KR20230056667A - Optical measuring system, optical measuring method and measuring program - Google Patents

Abstract

An optical measuring system for measuring film thickness, which is the thickness of a layer included in a sample, is provided. The optical measurement system includes a light source that generates measurement light, a light receiver that receives reflected or transmitted light generated by irradiating the sample with the measurement light as observation light, and a probe that is optically connected to the light source and the light receiver and can be placed at any position. And, a film thickness calculation unit for calculating 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 how appropriately the film thickness calculated by the film thickness calculation unit is measured. and a reliability calculation unit that calculates measurement reliability.

Description

Optical measuring system, optical measuring method and measuring program

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 need to manage the film thickness of manufactured products. In response to such a demand, a measuring device and a measuring method for measuring the film thickness are known.

As an example, a measuring device using electromagnetic induction or eddy current is known. For example, Japanese Unexamined Patent Publication No. Hei 07-332916 (Patent Document 1) discloses a film thickness gauge that measures the film thickness of a magnetic film with good precision using a current of a practical frequency. Further, Japanese Unexamined Patent Publication No. 06-317401 (Patent Document 2) discloses a hand-held combined coating thickness gauge capable of measuring the thickness of both non-ferrous coating on an iron substrate and non-conductive coating on a conductive non-ferrous substrate. do.

In addition, a measuring device using ultrasonic waves is also known. For example, Japanese Unexamined Patent Publication No. Hei 07-167639 (Patent Document 3) discloses a thickness gauge provided with a transducer that emits ultrasonic waves into a coating, receives ultrasonic waves, and generates a conversion signal proportional to the ultrasonic signal. Initiate.

In addition, 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 obtaining the film thickness of a film formed on a substrate surface by measuring spectral reflectance.

Among the measuring devices and measuring methods for measuring these film thicknesses, the measurement accuracy of devices using electromagnetic induction or eddy current and devices using ultrasonic waves is lower than that of devices using light. Therefore, it is preferable to use a measuring device using light to measure 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 No. 2010/013429

The film thickness measuring device disclosed in Patent Literature 4 described above is configured such that light from a light source is perpendicularly incident on a measurement target surface having a film, and light reflected from the measurement target surface is incident on a spectral sensor. In order to make the light from the light source perpendicularly incident on the surface to be measured, a stationary configuration is assumed.

In order to perform product quality control and the like, there is a demand for easy measurement at an arbitrary position on a production line, for example. In addition, there is also a need to easily measure a sample with a curved surface or a sample with a complicated shape. However, the prior art described above does not provide a solution that satisfies such a demand.

One object of the present invention is to provide an optical measuring system or the like capable of appropriately measuring the film thickness of a sample.

According to one aspect of the present invention, an optical measurement system for measuring film thickness, which is the thickness of a layer included in a sample, is provided. The optical measurement system includes a light source that generates measurement light, a light receiver that receives reflected or transmitted light generated by irradiating the sample with the measurement light as observation light, and a probe that is optically connected to the light source and the light receiver and can be placed at any position. And, a film thickness calculation unit for calculating 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 how appropriately the film thickness calculated by the film thickness calculation unit is measured. and a reliability calculation unit that calculates measurement reliability.

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

The output unit may generate a notification sound corresponding to the height of the 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, as a measurement result, the film thickness at the time when the measurement reliability satisfies a predetermined condition.

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

The film thickness calculation unit may calculate the film thickness of the sample by fitting a parameter of a model representing the spectral reflectance or spectral transmittance to match the spectral reflectance or spectral transmittance calculated based on the observed light. The reliability calculation unit may calculate measurement reliability based on the result of the fitting determined by the film thickness calculation unit.

The probe may be configured to be changeable into different types depending on the sample.

At least the film thickness calculation unit and the reliability calculation unit may be mounted in a casing independent of the probe.

At least the probe, light source and light receiving unit may be mounted in a single casing.

