JP7055523B1 - Optical measurement system, optical measurement method and measurement program - Google Patents

Abstract

An optical measurement system for measuring a film thickness, which is the thickness of a layer contained in a sample, is provided. The optical measurement system is optically connected to an arbitrary light source that generates measurement light, a light receiving unit that receives reflected light or transmitted light generated by irradiating the sample with measurement light as observation light, and an arbitrary light source and light receiving unit. A probe that can be placed at a position, a film thickness calculation unit that calculates the sample film thickness from the spectral reflectance or spectral transmission rate calculated based on the detection result by the light receiving unit, and a film thickness calculated by the film thickness calculation unit. Includes a reliability calculation unit that calculates the measurement reliability, which indicates how appropriately the measurement is.

Description

The present invention relates to a portable optical measurement system, an optical measurement method in the optical measurement system, and a measurement program for realizing the optical measurement method.

There is a demand to control the film thickness of manufactured products. In response to such a requirement, a measuring device and a measuring method for measuring a film thickness are known.

As an example, a measuring device using electromagnetic induction or eddy current is known. For example, Japanese Patent Application Laid-Open No. 07-332916 (Patent Document 1) discloses a film thickness meter that accurately measures the film thickness of a magnetic film using a current having a practical frequency. Further, Japanese Patent Application Laid-Open No. 06-317401 (Patent Document 2) describes a handheld type combined coating thickness capable of measuring the thicknesses of both non-iron coating on an iron substrate and non-conductive coating on a conductive non-iron substrate. Disclose the gauge.

Further, a measuring device using ultrasonic waves is also known. For example, Japanese Patent Application Laid-Open No. 07-167639 (Patent Document 3) is a thickness gauge provided with a converter that radiates an ultrasonic wave in a coating, receives the ultrasonic wave, and generates a conversion signal proportional to the ultrasonic signal. To disclose.

Further, a measuring device using light is also known. For example, International Publication No. 2010/013429 (Patent Document 4) discloses a film thickness measuring device for determining the film thickness of a film formed on a substrate surface by measuring the spectral reflectance.

Among the measuring devices and measuring methods for measuring these film thicknesses, the measuring accuracy of the device using electromagnetic induction or eddy current and the device using ultrasonic waves is inferior to the device using light. .. Therefore, it is preferable to use a measuring device using light for measuring the film thickness.

Japanese Unexamined Patent Publication No. 07-332916 Japanese Unexamined Patent Publication No. 06-317401 Japanese Unexamined Patent Publication No. 07-167639 International Publication 2010/013429

In the film thickness measuring device disclosed in Patent Document 4 described above, the light from the light source is vertically incident on the measurement target surface provided with the film, and the light reflected on the measurement target surface is incident on the spectroscopic sensor. It is configured. In order to allow the light from the light source to enter perpendicularly to the surface to be measured, a stationary configuration is assumed.

In order to perform quality control of products, for example, there is a demand for easy measurement at an arbitrary position on a production line. There is also a demand for easy measurement of a sample having a curved surface or a sample having a complicated shape. However, the prior art described above does not provide a solution that meets such requirements.

One object of the present invention is to provide an optical measurement system or the like that can appropriately measure the film thickness of a sample.

According to an aspect of the present invention, there is provided an optical measurement system for measuring a film thickness, which is the thickness of a layer contained in a sample. The optical measurement system is optically connected to an arbitrary light source that generates measurement light, a light receiving unit that receives reflected light or transmitted light generated by irradiating the sample with measurement light as observation light, and an arbitrary light source and light receiving unit. A probe that can be placed at a position, a film thickness calculation unit that calculates the sample film thickness from the spectral reflectance or spectral transmission rate calculated based on the detection result by the light receiving unit, and a film thickness calculated by the film thickness calculation unit. Includes a reliability calculation unit that calculates the measurement reliability, which indicates how appropriately the measurement is.

The optical measurement system may further include an output unit that notifies the measurement reliability calculated by the reliability calculation unit.

The output unit may generate a notification sound corresponding to the high measurement reliability.
The output unit may output at least one of light and an image indicating measurement reliability.

The optical measurement system may further include a determination unit that determines the film thickness at a time when the measurement reliability satisfies a predetermined condition as a measurement result.

The film thickness calculation unit may calculate the film thickness of the sample based on the peak appearing in the spectrum calculated by frequency-converting the spectral reflectance or the spectral transmittance. The reliability calculation unit may calculate the measurement reliability based on the magnitude of the peak appearing in the spectrum.

The film thickness calculation unit fits the parameters of the model indicating the spectral reflectance or the spectral transmittance so as to match the spectral reflectance or the spectral transmittance calculated based on the observed light, thereby forming the thickness of the sample. May be calculated. The reliability calculation unit may calculate the measurement reliability based on the fitting result determined by the film thickness calculation unit.

The probe may be configured to be modifiable to different types depending on the sample.
At least the film thickness calculation unit and the reliability calculation unit may be mounted in a housing independent of the probe.

At least the probe, the light source and the light receiving part may be mounted in a single housing.
According to another aspect of the present invention, there is provided an optical measuring method for measuring a film thickness, which is the thickness of a layer contained in a sample. The optical measurement method consists of a step of irradiating the sample with the measurement light generated by the light source through a probe that can be placed at an arbitrary position, and a light receiving unit using the reflected light or transmitted light generated by irradiating the sample with the measurement light as observation light. The step of calculating the thickness of the sample from the spectral reflectance or spectral transmittance calculated based on the detection result by the light receiving unit after receiving light, and how appropriately the calculated film thickness is measured. Includes a step to calculate the indicated measurement reliability.

According to yet another aspect of the present invention, there is provided a measurement program for measuring the film thickness, which is the thickness of the layer contained in the sample. The measurement program is calculated based on the detection result obtained by receiving the reflected light or transmitted light generated when the sample is irradiated with the measurement light generated by the light source through a probe that can be placed at an arbitrary position on the computer. The step of calculating the film thickness of the sample from the spectral reflectance or the spectral transmittance and the step of calculating the measurement reliability indicating how appropriately the calculated film thickness is measured are executed.

According to an embodiment of the present invention, the film thickness of a sample can be appropriately measured.

It is a schematic diagram which shows the structural example of the optical measurement system according to this embodiment. It is a schematic diagram which shows the functional structure example of the optical measurement system according to this embodiment. It is a schematic diagram which shows the functional structure example of the arithmetic processing part included in the measuring apparatus according to this embodiment. It is a schematic diagram which shows an example of the appearance of the probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the cross-sectional structure of the probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the pen type probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the attachment attached to the pen type probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the V-groove type probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the L-shaped probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the non-contact type probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the non-contact type probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the tip movable probe used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the probe for the curved surface used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the probe for the liquid used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the probe for an oil film used in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the probe of a plurality of angles used in the optical measurement system according to this embodiment. It is a figure which shows an example of the usage form of the measuring apparatus and a probe in the optical measuring system according to this embodiment. It is a schematic diagram which shows the optical measurement system which follows the modification of this Embodiment. It is a schematic diagram which shows the optical measurement system according to another modification of this embodiment. It is a schematic diagram which shows an example of the cross-sectional structure of the sample which is the object of film thickness measurement in the optical measurement system which follows this embodiment. It is a figure for demonstrating the factor which makes film thickness measurement unstable in the optical measurement system according to this embodiment. It is a figure for demonstrating another factor which makes film thickness measurement unstable in the optical measurement system according to this embodiment. It is a figure for demonstrating yet another factor which makes film thickness measurement unstable in the optical measurement system according to this embodiment. It is a figure for demonstrating an example of the method of calculating the measurement reliability in the optical measurement system according to this embodiment. It is a figure for demonstrating another example of the method of calculating the measurement reliability in the optical measurement system according to this embodiment. It is a figure for demonstrating still another example of the method of calculating the measurement reliability in the optical measurement system according to this embodiment. It is a figure which shows an example of the spectral reflectance measured in each state of the probe shown in FIG. 21. It is a figure for demonstrating the process in the search support mode of the optical measurement system according to this embodiment. It is a flowchart which shows the processing procedure in the search support mode of the optical measurement system according to this embodiment. It is a figure for demonstrating the process in the automatic measurement mode of the optical measurement system according to this embodiment. It is a flowchart which shows the processing procedure in the automatic measurement mode of the optical measurement system according to this embodiment. It is a figure for demonstrating the process in the automatic measurement mode with search support of the optical measurement system according to this embodiment. It is a flowchart which shows the processing procedure in the automatic measurement mode with search support of the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the notification form of the measurement reliability in the optical measurement system according to this embodiment. It is a schematic diagram which shows an example of the functional structure provided by the optical measurement system according to this embodiment.

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

<A. Optical measurement system>
First, a configuration example of the optical measurement system 1 according to the present embodiment will be described. The optical measurement system 1 is an optical film thickness measuring device that measures the film thickness of a sample by using light. More specifically, the optical measurement system 1 is a spectral interferometry type film thickness measuring device.

As used herein, "film thickness" means the thickness of a particular layer or film contained in any sample. That is, the optical measurement system 1 measures the film thickness, which is the thickness of the layer contained in the sample.

In the following description, the optical system that irradiates the sample with light and observes the reflected light (reflected light observation system) will be mainly described, but the optical system that irradiates the sample with light and observes the transmitted light (transmitted light). Of course, it can also be applied to optical observation systems). Therefore, in the following description, unless otherwise specified, the term "reflected light" includes "transmitted light" in addition to the original "reflected light". Similarly, the term "reflectance" includes "transmittance" in addition to the original "reflectance".

