneously observe the same observation region with an interferometer and a spectrometer, and the observation result with a spectrometer at a specific location in the observation region designated based on the observation result with the interferometer has a simple configuration. An object of the present invention is to provide a planar spectroscopic interferometer that can be quickly acquired by an apparatus.

  The invention according to claim 1, which solves the above-mentioned problem, divides the first light source that generates the first irradiation light and the first light source into two parts, and uses the first irradiation light as one of the objects to be measured. And irradiating the other first irradiation light toward the reference mirror and emitting part of the object reflected light from the object to be measured and part of the reference reflected light from the reference mirror in the same direction. An interference measurement unit comprising: a first beam splitter; and an interference detector that acquires an interference image by the object reflected light from the first beam splitter and the reference reflected light from the reference mirror; and second irradiation A spectroscopic measurement unit including a second light source that generates light, a spectroscopic unit that splits reflected light of the second irradiation light from the object to be measured, and a spectroscopic detector that acquires a spectroscopic image of the spectroscopic unit; The spectroscopic measurement unit includes the second A second beam splitter that reflects part of the incident light, irradiates the object to be measured with the reflected second irradiation light, and transmits part of the object reflected light from the object to be measured; The first beam splitter and the second beam splitter are arranged on an observation axis intersecting an observation region of the object to be measured, and the first irradiation light and the second irradiation light are simultaneously measured. A surface shape information processing means arranged to irradiate the observation region of the object at the same time, and outputs surface shape information at each position of the observation region of the object to be measured based on an interference image from the interference detector; The spectral information processing means for outputting spectral information at each position of the observation area of the object to be measured based on the interference image from the spectral detector, the display means for displaying an image, and the display means Previous Position specifying means for specifying the position of an image, surface information storage means for storing surface shape information of the observation area, spectral information storage means for storing spectral information of the observation area, and surface shape information of the observation area are imaged The surface information display means for displaying on the display means, and the spectral information display for acquiring the spectral information corresponding to the designated portion in the surface shape information designated by the position designation means and displaying the spectral information on the display means A plane spectroscopic interferometer comprising display control means.

  Similarly, the invention according to claim 2 is the planar spectroscopic interferometer according to claim 1, wherein the arranged object to be measured is moved at a predetermined direction and speed, and the position of the observation region in the object to be measured is measured. It is characterized by comprising a sample stage for changing the above.

  Similarly, the invention according to claim 3 is the planar spectral interferometer according to claim 1 or 2, wherein the spectroscopic means is a linear variable filter in which the wavelength of continuous transmission is changed. To do.

  Similarly, the invention according to claim 4 is the planar spectroscopic interferometer according to any one of claims 1 to 3, wherein the spectroscopic means is removable, and the spectroscopic means is removed, An observation image with the first irradiation light from the object to be measured is acquired by the spectral detector.

  Similarly, the invention according to claim 5 is the planar spectroscopic interferometer according to any one of claims 1 to 4, which is arranged on an emission side of the second light source, and has a positive power of a predetermined one. A first cylindrical lens for irradiating the object to be measured with a linear first irradiation light image, and disposed on the incident side of the interference detector, and only in a direction different from the first cylindrical lens. It has the 2nd cylindrical lens which has positive power, It is characterized by the above-mentioned.

  Similarly, the invention according to claim 6 is the planar spectroscopic interferometer according to any one of claims 1 to 5, wherein the first irradiation light is coherent near infrared light, The irradiation light 2 is visible light.

  Similarly, the invention according to claim 7 is the planar spectroscopic interferometer according to any one of claims 1 to 5, wherein the first irradiation light is visible light and the second irradiation light is coherent. It is characterized by being near-infrared light.

  Similarly, the invention according to claim 8 is the planar spectroscopic interferometer according to claim 6, wherein the near-infrared light is reflected between the first beam splitter and the second beam splitter, A dichroic mirror that transmits visible light is disposed, and the interference detector detects the near-infrared light reflected by the dichroic mirror.

  Similarly, in the ninth aspect of the present invention, the planar spectroscopic interferometer according to any one of the first to eighth aspects is configured such that the reference mirror has a minute amount with respect to the incident optical axis of the incident first irradiation light. It is characterized by being arranged at an angle.