According to another aspect of the present invention, an optical measurement method for measuring a film thickness, which is the thickness of a layer included in a sample, is provided. The optical measurement method includes irradiating a sample with measurement light generated by a light source through a probe that can be placed at an arbitrary position, irradiating the sample with the measurement light, and receiving reflected or transmitted light as observation light in a light receiving unit, A step of calculating 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 a step of calculating measurement reliability indicating how properly the calculated film thickness is measured.

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

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

1 is a schematic diagram showing a configuration example of an optical measurement system according to the present embodiment.
Fig. 2 is a schematic diagram showing an example of functional configuration of the optical measurement system according to the present embodiment.
3 is a schematic diagram showing an example of a functional configuration of an arithmetic processing unit included in the measuring device according to the present embodiment.
Fig. 4 is a schematic diagram showing an example of the external appearance of a probe used in the optical measurement system according to the present embodiment.
5 is a schematic diagram showing an example of a cross-sectional structure of a probe used in the optical measurement system according to the present embodiment.
Fig. 6 is a schematic diagram showing an example of a pen-shaped probe used in the optical measurement system according to the present embodiment.
Fig. 7 is a schematic diagram showing an example of an attachment attached to a pen-shaped probe used in the optical measurement system according to the present embodiment.
Fig. 8 is a schematic diagram showing an example of a V-groove probe used in the optical measurement system according to the present embodiment.
Fig. 9 is a schematic diagram showing an example of an L-shaped probe used in the optical measurement system according to the present embodiment.
Fig. 10 is a schematic diagram showing an example of a non-contact type probe used in the optical measurement system according to the present embodiment.
Fig. 11 is a schematic diagram showing an example of a non-contact type probe used in the optical measurement system according to the present embodiment.
Fig. 12 is a schematic diagram showing an example of a tip movable probe used in the optical measurement system according to the present embodiment.
Fig. 13 is a schematic diagram showing an example of a probe for a curved surface used in the optical measurement system according to the present embodiment.
Fig. 14 is a schematic diagram showing an example of a liquid probe used in the optical measurement system according to the present embodiment.
Fig. 15 is a schematic diagram showing an example of an oil film probe used in the optical measurement system according to the present embodiment.
16 is a schematic diagram showing an example of a multi-angle probe used in the optical measurement system according to the present embodiment.
Fig. 17 is a diagram showing an example of a usage mode of a measuring device and a probe in the optical measuring system according to the present embodiment.
Fig. 18 is a schematic diagram showing an optical measurement system according to a modified example of the present embodiment.
Fig. 19 is a schematic diagram showing an optical measurement system according to another modified example of the present embodiment.
20 is a schematic diagram showing an example of a cross-sectional structure of a sample to be measured by the optical measurement system according to the present embodiment.
21 is a diagram for explaining factors that cause film thickness measurement to become unstable in the optical measurement system according to the present embodiment.
22 is a diagram for explaining other factors that cause film thickness measurement to become unstable in the optical measurement system according to the present embodiment.
23 is a diagram for explaining another factor that causes film thickness measurement to become unstable in the optical measurement system according to the present embodiment.
24 is a diagram for explaining an example of a method for calculating measurement reliability in the optical measurement system according to the present embodiment.
25 is a diagram for explaining another example of a method for calculating measurement reliability in the optical measurement system according to the present embodiment.
26 is a diagram for explaining another example of a method for calculating measurement reliability in the optical measurement system according to the present embodiment.
Fig. 27 is a diagram showing an example of the spectral reflectance measured in each state of the probe shown in Fig. 21;
Fig. 28 is a diagram for explaining processing in the search support mode of the optical measurement system according to the present embodiment.
Fig. 29 is a flowchart showing the processing procedure in the search support mode of the optical measurement system according to the present embodiment.
Fig. 30 is a diagram for explaining processing in the automatic measurement mode of the optical measurement system according to the present embodiment.
Fig. 31 is a flowchart showing the processing procedure in the automatic measurement mode of the optical measurement system according to the present embodiment.
Fig. 32 is a diagram for explaining processing in the automatic measurement mode with search support of the optical measurement system according to the present embodiment.
Fig. 33 is a flow chart showing the processing procedure in the automatic measurement mode with search support of the optical measurement system according to the present embodiment.
34 is a schematic diagram showing an example of a form of notification of measurement reliability in the optical measurement system according to the present embodiment.
35 is a schematic diagram showing an example of a functional configuration provided by the optical measurement system according to the present embodiment.