(A1: System configuration example)
FIG. 1 is a schematic diagram showing a configuration example of an optical measurement system 1 according to the present embodiment. The optical measuring system 1 includes a measuring device 100 and a probe 200 optically connected to the measuring device 100.

In particular, the optical measurement system 1 according to the present embodiment is configured as a portable type capable of measuring at an arbitrary position. In the configuration example shown in FIG. 1, the user can measure an arbitrary sample at an arbitrary position by grasping the measuring device 100 with one hand and the probe 200 with the other hand. It is not necessary for the user to always hold the measuring device 100 and / or the probe 200 during the measurement. In this way, the probe 200 can be arranged at an arbitrary position.

The measuring device 100 and the probe 200 are connected via an optical fiber 10 and an optical fiber 20. One end of the optical fiber 10 and one end of the optical fiber 20 are detachably connected via a coupler 28.

A plurality of types of probes 200 may be prepared depending on the shape and characteristics of the sample. In this case, the coupler 28 may be provided so that the probe 200 can be easily replaced. For the coupler 28, for example, it is preferable to adopt a configuration in which the probe 200 can be attached / detached with one touch. The coupler 28 preferably has a structure that does not affect the measurement due to connection, disconnection, replacement, or the like. However, if only one type of probe 200 is used, the coupler 28 may be omitted.

The optical fiber 10 is a Y-type optical fiber, and the branch fiber 12 and the branch fiber 14 extend from the branch portion 16 of the optical fiber 10.

(A2: Configuration example of measuring device 100)
FIG. 2 is a schematic diagram showing a functional configuration example of the optical measurement system 1 according to the present embodiment. With reference to FIG. 2, the measuring device 100 irradiates the sample with light and receives light (reflected light or transmitted light) generated by irradiating the sample with light. In the following description, the light irradiating the sample is referred to as "measurement light" (measurement light 22 shown in FIG. 2), and the light generated by irradiating the sample with light is "observation light" (observation light shown in FIG. 2). 24) Also called.

More specifically, the measuring device 100 includes a light source 102, a spectroscopic measuring unit 104, an output unit 106, an operating unit 108, an arithmetic processing unit 110, and a power supply unit 130 as typical components. .. The components included in the measuring device 100 are packaged and housed in a housing. In the configuration example shown in FIG. 2, the arithmetic processing unit 110 is mounted in a housing independent of the probe 200.

The probe 200 is optically connected to the light source 102 and the spectroscopic measurement unit 104. More specifically, the branched fiber 12 is optically connected to the light source 102, and the branched fiber 14 is optically connected to the spectroscopic measurement unit 104. The branched fiber 12 irradiates (projects) the sample with the measurement light 22 from the light source 102, and guides the observation light 24 from the sample to the spectroscopic measurement unit 104.

The light source 102 has a light emitting body such as a white LED or a natural light LED, and generates measurement light 22. The measurement light 22 generated by the light source 102 is preferably broad light having a component over a predetermined wavelength range. In order to reduce the size of the measuring device 100, the light source 102 preferably operates even at a relatively low voltage.

The spectroscopic measurement unit 104 corresponds to a light receiving unit that receives the reflected light or transmitted light generated by irradiating the sample with the measurement light 22 as the observation light 24. The spectroscopic measurement unit 104 outputs the intensity of the observed light 24 for each wavelength. Typically, the spectroscopic measurement unit 104 includes a diffraction grating that diffracts the observation light 24 incident via the branched fiber 14, and a light receiving element having a plurality of channels arranged in association with the diffraction grating. The light receiving element is composed of a line sensor, a two-dimensional sensor, or the like, and can output the intensity of each wavelength component as a detection result.

As the optical system of the spectroscopic measurement unit 104, for example, a Czerny-Turner type, a Fastie-Ebert type, a Paschen-Runge type, or the like can be adopted.

The output unit 106 outputs the calculation result of the calculation processing unit 110 to the user. In particular, the output unit 106 notifies the measurement reliability calculated by the arithmetic processing unit 110. As the output unit 106, a display, a touch panel, or an LED that notifies the user of information by image or light may be adopted, or a voice generation unit (speaker) that notifies the user of information by voice may be adopted. , An oscillator that notifies the user of information by vibration may be adopted.

The operation unit 108 accepts user operations. The operation unit 108 may employ any input device such as a touch panel, keyboard, mouse, pen tablet, and buttons.

The arithmetic processing unit 110, as a film thickness calculation function, measures the film thickness of the sample from the spectral reflectance (or spectral transmittance) calculated based on the detection result (intensity of each wavelength of the observed light 24) by the spectroscopic measurement unit 104. Is calculated. The arithmetic processing unit 110 has a reliability calculation function in addition to the film thickness calculation function. That is, the arithmetic processing unit 110 calculates the measurement reliability indicating how appropriately the calculated film thickness is measured. Further, the arithmetic processing unit 110 also executes various processes as described later.

As an algorithm for determining the film thickness of the sample, an FFT (Fast Fourier Transform) method, an optimization method, or the like can be adopted.

The power supply unit 130 supplies electric power to each component of the measuring device 100 including the arithmetic processing unit 110. The power supply unit 130 adjusts the voltage of the electric power supplied from the external power source and provides it to each component of the measuring device 100. The power supply unit 130 may include a battery 132 so that the power supply to each component of the measuring device 100 can be continued even if the power supply from the external power supply is cut off.

FIG. 3 is a schematic diagram showing a functional configuration example of the arithmetic processing unit 110 included in the measuring device 100 according to the present embodiment. With reference to FIG. 3, the arithmetic processing unit 110 includes a processor 112, a main memory 114, an internal interface 116, a general-purpose interface 117, a network interface 118, and a storage 120.

The processor 112 is typically an arithmetic processing unit such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and reads one or a plurality of programs stored in the storage 120 into the main memory 114 and executes them. do. The main memory 114 is a volatile memory such as a DRAM (Dynamic Random Access Memory) or a SRAM (Static Random Access Memory), and functions as a working memory for the processor 112 to execute a program.

The storage 120 is composed of a non-volatile memory such as a hard disk or a flash memory, and stores various programs and data. More specifically, the storage 120 stores an operating system 122 (OS: Operating System), a measurement program 124, a detection result 126, and a measurement result 128.

The operating system 122 provides an environment in which the processor 112 executes a program. The measurement program 124 is executed by the processor 112 to realize an optical measurement method or the like according to the present embodiment. The detection result 126 includes data on the intensity of the observation light 24 output by the spectroscopic measurement unit 104 for each wavelength. The measurement result 128 includes the measurement result of the film thickness of the sample obtained by executing the measurement program 124.

The internal interface 116 mediates data transmission to and from the components included in the measuring device 100.

The general-purpose interface 117 is configured by, for example, USB (Universal Serial Bus) or the like, and mediates data transmission with an external device. The network interface 118 is configured by, for example, a wired LAN or a wireless LAN, and mediates data transmission with an external device. The general-purpose interface 117 and / or the network interface 118 transmits the detection result 126 stored in the storage 120 to another information processing device, receives the measurement result 128 processed by the other information processing device, and the like. You may. By providing an interface with such another information processing device, the other information processing device can be in charge of all or part of the necessary analysis processing.

The measurement program 124 and the like stored in the storage 120 may be installed via an arbitrary recording medium (for example, an optical disk or the like), or may be downloaded from the server device via the network interface 118 or the like.

The measurement program 124 may call the necessary modules in a predetermined array at a predetermined timing among the program modules provided as a part of the operating system 122 to execute the process. In such a case, the measurement program 124 that does not include the module is also included in the technical scope of the present invention. The measurement program 124 may be provided by being incorporated into a part of another program.

It should be noted that all or part of the functions provided by the processor 112 of the arithmetic processing unit 110 executing the program are hard-wired logic circuits (for example, FPGA (field-programmable gate array), ASIC (application specific integrated circuit), etc.). ) May be realized. Further, in addition to a processor such as a CPU or GPU, a SoC (System on Chip) that integrates a DSP (Digital Signal Processor) and an ISP (Image Signal Processor) may be used.

(A3: Configuration example of probe 200)
FIG. 4 is a schematic diagram showing an example of the appearance of the probe 200 used in the optical measurement system 1 according to the present embodiment. The probe 200 shown in FIG. 4 has a light emitting / receiving unit 202 that irradiates the measurement light 22 supplied from the measuring device 100 and receives the observation light 24 generated by the sample. The end face of the probe 200 has a flat circular shape, and the light emitting / receiving portion 202 is formed in a recess formed in the central portion of the circular shape.

FIG. 5 is a schematic view showing an example of the cross-sectional structure of the probe 200 used in the optical measurement system 1 according to the present embodiment.

As shown in FIG. 5A, a light guide path 204 optically connected to the optical fiber 20 is formed inside the probe 200. The light guide path 204 guides the light supplied through the optical fiber 20 to the light emitting / receiving unit 202, and guides the light incident on the light emitting / receiving unit 202 to the optical fiber 20.

In the measurement state, the sample 4 is irradiated with the measurement light 22 with the end face of the probe 200 shown in FIG. 5A in contact with the sample 4. The observation light 24 generated in the sample 4 is analyzed by the measuring device 100, and the film thickness of the sample 4 is measured.

As shown in FIG. 5B, a reference cap 30 to be attached to the probe 200 may be prepared. The reference cap 30 is used for calibration of the optical measurement system 1. Further, the reference cap 30 can also be used to prevent the intrusion of dust and the like during storage of the probe 200.