  Similarly, the invention according to claim 10 is the planar spectroscopic interferometer according to any one of claims 1 to 9, wherein the surface shape information processing means is configured to perform the observation in the observation region based on the interference image. It is characterized by calculating surface shape information.

  According to the planar spectroscopic interferometer of the present invention, the same observation area can be observed simultaneously with the interferometer and the spectrometer with a simple configuration, and the spectroscope in the specified area while referring to the observation result with the interferometer. Observation results can be quickly acquired and displayed.

It is a schematic diagram which shows the irradiation optical system of the plane spectral interferometer which concerns on embodiment of this invention. The image acquired with the same plane spectroscopic interferometer is shown, (a) is an observation image, (b) is an interferometer image, (c) is a spectroscopic image. It is a block diagram which shows the control system of the same plane spectral interferometer. It is a figure which shows the flow of a process in the same plane spectroscopic interferometer. It is a figure which shows a three-dimensional distribution image and a spectral information image. It is a flowchart which shows the process in the same plane spectral interferometer. It is a flowchart which shows the image display process in the same plane spectral interferometer. It is a schematic diagram which shows the optical system which shows the plane spectral interferometer which concerns on 2nd Embodiment concerning this invention. It is a schematic diagram which shows the optical system which shows the plane spectral interferometer which concerns on 3rd Embodiment concerning this invention. It shows a conventional technique, (a) is a schematic diagram showing an interferometer, (b) is a surface spectrometer.

<First Embodiment>
A planar spectroscopic interferometer according to an embodiment for carrying out the present invention will be described with reference to the drawings. First, the irradiation optical system of the planar spectroscopic interferometer according to the first embodiment will be described. FIG. 1 is a schematic diagram showing an irradiation optical system of a planar spectral interferometer according to an embodiment of the present invention, FIG. 2 shows an image acquired by the planar spectral interferometer, (a) is an observation image, ( b) is an interferometer image, and (c) is a spectroscopic image.

  The optical system 20 of the planar spectroscopic interferometer 100 includes an interference measuring unit 20A and a spectroscopic measuring unit 20B arranged along an optical axis O that is an observation axis that intersects the measured object S at right angles. The interference measurement unit 20A includes a first light source 1, a dichroic mirror 2, a prism beam splitter 3 that is a first beam splitter, a reference mirror 4, an interference detector 5, a visible region cut filter 6, A light source side cylindrical lens 7 that is a first cylindrical lens, an interference detector side cylindrical lens 8 that is a second cylindrical lens, a collimating lens 9, and an imaging lens 10 are provided. Thereby, the surface of the object to be measured S and the internal state are observed and inspected.

  The object to be measured S is arranged on the sample stage 17 that can move the object to be measured S in the linear direction, and the same observation region is simultaneously observed and inspected by the interference measuring unit 20A and the spectroscopic measuring unit 20B. The object to be measured S is a semiconductor wafer or the like. In the present embodiment, the sample stage 17 has a six-axis moving mechanism as shown in FIG. 1B, and the object S to be measured has six directions (x, y, z, α, β, θ). In addition, the freedom degree of the sample stand 17 can be selected as needed.

First, the interference measurement unit 20A will be described. The first light source 1 includes two laser diodes that generate two coherent near-infrared lights having wavelengths λ ₁ = 800 nm and λ ₂ = 880 nm as the first irradiation light, for example. Irradiation light from the two laser diodes is emitted along a common axis. By using these two laser diodes at a current equal to or lower than the laser oscillation threshold, a light source having a wider half-value width than that of a normal laser can be formed, and the coherence length can be shortened. Further, the equivalent wavelength λ _eq is expressed by λ ₁ λ ₂ / (λ ₂ -λ ₁ ) by a two-wavelength interferometer using two oscillation wavelengths, and is approximately 8.8 μm. By adopting irradiation light of these two wavelengths, it is possible to obtain interference light that can easily detect an uneven shape of about 100 μm with a resolution of 0.1 μm. As the first light source, two light emitting elements that oscillate two optimum wavelengths according to a required measurement range and a required height resolution can be used. Furthermore, as the light source, a single element having a wide half-value width such as a super luminescent diode (SLD) can be similarly used.