EMBODIMENT OF THE INVENTION Embodiment of this invention is described in detail, referring drawings. In addition, the same code|symbol is attached|subjected to the same or equivalent part in drawing, and the description is not repeated.

<A. Optical measuring 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 measurement device that measures the film thickness of a sample using light. More specifically, the optical measuring system 1 is a spectral interference type film thickness measuring device.

In this specification, "film thickness" means the thickness of a specific layer or film included in an arbitrary sample. That is, the optical measurement system 1 measures the film thickness, which is the thickness of a layer included in the sample.

In the following description, an optical system (reflection light observation system) that irradiates light on a sample and observes the reflected light is mainly described, but it can naturally be applied to an optical system (transmitted light observation system) that irradiates light on a sample and observes the transmitted light. do. 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: example of system configuration)

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 measuring 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 any sample at any position by holding the probe 200 with the other hand while holding the measuring device 100 with one hand. . In addition, during measurement, it is not necessary for the user to always hold the measuring device 100 and/or the probe 200. In this way, the probe 200 can be placed at any 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 connected via a coupler 28 so that attachment or detachment is possible.

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

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

(a2: configuration example of measuring device 100)

2 is a schematic diagram showing an example of a functional configuration of the optical measurement system 1 according to the present embodiment. Referring to FIG. 2 , the measuring apparatus 100 irradiates a sample with light and receives light (reflected light or transmitted light) generated by irradiating the sample with light. In the following description, the light irradiated to 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 referred to as "observation light" (observation It is also referred to as light (24).

More specifically, the measuring device 100 includes, as typical components, a light source 102, a spectroscopic measurement unit 104, an output unit 106, an operation unit 108, an arithmetic processing unit 110, and , including the power supply unit 130. Components included in the measuring device 100 are packaged and housed in a casing. In the configuration example shown in FIG. 2 , the arithmetic processing unit 110 is mounted in a casing 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 branch fiber 12 is optically connected to the light source 102 , and the branch fiber 14 is optically connected to the spectroscopic measurement unit 104 . The branching fiber 12 irradiates (transmits) the measurement light 22 from the light source 102 onto the sample and guides the observation light 24 from the sample to the spectroscopic measurement unit 104 .

The light source 102 has a luminous body such as a white LED or a natural light LED, and generates the measurement light 22 . The measurement light 22 generated by the light source 102 is preferably broad light having a component covering a predetermined wavelength range. In order to downsize the measuring device 100, it is preferable that the light source 102 operates even at a relatively low voltage.

The spectroscopic measuring unit 104 corresponds to a light receiving unit that receives reflected light or transmitted light generated by irradiating the sample with measurement light 22 as observation light 24 . The spectroscopic measuring unit 104 outputs the intensity of each wavelength of the observation light 24 . Typically, the spectrometer 104 includes a diffraction grating that diffracts the observation light 24 incident through the branch fiber 14, and a light receiving element having a plurality of channels disposed corresponding to the diffraction grating. The light-receiving element is constituted by a line sensor or a two-dimensional sensor, and can output intensity for each wavelength component as a detection result.

As the optical system of the spectrometer 104, for example, a Czerny-Turner type, a Fastie-Ebert type, a Paschen-Runge type or the like can be employed.

The output unit 106 outputs the calculation result by 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, touch panel, or LED that notifies the user of information by image or light may be employed, or an audio generating unit (speaker) that notifies the user of information by sound may be employed, or vibration of the information may be employed. A vibrator that notifies the user may be employed.