The reference cap 30 is provided with a mirror 32 at a position facing the light emitting / receiving unit 202 of the probe 200 in a state of being attached to the probe 200. The mirror 32 reflects the measurement light 22 emitted from the light emitting / receiving unit 202 and returns it to the light emitting / receiving unit 202 as the observation light 24. The observation light 24 measured with the reference cap 30 attached to the probe 200 is used as a reference (reference) for the reflectance. That is, the observation light 24 measured with the reference cap 30 attached to the probe 200 is acquired as a reference signal.

As described above, a plurality of types of probes 200 may be prepared depending on the shape and characteristics of the sample 4. The user optically connects the appropriate probe 200 out of the plurality of types of probes 200 to the measuring device 100 via the coupler 28 according to the sample 4. As described above, the probe 200 is configured to be changeable to a different type according to the sample 4.

Examples of the plurality of types of probes 200 include (1) stethoscope type probe, (2) pen type probe, (3) V-groove type probe, (4) L-shaped probe, (5) mini spot probe, and (6). ) Non-contact probe, (7) movable tip probe, (8) curved surface probe, (9) liquid probe, (10) oil film probe, (11) multi-angle probe, and the like.

(1) The stethoscope-type probe has a shape as shown in FIG. 4 described above, and is suitable for measuring the film thickness of the sample 4 that can be pressed against the measurement surface. For example, to measure the film thickness of a transparent or translucent planar sample (for example, food packaging wrap, PET film, glass substrate, planar substrate such as semiconductor, coating layer formed on the planar substrate, etc.). Can be used for. Since the stethoscope-type probe has a flat end face, it is easy to set the light irradiation angle vertically to the measurement surface (optical axis adjustment to set the incident angle and reflection angle to 0 °) by pressing it against the sample 4. Can be realized. That is, the measurement light 22 can be irradiated perpendicularly to the measurement surface without the user being aware of it.

(2) The pen-type probe is mainly used for measuring the local film thickness of the sample 4.

FIG. 6 is a schematic diagram showing an example of a pen-type probe 200C used in an optical measurement system according to the present embodiment. With reference to FIG. 6, the probe 200C measures the film thickness of the sample 4 having the contained local three-dimensional structure. By making the shape similar to that of a pen, it is possible to improve the grip and workability of the user.

An attachment corresponding to the sample 4 may be attached to the tip of the probe 200C.

FIG. 7 is a schematic diagram showing an example of an attachment attached to the pen-shaped probe 200C used in the optical measurement system according to the present embodiment. FIG. 7A shows an example of the attachment 210 that becomes wider toward the tip. By attaching the attachment 210, it becomes easy to press the probe 200C when the measurement surface of the sample 4 is flat. FIG. 7B shows an example of the attachment 212 that becomes thinner toward the tip. By attaching the attachment 212, it becomes easy to press the probe 200C even when the measurement surface of the sample 4 is narrow. In this way, by preparing an attachment that can be attached to the tip of the probe 200C, it is possible to handle the sample 4 having various shapes.

(3) The V-groove type probe is mainly used for measuring the film thickness of the coating layer formed on the outside of the cylindrical sample 4 (for example, a catheter or a metal tube).

FIG. 8 is a schematic diagram showing an example of a V-groove type probe 200D used in an optical measurement system according to the present embodiment. With reference to FIG. 8, the probe 200D includes a pair of support members 214 that support the sample 4. The support members 214 are provided with an interval through which the measurement light 22 and the observation light 24 pass.

By supporting the sample 4 with the support member 214 of the V-groove type probe 200D, it is possible to easily realize the verticalization of the light irradiation angle with respect to the measurement region portion (micro surface) on the curved surface of the sample 4. A mechanism that can adjust the opening angle of the support member 214 according to the curvature of the sample 4 may be adopted. Specifically, a mechanism is adopted in which a spring or the like is arranged between the support members 214 constituting the V-shaped groove so that the opening angle can be adjusted according to the magnitude of the force for pressing the sample 4. May be good.

(4) The L-shaped probe is mainly used for measuring the film thickness of the coating layer formed inside the cylindrical sample. The L-shaped probe is configured to be bent so that it can be accessed even when there is limited space above the sample.

FIG. 9 is a schematic diagram showing an example of an L-shaped probe used in an optical measurement system according to the present embodiment. With reference to FIG. 9A, a light guide path 204 optically connected to the optical fiber 20 and a mirror 216 are provided inside the L-shaped probe 200E. The measurement light 22 emitted from the light guide path 204 changes its propagation direction by 90 ° by the mirror 216 and irradiates the measurement surface of the sample 4. Similarly, the observation light 24 from the sample 4 is guided to the light guide path 204 with the propagation direction changed by 90 ° by the mirror 216.

FIG. 9B shows a probe 200F provided with a support member 218 on the outer peripheral side of the probe 200E shown in FIG. 9A. By selecting the support member 218 of the probe 200F according to the inner diameter of the sample 4, the probe 200F can be easily rotated in the cylindrical sample 4. Thereby, the film thickness of the coating layer formed on the inside of the sample 4 can be measured over the entire circumference.

(5) The mini-spot probe is mainly used for measuring the film thickness of a stethoscope-type probe such as a sample having a rough surface, a sample having an uneven surface, and a sample having a light diffusing surface. Since the irradiation region (light receiving region) of the measurement light 22 is a minute spot in the mini spot probe, the noise component contained in the observation light 24 can be reduced.

(6) The non-contact probe has an optical system designed so that measurement can be performed even if the distance from the measurement position on the sample to the probe is relatively long, and measurement can be performed without direct contact with the sample. ing.

FIG. 10 is a schematic diagram showing an example of a non-contact probe 200G used in an optical measurement system according to the present embodiment. With reference to FIG. 10, the probe 200G includes a lens 220 and a lens 222, and the measurement light 22 emitted from the light guide path 204 is converged on the sample 4. Similarly, the lens 220 and the lens 222 guide the observation light 24 from the sample 4 to the light guide path 204. By adopting such an optical system, the film thickness of the sample 4 can be measured without directly contacting the probe 200G with the sample 4.

Since the non-contact probe is gripped and used by the user, the measurement mode (described later) provided by the optical measurement system 1 is more effective.

Although FIG. 10 shows a configuration example in which the focal position is fixed, the focal position may be variable.

FIG. 11 is a schematic diagram showing an example of a non-contact probe 200H used in an optical measurement system according to the present embodiment. With reference to FIGS. 11A and 11B, in the probe 200H, the lens 222 is configured to be repositionable in the optical axis direction. By moving the lens 222 away from the lens 220, the focal position becomes longer (see FIG. 11 (A)), and by moving the lens 222 closer to the lens 220, the focal position becomes shorter (see FIG. 11 (B)).

(7) The movable tip probe is used, for example, to measure the film thickness inside a structure having a narrow inlet and the film thickness of a sample having a curved access path.

FIG. 12 is a schematic diagram showing an example of the tip movable probe 200I used in the optical measurement system according to the present embodiment. With reference to FIG. 12, the tip of the probe 200I is provided with a mirror (not shown) that changes the propagation direction of the measurement light 22 and the observation light 24, similar to the L-shaped probe shown in FIG. As shown in FIGS. 12A and 12B, the tip of the probe 200I has a structure in which the tip can be freely bent by being operated by the user. This is useful when the user cannot press the probe directly.

(8) The curved surface probe is mainly used for measuring the film thickness of a sample whose measurement position is a curved surface.

FIG. 13 is a schematic diagram showing an example of a probe 200J for a curved surface used in an optical measurement system according to the present embodiment. With reference to FIG. 13, a bendable flexible portion 226 is provided at the tip of the probe 200J. The flexible portion 226 is made of a soft material. By pressing the probe 200J against an arbitrary measurement position of the sample 4, the user deforms the flexible portion 226 to obtain an appropriate state (that is, a state in which the light irradiation angle is vertically set with respect to the measurement surface). realizable.

A contact portion 228 that comes into contact with the sample 4 is provided at the tip of the flexible portion 226. A light emitting / receiving unit 202 is provided at the center of the contact portion 228, and a rubber packing 230 is provided on the outer periphery of the exposed surface of the contact portion 228. By providing the rubber packing 230, the contact with the sample 4 can be improved.

(9) The probe in a liquid is mainly used for measuring the film thickness of a sample existing in the liquid.

FIG. 14 is a schematic diagram showing an example of a probe 200K for a liquid used in an optical measurement system according to the present embodiment. With reference to FIG. 14, the probe 200K adopts the same form as the stethoscope type probe as an example, but each part is sealed so that it can be used even in a liquid.

(10) The oil film probe has a needle-shaped portion in contact with the measurement position of the probe tip, and the film thickness of the liquid film including the oil film can be easily measured.

FIG. 15 is a schematic diagram showing an example of a probe 200L for an oil film used in an optical measurement system according to the present embodiment. With reference to FIG. 15, the probe 200L adopts the same form as the stethoscope type probe as an example, but is provided with a needle portion 234 so as to reduce the influence on the oil film.

(11) The multi-angle probe adopts a configuration in which the incident angles of the measurement light 22 with respect to the sample 4 can be different.

FIG. 16 is a schematic diagram showing an example of a multi-angle probe 200M used in an optical measurement system according to the present embodiment. With reference to FIG. 16, the probe 200M is capable of incident the measurement light 22 at an angle that is not perpendicular to the measurement surface of the sample 4. Further, since the observation light 24 from the sample 4 also propagates at an angle that is not perpendicular to the measurement surface of the sample 4, such observation light 24 is also configured to be received.

Although the above-mentioned FIGS. 1 and 2 show a configuration example in which the measuring device 100 and the probe 200 are separate bodies, the measuring device 100 and the probe 200 may be connected to each other, or the measuring device may be connected. The 100 and the probe 200 may be integrated.

