Shape measuring device, surface layer measurement and analysis system, and method for acquiring data on the object to be measured.

Abstract

This invention provides a measuring device capable of quickly measuring the surface shape and distance of large-area objects. [Solution] A shape measuring device is provided, comprising a detector that detects interference light obtained by interfering a first light and a second light emitted from a light source and reflected by the object to be measured, and an image generation unit that generates an image using the output of the photodetector as pixel values. The photodetector has a light-receiving region that receives interference light and generates an electric charge, a plurality of inflow regions for allowing the charge generated in the light-receiving region to flow in, and a switch that sequentially switches the charge generated in the light-receiving region into the plurality of inflow regions at predetermined time intervals. The image generation unit generates an image using pixel values ​​corresponding to the amount of charge that flowed into the inflow region within a predetermined time period switched by the switch of the photodetector. This sequentially generates images at predetermined time intervals.

Description

Technical Field

[0004] , , , , , , , , , , , ,

[0001] The present invention relates to an apparatus for measuring the surface shape of an object.

Background Art

[0002] An interferometer capable of measuring a fine uneven shape non-destructively and non-invasively by interfering lights having a wide wavelength range such as white light is disclosed in Patent Document 1.

[0003] On the other hand, as a detection element of a distance image sensor that detects distance by the time-of-flight method (TOF: Time of Flight), a semiconductor device is disclosed in Patent Document 2. This semiconductor device has a first transfer gate and a second transfer gate disposed on both sides of one photogate, and the charge generated by the light reaching the photogate is transferred to the first floating semiconductor region by applying a voltage to the first transfer gate, and then the charge generated at the photogate after transfer at the first transfer gate is transferred to the second floating semiconductor region by applying a voltage to the second transfer gate. As a result, when irradiating a measurement target with one light pulse, the light reflected by the measurement target with a short distance and reaching the photogate is detected as the charge transferred to the first floating semiconductor region via the first transfer gate, and the light reflected by the measurement target with a long distance and reaching the photogate can be detected as the charge transferred to the second floating semiconductor region via the second transfer gate. Thereby, the range of distances that can be detected by one light pulse is widened.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The interference system described in Patent Document 1 uses an image sensor, making high-speed readout of the charge difficult.

[0006] On the other hand, the distance image sensor in Patent Document 2 uses the time-of-flight method, and therefore has a structure that detects the distance to one measurement target irradiated by a single light pulse. It cannot measure the unevenness and distance of a wide range of measurement targets all at once with a single light pulse.

[0007] The object of the present invention is to provide a measuring device capable of measuring the surface shape and distance of a large area of ​​measurement target at high speed. [Means for solving the problem]

[0008] According to one aspect of the present invention, a shape measuring device is provided, comprising a light source unit, a photodetector that detects interference light obtained by interfering a first light and a second light emitted from the light source unit and reflected by a measurement object, and an image generation unit that generates an image using the output of the photodetector as pixel values. The photodetector has a light-receiving region that receives interference light and generates an electric charge, a plurality of inflow regions for allowing the charge generated in the light-receiving region to flow in, and a switch that sequentially switches the charge generated in the light-receiving region into the plurality of inflow regions at predetermined time intervals. The image generation unit generates an image using pixel values ​​corresponding to the amount of charge that has flowed into the inflow regions within a predetermined time interval switched by the switch of the photodetector. This sequentially generates the image at predetermined time intervals. [Effects of the Invention]

[0009] According to the present invention, the surface shape and distance of a large area of ​​measurement target can be measured at high speed. [Brief explanation of the drawing]

[0010] [Figure 1] A block diagram showing the overall configuration of the surface shape measuring device 1 of the first embodiment of the present invention. [Figure 2] A block diagram showing the configuration of the interferometer 10 of the surface shape measuring device 1 of the first embodiment. [Figure 3] In the surface shape measuring device 1 of the first embodiment, (a) an explanatory diagram showing that a light beam with a linear beam cross-section (first light 101) is irradiated onto the object to be measured 100, (b) a cross-sectional view of the object to be measured 100 in zx, (c) a perspective view of the optical path length modulator 70, (d) a diagram showing the light intensity distribution of the two-dimensional detection surface of the photodetector 80, and (e) a diagram explaining how to acquire images of the light intensity distribution of the two-dimensional detection surface of the photodetector 80 in a time series. [Figure 4] A diagram illustrating the configuration of the detection elements of the photodetector 80 of the surface shape measuring device 1 according to the first embodiment. [Figure 5] A diagram illustrating the configuration of the detection elements of the photodetector 80 of the surface shape measuring device 1 according to the first embodiment. [Figure 6] A diagram illustrating the configuration of the detection elements of the photodetector 80 of the surface shape measuring device 1 according to the first embodiment. [Figure 7] A flowchart illustrating the operation of the photodetector 80, control unit 35, and image generation unit 31 of the surface shape measuring device 1 according to the first embodiment. [Figure 8] A block diagram showing the overall configuration of the surface layer measurement and analysis system 200 of the second embodiment of the present invention. [Figure 9] A graph showing the time change of the peak position of the surface wave in the surface shape measuring device 1 of the first embodiment. [Figure 10] Cross-sectional view of a case of carcinoma in situ. [Figure 11] A diagram showing the frequency of the comb light emitted from the light source 11 in the modified example 1 of the first and second embodiments. [Figure 12] A block diagram showing the configuration of the interference system 10 in a modified example 2 of the first and second embodiments. [Figure 13] Figure 12 is an explanatory diagram showing the light waveform and detection signal of the interferometer 10. [Figure 14] A block diagram showing the configuration of the interference system 10 in modified example 3 of the first and second embodiments. [Figure 15] (a) and (b) are diagrams showing the frequencies of the comb light emitted from the first comb light generator 511-1 and the second comb light generator 511-2, respectively, in the modified example 3 of the first and second embodiments.

Embodiments for Carrying Out the Invention

[0011] An embodiment of the present invention will be described with reference to the drawings.

[0012] <<First Embodiment>> The surface shape measuring device 1 of the first embodiment will be described.

[0013] FIG. 1 is a diagram showing the overall configuration of the surface shape measuring device 1, and FIG. 2 is a diagram showing the configuration of the interference system 10. FIGS. 3(a) to (e) are diagrams for explaining the interference system 10, and FIGS. 4(a) and (b) are diagrams for explaining the structure of the photodetector 80.

[0014] As shown in FIG. 1, the surface shape measuring device 1 includes an interference system 10 that measures the shape of the surface of the measurement object 100, an image generation unit 31, a surface shape detection unit 32, a display unit 34, and a control unit 35.

[0015] [[ID=**23]]In this embodiment, a device that measures the surface shape of the measurement object 100 by irradiating the measurement object 100 with light and detecting the light reflected from the surface of the measurement object 100 will be described. However, the surface shape measuring device 1 of this embodiment is not limited to a device that measures the surface shape. The wavelength of the light irradiated on the measurement object 100 can be set to a wavelength that can penetrate to the inside of the measurement object 100, and the internal structure of the measurement object 100 can be examined by performing tomographic measurement (measurement in the depth direction) by detecting the light reflected or scattered inside the measurement object by the interference system 10. A tomographic image of the measurement object can be generated and displayed from the obtained depth direction measurement data.

[0016] <Interference System 10> First, the configuration of the interference system 10 will be described with reference to FIGS. 2 to 3.

[0017] The interference system 10 includes a light source 11 that emits broadband light, an optical path length modulator 70, an optical system 20, and a photodetector 80.

[0018] The light source 11 and the optical system 20 constitute the light source unit, forming a first light 101 that irradiates the object to be measured 100 and a second light 102 that irradiates the optical path length modulator 70.