  The dichroic mirror 2 reflects near-infrared light and transmits visible light, and is disposed at an angle of 45 degrees with respect to the optical axis O. For this reason, the dichroic mirror 2 reflects near infrared light from the first light source 1 toward the object S to be measured, and transmits visible light from the second light source 11. The prism type beam splitter 3 divides the near-infrared light from the dichroic mirror 2 into two, and irradiates one irradiation light to the reference mirror 4 and the other irradiation light toward the object S to be measured. Also, the prism type beam splitter 3 emits the measured object reflected light from the measured object S and a part of the reference reflected light from the reference mirror 4 in the same direction, that is, toward the interference detector 5.

  The reference mirror 4 reflects near-infrared light from the prism beam splitter 3 and emits reference reflected light. The reference mirror 4 is disposed so as to be inclined by a minute amount with respect to the incident optical axis. By inclining the arrangement, an interference image in the height direction can be obtained with one shot without scanning the laser beam. The light source side cylindrical lens 7 is provided on the emission side of the first light source 1 and projects an infrared image orthogonal to the moving direction of the sample stage 17 onto the object S to be measured (B in FIG. 4A). Indicated).

  The interference detector 5 is an image pickup device including, for example, a charge coupled device (CCD) and a complementary metal oxide semiconductor (CMOS). The interference detector 5 does not include an infrared cut filter. The visible region cut filter 6 blocks visible light incident through the second light source 11, the prism type beam splitter 3, and the reference mirror 4. The interference detector-side cylindrical lens 8 is provided on the incident side of the interference detector 5 and projects an interference image on the interference detector 5. The bending direction of the interference detector side cylindrical lens 8 is set in a direction orthogonal to the light source side cylindrical lens 7 so as to have a predetermined positive power. Thereby, the interference fringe image 52 (FIG. 2B) can be acquired. In this interference measuring unit 20A, since the tilted illumination that irradiates near-infrared light from the first light source 1 from the observation side, a shadow due to the structure of the object S to be measured does not occur, and accurate measurement can be performed.

  The imaging lens 10 is used in common by the interference measuring unit 20A and the spectroscopic measuring unit 20B, and uses near-infrared light from the first light source 1 and visible light from the second light source 11 to be measured S. Irradiate.

  Next, the spectroscopic measurement unit 20B will be described. The spectroscopic measurement unit 20B includes a second light source 11, a half mirror 12 that is a second beam splitter, a spectroscopic detector 13, a collimating lens 14, an imaging lens 15, and a linear variable filter 16 that is a spectroscopic means. With.

  The second light source 11 generates visible light (for example, 380 nm to 780 nm). For example, a white light bulb or a white light emitting diode can be used. The half mirror 12 is disposed at an angle of 45 degrees with respect to the optical axis O. The half mirror 12 reflects the visible light from the second light source 11 toward the measurement object S along the optical axis O, and transmits the measurement object reflected light from the measurement object S toward the spectral detector 13. To do.

  The spectroscopic detector 13 is configured by, for example, a charge-coupled device (CCD) image sensor, a complementary MOS (CMOS) image sensor, or the like. The linear variable filter 16 is a known filter having different transmission wavelengths continuously in the one-dimensional direction of the planar space. By using this linear variable filter 16, it is possible to obtain a spectral image 54 (FIG. 2C) about the observation region A of the object S to be measured moved on the sample stage 17.

  Further, the linear variable filter 16 is detachably disposed from the spectroscopic detector 13, and the observation image 51 (FIG. 2A) obtained by visible light of the object S to be measured is obtained by removing the linear variable filter 16. Can do. Instead of the linear variable filter 16, other spectroscopic elements such as a diffraction grating and a prism can be used. In this case, the dispersed light is arranged so as to enter the spectral detector 13.

  The optical system 20 has the above-described configuration, and can acquire an interference image for the same observation region A of the object S to be measured with the interference detector 5 and a spectral image with the spectral detector 13.