FIG. 17 is a diagram showing an example of usage of the measuring device 100 and the probe 200 in the optical measuring system according to the present embodiment.

FIG. 17A shows a configuration example in which the measuring device 100 and the probe 200 are connected and integrated. By configuring the probe 200 so as to irradiate the measurement light 22 upward, it is possible to realize a desktop optical measurement system suitable for measuring the film thickness of the sample 4 such as a film.

With reference to FIG. 17B, a configuration example in which the measuring device 100 and the probe 200 are integrated is shown. By adopting such an integrated configuration, the overall configuration of the optical measurement system can be simplified.

(A4: Modification example 1: Integrated type)
FIG. 18 is a schematic diagram showing an optical measurement system 1A according to a modification of the present embodiment. With reference to FIG. 18, the optical measuring system 1A includes a measuring device 100A that packages the functions of the measuring device 100 and the probe 200 shown in FIGS. 1 and 2.

More specifically, the measuring device 100A has, as typical components, a light source 102, a spectroscopic measuring unit 104, an output unit 106, an operation unit 108, an arithmetic processing unit 110, a power supply unit 130, and a probe. Includes 200 and. The probe 200 is arranged in a portion exposed from the housing of the measuring device 100A so as to be in contact with the sample. As described above, in the configuration example shown in FIG. 18, the probe 200, the light source 102, and the spectroscopic measurement unit 104 are mounted in a single housing.

Since each component shown in FIG. 18 has substantially the same function as the component having the same reference numeral shown in FIG. 2, detailed description is not given here. However, the light source 102 is optically connected to the probe 200 via the optical fiber 52 arranged in the housing of the measuring device 100A, and the spectroscopic measuring unit 104 is the optical fiber 54 arranged in the housing of the measuring device 100A. It is optically connected to the probe 200 via.

(A5: Modification example 2: Wireless connection configuration)
Although the above-mentioned FIGS. 1 and 2 show a configuration example in which the measuring device 100 and the probe 200 are optically connected, the measuring device 100 and the probe 200 may be made wireless.

FIG. 19 is a schematic diagram showing an optical measurement system 1B according to another modification of the present embodiment. With reference to FIG. 19, the optical measuring system 1B includes a measuring device 100B and an enhanced probe 200B.

The measuring device 100B includes an output unit 106, an operation unit 108, an arithmetic processing unit 110, a power supply unit 130, and a communication unit 134 as typical components. The components included in the measuring device 100B are packaged and housed in a housing.

In addition to the probe 200, the high-performance probe 200B includes a light source 102, a spectroscopic measurement unit 104, a power supply unit 130, and a communication processing unit 136. The components included in the high-performance probe 200B are packaged and housed in a housing. As described above, in the configuration example shown in FIG. 19, the probe 200, the light source 102, and the spectroscopic measurement unit 104 are mounted in a single housing.

The communication unit 134 of the measuring device 100B and the communication processing unit 136 of the high-performance probe 200B exchange the detection result (intensity of the observed light 24 for each wavelength) by the spectroscopic measuring unit 104 by wireless communication. As the wireless communication, any method such as wireless LAN, Bluetooth (registered trademark), infrared communication, and public wireless line such as 4G and 5G can be adopted.

The communication processing unit 136 wirelessly transmits the detection result by the spectroscopic measurement unit 104 in addition to various processing in the high-performance probe 200B. The communication unit 134 outputs the detection result by the spectroscopic measurement unit 104 wirelessly transmitted by the communication processing unit 136 to the arithmetic processing unit 110.

Since each of the other components shown in FIG. 19 has substantially the same function as the component with the same reference numeral shown in FIG. 2, detailed description is not given here.

The operating state of the high-performance probe 200B may be controlled by a command from the measuring device 100B. For example, in response to a command from the measuring device 100B, the irradiation of the measurement light 22 from the light source 102 of the enhanced probe 200B may be enabled / disabled, or the communication processing unit of the enhanced probe 200B may be enabled / disabled. 136 wireless transmissions may be enabled / disabled.

When the high-performance probe 200B is used, it may be operated by the power supply from the battery 132 of the power supply unit 130 instead of the power supply from the external power supply.

(A6: Mounting method)
The above-mentioned measuring devices 100, 100A, 100B may be mounted by using a small personal computer. In this case, many components included in the measuring devices 100, 100A, 100B will be included in the personal computer. Alternatively, the above-mentioned measuring devices 100, 100A, 100B may be mounted using a smartphone, a tablet, or the like.

The mounting method of the optical measurement system 1 according to the present embodiment may be any form, and may be appropriately mounted by using the techniques available in each era.

<B. Film thickness measurement processing example>
Next, a processing example of film thickness measurement by the optical measurement system 1 according to the present embodiment will be described.

FIG. 20 is a schematic view showing an example of the cross-sectional structure of the sample 4 whose film thickness is measured by the optical measurement system 1 according to the present embodiment. For convenience of explanation, FIG. 20 shows a sample 4 in which the coating layer 41 is formed on the substrate layer 42. It is assumed that the coating layer 41 is in contact with the air layer 40.

With reference to FIG. 20, consider the reflected light generated by the measurement light 22 emitted from the probe 200 reflected at the interface between the coating layer 41 and the substrate layer 42. In the following description, each layer is expressed using the subscript i. That is, the air layer 40 is a subscript "0", the coating layer 41 of the sample is a subscript "1", and the substrate layer 42 is a subscript "2". Further, the refractive index in each layer is expressed as the refractive index ni by using the subscript _i .

Since light is reflected at the interface of layers having different refractive indexes ni, the amplitude reflectance (Fresnel) of the P-polarized component and the S-polarized component at each interface between the _i layer and the i + 1 layer having different refractive indexes. The coefficient) r ^(P) _{i, i + 1} , r ^(S) _{i, i + 1} can be expressed as follows.

Here, φ _i is the angle of incidence in the i layer. This incident angle φ _i can be calculated from the incident angle of the measured light 22 in the uppermost air layer 40 by Snell's law as follows.

N ₀ sinφ ₀ = N _i sinφ _i
In a layer having a film thickness at which light can interfere, the light reflected by the amplitude reflectance expressed by the above equation reciprocates in the layer many times. Therefore, the optical path lengths of the light directly reflected at the interface with the adjacent layer and the light after multiple reflection in the layer are different, so that the phases are different from each other, and the light is transmitted on the surface of the coating layer 41. Interference occurs. When the phase angle β _i of light in the layer i is introduced in order to show such an interference effect of light in each layer, it can be expressed as follows.

Here, di indicates the film thickness of the _i layer, and λ indicates the wavelength of the incident light.
For the sake of simplicity, when light is irradiated perpendicularly to the sample 4, that is, when the incident angle φ _i = 0, there is no distinction between P-polarization and S-polarization, and the amplitude reflectance at the interface between the layers disappears. And the phase angle β ₁ of the film thickness is as follows.

Further, the reflectance R for the sample 4 shown in FIG. 20 is as follows.

Considering the frequency transform (Fourier transform) for the phase angle β ₁ in the above equation, cos 2 β ₁ which is a phase factor (Phase Factor) is non-linear with respect to the reflectance R. Therefore, the phase factor cos2β ₁ is converted into a function having linearity. As an example, this reflectance R is converted as shown in the following equation to define the wavenumber conversion reflectance R', which is a unique variable.

This wavenumber conversion reflectance R'is a linear equation for the phase factor cos2β ₁ and has linearity. _{Here, Ra in the equation is an intercept at the wavenumber conversion reflectance R', and R b is} the slope at the wavenumber conversion reflectance R'. That is, this wavenumber conversion reflectance R'is a function for linearizing the value of the reflectance R at each wavelength with respect to the phase factor cos2β ₁ related to frequency conversion. As a function for linearizing such a phase factor, a function of 1 / (1-R) may be used.

Therefore, the wave _number K1 in the target coating layer 41 can be defined as follows.

Here, the propagation characteristics of the electromagnetic wave in the coating layer 41 depend on the wave _number K1. That is, it can be seen that the wavelength of light having a wavelength λ in a vacuum increases from λ to λ / n ₁ because the speed of light decreases in the layer. In consideration of such a wavelength dispersion phenomenon, the wavenumber conversion reflectance R'is defined as follows.

From this relationship, when the wavenumber conversion reflectance R'is frequency-converted (Fourier transform) with respect to the wavenumber K, _a peak appears in the periodic component corresponding to the film thickness d1 of the coating layer 41, and this peak position can be specified. , _The film thickness d1 of the coating layer 41 can be calculated.

That is, the correspondence between the spectral reflectance measured from the sample 4 and the reflectance at each wavelength is the correspondence between the wavenumber calculated from each wavelength and the wavenumber conversion reflectance R'calculated according to the above relational expression ( The wave number distribution characteristic) is converted, and the function of the wave number conversion reflectance R'including this wave number K is frequency-converted for the wave number K to calculate the spectrum, and the sample 4 is configured based on the peak appearing in the calculated spectrum. _The film thickness d1 of the coating layer 41 to be formed is calculated. This means that the amplitude value of _each wavenumber component included in the wavenumber distribution characteristic is acquired, and the film thickness d1 of the coating layer 41 is calculated based on the wavenumber component having a large amplitude value.

As a method for analyzing a wavenumber component having a large amplitude value from a wavenumber distribution characteristic, a method using an FFT method using a discrete Fourier transform such as FFT or an optimization method such as a maximum entropy method (Maximum Entropy Method) can be adopted. ..