[0019] The photodetector 80 has a configuration in which detection elements 400 (see Figure 4(a)) are arranged in two dimensions. Multiple detection elements 400 constitute a two-dimensional detection surface. The photodetector 80 detects light resulting from the interference of a first light 101 and a second light 102 reflected from the object to be measured 100. Preferably, the detection elements 400 are arranged for each pixel of the image output by the photodetector 80.

[0020] The light source 11 emits broadband light, such as low-coherence light like LED light, supercontinuum light, or short-pulse laser light.

[0021] The optical system 20 includes a mirror 21, a neutral density filter 22, a beam expander 23, a beam splitter 24, a cylindrical lens 25, and a focusing lens 26, arranged in order along the optical axis 91 between the light source 11 and the object to be measured 100. An optical path length modulator 70 is positioned on the optical axis 92, which is branched from the optical axis 91 by the beam splitter 24. Focusing lenses 27 and 28 are positioned between the beam splitter 24 and the optical path length modulator 70.

[0022] Light emitted from the light source 11 is reflected by the mirror 21, attenuated by the neutral density filter 22, then the beam diameter is expanded by the beam expander 23, a portion of which is reflected in the direction of the optical axis 92 by the beam splitter 24, and the remaining light passes through the beam splitter 24 and travels along the optical axis 91. The light traveling along the optical axis 91 is focused in the y-axis direction by the cylindrical lens 25 and the focusing lens 26, and the cross-sectional shape of the beam is transformed into a linear beam of light that is long in the first direction (x-axis direction). This linear beam of light, as the first beam 101, is irradiated as the first beam 101 onto a linear measurement area 100a of the measurement target 100 that is parallel to the x-axis and at a predetermined position in the y-axis direction, as shown in Figure 3(a).

[0023] Multiple beams of light from the first light 101 irradiated onto the measurement area 100a of the object to be measured 100 are reflected by the surface of the irradiated measurement area 100a.

[0024] As schematically shown in Figure 3(b) in the cross-sectional view of the zx plane, the position (depth) in the z-axis direction of the linear measurement area 100a of the measurement target 100 changes depending on the position in the x-axis direction if there are irregularities on the surface or if the surface is inclined. Therefore, the reflected light from the measurement area 100a of multiple luminous beams of the first light 101 has different optical path lengths for each of the multiple luminous beams.

[0025] As shown in Figure 4(c), the first light 101 reflected at the measurement area 100a of the object to be measured 100 is expanded in the y-axis direction by passing through the focusing lens 26 and the cylindrical lens 25 in sequence, then incident on the beam splitter 24, is reflected, and irradiates the two-dimensional detection surface of the photodetector 80.

[0026] Meanwhile, the light emitted from the light source 11 that is reflected in the direction of the optical axis 92 by the beam splitter 24 passes through the focusing lenses 27 and 28 and reaches the optical path length modulator 70.

[0027] The optical path length modulator 70 changes the optical path length according to a predetermined one-dimensional position (y-axis direction) on the beam cross-section by reflecting the irradiated light beam. In this case, the optical path length modulator 70 uses a stepped reflecting element with a number of steps in a predetermined direction (y-axis direction), as shown in Figure 3(c).

[0028] The light whose optical path length has been modulated by the optical path length modulator 70 passes through the focusing lenses 28, 27 and the beam splitter 24 as a second beam 102 and is irradiated onto the two-dimensional detection surface of the photodetector 80.

[0029] The optical path length modulator 70 is not limited to a stepped reflective element; a diffraction grating can also be used. The groove shape of the diffraction grating can be any shape; for example, a sawtooth, sinusoidal, or rectangular shape can be used. When a diffraction grating is used as the optical path length modulator 70, diffracted light of a predetermined order is used as the second light 102 and irradiated onto the object to be measured 100. Therefore, the diffraction grating is arranged so that its main plane is inclined with respect to the optical axis 92, and the wavefront of the diffracted light of a predetermined order used as the second light 102 reaches the surface of the object to be measured 100. In this case, it is preferable to incline the diffraction grating so that the wavefront of the diffracted light of a predetermined order, which is the second light 102, is irradiated onto the surface of the object to be measured 100 at an angle parallel or nearly parallel.

[0030] The focusing lenses 28 and 27 align the direction in which the optical path length of the second light 102 is changing (y-axis direction) with the direction in which the light reflected from the object being measured 100 is magnified (y-axis direction) on the two-dimensional detection surface of the photodetector 80 (see Figure 3(d)).

[0031] As a result, on the two-dimensional detection surface of the photodetector 80, the first light 101, which is reflected light from a linear measurement area 100a parallel to the x-axis direction of the object to be measured 100 and is amplified in the y-axis direction, and the second light 102, whose optical path length is changing in the y-axis direction, interfere with each other, and the intensity of the interference light is detected on the two-dimensional plane of the photodetector 80.

[0032] <Photodetector 80> Let's explain the photodetector 80 in detail.

[0033] The photodetector 80 has a structure in which the detection elements 400 configured in Figure 4 are arranged in two dimensions. Each detection element 400 corresponds one-to-one with a pixel in the light intensity distribution image generated from the output of the two-dimensional detection surface of the photodetector 80.

[0034] Each detection element 400, positioned on the photodetector surface of the photodetector 80, comprises a light-receiving region 410, a plurality of charge inflow regions 430-1, 430-2, and switches 420-1, 420-2, all formed in a semiconductor layer 401. The detection element 400 is also equipped with a shield 460 to block interference light from irradiating areas other than the light-receiving region 410. The semiconductor layer 401 can be, for example, a p-type Si layer.

[0035] The charge inflow regions 430-1 and 430-2 are located on either side of the light-receiving region 410. The switches 420-1 and 420-2 are located between the light-receiving region 410 and the charge inflow regions 430-1 and 430-2.

[0036] Outside the charge inflow regions 430-1 and 430-2, charge reset regions 450-1 and 450-2 are provided. Between the charge inflow regions 430-1 and 430-2 and the charge reset regions 450-1 and 450-2, reset gates 440-1 and 440-2 are provided.

[0037] The structure of the detection element 400 is known from, for example, Japanese Patent Publication No. 2010-32425, so a detailed explanation of the specific shape of the layers and the dopants will be omitted.

[0038] The light-receiving region 410 is a MIS (metal-insulator-semiconductor) type semiconductor light-receiving region. Specifically, it has a semiconductor layer 410b formed on a semiconductor layer 401, a transparent insulating layer 402 placed on the upper surface of the semiconductor layer 410b, and a metal electrode 410a placed on the insulating layer 402. Interference light that passes through the transparent insulating layer 402 from around the metal electrode 410a and reaches the semiconductor layer 410b generates an electric charge in the semiconductor layer 410b.

[0039] For example, the semiconductor layer 410b may be p-type. As the transparent insulating layer 402, an oxide insulator such as SiO2 is used (MOS type). As is widely known, a semiconductor layer (buried channel) with a conductivity opposite to that of semiconductor layer 401 (e.g., n-type) may be placed between the semiconductor layer 401 and the insulating layer 402.

[0040] Switches 420-1 and 420-2 have an MIS structure, similar to the light-receiving region 410, and consist of a laminated structure of a semiconductor layer 420b, an insulating layer 402, and an electrode 420a. The insulating layer 402 of switches 420-1 and 420-2 is continuous with the insulating layer 402 of the light-receiving region 410. The semiconductor layer 420b of switches 420-1 and 420-2 is continuous with the semiconductor layer 410b of the light-receiving region 410.

[0041] The charge inflow regions 430-1 and 430-2 are semiconductor regions. For example, if the semiconductor layer 410b of the light-receiving region 410 is p-type, then it is made n-type with a high impurity concentration.