  Here, an image acquired by the interference detector 5 and the spectral detector 13 will be described. An observation image 51 shown in FIG. 2A is an enlarged image of the object S to be measured by visible light, and is a visible image on the xy plane on the object S to be measured. A quadrangular uneven geometric pattern appears in the object S to be measured. Moreover, the interference fringe image 52 shown in FIG. 2 represents the interference fringes obtained based on the height (z) in the straight line part (y direction) irradiated with near infrared rays in the observation region of the object S to be measured. Yes. Stripes corresponding to the displacement of the image height are displayed, and the position in the x direction where the interference fringe intensity is maximum indicates the height of the near infrared irradiation position. Further, the spectral image 54 shown in FIG. 2C is a transmission image of the linear variable filter 16 in the xy plane, and the brightness according to the intensity of the transmitted wavelength λ is displayed in the x direction. .

  Next, a control system of the planar spectroscopic interferometer 100 according to the embodiment will be described. FIG. 3 is a block diagram showing a control system of the same plane spectroscopic interferometer, FIG. 4 is a view showing a flow of processing in the same plane spectroscopic interferometer, and FIG. 5 is a view showing a three-dimensional distribution image and a spectral information image. In the planar spectroscopic interferometer 100, the interference detector 5, the spectroscopic detector 13, and the linear variable filter 16 are connected to the control device 30. The control device 30 includes surface shape information processing means 31, spectral information processing means 32, sample stage control means 33, and display control means 34. The display control unit 34 includes a three-dimensional information storage unit 35, which is a surface information storage unit, a spectral information storage unit 36, a three-dimensional information display unit 37 which is a surface information display unit, and a spectral information display unit 38.

  In the present embodiment, the control device 30 is a computer including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disc Drive), and the like, and the CPU executes a control program. By executing, the function of each means is realized.

  A display unit 40 and an input unit 50 are connected to the control device 30. The display means 40 includes a liquid crystal display for displaying various acquired images, a CRT (Cathode-ray Tube), and the like. The input unit 50 includes a pointing device such as a keyboard and a mouse for inputting information for controlling the control device 30. The input means 50 performs an input instruction for performing general control of the control device 30 and an instruction for designating an observation region of the object S to be observed. Further, the control device 30 is used as a position specifying means for specifying the position of the measured object S displayed while observing the display means 40.

  The surface shape information processing means 31 calculates the height distribution information 53 (FIG. 4) of each position of the measurement object S from the interference fringe image 52 (FIG. 3B, FIG. 4B) output from the interference detector 5. (C)) is calculated and output. In this example, an interference fringe image 52 is obtained for the observation region A located at the center in FIG. 4A, and the height distribution information of the observation region A is obtained based on the interference fringe distribution of the interferometer image. 53 is output. The height distribution information 53 corresponds to the irradiation position of the linear infrared ray irradiated to the object S to be measured (position of the broken line B in FIG. 4A).

  The height distribution information 53 is associated with the y coordinate of the object to be measured S, and the height information in the xy plane can be acquired by moving the object to be measured S in the x direction. Further, the surface shape information processing means 31 generates a height three-dimensional distribution image 55 (FIG. 4E) based on the height distribution information 53. The three-dimensional distribution image 55 is stored in the three-dimensional information storage unit 35 of the display control unit 34 and displayed on the display unit 40.

  In the spectral information processing means 32, a spectral information image 56 (FIG. 4 (f)) about the relative spectral distribution of the object S to be measured is generated based on the spectral image 54 (FIG. 2 (c), FIG. 4 (d)). To do. The spectral information image 56 is stored in the spectral information storage unit 36 and displayed on the display unit 40 as necessary.

  Further, the sample stage control means 33 controls the movement of the sample stage 17 in the x direction in normal measurement. The sample stage 17 has six directions (x, y, z, α) as shown in FIG. , Β, θ), the object S can be moved, and the position, inclination angle, and moving speed of the object S can be changed as necessary.

  As described above, the display control unit 34 includes the three-dimensional information storage unit 35, the spectral information storage unit 36, the three-dimensional information display unit 37, and the spectral information display unit 38. The display control unit 34 displays on the display unit 40 the spectral information at the designated location in the xy coordinates of the three-dimensional distribution image 55 displayed by the display unit 40. For example, when a point of interest (a, b) in the three-dimensional distribution image 55 is designated by the input unit 50, the spectral information image 56 at this point (a, b) is displayed on the display unit 40. Alternatively, the spectral data at the point (a, b) is numerically output.