<C. Measurement reliability>
Next, the measurement reliability provided by the optical measurement system 1 according to the present embodiment will be described.

The optical measurement system 1 according to the present embodiment is configured as a portable type that can be grasped by a user and measured at an arbitrary position. Further, in the spectroscopic interference type using the reflected light observation system adopted by the optical measurement system 1, it is necessary for the probe 200 to receive the observation light 24 that can be generated in the sample 4 by the measurement light 22 emitted from the probe 200. Therefore, the measurement may become unstable depending on the state of being gripped by the user. Hereinafter, some factors that make the film thickness measurement unstable will be described.

FIG. 21 is a diagram for explaining factors that make film thickness measurement unstable in the optical measurement system 1 according to the present embodiment. FIG. 21 shows an example in which the incident angle of the measurement light 22 with respect to the measurement surface of the sample 4 is inappropriate.

With reference to FIG. 21, when the probe 200 faces the measurement surface of the sample 4, the observation light 24 generated by the measurement light 22 emitted from the probe 200 will be incident on the probe 200. ..

However, when the probe 200 is tilted with respect to the measurement surface of the sample 4, the observation light 24 generated by the measurement light 22 emitted from the probe 200 cannot be properly incident on the probe 200.

In particular, when using a non-contact probe or a curved surface probe, the user must hold the probe 200 during measurement, so that the angle of incidence of the measurement light 22 on the measurement surface of the sample 4 is appropriately maintained. Measurements can be unstable because it is difficult to keep.

Further, even when the surface of the sample 4 is a curved surface or has a complicated shape, it is difficult to properly maintain the incident angle of the measurement light 22 with respect to the measurement surface of the sample 4, so that the measurement is not possible. Can be stable.

FIG. 22 is a diagram for explaining another factor that makes the film thickness measurement unstable in the optical measurement system 1 according to the present embodiment. FIG. 22 shows an example in which the measurement light 22 is improperly focused on the measurement surface of the sample 4.

With reference to FIG. 22, if the distance between the probe 200 and the measurement surface of the sample 4 is appropriate, the measurement light 22 emitted from the probe 200 focuses on the measurement surface of the sample 4, so that the sample 4 From this, an appropriate observation light 24 is generated and is incident on the probe 200.

However, if the distance between the probe 200 and the measurement surface of the sample 4 is too far or too close, the measurement light 22 emitted from the probe 200 focuses at a position away from the measurement surface of the sample 4, which is appropriate. No observation light 24 is generated.

In particular, when using a non-contact probe or a curved surface probe, the user must hold the probe 200 during measurement, so that the distance between the probe 200 and the measurement surface of the sample 4 is appropriately maintained. Measurements can be unstable because they are difficult to keep.

Further, even when the surface of the sample 4 is a curved surface or has a complicated shape, it is difficult to maintain an appropriate distance between the probe 200 and the measurement surface of the sample 4, so that the measurement is unstable. Can be.

FIG. 23 is a diagram for explaining yet another factor that makes the film thickness measurement unstable in the optical measurement system 1 according to the present embodiment. FIG. 23 shows an example caused by the fine structure of the sample 4.

Assuming a sample 4 in which the coating layer 41 is formed on the substrate layer 42 with reference to FIG. 23, fine irregularities may be present in the coating layer 41. Alternatively, the surface of the coating layer 41 may also have fine irregularities. Further, a sample 4 or the like having a structure in which only a part of the region can be measured is assumed.

Since it is necessary for the probe 200 to receive the observation light 24 that may be generated in the sample 4, the film thickness may not be appropriately measured in such a sample 4 depending on the measurement position.

With reference to FIG. 23, when the measurement surface of the sample 4 is substantially parallel to the end surface of the probe 200, the observation light 24 generated by the measurement light 22 emitted from the probe 200 will be incident on the probe 200. ..

However, when the measurement surface of the sample 4 is greatly tilted from the end surface of the probe 200, the observation light 24 generated by the measurement light 22 emitted from the probe 200 cannot be appropriately incident on the probe 200.

Therefore, in order to prevent the film thickness measured in the unstable state as described above from being output, the optical measurement system 1 calculates the measurement reliability related to the film thickness measurement.

As used herein, "measurement reliability" means the degree to which the measured or calculated measurement result (for example, film thickness) is measured appropriately.

Any method can be adopted as the method for calculating the measurement reliability, but as a typical example, some calculation methods will be described.

(C1: Calculation method of measurement reliability by FFT method)
First, a method suitable for calculating the film thickness by the FFT method will be described.

FIG. 24 is a diagram for explaining an example of a method of calculating the measurement reliability in the optical measurement system 1 according to the present embodiment. FIG. 24 shows a method of calculating the measurement reliability when calculating the film thickness of the sample by the FFT method.

With reference to FIG. 24, the spectral reflectance is calculated from the observed light 24 measured from the sample 4, converted to the wavenumber conversion reflectance R'as described above, and then frequency-converted (Fourier transform) with respect to the wavenumber K. Therefore, a spectrum having the horizontal axis as the film thickness and the vertical axis as the power (hereinafter, also referred to as “power spectrum”) can be calculated.

As described above, in the FFT method, the film thickness of the sample 4 is calculated based on the peak appearing in the spectrum calculated by frequency-converting the spectral reflectance or the spectral transmittance.

With respect to the calculated power spectrum, the measurement reliability can be calculated based on the peak appearing at the position corresponding to the film thickness of the sample 4. That is, the more appropriate the measurement state, the larger and sharper the peak appears in the power spectrum. Therefore, the measurement reliability can be calculated according to the magnitude or sharpness of the peak.

For example, as shown in FIG. 24, the area indicated by the peak appearing at the position corresponding to the film thickness of the sample 4 (peak area) and the area of the other portion (noise area) are calculated and the ratio of the calculated areas. May be used as the measurement reliability. Specifically, the measurement reliability can be calculated according to the following formula.

Measurement reliability = peak area / noise area Alternatively, any of the following equations may be adopted.

Measurement reliability = peak area / (peak area + noise area)
Measurement reliability = (peak area-noise area) / (peak area + noise area)
Further, the measurement reliability may be calculated based on the height of the peak (magnitude of power). Specifically, the measurement reliability can be calculated according to any of the following equations.

Measurement reliability = Peak height / Noise height Measurement reliability = Peak height / (Peak height + Noise height)
Measurement reliability = (peak height-noise height) / (peak height + noise height)
As described above, when the film thickness of the sample is calculated by the FFT method, the measurement reliability can be calculated based on the magnitude of the peak appearing in the calculated power spectrum.

(C2: Measurement reliability calculation method by optimization method)
Next, a method suitable for calculating the film thickness by the optimization method will be described.

The optimization method fits the parameters of the model showing the spectral reflectance to match the measured spectral reflectance (or the wavenumber conversion reflectance R'obtained by converting the measured spectral reflectance). How to do it.

Thus, in the optimization method, the parameters of the model showing the spectral reflectance or the spectral transmittance are fitted so as to match the spectral reflectance or the spectral transmittance calculated based on the observed light 24. Calculate the thickness of the sample.

How well the spectral reflectance (theoretical value) calculated by the model defined by the parameters determined by the optimization method matches the measured spectral reflectance (that is, the coincidence with the measured spectral reflectance). The measurement reliability can be calculated based on the degree or the degree of deviation from the measured spectral reflectance).

More specifically, the correlation coefficient between the measured spectral reflectance and the spectral reflectance (theoretical value) calculated by the model defined by the parameters determined by the optimization method is determined as the measurement reliability. May be good.

Alternatively, the reciprocal of the square error between the measured spectral reflectance and the spectral reflectance (theoretical value) calculated by the model defined by the parameters determined by the optimization method may be determined as the measurement reliability. good.

In this way, when the film thickness of the sample is calculated by the optimization method, it is based on the degree of agreement between the spectral reflectance calculated by the model defined by the determined parameters and the measured spectral reflectance. , Measurement reliability can be calculated. That is, when the film thickness of the sample is calculated by the optimization method, the measurement reliability can be calculated based on the determined fitting result.

(C3: Method for calculating measurement reliability based on reflectance)
FIG. 25 is a diagram for explaining another example of the method of calculating the measurement reliability in the optical measurement system 1 according to the present embodiment.

FIG. 25A shows an example of the spectral reflectance when the measurement state is bad, and FIG. 25B shows an example of the spectral reflectance when the measurement state is appropriate. As shown in FIG. 25, under an appropriate measurement state, the amplitude of the spectral reflectance (the difference between the maximum value and the minimum value of the reflectance) becomes relatively large. Therefore, the measurement reliability may be calculated based on the magnitude of the amplitude of the spectral reflectance. For example, the ratio to the reference amplitude may be calculated as the measurement reliability based on the amplitude of the spectral reflectance measured with the reference cap 30 attached.

In this way, the measurement reliability can be calculated based on the measured amplitude of the spectral reflectance without depending on the algorithm for calculating the film thickness of the sample.

Further, the measurement reliability may be calculated from the value of the reflectance (amplitude reflectance). For example, the reflectance may be output as it is as the measurement reliability, or the reflectance may be input to a predetermined function (for example, a function whose output monotonically increases with respect to the reflectance) to calculate the measurement reliability. You may.

If the angle or distance of the probe 200 to the sample is not appropriate, or if the light diffusion on the sample surface is large, the calculated reflectance (amplitude reflectance) will be small, which means that the measurement reliability is low. Means.

In this way, the measurement reliability can be calculated based on the magnitude of the measured reflectance (amplitude reflectance) without depending on the algorithm for calculating the film thickness of the sample.