[0042] By selectively applying a voltage to one electrode 420a of switches 420-1 and 420-2, the conduction band of the energy band of the semiconductor layer 420b of switches 420-1 and 420-2 is tilted. As a result, the charge generated in the semiconductor layer 420b of the light-receiving region 410 flows into switch 420-1 or 420-2 to which the voltage is selectively applied, and then flows through switch 420-1 or 420-2 to the adjacent charge inflow region 430-1 or charge inflow region 430-2.

[0043] The reset gates 440-1 and 440-2 have an MIS structure, which consists of a semiconductor layer 440b, an insulating layer 402, and a reset electrode 440a stacked together.

[0044] The charge reset regions 450-1 and 450-2, and the charge inflow regions 430-1 and 430-2, are semiconductor regions, and like the switches 420-1 and 420-2, they are also semiconductor regions.

[0045] By selectively applying a voltage to one of the reset electrodes 440a of reset gates 440-1 and 440-2, the conduction band of the energy band of the semiconductor layer 440b of reset gates 440-1 and 440-2 is tilted. As a result, the charge that has flowed into the charge inflow region 430-1 or 430-2 flows into the reset gate 440-1 or 440-2 to which the voltage has been selectively applied, and flows into the adjacent charge reset region 450-1 or 450-2. Therefore, the charge inflow regions 430-1 and 430-2 become a state of charge outflow and are reset.

[0046] The charge inflow regions 430-1 and 430-2 are equipped with contact electrodes 430a. The contact electrodes 430a in the charge inflow regions 430-1 and 430-2 are each connected to the image generation unit 31.

[0047] <Image generation unit 31> The image generation unit 31 generates an image using the output of detection elements arranged on the two-dimensional detection surface of the photodetector 80 as pixel values.

[0048] In this embodiment, the image generation unit 31 includes a charge detector 310 for detecting the amount of charge accumulated in each charge inflow region 430-1, 430-2, and an A / D converter 320 for performing A / D conversion of the detection results. The charge detector 310 is connected to the charge inflow regions 430-1, 430-2.

[0049] Specifically, charge inlet region 430-1 is connected to charge detector 310-1 and A / D converter 320-1. Charge inlet region 430-2 is connected to charge detector 310-2 and A / D converter 320-2.

[0050] At the moment a voltage is applied to switch 420-1 (t=t1), the image generation unit 31 sets a pixel value for the corresponding pixel of the detection element 400 that corresponds to the amount of charge that has flowed into the charge inflow region 430-1. As a result, as shown in Figure 3(e), at time t=t1, an image is generated that represents the light intensity distribution of the two-dimensional detection surface of the photodetector 80 based on the amount of charge that has flowed into the charge inflow region 430-1.

[0051] On the other hand, at the time when a voltage is applied to the switch 420-2 (t=t2), the image generation unit 31 sets a pixel value for the corresponding pixel of the detection element 400 that corresponds to the amount of charge that has flowed into the charge inflow region 430-2. As a result, as shown in Figure 3(e), at time t=t2, an image is generated that represents the light intensity distribution of the two-dimensional detection surface of the photodetector 80 based on the amount of charge that has flowed into the charge inflow region 430-2.

[0052] The control unit 35 simultaneously switches switches 420-1 and 420-2 of all detection elements 400 constituting the photodetector 80 alternately at predetermined time intervals.

[0053] As a result, in order to detect the amount of charge in charge inflow regions 430-1 and 430-2, the images in Figure 3(d) can be sequentially generated at the switching timing of switches 420-1 and 420-2 of the detection element 400, without being affected by the time it takes to read out the charge. Therefore, the time-series image data t=t1~tN shown in Figure 3(e) can be generated at high speed.

[0054] The intensity of the interference light is maximized when the optical path length of the first light 101 matches the optical path length of the second light 102, which is modulated in the y-axis direction. Therefore, on the two-dimensional detection surface of the photodetector 80, the y-axis position where the light intensity is maximized for each x-axis position, as shown in Figure 3(d), indicates the position (depth, z-direction) on the surface of the measurement area 100a of the object to be measured 100.

[0055] Therefore, as shown in Figure 3(d), the z-axis direction irregularities of the measurement area 100a of the measurement target 100 can be detected as the position of the interference light emission lines in the y-axis direction from the output image of the two-dimensional detection surface of the photodetector 80.

[0056] The image generation unit 31 repeats the operation of acquiring the output image of the two-dimensional detection surface of the photodetector 80 described above at predetermined time intervals while moving the object to be measured 100 in the y-axis direction relative to the first light 101, as shown in Figure 3(a). In this way, the image generation unit 31 sequentially acquires two-dimensional images of the photodetector 80 at predetermined time intervals (t=t1~tN) while sequentially moving the measurement area 100a of the object to be measured 100 in the y-axis direction (Figure 3(e)).

[0057] In this embodiment, the photodetector 80 is configured such that multiple charge inflow regions 430-1 and 430-2 are provided for a single light-receiving region 410. By alternately reading out the charges, it is possible to quickly acquire N (t=t1~tN) two-dimensional images, the number required for surface shape measurement, at predetermined time intervals, without being affected by the charge readout time for detecting the amount of charge from the charge inflow regions 430-1 and 430-2.

[0058] Furthermore, the number of charge inflow regions 430-1 and 430-2 of the detection element 400 is not limited to two, but can be three or more. By increasing the number of charge inflow regions 430-1 and 430-2, it becomes possible to generate the number of image data N required for surface shape measurement even faster and sequentially.

[0059] <Surface shape detection unit 32> The surface shape detection unit 32 can detect the unevenness in the z-axis direction of a linear measurement area 100a parallel to the x-axis direction of the measurement target 100 by determining the position in the y-axis direction where the light intensity is maximum at each x-axis position in each image generated by the image generation unit 31. From a single image, the unevenness shape in the z-axis direction of a single linear measurement area 100a along the x-axis direction can be obtained.

[0060] The surface shape detection unit 32 obtains the three-dimensional shape of the surface (xy plane) of the measurement target 100 by determining the uneven shape of linear measurement areas 100a parallel to the x-axis direction from all images acquired while relatively moving the measurement target 100 in the y-axis direction, and arranging them in the y-axis direction.

[0061] Furthermore, as shown in Figure 3(a), the operation of moving the object to be measured 100 in the y-axis direction relative to the first light 101 can be achieved by moving the object to be measured 100, or by moving the irradiation position of the first light 101 on the object to be measured 100 in the y-axis direction. In the latter case, this can be achieved by oscillating an optical system that moves the first light 101 in the y-axis direction, such as the mirror 21. For this purpose, a motor for oscillating the optical system can be provided in the interference system 10.

[0062] <Display section 34> The display unit 34 displays the surface shape of the measurement target 100 determined by the surface shape detection unit 32.

[0063] <Control Unit 35> The control unit 35 synchronizes the timing of moving the object to be measured 100 in the y-axis direction relative to the first light 101, the timing of irradiating light from the light source 11, and the timing of switching the switches 420-1 and 420-2 of the photodetector 80 to detect interference light.

[0064] <Operation of the control unit 35, image generation unit 31, and photodetector 80> Here, the operation of the photodetector 80, the control unit 35, and the image generation unit 31 will be further explained using the flowcharts in Figures 3 to 6 and Figure 7.

[0065] (Step 701) First, the control unit 35 aligns the object to be measured 100 so that the first light 101 is irradiated onto a linear measurement area 100a parallel to the x-axis direction of the object to be measured 100, for example, as shown in Figure 3(a).

[0066] (Step 702) The control unit 35 emits light from the light source 11.

[0067] As a result, as shown in Figure 3(a), the first light 101 is irradiated onto the measurement area 100a of the object to be measured 100 and reflected by the surface of the measurement area 100a. The reflected light is amplified in the y-axis direction, further amplified in the y-axis direction by the focusing lenses 28 and 27, and irradiated onto the two-dimensional detection surface of the photodetector 80.