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, or button.

The arithmetic processing unit 110, as a film thickness calculation function, calculates a sample from the spectral reflectance (or spectral transmittance) calculated based on the detection result by the spectroscopic measuring unit 104 (intensity for each wavelength of the observation light 24). Calculate the film thickness of 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 measurement reliability indicating how properly the calculated film thickness is measured. In addition, the arithmetic processing unit 110 also executes various processes as will be 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 employed.

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

3 is a schematic diagram showing an example of a functional configuration of the arithmetic processing unit 110 included in the measuring device 100 according to the present embodiment. Referring 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 ), including

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. print and run The main memory 114 is a volatile memory such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory), and functions as a working memory for the processor 112 to execute a program.

The storage 120 is made of a non-volatile memory such as a hard disk or 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 the optical measurement method and the like according to the present embodiment. The detection result 126 includes intensity data for each wavelength of the observation light 24 output from the spectrometer 104 . The measurement result 128 includes a measurement result of the film thickness of the sample obtained by executing the measurement program 124 .

The internal interface 116 mediates data transmission between components included in the measurement device 100.

The general-purpose interface 117 is constituted by, for example, USB (Universal Serial Bus) or the like, and mediates data transfer with an external device. The network interface 118 is constituted 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, and the measurement result processed by the other information processing device ( 128) may be received. By providing such an interface with other information processing devices, the other information processing devices can take charge of all or part of necessary analysis processing.

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

The measurement program 124 may call necessary modules from among program modules provided as part of the operating system 122 in a predetermined arrangement at a predetermined timing to execute processing. 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 introduced and provided as part of another program.

In addition, all or part of the functions provided by the processor 112 of the operation processing unit 110 executing a program may be converted into a hard-wired logic circuit (eg, a field-programmable gate array (FPGA) or an application specific integrated circuit (ASIC)). etc.) can be realized. Further, it may be realized using a SoC (System on Chip) in which a DSP (Digital Signal Processor), an ISP (Image Signal Processor), and the like are integrated in addition to a processor such as a CPU or GPU.

(a3: configuration example of probe 200)

4 is a schematic diagram showing an example of the external 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 transmitting/receiving unit 202 that irradiates measurement light 22 supplied from the measuring device 100 and receives observation light 24 generated from a sample. The cross section of the probe 200 is a flat circular shape, and a light transmitting/receiving portion 202 is formed in a concave portion formed in the center of the circular shape.

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

As shown in FIG. 5(A), inside the probe 200, an optical fiber 20 and a light guide path 204 optically connected are formed. The light guide passage 204 guides the light supplied through the optical fiber 20 to the light transmitting/receiving portion 202 and guides the light incident on the light transmitting/receiving portion 202 to the optical fiber 20 .

In the measurement state, the sample 4 is irradiated with the measurement light 22 in a state where the end face of the probe 200 shown in FIG. 5(A) is brought into contact with the sample 4 . Observation light 24 generated from the sample 4 is analyzed and processed by the measuring device 100, and the film thickness of the sample 4 is measured.

As shown in FIG. 5(B) , a reference cap 30 attached to the probe 200 may be prepared. The reference cap 30 is used for calibration of the optical measuring system 1 . In addition, the reference cap 30 can also be used to prevent entry of dust or the like when the probe 200 is stored.

In the state where the reference cap 30 is attached to the probe 200, a mirror 32 is formed at a position facing the light transmitting/receiving portion 202 of the probe 200. The mirror 32 reflects the measurement light 22 emitted from the light transmitting/receiving unit 202 and returns it to the light transmitting/receiving unit 202 as observation light 24 . The observation light 24 measured with the reference cap 30 attached to the probe 200 is used as a standard (reference) of 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 according to the shape and characteristics of the sample 4 . According to the sample 4, the user optically connects an appropriate probe 200 among a plurality of types of probes 200 to the measuring device 100 via the coupler 28. In this way, according to the sample 4, the probe 200 is configured to be changeable into different types.