Further, the measurement reliability may be calculated from the variation of the reflectance (amplitude reflectance). For example, when the user's grip of the probe 200 is not stable and the angle or distance of the probe 200 fluctuates, or when there is a fine film thickness distribution on the sample surface, the calculated reflectance (amplitude) is calculated. The variation of (reflectance) becomes large, which means that the measurement reliability is low.

FIG. 26 is a diagram for explaining still another example of the method of calculating the measurement reliability in the optical measurement system 1 according to the present embodiment.

FIG. 26A shows an example of the reflectance when the measurement is unstable, and FIG. 26B shows an example of the reflectance when the measurement is stable. As shown in FIG. 26, when the measurement is stable, the measured reflectance is also stable, so that the variation is relatively small. Therefore, the measurement reliability may be calculated based on the magnitude of the variation in the reflectance.

More specifically, the measurement reliability may be calculated from the standard deviation or variance of the reflectance for a predetermined number of times from the latest measurement.

In this way, the measurement reliability can be calculated based on the variation in the measured reflectance (amplitude reflectance) without depending on the algorithm for calculating the film thickness of the sample.

(C4: Method for calculating measurement reliability based on reference signal)
The measurement reliability may be calculated based on the reference signal, which is the observation light 24 measured with the reference cap 30 attached to the probe 200.

For example, if the light source 102 is deteriorated due to use, the amount of measurement light generated by the light source 102 is reduced. In such a state, it can be considered that the measurement reliability is lowered. Therefore, the measurement reliability may be calculated based on the magnitude of the reference signal before or immediately after the product shipment and the magnitude of the reference signal at the time of actual measurement.

More specifically, the ratio of the magnitude of the reference signal at the time of actual measurement to the magnitude of the reference signal before or immediately after the product shipment may be calculated as the measurement reliability.

In this way, the measurement reliability can be calculated based on the magnitude of the measured reference signal without depending on the algorithm for calculating the film thickness of the sample.

(C5: Measurement reliability calculation method based on variation in measurement results)
The measurement reliability may be calculated from the variation in the measurement result (for example, the film thickness). For example, when the grip of the probe 200 of the user is not stable and the angle or distance of the probe 200 fluctuates, or when there is a fine film thickness distribution on the sample surface, the measurement result is measured or calculated. The variability is large, which means that the measurement reliability is low.

Similar to FIGS. 26 (A) and 26 (B) described above, when the measurement is stable, the measured or calculated measurement result is also stable, so that the variation is relatively small. Therefore, the measurement reliability may be calculated based on the magnitude of the variation in the measurement or the calculated measurement result.

More specifically, the measurement reliability may be calculated from the standard deviation or variance of the measurement results for a predetermined number of times from the latest measurement.

In this way, the measurement reliability can be calculated based on the variation in the measurement or the measurement result calculated without depending on the algorithm for calculating the film thickness of the sample.

(C6: Method using multiple types of measurement reliability)
As described above, the measurement reliability can be calculated by a plurality of methods. Therefore, a plurality of measurement reliability calculated by different methods may be combined and calculated as the final measurement reliability. In this case, the final measurement reliability may be calculated by normalizing a plurality of measurement reliability of the target and then simply averaging them.

Alternatively, the final measurement reliability may be calculated by multiplying the plurality of measurement reliability of the target by the corresponding weighting factors. Further, the weighting coefficient may be changed depending on the conditions.

In this way, by using a plurality of types of measurement reliability to determine the final measurement reliability, the accuracy of the measurement reliability can be improved.

<D. Film thickness measurement mode>
In the optical measurement system 1 according to the present embodiment, the following measurement modes may be implemented by utilizing the measurement reliability as described above.

(D1: Search support mode)
The search support mode is a measurement mode that makes it easier for the user to find an appropriate measurement state by calculating the measurement reliability in real time and notifying the user of the calculated measurement reliability.

FIG. 27 is a diagram showing an example of the spectral reflectance measured in each state of the probe 200 shown in FIG. 21. In the state where the film thickness measurement shown in FIGS. 27 (A) and 27 (C) is unstable, the amplitude of the measured spectral reflectance also becomes small. On the other hand, under an appropriate measurement state as shown in FIG. 27 (B), the amplitude of the measured spectral reflectance also increases.

The user changes the angle, distance, and position (measurement position) of the probe 200 with respect to the measurement surface of the sample 4 while the measurement light 22 is being irradiated from the probe 200. The measuring device 100 repeats a process of calculating the spectral reflectance from the observation light 24 generated in the sample 4 and calculating the film thickness of the sample 4 through a Fourier transform or the like. At the same time, the measuring device 100 also calculates the measurement reliability. Further, the measuring device 100 sequentially notifies the user of the calculated measurement reliability.

The measurement reliability may be notified to the user by any method, but the measurement reliability is shown so that the user can easily recognize the measurement reliability while holding and scanning the probe 200. A notification sound may be used. For example, as shown below, the high measurement reliability may be associated with the generation cycle or frequency of the notification sound.

Measurement reliability: Low pip (silence) Pip Measurement reliability: Medium pip (silence) Pip Pip Measurement reliability: High pip (silence) Pip Pip In this way, even if a notification sound corresponding to the high measurement reliability is generated. good. Since the user can grasp the measurement reliability in real time by such a notification sound, the probe 200 can be adjusted to an appropriate angle, distance, and position (measurement position). By such adjustment, the film thickness of the sample 4 under an appropriate measurement state can be obtained.

The user may perform an operation on the operation unit 108 (for example, a trigger switch) when it is determined that the measurement state is appropriate. The measuring device 100 outputs or stores the film thickness at the time when the operation unit 108 is operated by the user as an appropriate measurement result.

FIG. 28 is a diagram for explaining the processing in the search support mode of the optical measurement system 1 according to the present embodiment. With reference to FIG. 28, the user adjusts the angle, distance, and position (measurement position) while holding the probe 200 while confirming the measurement reliability by the notification sound 38. At this time, it is assumed that the measurement light 22 is continuously or intermittently irradiated from the probe 200. Then, the user maintains the probe 200 in a state where it is determined that the measurement reliability is sufficiently high, and measures the film thickness of the sample 4.

By using the measurement mode as described above, the user can measure the film thickness of the sample 4 in an appropriate measurement state.

FIG. 29 is a flowchart showing a processing procedure in the search support mode of the optical measurement system 1 according to the present embodiment. Each step shown in FIG. 29 is typically realized by the processor 112 of the arithmetic processing unit 110 of the measuring device 100 executing the measuring program 124.

With reference to FIG. 29, when the measurement start is instructed (YES in step S100), the measuring device 100 gives a drive command to the light source 102 to enable irradiation of the measurement light 22 from the light source 102 (step). S102). In this way, the measuring device 100 irradiates the sample 4 with the measurement light 22 generated by the light source 102 through the probe 200 that can be arranged at an arbitrary position.

Then, the measuring device 100 calculates the film thickness of the sample 4 based on the detection result (intensity of the observed light 24 for each wavelength) output when the observed light 24 from the sample 4 is incident on the spectroscopic measuring unit 104. (Step S104). As described above, the measuring device 100 receives the reflected light (or transmitted light) generated by irradiating the sample 4 with the measuring light 22 as the observation light in the spectroscopic measuring unit 104, and based on the detection result by the spectroscopic measuring unit 104. The film thickness of the sample 4 is calculated from the calculated spectral reflectance (or spectral transmittance).

Further, the measuring device 100 calculates the measurement reliability based on the data used in the process of calculating the film thickness of the sample 4 (step S106). In this way, the measuring device 100 calculates the measurement reliability indicating how appropriately the calculated film thickness is measured. Then, the measuring device 100 generates a notification sound corresponding to the calculated high measurement reliability (step S108).

When the measuring device 100 is instructed to output the measurement result by the trigger switch or the like (YES in step S110), the measuring device 100 determines the film thickness of the sample 4 calculated in the current calculation cycle as the measurement result (step S112). If the output of the measurement result is not instructed (NO in step S110), the process of step S112 is skipped.

When the measurement end is instructed (YES in step S114), the measuring device 100 ends the film thickness measurement process, and if not (NO in step S114), repeats the process of step S104 and the like.

By using the search support mode as described above, the user can search for an appropriate measurement state.

(D2: Automatic measurement mode)
The automatic measurement mode is a measurement mode that automatically extracts measurement results with high measurement reliability from the start of measurement to the end of measurement.

The user changes the angle, distance, and position (measurement position) of the probe 200 with respect to the measurement surface of the sample 4 while the measurement light 22 is being irradiated from the probe 200. The measuring device 100 repeats a process of calculating the spectral reflectance from the observation light 24 generated in the sample 4 and calculating the film thickness of the sample 4 through a Fourier transform or the like. At the same time, the measuring device 100 also calculates the measurement reliability corresponding to each film thickness.

When a series of film thickness measurements are completed, the measuring device 100 determines the calculated film thickness having the corresponding high measurement reliability as the measurement result.

FIG. 30 is a diagram for explaining the processing in the automatic measurement mode of the optical measurement system 1 according to the present embodiment. With reference to FIG. 30, the measuring device 100 calculates the film thickness of the sample 4 and the corresponding measurement reliability from the start of the measurement to the end of the measurement, and determines a predetermined condition (for example, for example) of the calculated measurement reliability. Extract one or more measurement reliability that satisfies (high measurement reliability). The measuring device 100 determines as a measurement result a film thickness corresponding to one or a plurality of extracted measurement reliabilitys.