[0068] Of the light emitted from the light source 11, the light reflected by the beam splitter 24 has its optical path length modulated by the optical path length modulator 70 and is then irradiated as a second beam 102 onto the two-dimensional detection surface of the photodetector 80.

[0069] (Step 703) The light-receiving region 410 of each detection element 400 of the photodetector 80 receives the interference light of the first light 101 and the second light 102, and an electric charge is generated in the light-receiving region 410 (see Figure 4).

[0070] (Step 704) The control unit 35 applies a voltage to the switch 420-1 of each detection element 400. As a result, the charge in the light-receiving region 410 of each detection element 400 flows into the switch 420-1 and reaches the charge inflow region 430-1 (see Figure 4).

[0071] (Steps 705, 706) The charge detector 310-1 of the image generation unit 31 reads out the charge that has reached the charge inflow region 430-1 and detects the amount of charge (see Figure 4) (step 705).

[0072] The image generation unit 31 generates an image of the detection surface of the photodetector 80 by using the value corresponding to the amount of charge detected by the charge detector 310-1 as the pixel value of the pixel corresponding to the detection element 400 (step 706). As a result, an image representing the light intensity distribution of the detection surface of the photodetector 80 at t=t1 is generated as shown in Figure 3(e).

[0073] (Step 707) While the image generation unit 31 is performing step 705 above, the control unit 35 moves the measurement target 100 relative to itself so that the first light 101 is irradiated onto the next linear measurement area 100a of the measurement target 100.

[0074] (Step 708) The control unit 35 emits light from the light source 11.

[0075] As a result, the first light 101 is irradiated onto the next measurement site 100a and reflected by the surface of the measurement site 100a. The reflected light is irradiated onto the two-dimensional detection surface of the photodetector 80.

[0076] Meanwhile, the second light 102, whose optical path length has been modulated by the optical path length modulator 70, is irradiated onto the two-dimensional detection surface of the photodetector 80.

[0077] (Step 709) The light-receiving region 410 of each detection element 400 of the photodetector 80 receives the interference light of the first light 101 and the second light 102, and an electric charge is generated in the light-receiving region 410 (see Figure 5).

[0078] (Step 704) The control unit 35 applies a voltage to the switch 420-2 of each detection element 400. As a result, the charge in the light-receiving region 410 of each detection element 400 flows into the switch 420-2 and reaches the charge inflow region 430-2 (see Figure 5).

[0079] (Steps 711, 712) The charge detector 310-2 of the image generation unit 31 reads out the charge that has reached the charge inflow region 430-2 and detects the amount of charge (see Figure 4) (step 711).

[0080] The image generation unit 31 generates an image of the detection surface of the photodetector 80 by using the value corresponding to the amount of charge detected by the charge detector 310-2 as the pixel value of the pixel corresponding to the detection element 400 (step 712). As a result, an image representing the light intensity distribution of the detection surface of the photodetector 80 at t=t2 is generated as shown in Figure 3(e).

[0081] (Step 713) While the image generation unit 31 is performing step 711, the control unit 35 simultaneously determines whether the number of images generated so far in steps 706 and 712 has reached the number N required to measure the surface shape of the entire surface of the object to be measured 100.

[0082] If the number of generated images reaches the required number N, the process terminates and the generated images are passed to the surface shape detection unit 32.

[0083] If the number of generated images has not reached the required number N, proceed to step 714.

[0084] (Step 714) In step 714, the control unit 35 applies a voltage to both reset electrodes 440a of the reset gates 440-1 and 440-2 of each detection element 400. As a result, any remaining charge in the charge inflow regions 430-1 and 430-2 moves to the charge reset regions 450-1 and 450-2, and in each detection element 400, the charge in the light receiving region 410 flows into the switch 420-1, and the charge inflow regions 430-1 and 430-2 become empty and reset (see Figure 6).

[0085] The charge in charge reset regions 450-1 and 450-2 is discarded via the contact electrode 450a.

[0086] (Step 714) The control unit 35 sets n=n+1 and repeats steps 701 and below.

[0087] <Effects of the First Embodiment> As explained using the flowchart in Figure 7, the detection element 400 of this embodiment has two charge inflow regions 430-1 and 430-2 for one light-receiving region 410. Therefore, in parallel with the charge detector 310-1 reading the charge amount in the charge inflow region 430-1 in step 705, steps 707 to 710 can be executed to move the object to be measured 100 and perform the next light irradiation. Thus, light can be irradiated from the light source 11 without waiting for the time required for charge reading to elapse, and two-dimensional images of the number N (t=t1 to tN) required for surface shape measurement can be acquired at high speed.

[0088] Furthermore, the surface shape measuring device of this embodiment detects interference light obtained by interfering a first broadband white light with a second broadband light. When the optical path length difference is used as a variable, the intensity of the detected interference light becomes a correlated waveform. The width of the correlated waveform narrows inversely proportional to the bandwidth of the broadband light. Therefore, in this embodiment, the resolution can be increased by using broadband light. This allows detection as a narrow emission line along the y-axis direction (corresponding to the depth position in the z-axis direction) of the two-dimensional detection surface of the photodetector 80 (see paragraph 0005 of Japanese Patent No. 5740701). Therefore, interference light from the entire area of ​​the measurement target 100 can be detected simply by moving the measurement target 100 relatively in one direction.

[0089] In the above description, the photodetector 80 was described as having a structure in which the detection elements 400 are arranged in two dimensions, but the photodetector 80 is not limited to this structure. When the object to be measured 100 is moved relative to the light source 11, or when the photodetector 80 is moved relative to the interference light, the photodetector 80 may consist of only one detection element 400, or the photodetector 80 may have a structure in which multiple detection elements 400 are arranged in one dimension.

[0090] <<Second Embodiment>> As a second embodiment, a surface layer measurement and analysis system 200 will be described with reference to Figure 8.

[0091] The surface layer measurement and analysis system 200 comprises an interferometer 10 for measuring the shape of the surface layer of the object to be measured 100, an image generation unit 31, a display unit 34, a control unit 35, a front-end server 810, and a back-end server (information processing device) 820.

[0092] The configurations of the interference system 10 and the image generation unit 31 are the same as in the first embodiment, so their description will be omitted.

[0093] The image generation unit 31 and the control unit 35 are connected to the front-end server 810 via the network 800. The network 800 may be an internal or hospital network such as a LAN or intranet, or it may be a network using a public network such as the Internet. The back-end server 820 is connected to the front-end server 810. The image generation unit 31 uses the output of the photodetector 80 of the interferometer 10 to generate a light intensity distribution image of the two-dimensional detection surface of the photodetector 80 as shown in Figure 3(e), and transmits it to the front-end server 810 via the network 800.

[0094] Alternatively, the image generation unit 31 may directly transmit the output of the photodetector 80 to the front-end server 810. In this case, the image generation unit 31 functions as a readout unit that reads the amount of charge from the photodetector 80.

[0095] The front-end server 810 communicates with the network 800 to receive light intensity distribution images transmitted by the image generation unit 31 and output data from the photodetector 80. A display unit 834 is connected to the front-end server 810.

[0096] The backend server 820 comprises an analysis / determination unit 821 and a storage unit 824. The analysis / determination unit 821 includes a feature detection unit 822 and a trained model 823, and receives light intensity distribution images and output data from the photodetector 80 from the frontend server 810 to perform analysis and determination.

[0097] The feature detection unit 822 performs predetermined processing on the light intensity distribution image received from the image generation unit 31 and the output data of the photodetector 80. This allows for the detection of features in the intensity distribution image and the output data of the photodetector 80. The feature detection unit 822 may also have a function to generate a light intensity distribution image of the two-dimensional detection surface of the photodetector 80 from the output of the photodetector 80 received from the image generation unit 31.