  The three-dimensional information storage unit 35 stores a three-dimensional distribution image 55 acquired from the height distribution information 53 generated by the surface shape information processing unit 31. The three-dimensional distribution image 55 displays the height (Z) at one point (X, Y) on the xy coordinate of the observation area A. In the example shown in FIG. 4, a rectangular concave portion Sa and a groove portion Sb are formed in the observation region A, and two step portions 53 a and 54 b appear as a cross-sectional shape in the height distribution information 53 and are three-dimensional. In the distribution image 55, a concave portion 55a appears. FIG. 5A shows an enlarged view of the three-dimensional distribution image 55.

  The spectroscopic information storage means 36 stores spectroscopic information generated by the spectroscopic information processing means 32. The spectroscopic information is stored at one point (X, Y) on the xy plane along the surface of the object S to be measured. Stored as a spectrum (relationship between wavelength λ and spectral radiation intensity).

  The three-dimensional information display unit 37 displays a three-dimensional distribution image 55 obtained by converting the height distribution information 53 stored in the three-dimensional information storage unit 35 into a three-dimensional image on the display unit 40 (FIG. 5A). The spectral information display means 38 obtains spectral information corresponding to the coordinates (a, b) in the three-dimensional distribution image 55 displayed on the display means 40 by the input means 50 that is a position designation means, and displays the spectral information 40. And is displayed as a spectral information image 56. A spectral information image 56 obtained from the spectral information on the point (a, b) is shown in FIG.

  Next, a procedure for observing the measurement object S using the planar spectroscopic interferometer 100 will be described. FIG. 6 is a flowchart showing processing in the plane spectroscopic interferometer. First, the first light source 1 and the second light source 11 are turned on (step S1). Next, the linear variable filter 16 disposed in the spectroscopic measurement unit 20B is removed and replaced with transparent glass (step S2). As a result, the object to be measured S can be observed with visible light.

  Then, while confirming the observation image 51, the sample stage 17 is moved, and the observation start point (scan start point) of the object to be measured S is arranged at the center of the field of view (step S3). Further, the sample stage 17 is moved to start the measurement (step S4), and the sample stage is positioned so that the position of the measured object S located at the center of the field of view of the measured object S in step S3 comes to the end of the field of view. The sample stage control means 33 is set so that 17 moves.

  Then, the transparent glass of the spectroscopic measurement unit 20B is replaced with the linear variable filter 16 (step S6), the interference fringe image 52 is acquired by the interference detector 5 in synchronization with the driving of the sample stage 17, and the spectral detector 13 A spectral image 54 is acquired (step S7). Next, a three-dimensional distribution image 55 is generated from the acquired interference fringe image 52 and stored in the three-dimensional information storage unit 35, spectral information is obtained from the spectral image 54, and stored in the spectral information storage unit 36.

  Next, the procedure for displaying the spectral information image 56 by designating the three-dimensional distribution image 55 displayed on the display means 40 in the planar spectroscopic interferometer 100 will be described. FIG. 7 is a flowchart showing image display processing in the same plane spectroscopic interferometer.

  First, the three-dimensional information display unit 37 displays the three-dimensional distribution image 55 stored in the spectral information storage unit 36 (step SA). Next, the operator designates one point in the three-dimensional distribution image 55, that is, one point in the observation region, for example, coordinates (a, b), while observing the three-dimensional distribution image 55 on the display unit 40. (Step SA2).

  The spectral information display means 38 refers to the spectral information from the spectral information storage means 36 with coordinates (a, b), acquires spectral information corresponding to these coordinates (step SA3), images this, and spectral information image 56 is displayed on the display means 40 (step SA4). Thereby, the spectral information image 56 at the specified coordinates (a, b) of the three-dimensional distribution image 55 is displayed on the display means 40. In this way, the operator can easily and quickly display the spectral information image 56 at the relevant location simply by designating one point of the image while observing the three-dimensional distribution image 55.