As shown in FIG. 30, the maximum value of the measurement reliability calculated from the start of the measurement to the end of the measurement (that is, one measurement reliability) may be extracted, or the maximum value exceeding a predetermined threshold value 1 Alternatively, a plurality of measurement reliabilitys may be extracted. Further, even when the maximum value of the measurement reliability is extracted, it may be an additional condition that the maximum value of the measurement reliability exceeds a predetermined threshold value.

As described above, any method may be adopted for extracting the measurement reliability.
FIG. 31 is a flowchart showing a processing procedure in the automatic measurement mode of the optical measurement system 1 according to the present embodiment. Each step shown in FIG. 31 is typically realized by the processor 112 of the arithmetic processing unit 110 of the measuring device 100 executing the measurement program 124.

With reference to FIG. 31, when the measurement start is instructed (YES in step S200), the measuring device 100 gives a drive command to the light source 102 to enable irradiation of the measurement light 22 from the light source 102 (step). S202). In this way, the measuring device 100 irradiates the sample 4 with the measurement light 22 generated by the light source 102 through the probe 200 that can be arranged at an arbitrary position.

Then, the measuring device 100 calculates the film thickness of the sample 4 based on the detection result (intensity of the observed light 24 for each wavelength) output when the observed light 24 from the sample 4 is incident on the spectroscopic measuring unit 104. (Step S204). As described above, the measuring device 100 receives the reflected light (or transmitted light) generated by irradiating the sample 4 with the measuring light 22 as the observation light in the spectroscopic measuring unit 104, and based on the detection result by the spectroscopic measuring unit 104. The film thickness of the sample 4 is calculated from the calculated spectral reflectance (or spectral transmittance).

Further, the measuring device 100 calculates the measurement reliability based on the data used in the process of calculating the film thickness of the sample 4 (step S206). In this way, the measuring device 100 calculates the measurement reliability indicating how appropriately the calculated film thickness is measured.

When the measurement end is instructed (YES in step S208), the measuring device 100 executes the process of step S210 or less (NO in step S208), and repeats the process of step S204 or less.

In step S208, the measuring device 100 extracts one or a plurality of measurement reliabilitys satisfying a predetermined condition from the measurement reliabilitys calculated from the start of the measurement to the end of the measurement (step S210). Then, the measuring device 100 outputs the film thickness corresponding to each of the extracted one or a plurality of measurement reliabilitys as a measurement result (step S212). Then, the process ends.

By using the automatic measurement mode as described above, the user can measure the film thickness in an appropriate measurement state without being conscious of the measurement reliability and the like.

(D3: Automatic measurement mode with search support)
The automatic measurement mode with search support is a measurement mode that automatically extracts measurement results with high measurement reliability from the start to the end of measurement while notifying the user of the improvement in measurement reliability.

The user changes the angle, distance, and position (measurement position) of the probe 200 with respect to the measurement surface of the sample 4 while the measurement light 22 is being irradiated from the probe 200. The measuring device 100 repeats a process of calculating the spectral reflectance from the observation light 24 generated in the sample 4 and calculating the film thickness of the sample 4 through a Fourier transform or the like. At the same time, the measuring device 100 also calculates the measurement reliability corresponding to each film thickness. Further, the measuring device 100 sequentially notifies the user whether or not the calculated measurement reliability is in the direction of improvement.

Any method may be used to notify the user whether or not the measurement reliability is in the direction of improvement, but the user recognizes the improvement in the measurement reliability while the probe 200 is being grasped and scanned. A notification sound indicating high measurement reliability may be used for easy measurement. For example, the notification sound may be generated only when the measurement reliability changes in a direction higher than the previous measurement reliability. Further, the notification sound to be generated may also be set according to the calculated high measurement reliability.

Alternatively, by generating a notification sound when the measurement reliability is improved and another notification sound when the measurement reliability is lowered, the user can improve the measurement reliability by adjusting himself / herself. It is easy to recognize whether or not it is in the direction.

When a series of film thickness measurements are completed, the measuring device 100 determines the calculated film thickness having the corresponding high measurement reliability as the measurement result.

FIG. 32 is a diagram for explaining the processing in the automatic measurement mode with search support of the optical measurement system 1 according to the present embodiment. With reference to FIG. 32, the measuring device 100 calculates the film thickness of the sample 4 and the corresponding measurement reliability from the start of the measurement to the end of the measurement, and when the calculated measurement reliability is improved, the user is notified. Notice.

When a series of film thickness measurements are completed, the measuring device 100 extracts one or a plurality of measured reliabilitys that satisfy a predetermined condition (for example, high measurement reliability) among the calculated measurement reliabilitys. The measuring device 100 determines as a measurement result a film thickness corresponding to one or a plurality of determined measurement reliabilitys.

As shown in FIG. 32, the peak appearing in the measurement reliability calculated from the start to the end of the measurement may be extracted, or one or a plurality of measurement reliabilitys exceeding a predetermined threshold value may be extracted. You may do so. Further, even when extracting a peak that appears in the measurement reliability, it may be an additional condition that the peak value exceeds a predetermined threshold value.

As described above, any method may be adopted for extracting the measurement reliability.
FIG. 33 is a flowchart showing a processing procedure in the automatic measurement mode with search support of the optical measurement system 1 according to the present embodiment. Each step shown in FIG. 33 is typically realized by the processor 112 of the arithmetic processing unit 110 of the measuring device 100 executing the measuring program 124.

With reference to FIG. 33, when the measurement start is instructed (YES in step S300), the measuring device 100 gives a drive command to the light source 102 to enable irradiation of the measurement light 22 from the light source 102 (step). S302). In this way, the measuring device 100 irradiates the sample 4 with the measurement light 22 generated by the light source 102 through the probe 200 that can be arranged at an arbitrary position.

Then, the measuring device 100 calculates the film thickness of the sample 4 based on the detection result (intensity of the observed light 24 for each wavelength) output when the observed light 24 from the sample 4 is incident on the spectroscopic measuring unit 104. (Step S304). As described above, the measuring device 100 receives the reflected light (or transmitted light) generated by irradiating the sample 4 with the measuring light 22 as the observation light in the spectroscopic measuring unit 104, and based on the detection result by the spectroscopic measuring unit 104. The film thickness of the sample 4 is calculated from the calculated spectral reflectance (or spectral transmittance).

Further, the measuring device 100 calculates the measurement reliability based on the data used in the process of calculating the film thickness of the sample 4 (step S306). In this way, the measuring device 100 calculates the measurement reliability indicating how appropriately the calculated film thickness is measured.

If the calculated measurement reliability is in the improvement direction (YES in step S308), the measuring device 100 generates a notification sound indicating that the measurement reliability is in the improvement direction (step S310). If the calculated measurement reliability is not in the direction of improvement (NO in step S308), the process of step S310 may be skipped.

Then, when the measurement end is instructed (YES in step S312), the measuring device 100 executes the process of step S314 or less (NO in step S312), and repeats the process of step S304 or less.

In step S310, the measuring device 100 extracts one or a plurality of measurement reliabilitys satisfying a predetermined condition from the measurement reliabilitys calculated from the start to the end of the measurement (step S314). Then, the measuring device 100 outputs the film thickness corresponding to each of the extracted one or a plurality of measurement reliabilitys as a measurement result (step S316). Then, the process ends.

By using the automatic measurement mode with search support as described above, the user can search for an appropriate measurement state.

(D4: Notification method)
In the above description, the notification form in which the high measurement reliability is associated with the generation cycle or the generation frequency of the notification sound has been illustrated, but the notification method is not limited to this, and any notification method can be adopted.

When notifying the measurement reliability by sound (that is, when the user audibly recognizes the measurement reliability), one or more of the volume, pitch, and timbre, depending on the calculated measurement reliability. May be changed. The user can easily recognize the change in the measurement reliability by changing any one of the volume, pitch, and timbre of the notification sound.

Further, not only the notification by sound but also the notification by vibration, light, image and the like can be adopted.

For example, when the measurement reliability is notified by vibration (that is, when the user recognizes the measurement reliability by tactile sensation), the measuring device 100 and / or the probe 200 is provided with a vibrator and the measured measurement reliability is calculated. One or more of the vibration strength, the vibration cycle, and the vibration interval of the vibrator may be changed according to the height of the vibrator. The user can easily recognize the change in the measurement reliability by changing the vibration that he / she feels.

Further, when the measurement reliability is notified by light or an image (that is, when the user visually recognizes the measurement reliability), the measurement device 100 and / or the probe 200 is provided with an arbitrary light emitting device and is calculated. The light emitting state of the light emitting device may be changed according to the high degree of measurement reliability. That is, at least one of the light and the image indicating the measurement reliability may be output from the output unit 106. The user can easily recognize the change in the measurement reliability by the light or the image that enters the eye.

FIG. 34 is a schematic diagram showing an example of a measurement reliability notification mode in the optical measurement system 1 according to the present embodiment. 34 (A) to 34 (C) show an example of the notification form when the display 1060 is adopted as the output unit 106 of the measuring device 100.

On the display 1060 of the measuring device 100 shown in FIG. 34 (A), the measured value 1062 of the film thickness and the status bar 1064 indicating the measurement reliability are displayed. By confirming the status bar 1064 indicating the measurement reliability, the user can obtain the measured value 1062 of the film thickness while recognizing the measurement reliability.

On the display 1060 of the measuring device 100 shown in FIG. 34 (B), the measured value 1062 of the film thickness and the numerical value 1066 indicating the measurement reliability are displayed. By confirming the numerical value 1066 indicating the measurement reliability, the user can obtain the measured value 1062 of the film thickness while recognizing the measurement reliability.