[0098] For example, if the object to be measured 100 is the surface of a living organism, the trained model 823 can use a pre-trained cancer detection model that has been trained in advance using the light intensity distribution image received by the front-end server 810 from the image generation unit 31 and the output data of the photodetector 80 as input data, and the presence or absence of cancer in the object to be measured 100 as ground truth data. The model can use, for example, a neural network.

[0099] Furthermore, if the object to be measured 100 is a semiconductor wafer, a glass substrate, or a mounted substrate, the trained model 823 can use a pre-trained model for defect detection that has been trained in advance using the light intensity distribution image received by the front-end server 810 from the image generation unit 31 and the output data of the photodetector 80 as input data, and the crystal defects, presence or absence of scratches, and the judgment results of whether the object to be measured 100 is good or defective as ground truth data.

[0100] By using such a pre-trained model for defect detection, it is possible to determine the presence or absence of crystal defects in semiconductor wafers and scratches that occurred during processing / transportation (grasping). Furthermore, it is possible to determine the presence or absence of scratches and whether a product is good or defective in glass substrates used in solar panels and organic EL displays, as well as in mounted substrates.

[0101] The analysis and judgment unit 821 inputs the light intensity distribution image of the measurement target 100 received from the image generation unit 31 and the output data of the photodetector 80 into the trained model 823, thereby obtaining output data indicating the presence or absence of cancer, crystal defects or scratches, and whether the measurement target 100 is a good or bad product. The judgment result is displayed on the display unit 834 via the front-end server 810. Alternatively, if the person inspecting the measurement target 100 with the interferometry system 10 wishes, the result can be passed to the control unit 35 via the front-end server 810 and the network 800, and the judgment result can be displayed on the display unit 34 under the control of the control unit 35. When displaying the judgment result on the display unit 834 or the display unit 34, information to identify the measurement target for which the judgment result was obtained (such as the time the measurement target was measured by the interferometry system 10, the ID or product number of the measurement target, and the measurement site and location information of the measurement target for which the judgment result was obtained) may be extracted from the light intensity distribution image of the measurement target 100 and the output data of the photodetector 80 and displayed together with the judgment result.

[0102] If permitted by the inspector, the light intensity distribution image of the object to be measured 100, received from the image generation unit 31 via the front-end server 810, the output data from the photodetector 80, and the output data from the trained model 823 are stored in the storage unit 824.

[0103] Furthermore, the surface layer measurement and analysis system 200 may include a surface wave generation unit 41 that generates surface waves on the surface of the object to be measured 100. The interferometer 10 measures the surface waves generated by the surface wave generation unit 41 on the surface of the object to be measured 100.

[0104] This section will provide a detailed explanation of an example in which 100 subjects are living organisms and cancer is being diagnosed.

[0105] The measurement target 100 is the epithelium (surface layer) covering the surface of the human or animal body, as well as the inner surfaces of body cavities and organs. The surface layer measurement and analysis system 200 determines the presence or absence of carcinoma in situ by measuring the distribution of surface layer characteristics.

[0106] <Surface wave generation unit 41> If the surface layer measurement and analysis system 200 includes a surface wave generation unit 41, the surface wave generation unit 41 generates vibrations in the measurement target 100 by, for example, irradiating the measurement target 100 with light or sound waves, or by contacting the measurement target 100. This generates and propagates surface waves in the surface layer of the measurement target 100. The frequency, amplitude, and waveform of the surface waves generated by the surface wave generation unit 41 in the surface layer of the measurement target 100 are set by the control unit 35. The waveform of the surface waves can be any waveform, such as a sine wave or a square wave.

[0107] If the depth direction of the object being measured 100 is defined as the z-direction, then at a certain time t, the surface of the object being measured 100 is undulating in the z-direction due to surface waves, resulting in unevenness.

[0108] Furthermore, if the measurement target 100 is epithelium (surface layer) and surface waves are generated by the pulsations of the heart and blood vessels or by respiratory movements, and there is no need for the surface wave generating unit 41 to provide light, sound waves or vibrations, then it is also possible to omit the surface wave generating unit 41.

[0109] <Interference System 10> The configuration of the interference system 10 is the same as that of the interference system 10 in the first embodiment.

[0110] <Image generation unit 31> The image generation unit 31 is the same as in the first embodiment, but unlike the first embodiment, it generates an image of the detection surface of the photodetector 80, where the output of the detection element 400 is used as the pixel value, in a predetermined number of images at predetermined time intervals (t=t1, t2, t3...t) as time t progresses, as shown in Figure 3(e), without moving the measurement area 100a of the object to be measured 100 that is irradiated with the first light 101.

[0111] Once the image generation unit 31 has generated a predetermined number of images, it moves the measurement area 100a, which is irradiated with the first light 101, by a predetermined distance in the y direction, and at that position, it generates a predetermined number of images at predetermined time intervals (t=t1, t2, t3...t) as time t progresses. This is repeated until the entire measurement target 100 is represented as the measurement area 100a.

[0112] In this embodiment, since the detection element 400 of the photodetector 80 is an element with the structure shown in Figure 4, as described in the first embodiment, images can be obtained at high speed.

[0113] <Feature detection unit 822> The feature detection unit 822 calculates the features of the surface layer of the object to be measured 100. The features of the surface layer include the thickness of the surface layer, the distribution of materials constituting the surface layer, the distribution of hardness (or elastic constant) of the surface layer, and the temperature distribution of the surface layer. In this embodiment, the feature detection unit 822 calculates the distribution of the thickness of the surface layer.

[0114] The feature detection unit 822 detects the peak position of the surface wave from each of the images of the detection surface of the photodetector 80 (Figure 3(e)) generated by the image generation unit 31 at predetermined time intervals for the same measurement area 100a. The feature detection unit 822 then plots the relationship between time and peak position, for example, as shown in Figure 9. From this, the feature detection unit 822 determines the time change (i.e., velocity c) of the peak position of the surface wave at that measurement area 100a.

[0115] The feature detection unit 822 calculates the surface layer characteristics of the surface layer from the following equation (1). Here, the thickness of the surface layer is calculated as the surface layer characteristic.

[0116] c = √(gh) ... (1) However, c is the velocity at the peak position of the surface wave, g is the acceleration due to gravity, and h is the thickness of the surface layer.

[0117] This allows the feature detection unit 822 to calculate the thickness distribution of the surface layer of a predetermined measurement area 100a parallel to the x-axis direction.

[0118] The feature detection unit 822 repeats the above calculation for all measurement areas 100a of the object to be measured 100, and measures the thickness distribution of the surface layer across the entire surface of the object to be measured 100.

[0119] <Analysis / judgment section 821> The analysis and determination unit 821 determines the possibility of cancer development based on the distribution of surface layer characteristics (in this case, thickness) obtained by the feature detection unit 822. Figure 10 shows a cross-section of an example of carcinoma in situ. Carcinoma in situ does not appear on the surface of the epithelium, but causes structural disturbance at the boundary between the epithelial layer and the subcutaneous layer. A characteristic of carcinoma in situ is that as it progresses, the structural disturbance at the boundary increases, and the thickness of the epithelium decreases.

[0120] Therefore, numerous samples of carcinoma in situ and normal epithelial samples are prepared, and the depth distribution of the surface layer is measured using the feature detection unit 822 of this embodiment. The measurement results are input as training data into a pre-trained model 823 such as a neural network and trained. The trained model 823 is then mounted in the analysis and judgment unit 821.

[0121] This makes it possible to determine the possibility of carcinoma in situ by inputting the surface layer characteristic distribution measured by the feature detection unit 822 for the actual measurement target 100 into the analysis and determination unit 821.

[0122] Furthermore, it is possible to configure the analysis and determination unit 821 without using the pre-trained model 823. For example, one or more features such as the ratio of the thickness of the normal region to the thickness of the carcinoma in situ region, the slope of the thickness change, and the size of the carcinoma in situ region are calculated in advance based on the thickness distribution of the surface layer measured for a sample of carcinoma in situ. The analysis and determination unit 821 can determine whether the thickness distribution obtained by the feature detection unit 822 for the actual measurement target 100 matches one or more of the pre-calculated features, thereby determining whether there is a suspicion of carcinoma in situ.