As an example of the plurality of types of probes 200, (1) a stethoscope-type probe, (2) a pen-type probe, (3) a V-groove probe, (4) an L-shaped probe, (5) a mini-spot probe, and (6) a non-contact probe. probe, (7) tip movable 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 applied to the measurement surface. For example, it can be used to measure the film thickness of a transparent or translucent planar sample (eg, food packaging wrap, PET film, glass substrate, planar substrate such as a semiconductor, coating layer formed on a planar substrate, etc.) can Since the stethoscope-type probe has a flat cross section, by holding it on the sample 4, it is possible to easily achieve vertical alignment of the light irradiation angle with respect to the measurement surface (optical axis adjustment with the incident angle and reflection angle set to 0°). That is, the measurement light 22 can be irradiated perpendicularly to the measurement plane without the user being aware of it.

(2) The pen-shaped probe is mainly used to measure the local film thickness of the sample 4.

6 is a schematic diagram showing an example of a pen-shaped probe 200C used in the optical measurement system according to the present embodiment. Referring to Fig. 6, the probe 200C measures the film thickness of the sample 4 having a contained local three-dimensional structure. By having the same shape as the pen, the user's gripping ability and workability can be improved.

An attachment according 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 a pen-shaped probe 200C used in the optical measurement system according to the present embodiment. Fig. 7(A) shows an example of an attachment 210 that widens as the distal end increases. By attaching the attachment 210, when the measurement surface of the sample 4 is flat, it becomes easy to hold the probe 200C. 7(B) shows an example of an attachment 212 that is tapered toward the tip. By attaching the attachment 212, even when the measurement surface of the sample 4 is narrow, it becomes easy to hold the probe 200C. In this way, by preparing an attachment that can be attached to the tip of the probe 200C, it is possible to respond to the samples 4 of various shapes.

(3) The V-grooved probe is mainly used to measure the film thickness of a coating layer formed on the outer side of a cylindrical sample 4 (for example, a catheter or a metal tube).

Fig. 8 is a schematic diagram showing an example of a V-groove probe 200D used in the optical measurement system according to the present embodiment. Referring to FIG. 8 , the probe 200D includes a pair of support members 214 supporting the sample 4 . Between the support members 214, a gap through which the measurement light 22 and the observation light 24 pass is formed.

By supporting the sample 4 with the support member 214 of the V-grooved probe 200D, it is possible to easily realize a vertical angle of light irradiation with respect to the measurement area portion (micro face) on the curved surface of the sample 4. . Moreover, you may employ|adopt the mechanism which can adjust the opening angle of the support member 214 according to the curvature of the sample 4. Specifically, a mechanism may be employed in which a spring or the like is disposed between the support members 214 constituting the V-shaped groove, and the opening angle can be adjusted according to the magnitude of the force applied to the sample 4 .

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

Fig. 9 is a schematic diagram showing an example of an L-shaped probe used in the optical measurement system according to the present embodiment. Referring to FIG. 9(A), inside the L-shaped probe 200E, an optical fiber 20, an optically connected light guide path 204, and a mirror 216 are formed. The propagation direction of the measurement light 22 emitted from the light guide path 204 is changed by 90° in the mirror 216, and then irradiated to the measurement surface of the sample 4. Similarly, the observation light 24 from the sample 4 is guided to the light guide path 204 after the propagation direction is changed by 90 degrees in the mirror 216 .

In FIG. 9(B), probe 200F in which the support member 218 was formed on the outer circumferential side of probe 200E shown in FIG. 9(A) is shown. 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 within 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) A mini-spot probe is mainly used in a stethoscope-type probe to measure the film thickness of a sample with a rough surface, a sample with irregularities on the surface, a sample with a light diffusive surface, or the like. In the mini-spot probe, since the irradiation area (light-receiving area) of the measurement light 22 is a small spot, noise components included in the observation light 24 can be reduced.