  According to the planar spectroscopic interferometer 100 according to the present embodiment, it is possible to measure the height of the submicron (0.1 um) height measurement resolution that cannot be shaded by falling light, and by continuously moving the sample stage 17, The three-dimensional information and spectral information of the measurement object S can be acquired simultaneously. For this reason, it is not necessary to stop the sample stage 17 at the time of measurement.

  Moreover, according to the planar spectroscopic interferometer 100 according to the present embodiment, the observation result of the interferometer and the observation result of the spectrometer in the same observation region of the object to be measured S can be quickly obtained with an apparatus having a simple configuration. Can be acquired and displayed in association. For this reason, for example, bumps, film surface shapes, film irregularities and the like on a semiconductor wafer can be measured and inspected at high speed.

  In the plane spectroscopic interferometer 100, as the first light source, the interference measurement unit 20A is used for shape measurement (for interference measurement), near infrared light is used as the second light source, and the spectrum measurement unit 20B is used for the observation side. Although visible light was used as (for the spectroscopic side), visible light can be emitted from the first light source and infrared light can be emitted from the second light source. In this case, the wavelength bands of the filters that select various wavelengths are switched.

  Thereby, in the interference measurement unit 20A, a portion having a wavelength of 400 nm to 500 nm in visible light can be used, and the interference measurement unit 20A can perform near infrared light to infrared light of 600 nm or more. By using irradiation light of near infrared light to infrared light for the spectroscopic measurement unit 20B, light enters the object to be measured S, and an internal structure of the object to be measured S, for example, an internal structure of silicon or a human body ( The internal state of the retina and skin) can be observed.

Second Embodiment
Next, a planar spectroscopic interferometer according to a second embodiment of the present invention will be described. FIG. 8 is a schematic view showing an optical system showing a planar spectral interferometer according to the second embodiment of the present invention. In the planar spectroscopic interferometer 200 according to the second embodiment, the first light source includes the light source unit 210, the irradiation unit 220, and the optical cable 230. The second light source includes a light source unit 240, an irradiation unit 250, and an optical cable 260. In the first and second light sources, the first and second irradiation lights generated by the light source units 210 and 240 are guided to the irradiation units 220 and 250 by the optical cables 230 and 260, and are irradiated in the same manner as in the first embodiment. Other configurations are the same as those of the planar spectroscopic interferometer 100 according to the first embodiment.

  According to the planar spectroscopic interferometer 200 according to the second embodiment, it is not necessary to arrange a light source near the optical system 20, and the degree of freedom in designing the planar spectroscopic interferometer 200 is increased.

<Third Embodiment>
Next, a planar spectroscopic interferometer according to a third embodiment of the present invention will be described. FIG. 9 is a schematic view showing an optical system showing a planar spectral interferometer according to the third embodiment of the present invention. In the planar spectroscopic interferometer 300 according to the third embodiment, the second light source directly irradiates visible light that is the second irradiation light from the oblique direction of the object S to be measured.

  That is, the optical system in the interference measuring unit 20A is the same as that of the planar spectroscopic interferometer 200 according to the second embodiment, the second light source is composed of the light source unit 310, the irradiation unit 320, and the optical cable 330, and the irradiation unit 320 is configured. In the vicinity of the sample stage control means 33, the object to be measured S is arranged at a position where it irradiates obliquely, for example, at an angle of 45 degrees. In connection with this, the structure which does not arrange | position the collimating lens 14 and the half mirror 12 which comprise the spectroscopic measurement part 20B is employ | adopted.

  According to the planar spectroscopic interferometer 300 according to the third embodiment, it is possible to split an inclined surface or the like of the measurement object S that cannot be irradiated as a shadow by falling illumination. As the second light source, an illuminating device in which a plurality of irradiation units 320 are arranged in a ring shape around the imaging lens 10 can be used. In this case, it is possible to prevent the occurrence of a shadow on the object S to be measured. .