[0123] <Display section 34, 834> The display units 34 and 834 display the surface layer characteristic distribution of the surface layer of the measurement target 100, determined by the feature detection unit 822, and the judgment result of the analysis and judgment unit 821, and inform the user.

[0124] <Control Unit 35> If the analysis and determination unit 821 determines that there is a high probability of cancer, the control unit 35 may change the frequency, amplitude, and waveform of the surface wave generated by the surface wave generation unit 41 on the surface layer of the measurement target 100 within a predetermined range, and perform cancer determination again by the analysis and determination unit 821. By repeating this process, the accuracy of the determination can be improved.

[0125] <Effects of the second embodiment> According to the second embodiment, not only can surface wave irregularities in the surface layer of the object to be measured 100 be detected with a resolution of several μm in the z direction (depth direction), but the thickness of a thin epithelium of about 10 μm can be measured non-contact and with high precision. Therefore, for example, cancer can be diagnosed and a suspicion of cancer can be determined. Thus, by using the surface shape measuring device of this embodiment, early detection of carcinoma in situ becomes possible.

[0126] In the second embodiment described above, the front-end server 810 and the image generation unit 31 and control unit 35 are connected via the network 800. However, due to communication line and security issues, it may be difficult to use public networks such as the internet. In this case, it is also possible to place a fog computing server between the image generation unit 31 and control unit 35 and the network 800.

[0127] <Example 1> In the first and second embodiments, the light source 11 was configured to emit broadband light, but the broadband light may be comb light in which a broadband spectrum is divided in a comb-like manner on multiple frequency axes, as shown in Figure 11. Each of the narrow spectra divided in a comb-like manner may be emitted simultaneously or sequentially.

[0128] By using comb light, the depth direction (z-axis direction) of the object to be measured 100 can be divided into multiple detection ranges equal to the number of interference orders, and these can be superimposed and displayed on the same two-dimensional detection surface of the photodetector 80. In particular, if we focus on the strong reflection or scattering light from the surface, even if the surface position is outside the detection range of one interference order, it will fall within the detection range of another interference order and can be detected. In other words, it becomes possible to detect interference light over a wide detection range at different positions in the y-axis direction on the detection surface of the photodetector 80.

[0129] <Modification 2> In the first and second embodiments, the interferometer shown in Figure 2 was used as the interferometer system 10, but other interferometers can also be used. For example, as shown in Figure 12, an interferometer that detects interference by interfering two lights 151 and 152 with different time delay amounts can be used (see Japanese Patent Application Publication No. 2023-137279).

[0130] In the interferometer of Figure 12, the first light 151 is broadband light repeatedly superimposed with a first time delay, with a widened beam diameter, irradiating the entire measurement range of the object to be measured 100, and being reflected by the surface of the measurement range of the object to be measured 100. Alternatively, if the wavelength of the first light 151 is such that it can be incident into the object to be measured 100, it is reflected or scattered inside the object to be measured 100. The second light 152 is broadband light repeatedly superimposed with a second time delay different from the first time delay. The interference light of the reflected (scattered) light of the first light 151 and the second light 152 is detected by the photodetector 80. Based on the detection result of the photodetector 80, the delay time of the first light 151 by the object to be measured 100 is detected by the time measurement unit 132, thereby detecting the unevenness of the two-dimensional measurement range of the object to be measured 100 or the structure of internal reflectors or scatterers. The photodetector 80 has the same configuration as the photodetector 80 described in the first embodiment, and has a configuration in which the detection elements 400 are arranged in two dimensions.

[0131] Specifically, as shown in Figure 12, the interference system 10 of the modified example 2 comprises a light source 110, a lens system 141, a beam splitter 142, a first optical resonator 121, a beam splitter 147, a mirror 143, a second optical resonator 122, a beam splitter 145, a photodetector 80, and a time measurement unit 132.

[0132] The interference system 10 in Figure 12 detects the interference light between the first light 151 emitted from the first optical resonator 121 and the second light 152 emitted from the second optical resonator 122 using a photodetector 80. By detecting the delay of the interference light, the delay time that occurs in the first light 151 reflected from the object to be measured 100 is measured. Based on the delay time of the first light 151, the optical path length of the light reflected from the object to be measured 100 can be calculated, and surface layer characteristics such as the thickness of the surface layer of the object to be measured 100 can be derived.

[0133] Light source 110 is a broadband light source that emits low-coherence light with a broad spectrum. As an example, light source 110 may be an SLD (Super Luminescent Diode) light source. An SLD light source can emit light that has a broad spectrum like an LED (Light Emitting Diode) and high brightness like an LD (Laser Diode). As another example, light source 110 may be an SC (Super Continuum) light source that generates broadband light.

[0134] The lens system 141 is an optical system that shapes the light emitted from the light source 110 and guides it to the beam splitter 142. The beam splitter 142 splits the collimated light incident from the lens system 141 into two mutually orthogonal beams of light. One beam split by the beam splitter 142 is incident on the first optical resonator 121, and the other beam split by the beam splitter 142 is reflected by the mirror 143 and then incident on the second optical resonator 122.

[0135] The first optical resonator 121 is an optical element that resonates incident light, thereby repeatedly superimposing incident broadband light with a first time delay. The second optical resonator 122 is an optical element that resonates incident light, thereby repeatedly superimposing incident broadband light with a second time delay different from the first time delay. The first optical resonator 121 and the second optical resonator 122 are, for example, Fabry-Perot etalons. The distances between etalon pairs in the first optical resonator 121 and the second optical resonator 122 are, for example, different from each other.

[0136] A Fabry-Perrault etalon includes a pair of translucent mirrors (etalon pairs) positioned opposite each other and parallel to one another. The Fabry-Perrault etalon transmits only light whose half-wavelength is an integer multiple of the light reflected between the etalon pairs, due to the interference of the light reflected multiple times between the etalon pairs. Therefore, the Fabry-Perrault etalon emits light with a wavelength period determined by the optical path length between the etalon pairs. Furthermore, since the Fabry-Perrault etalon emits light to the outside of the etalon pairs each time light reflected multiple times inside the etalon pairs travels back and forth between them, the above light is superimposed and emitted with a time delay corresponding to the time it takes for the light to travel back and forth between the etalon pairs.

[0137] As a result, the Fabry-Perot etalons of the first optical resonator 121 and the second optical resonator 122 output the first light 151 and the second light 152, respectively, which are formed by repeatedly superimposing light having a wavelength period determined by the optical path length between the etalon pair, with a time delay corresponding to the round-trip time of the light between the etalon pair, as shown in the waveforms in Figures 13(a) and (b).

[0138] The beam splitter 147 transmits the first light 151 emitted from the first optical resonator 121, irradiates the object to be measured 100, and reflects the first light 151 reflected by the object to be measured 100.

[0139] The beam splitter 145 interferes with the first light 151 reflected by the beam splitter 147 and the second light 152 emitted from the second optical resonator 122 by combining them. The photodetector 80 detects the interference light of the first light 151 and the second light 152 by photoelectric conversion.

[0140] As shown in Figure 13(c), the waveform of the interference light between the first light 151, which is broadband light repeatedly superimposed with a first time delay, and the second light 152, which is broadband light repeatedly superimposed with a second time delay, becomes a beat created by the interference of light of different frequencies. Therefore, the photodetector 80 detects the beat as an electrical signal (Figure 13(d)). Since the photodetector 80 is configured to include a detection element 400, the number of charge inflow regions 430-1 and 430-2 of the detection element 400 is two or more. Therefore, charges can be read alternately from the charge inflow regions 430-1 and 430-2, and the beat can be read out as an electrical signal at high speed.