The display 1060 of the measuring device 100 shown in FIG. 34 (C) displays the measured value 1062 of the film thickness, and the measuring device 100 is provided with an indicator 1068 indicating the measurement reliability. The number of indicators 1068 is lit according to the calculated measurement reliability. By confirming the indicator 1068 indicating the measurement reliability, the user can obtain the measured value 1062 of the film thickness while recognizing the measurement reliability.

The measurement reliability can be notified to the user in any form, not limited to the notification form shown in FIGS. 34 (A) to 34 (C).

<E. Functional block diagram>
FIG. 35 is a schematic diagram showing an example of the functional configuration provided by the optical measurement system 1 according to the present embodiment. Each function shown in FIG. 35 is typically realized by the processor 112 of the arithmetic processing unit 110 of the measuring device 100 executing the measurement program 124.

With reference to FIG. 35, the measuring device 100 has a buffer 150, a wave number conversion unit 152, a Fourier transform unit 154, a peak search unit 156, a film thickness determination unit 158, and a measurement reliability calculation unit as functional configurations. 160 and an output processing unit 162 are included.

The buffer 150 stores the detection result (intensity of the observed light 24 for each wavelength) from the spectroscopic measurement unit 104.

The wave number conversion unit 152 calculates the spectral reflectance from the intensity of the observed light 24 stored in the buffer 150 for each wavelength, and calculates the wave number conversion reflectance from the calculated spectral reflectance.

The Fourier transform unit 154 Fourier transforms the wave number conversion reflectance calculated by the wave number conversion unit 152.

The peak search unit 156 searches for a peak included in the power spectrum calculated by the Fourier transform by the Fourier transform unit 154, and outputs the position (thickness) of the power spectrum corresponding to the searched peak. That is, the peak search unit 156 corresponds to a film thickness calculation unit that calculates the film thickness of the sample from the spectral reflectance (or spectral transmittance) calculated based on the detection result by the spectroscopic measurement unit 104.

The measurement reliability calculation unit 160 calculates the measurement reliability indicating how appropriately the film thickness calculated by the peak search unit 156 is measured. More specifically, the measurement reliability calculation unit 160 calculates the measurement reliability based on the power spectrum calculated by the Fourier transform by the Fourier transform unit 154.

When the predetermined condition is satisfied, the film thickness determination unit 158 determines the film thickness output from the peak search unit 156 as a measurement result. The predetermined conditions may include that the user operates the operation unit 108, that the measurement reliability in a predetermined period becomes the maximum value, that the measurement reliability exceeds a predetermined threshold value, and the like. As described above, the film thickness determining unit 158 typically determines the film thickness at the time when the measurement reliability satisfies a predetermined condition as the measurement result.

The output processing unit 162 outputs the film thickness output from the peak search unit 156, the measurement reliability output from the measurement reliability calculation unit 160, the measurement result (film thickness) output from the film thickness determination unit 158, and the like. Responsible for the process of outputting from 106. The output processing unit 162 notifies the user of the measurement reliability calculated by the measurement reliability calculation unit 160 by the output unit 106.

Note that FIG. 35 shows a configuration example when calculating the film thickness by the FFT method as a typical example, but when measuring the film thickness by the optimization method, a model including the film thickness of the sample as a parameter is used. , A fitting unit for fitting the actually measured reflectance (or transmittance) may be provided.

<F. Modification example>
In the above description, a configuration example in which the measuring device 100 of the optical measuring system 1 executes necessary processing has been described, but the present invention is not limited to this, and for example, the processing may be shared by a plurality of processing devices. The probe 200 may be in charge of processing the unit. Further, a computing resource (so-called cloud) on a network (not shown) may be responsible for all or part of the required processing.

When a lot of computing resources are available, machine learning is performed using the measurement results acquired in the past and / or the measurement results acquired by the other optical measurement system 1 and obtained by machine learning. The trained model may be used to notify the user of the optimum conditions for film thickness measurement.

<G. Summary>
In the optical measurement system according to the present embodiment, the film thickness of the sample is optically calculated based on the observation light acquired through the probe that can be placed at an arbitrary position, so that the measurement accuracy of the film thickness can be improved. ..

Further, in the optical measurement system according to the present embodiment, the measurement reliability indicating how appropriately the calculated film thickness is measured is also calculated, so that the film thickness of the sample is more appropriately measured. Can be measured.

Further, in the optical measurement system according to the present embodiment, since an arbitrary sample can be arranged and measured by a probe that can be arranged at an arbitrary position, the film thickness can be easily measured at a production site or a production line. Further, even a sample having a curved surface or a sample having a complicated shape can be easily measured.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

1,1A, 1B optical measurement system, 4 samples, 10,20,52,54 optical fiber, 12,14 branch fiber, 16 branch, 22 measurement light, 24 observation light, 28 coupler, 30 reference cap, 32,216 mirror , 38 notification sound, 40 air layer, 41 coating layer, 42 substrate layer, 100, 100A, 100B measuring device, 102 light source, 104 spectroscopic measuring unit, 106 output unit, 108 operation unit, 110 arithmetic processing unit, 112 processor, 114 Main memory, 116 internal interface, 117 general-purpose interface, 118 network interface, 120 storage, 122 operating system, 124 measurement program, 126 detection result, 128 measurement result, 130 power supply unit, 132 battery, 134 communication unit, 136 communication processing unit, 150 buffer, 152 wave number conversion unit, 154 Fourier conversion unit, 156 peak search unit, 158 film thickness determination unit, 160 measurement reliability calculation unit, 162 output processing unit, 200, 200C, 200D, 200E, 200F, 200G, 200H, 200I, 200J, 200K, 200L, 200M probe, 200B high-performance probe, 202 light-receiving part, 204 light guide path, 210,212 attachment, 214,218 support member, 220,222 lens, 226 flexible part, 228 contact part, 230 rubber packing, 234 needles, 1060 display, 1062 measurements, 1064 status bar, 1066 numbers, 1068 indicators.

Claims (9)

An optical measurement system that measures the film thickness, which is the thickness of the layers contained in the sample.
A light source that generates measurement light and
A light receiving unit that receives the reflected light or transmitted light generated by irradiating the sample with the measurement light as observation light.
A probe that is optically connected to the light source and the light receiving portion and can be placed at an arbitrary position.
A film thickness calculation unit that calculates the film thickness of the sample from the spectral reflectance or spectral transmittance calculated based on the detection result by the light receiving unit, and the film thickness calculation unit.
A reliability calculation unit that calculates the measurement reliability, which indicates how appropriately the film thickness calculated by the film thickness calculation unit is measured .
It is equipped with an output unit that notifies the measurement reliability calculated by the reliability calculation unit .
The output unit is
Generation of notification sound corresponding to the high measurement reliability,
Light output indicating the measurement reliability,
The generation of vibration according to the high measurement reliability, and
An optical measurement system that outputs at least one of the images showing the measurement reliability . The optical measurement system according to claim 1 , further comprising a determination unit for determining a film thickness at a time when the measurement reliability satisfies a predetermined condition as a measurement result. The film film calculation unit calculates the film film of the sample based on the peak appearing in the spectrum calculated by frequency-converting the spectral reflectance or the spectral transmittance.
The optical measurement system according to claim 1 or 2 , wherein the reliability calculation unit calculates measurement reliability based on the magnitude of a peak appearing in the spectrum. The film thickness calculation unit fits the parameters of the model showing the spectral reflectance or the spectral transmittance so as to match the spectral reflectance or the spectral transmittance calculated based on the observed light, thereby fitting the sample. Calculate the film thickness of
The optical measurement system according to any one of claims 1 to 3 , wherein the reliability calculation unit calculates measurement reliability based on a fitting result determined by the film thickness calculation unit. The optical measurement system according to any one of claims 1 to 4 , wherein the probe can be changed to a different type according to the sample. The optical measurement system according to any one of claims 1 to 5 , wherein at least the film thickness calculation unit and the reliability calculation unit are mounted in a housing independent of the probe. The optical measurement system according to any one of claims 1 to 6 , wherein at least the probe, the light source, and the light receiving unit are mounted in a single housing. It is an optical measurement method that measures the film thickness, which is the thickness of the layer contained in the sample.
A step of irradiating the sample with the measurement light generated by the light source through a probe that can be placed at an arbitrary position.
The light receiving unit receives the reflected light or transmitted light generated by irradiating the sample with the measurement light as observation light, and the film of the sample is obtained from the spectral reflectance or the spectral transmittance calculated based on the detection result by the light receiving unit. Steps to calculate the thickness and
A step to calculate the measurement reliability, which indicates how appropriately the calculated film thickness is measured , and
A step of notifying the calculated measurement reliability is provided .
The step of notifying the measurement reliability is
Generation of notification sound corresponding to the high measurement reliability,
Light output indicating the measurement reliability,
The generation of vibration according to the high measurement reliability, and
An optical measurement method comprising the step of performing at least one of the output of an image indicating the measurement reliability . It is a measurement program that measures the film thickness, which is the thickness of the layer contained in the sample, and is applied to a computer.
Spectral reflectance or spectral transmittance calculated based on the detection result obtained by receiving the reflected light or transmitted light generated when the sample is irradiated with the measurement light generated by the light source through a probe that can be placed at an arbitrary position. The step of calculating the film thickness of the sample from the rate, and
A step to calculate the measurement reliability, which indicates how appropriately the calculated film thickness is measured , and
To execute the step of notifying the calculated measurement reliability ,
The step of notifying the measurement reliability is
Generation of notification sound corresponding to the high measurement reliability,
Light output indicating the measurement reliability,
The generation of vibration according to the high measurement reliability, and
A measurement program comprising the step of performing at least one of the output of an image indicating the measurement reliability .

Images