(6) The non-contact probe has an optical system designed to enable measurement even when the distance from the measurement position on the sample to the probe is relatively long, and allows measurement without direct contact with the sample.

Fig. 10 is a schematic diagram showing an example of a non-contact type probe 200G used in the optical measurement system according to the present embodiment. Referring to FIG. 10 , the probe 200G includes a lens 220 and a lens 222 and converges the measurement light 22 emitted from the light guide path 204 onto the sample 4 . Similarly, lenses 220 and 222 guide observation light 24 from sample 4 to light guide path 204 . By employing such an optical system, the film thickness of the sample 4 can be measured without bringing the probe 200G into direct contact with the sample 4 .

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

10 shows a configuration example in which the focus position is fixed, but the focus position may be variable.

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

(7) The tip movable probe is used to measure, for example, the film thickness of the inside of a structure with a narrow entrance or the film thickness of a sample in which an access path is bent.

Fig. 12 is a schematic diagram showing an example of a tip movable probe 200I used in the optical measurement system according to the present embodiment. Referring to FIG. 12 , the tip of the probe 200I is provided with a mirror (not shown) for changing the propagation directions of the measurement light 22 and the observation light 24, similarly to the L-shaped probe shown in FIG. 9 . has been Then, as shown in Figs. 12(A) and 12(B), the tip of the probe 200I has a structure in which the tip is bent freely when the user operates the tip. This is effective when the user cannot directly touch the probe.

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

Fig. 13 is a schematic diagram showing an example of a curved surface probe 200J used in the optical measurement system according to the present embodiment. Referring to Fig. 13, a bendable flexible portion 226 is formed at the tip of the probe 200J. The flexible portion 226 is made of a soft material. By bringing the probe 200J to an arbitrary measurement position of the sample 4, the user deforms the flexible part 226 to an appropriate state (ie, a state where the light irradiation angle with respect to the measurement surface is perpendicular to the measurement surface) ) can be realized.

A contact portion 228 that contacts the sample 4 is formed at the tip of the flexible portion 226 . A light transmitting/receiving portion 202 is formed in the center of the contact portion 228, and a rubber packing 230 is formed on the outer periphery of the exposed surface of the contact portion 228. By forming the rubber packing 230, the contactability with the sample 4 can be improved.

(9) The in-liquid probe is mainly used to measure the film thickness and the like of a sample present in a liquid.

Fig. 14 is a schematic diagram showing an example of a liquid probe 200K used in the optical measurement system according to the present embodiment. Referring to Fig. 14, the probe 200K has, as an example, the same shape as the stethoscope-type probe, but each part is sealed so that it can be used even in liquid.

(10) The oil film probe has a needle-shaped portion at the tip of the probe that contacts the measuring position, and can easily measure the film thickness of a liquid film including an oil film.

Fig. 15 is a schematic diagram showing an example of an oil film probe 200L used in the optical measurement system according to the present embodiment. Referring to FIG. 15 , the probe 200L adopts the same shape as the stethoscope-type probe as an example, but has a needle 234 so as to reduce the influence on the oil film.

(11) The multi-angle probe employs a structure capable of making the angle of incidence of the measurement light 22 to the sample 4 different.

Fig. 16 is a schematic diagram showing an example of a multi-angle probe 200M used in the optical measurement system according to the present embodiment. Referring to FIG. 16 , the probe 200M is configured to allow the measurement light 22 to be incident at an angle that is not perpendicular to the measurement surface of the sample 4 . In addition, since the observation light 24 from the sample 4 propagates at an angle other than perpendicular to the measurement surface of the sample 4, the observation light 24 can also be received.

1 and 2 described above show a configuration example in which the measuring device 100 and the probe 200 are separate bodies, but the measuring device 100 and the probe 200 may be connected, and the measuring device (100) and probe (200) may be integrated.

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

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

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

(a4: modified example, the first: integral type)

Fig. 18 is a schematic diagram showing an optical measurement system 1A according to a modified example of the present embodiment. Referring to FIG. 18 , the optical measuring system 1A includes a measuring device 100A in which functions of the measuring device 100 and the probe 200 shown in FIGS. 1 and 2 are packaged.