[0141] The time measurement unit 132 measures the delay time of the first light 151 reflected by the object to be measured 100 based on the light detection result by the photodetector 80. For example, the time measurement unit 132 includes, for example, a time-to-digital converter (TDC).

[0142] In the interference system 10 configured as shown in Figure 12, the light emitted from the first optical resonator 121 is delayed by reflection from the object to be measured 100, which changes the shape or arrival timing of the beats generated by interference. Therefore, the interference system 10 can calculate the thickness of the surface layer of the object to be measured 100 by measuring the delay in the arrival timing of the waveform of the sampled value (also called an interferogram) detected by the photodetector 80 using the time measurement unit 132. Alternatively, the interference system 10 may derive the delay in the arrival timing of the sampled waveform due to the object to be measured 100 from the slope of the phase difference spectrum derived by performing a Fourier transform on the waveform of the sampled value.

[0143] As explained above, the interference system 10 of the modified example 2 can derive the delay time of light due to the object to be measured 100 by the timing of the arrival of the beat resulting from the interference between the light emitted from the first optical resonator 121 and the light emitted from the second optical resonator 122, and calculate the unevenness of the object to be measured 100.

[0144] <Variation 3> As a third modification, a dual-comb spectroscopic interferometer is used as the interferometer system 10 of the first and second embodiments, using a first-comb light generator 511-1 and a second-comb light generator 511-2 as light sources, as shown in Figure 14.

[0145] The first comb light generator 511-1 emits first comb light 501, which includes multiple lights with center frequencies shifted by Δf1, as shown in the spectrum in Figure 15(a). The multiple lights with center frequencies shifted by Δf1 may be emitted simultaneously or sequentially in time series. For example, the first comb light 501 includes multiple longitudinal modes of light with frequencies shifted by Δf1, centered around a light of mode N=0 with frequency f1c.

[0146] The second comb light generator 511-2 emits second comb light 502, which includes multiple lights with center frequencies shifted by Δf2, as shown in the spectrum in Figure 15(b). The multiple lights with center frequencies shifted by Δf2 may be emitted simultaneously or in a time series. For example, the second comb light 502 includes multiple longitudinal modes of light with frequencies shifted by Δf2 (where Δf2 ≈ Δf1) around a light of mode N=0 with frequency f2c.

[0147] The configuration of the first and second comb light generators 511-1 and 511-2 can be anything, but for example, a comb light generator using a Fabry-Perot electro-optic modulator (see Journal of the Japan Society for Laser Sensing, Vol. 3, No. 2 (2022)) can be used.

[0148] The interference system 10 in Figure 14 includes a beam splitter 513 positioned on the optical axis of the first comb light generator 511-1 and a beam splitter 515 positioned on the optical axis of the second comb light generator 511-2. The object to be measured 100 is positioned on the optical axis of the first comb light generator 511-1.

[0149] A photodetector 80 is positioned at the location where the light reflected by the beam splitters 513 and 515 reaches. The photodetector 80 has a structure in which the detection elements 400 are arranged in two dimensions, similar to the photodetector 80 of the first embodiment.

[0150] The first comb light 501 emitted from the first comb light generator 511-1 passes through the beam splitter 513, irradiates the entire measurement range of the object to be measured 100, and is reflected by the surface of the measurement range of the object to be measured 100. Alternatively, if the first light 151 has a wavelength that can be incident into the object to be measured 100, it is reflected or scattered inside the object to be measured 100. The first comb light 501 reflected (scattered) by the object to be measured 100 is reflected by the beam splitter 513, passes through the beam splitter 515, and reaches the photodetector 80. At this time, the second comb light 502 emitted from the second comb light generator 511-2 is reflected by the beam splitter 515 and reaches the photodetector 80. Therefore, the photodetector 80 detects the interference light resulting from the interference of the first comb light 501 and the second comb light 502.

[0151] The first comb light 501 and the second comb light 502 have a difference in the frequency interval of the mode light by Δf1-Δf2, resulting in interference light in which peaks repeatedly appear with a predetermined period T=1 / (Δf1-Δf2). At this time, the timing of the appearance of the interference light peaks shifts depending on the change in optical path length caused by the surface irregularities of the object being measured 100.

[0152] Therefore, by calculating the distance (optical path length) from the output of each detection element 400 arranged in two dimensions on the photodetector 80 to the object to be measured 100, the irregularities of the two-dimensional measurement range of the object to be measured 100 or the structure of internal reflectors or scatterers can be detected. By obtaining an output from the two-dimensionally arranged detection elements 400 every Δf1 second, the three-dimensional structure of the object to be measured 100 can be obtained.

[0153] In Modification 3, the photodetector 80 is equipped with the detection element 400 of the first embodiment, so the number of charge inflow regions 430-1 and 430-2 of the detection element 400 is two or more. Therefore, charges can be read alternately from the charge inflow regions 430-1 and 430-2 and read out at high speed as electrical signals of interference light. Thus, it is possible to measure the surface irregularities of the object to be measured 100 with high precision and at high speed.

[0154] The detection elements 400 included in the photodetector 80 are not limited to a two-dimensional arrangement; they may be single or one-dimensional. In that case, a one-dimensional or two-dimensional image of the surface of the object to be measured 100 can be generated by relatively moving the object to be measured 100 in a direction perpendicular to the optical axis of the first comb light 501 and connecting the calculated distances in a time series.

[0155] Furthermore, in the interference system of Modification 3, a second photodetector can be placed to measure the reference interference light. In this case, the second photodetector is positioned to detect the interference light of the first comb light 501 and the second comb light reflected from a predetermined reference plane. This allows for the detection of the timing at which the peak of the interference light of the reference interference appears and, by comparing it with the detection result of the photodetector 80, the position of the object to be measured 100 relative to the reference plane can be calculated. [Explanation of Symbols]

[0156] 1. Surface shape measuring device 10 Interferential Systems 11 Light source 20 Optical system 21 Mirror 22 Neutral Density Filters 23 Beam Expander 24 Beam Splitter 25 Cylindrical Lens 26 Focusing lens 27. Focusing lens 28 Focusing lens 31 Image generation unit 32 Surface shape detection unit 34 Display section 35 Control Unit 41 Surface wave generation unit 70 Optical path length modulator 80 Photodetectors 91 Optical axis 92 Optical axis 100 items to measure 100a Measurement site 101 The First Light 102 The Second Light 110 Light source 121 First Optical Resonator 122 Second Optical Resonator 132 Time measurement section 141 Lens System 142 Beam Splitter 143 Miller 145 Beam Splitter 147 Beam Splitter 151 The First Light 152 The Second Light 200 Surface Layer Measurement and Analysis System 310-1 Charge detector 310-2 Charge detector 320-1 A / D Converter 320-2 A / D Converter 400 detection elements 401 Semiconductor layer 402 Insulating layer 410 Light receiving area 410a metal electrode 410b semiconductor layer 420-1 Switch 420-2 Switch 420a electrode 420b semiconductor layer 430-1 Charge inflow region 430-2 Charge inflow region 430a Contact Electrode 440-1 Reset Gate 440-2 Reset Gate 440a Reset electrode 440b semiconductor layer 450-1 Charge Reset Region 450-2 Charge Reset Region 450a Contact Electrode 460 Shield 501 First Com Hikari 502 Dai-2 Com Hikari 511-1 First Comb Light Generator 511-2 Second Comb Light Generator 513 Beam Splitter 515 Beam Splitter 800 Network 810 Frontend Server 820 Backend Server (Information Processing Unit) 821 Analysis / judgment section 822 Feature detection unit 823 Pre-trained models 824 Storage section

Claims

1. A light source unit, a photodetector that detects interference light obtained by interfering a first light emitted from the light source unit and reflected by the object to be measured with a second light, The system includes an image generation unit that generates an image using the output of the photodetector as pixel values, The photodetector includes a light-receiving region that receives the interference light and generates an electric charge, a plurality of inflow regions for allowing the charge generated in the light-receiving region to flow into, and a switch that sequentially switches the charge generated in the light-receiving region into the plurality of inflow regions at predetermined time intervals. The shape measuring device is characterized in that the image generation unit generates the image using pixel values ​​corresponding to the amount of charge that flows into the inflow region within a predetermined time period switched by the switch of the photodetector, thereby sequentially generating the images at predetermined time intervals.