1: First light source 2: Dichroic mirror 3: Beam splitter (first beam splitter)
4: Reference mirror 5: Interference detector 6: Visible region cut filter 7: Light source side cylindrical lens 8: Light source side cylindrical lens 9: Collimate lens 10: Imaging lens 11: Second light source 12: Half mirror (first mirror 2 beam splitter)
13: Spectral detector 14: Collimating lens 15: Imaging lens 16: Linear variable filter 17: Sample stage 20: Optical system 20A: Interference measuring unit 20B: Spectroscopic measuring unit 30: Controller 31: Surface shape information processing means 32: Spectral information processing means 33: Sample stage control means 34: Display control means 35: Three-dimensional information storage means 36: Spectral information storage means 37: Three-dimensional information display means 38: Spectral information display means 40: Display means 50: Input means 51 : Observation image 52: Interferometer image 53: Height distribution information 54: Spectral image 55: Three-dimensional distribution image 56: Spectral information image 100 Planar spectral interferometer

Claims (10)

A first light source that generates first irradiation light, the first irradiation light is divided into two, one of the first irradiation lights is irradiated toward the object to be measured, and the other first irradiation light is irradiated A first beam splitter that irradiates a reference mirror and emits the object reflected light from the object to be measured and a part of the reference reflected light from the reference mirror in the same direction, and the first beam splitter An interference detector that includes an interference detector that acquires an interference image due to the reflected light from the object to be measured and the reference reflected light from the reference mirror;
A spectroscope including a second light source that generates second irradiation light, a spectroscopic unit that splits reflected light of the second irradiation light from the object to be measured, and a spectroscopic detector that acquires a spectroscopic image of the spectroscopic unit A measuring section;
With
The spectroscopic measurement unit reflects a part of the second irradiation light, irradiates the measurement object with the reflected second irradiation light, and reflects the measurement object reflected light from the measurement object. A second beam splitter that partially transmits,
The first beam splitter and the second beam splitter are arranged on an observation axis that intersects an observation region of the object to be measured, and the first irradiation light and the second irradiation light are simultaneously applied to the object to be measured. Arranged to irradiate the observation area at the same time,
Surface shape information processing means for outputting surface shape information at each position of the observation region of the object to be measured based on an interference image from the interference detector;
Spectral information processing means for outputting spectral information at each position of the observation region of the object to be measured based on an interference image from the spectral detector;
Display means for displaying an image;
Position specifying means for specifying the position of the image displayed on the display means;
Surface information storage means for storing surface shape information of the observation area, spectral information storage means for storing spectral information of the observation area, surface information display means for imaging the surface shape information of the observation area and displaying it on the display means And a display control means comprising spectral information display means for acquiring and displaying the spectral information corresponding to the designated portion in the surface shape information designated by the position designation means, and forming an image on the display means.
A planar spectroscopic interferometer, comprising:   2. The planar spectroscopic interferometer according to claim 1, further comprising a sample stage for moving the arranged object to be measured at a predetermined direction and speed to change a position of the observation region in the object to be measured. .   The planar spectroscopic interferometer according to claim 1 or 2, wherein the spectroscopic means is a linear variable filter in which a wavelength of continuous transmission is changed.   The spectroscopic means is removable, and an observation image with the first irradiation light from the object to be measured is acquired by the spectroscopic detector with the spectroscopic means removed. The planar spectroscopic interferometer according to any one of claims 1 to 3.   A first cylindrical lens disposed on an emission side of the second light source and having a predetermined positive power and irradiating the object to be measured with an image of linear first irradiation light; and the interference detection 5. A second cylindrical lens disposed on the incident side of the instrument and having a positive power only in a direction different from that of the first cylindrical lens. 6. Planar spectroscopic interferometer described in 1.   6. The planar spectroscopy according to claim 1, wherein the first irradiation light is coherent near-infrared light, and the second irradiation light is visible light. Interferometer.   6. The planar spectroscopy according to claim 1, wherein the first irradiation light is visible light, and the second irradiation light is coherent near-infrared light. Interferometer.   A dichroic mirror that reflects the near infrared light and transmits the visible light is disposed between the first beam splitter and the second beam splitter, and the interference detector reflects the dichroic mirror. The planar spectroscopic interferometer according to claim 6, wherein the near-infrared light is detected.   The plane according to any one of claims 1 to 8, wherein the reference mirror is arranged to be inclined by a minute amount with respect to an incident optical axis of the incident first irradiation light. Spectroscopic interferometer.   The planar spectral interferometer according to claim 1, wherein the surface shape information processing unit calculates the surface shape information in the observation region based on the interference image.