2. A shape measuring device according to claim 1, further comprising a control unit that controls the light source unit, the image generation unit, and the switch, The shape measuring device is characterized in that, while the image generation unit detects the amount of charge flowing into one of the plurality of inflow regions and generates the image, the control unit simultaneously generates light from the light source unit, causes the interference light to be received by the light receiving region, switches the switch, and causes the charge generated by the light receiving region to flow into another of the plurality of inflow regions.

3. A shape measuring device according to claim 1, The aforementioned light source unit is A light source that emits broadband light, An optical path length modulator generates modulated light by changing the optical path length of the broadband light according to its one-dimensional position on a beam cross-section perpendicular to the propagation direction, An optical system is used to interfere with the broadband light and the modulated light emitted from the light source, with one of them being used as the first light to irradiate the object to be measured and reflect it, and the other being used as the second light, and the second light and the reflected light from the object to be measured of the first light. A shape measuring device further characterized by having the following.

4. A shape measuring device according to claim 1, The photodetector includes a plurality of detection elements, the detection elements are arranged in two dimensions, and constitute a two-dimensional detection surface. The light source unit comprises a light source that emits broadband light, an optical path length modulator, and an optical system. The optical system forms a linear beam with a cross-sectional shape elongated in a first direction from a portion of the light beam emitted from the light source, irradiates the object to be measured with the linear beam as the first light, and irradiates the optical path length modulator with the other portion of the light beam. The optical path length modulator generates a second light by changing the optical path length of the other portion of the light beam according to a predetermined one-dimensional position on the beam cross-section. The optical system causes the optical system to detect interference light between the reflected light of the first light from the object being measured and the second light from the first light, which has a beam cross-section that is elongated in the first direction, onto the two-dimensional detection surface of the photodetector by spreading the cross-section of the beam in a second direction perpendicular to the first direction, and by causing the reflected light of the first light from the object being measured and the second light from the optical path length modulator to be incident onto the two-dimensional detection surface of the photodetector so that the one-dimensional direction in which the optical path length has been changed coincides with the second direction of the first light, thereby causing the optical system to detect interference light between the reflected light of the first light from the object being measured and the second light from the first light on the two-dimensional detection surface of the photodetector. A shape measuring device characterized by the following features.

5. A shape measuring device according to claim 1, It further includes a time measurement unit, The first light includes broadband light that is repeatedly superimposed with a first time delay, The second light includes broadband light that is repeatedly superimposed with a second time delay different from the first time delay, The time measurement unit measures the delay time of the first light from the object to be measured based on the detection result from the photodetector. A shape measuring device characterized by the following features.

6. A shape measuring device according to claim 1, The light source unit includes a first comb light generator and a second comb light generator. The first comb light generator emits the first light, and the first light includes a plurality of lights whose center frequencies are shifted by Δf1 each. The second comb light generator emits the second light, and the second light includes a plurality of lights whose center frequencies are shifted by Δf2. The photodetector detects interference light obtained by interfering the first light reflected from the object being measured with the second light. A shape measuring device characterized by the following features.

7. A shape measuring device according to claim 4, The shape measuring device according to claim 2, characterized in that the optical system includes a focusing optical system that divides the broadband light into a plurality of light beams between the light source and the object to be measured, focuses each of the divided plurality of light beams, and irradiates them onto the object to be measured in a line.

8. A shape measuring device according to claim 4, The shape measuring device according to claim 2, characterized in that the optical path length modulator changes the optical path length by reflecting the light with the reflection distance changed in a step-like manner according to the one-dimensional position on the cross-section of the broadband light.

9. A light source unit, and a photodetector arranged in one or two dimensions that detects interference light obtained by interfering a first light emitted from the light source unit and reflected by the object to be measured with a second light, A reading unit that reads out the output of the photodetector, A control unit that controls the reading unit, The reading unit and the control unit are connected to a server via a network, The photodetector includes a light-receiving region that receives the interference light and generates an electric charge, a plurality of inflow regions for allowing the charge generated in the light-receiving region to flow into, and a switch that sequentially switches the charge generated in the light-receiving region into the plurality of inflow regions at predetermined time intervals. The reading unit detects the amount of charge that has flowed into the inflow area within the predetermined time period switched by the switch of the photodetector, and transmits the amount of charge, or an image generated by using the detected amount of charge as a pixel value, to the server via the network. The surface layer measurement and analysis system is characterized in that the server performs predetermined processing on the amount of charge or the image received from the reading unit, and transmits the processing results to the control unit via the network.

10. A surface layer measurement and analysis system according to claim 9, wherein the server is equipped with a trained model, the server inputs the amount of charge or the image received via the network to the trained model, and transmits the output of the trained model as a determination result to the control unit via the network.

11. A method for acquiring data of a measurement target using a shape measuring device having a light source unit, a one-dimensional or two-dimensionally arranged photodetector that detects interference light obtained by interfering a first light emitted from the light source unit and reflected by the measurement target with a second light, and an image generation unit that generates an image using the output of the photodetector as pixel values, The photodetector includes a light-receiving region that receives the interference light and generates an electric charge, a plurality of inflow regions for allowing the charge generated in the light-receiving region to flow into, and a switch that sequentially switches the charge generated in the light-receiving region into the plurality of inflow regions at predetermined time intervals. Light is generated from the light source, the interference light is irradiated onto the light-receiving region of the photodetector, and an electric charge is generated in the light-receiving region. The steps include switching the switch of the photodetector to allow the charge generated in the light-receiving region to flow into one of the plurality of inflow regions, The steps include detecting the amount of charge in the inflow region into which the charge has flowed, while simultaneously generating light from the light source unit, irradiating the light-receiving region of the photodetector with the interference light, and generating charge in the light-receiving region, The steps include switching the switch of the photodetector to allow the charge generated in the light-receiving region to flow into another of the plurality of inflow regions, The step includes detecting the amount of charge in another inflow region into which the charge has flowed, while simultaneously generating light from the light source unit, irradiating the light-receiving region of the photodetector with the interference light, and generating a charge in the light-receiving region, A method for acquiring data of a target to be measured, characterized by repeatedly detecting the amount of charge generated in the light-receiving area at predetermined time intervals by repeating all of the above steps.

12. A method for acquiring data of a measurement target as described in claim 11, The steps include transmitting the charge quantity data acquired sequentially at predetermined time intervals, or image data generated from the charge quantity data, to a server via a network, The steps include: performing predetermined processing on the data of the amount of charge or the image data received by the server; A method for acquiring data of a target to be measured, further comprising the step of transmitting the results of the above processing from the server to the shape measuring device.

13. A method for acquiring data to be measured according to claim 12, wherein the server includes a trained model, A method for acquiring data to be measured, characterized in that the step of performing predetermined processing on the server is to input the charge quantity data, or the image data, or feature data obtained from the charge quantity data or the image data, into the trained model, and to obtain the output from the trained model as the result of the processing.

14. A method for acquiring data of a measurement target according to claim 13, wherein the measurement target is a living organism, A method for acquiring data of a measurement target, characterized in that the trained model determines the possibility that the measurement target is cancerous based on the charge quantity data, the image data, or feature data obtained from the charge quantity data or the image data.

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