More specifically, the measuring device 100A includes, as typical components, a light source 102, a spectroscopic measurement unit 104, an output unit 106, an operation unit 108, an arithmetic processing unit 110, and , a power supply unit 130, and a probe 200. The probe 200 is disposed in a portion exposed from the casing of the measuring device 100A so as to be able to contact the sample. Thus, in the configuration example shown in Fig. 18, the probe 200, the light source 102, and the spectroscopic measuring unit 104 are mounted in a single casing.

Each component shown in FIG. 18 has substantially the same function as the component with the same reference numerals shown in FIG. 2, and therefore detailed description is not performed here. However, the light source 102 is optically connected to the probe 200 through an optical fiber 52 disposed in the casing of the measuring device 100A, and the spectroscopic measuring unit 104 is It is optically connected to the probe 200 through an optical fiber 54 arranged in the casing.

(a5: modified example 2nd: wireless connection configuration)

1 and 2 described above show configuration examples in which the measuring device 100 and the probe 200 are optically connected, but 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 modified example of the present embodiment. Referring to FIG. 19 , the optical measurement system 1B includes a measurement device 100B and a highly functional 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. Components included in the measuring device 100B are packaged and housed in a casing.

In addition to the probe 200, the highly functional probe 200B includes a light source 102, a spectroscopic measurement unit 104, a power supply unit 130, and a communication processing unit 136. Components included in the highly functional probe 200B are packaged and housed in a casing. Thus, 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 casing.

The communication unit 134 of the measuring device 100B and the communication processing unit 136 of the highly functional probe 200B transfer the detection result by the spectroscopic measurement unit 104 (the intensity of the observation light 24 for each wavelength) to wireless communication. exchanged by As wireless communication, any method such as wireless LAN, Bluetooth (registered trademark), infrared communication, public wireless circuit such as 4G or 5G can be adopted.

The communication processing unit 136 wirelessly transmits the detection result by the spectroscopy measurement unit 104 in addition to various processes performed by the highly functional probe 200B. The communication unit 134 outputs the detection result by the spectral measurement unit 104 wirelessly transmitted by the communication processing unit 136 to the calculation processing unit 110 .

Each of the other components shown in FIG. 19 has substantially the same functions as the components with the same reference numerals shown in FIG. 2 , and therefore detailed descriptions are not performed here.

The operating state of the highly functional probe 200B may be controlled by a command from the measuring device 100B. For example, irradiation of the measurement light 22 from the light source 102 of the highly functional probe 200B may be enabled/disabled according to a command from the measurement device 100B, and the communication processing unit of the highly functional probe 200B The radio transmission of (136) may be enabled/disabled.

When using the highly functional probe 200B, it may be operated not by power supply from an external power supply, but by power supply from the battery 132 of the power supply unit 130.

(a6: mounting method)

You may mount using the above-mentioned measuring apparatus 100, 100A, 100B using a small personal computer. In this case, many components included in the measurement devices 100, 100A, and 100B are included in the personal computer. Alternatively, the above-described measuring devices 100, 100A, and 100B may be mounted using a smartphone, tablet, or the like.

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

<B. Process example of film thickness measurement>

Next, processing examples of film thickness measurement by the optical measurement system 1 according to the present embodiment will be described.

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

Referring to FIG. 20 , consider the reflected light generated when the measurement light 22 irradiated from the probe 200 is reflected at the interface between the coating layer 41 and the substrate layer 42 . In the following description, the subscript i is used to represent each layer. That is, the air layer 40 is denoted by "0", the sample coating layer 41 is denoted by "1", and the substrate layer 42 is denoted by "2". In addition, the refractive index in each layer is represented by the refractive index n _i using the subscript i.

Since light is reflected at the interface between the layers having different refractive indices n _i , the amplitude reflectance (Fresnel coefficient) r ^(P) 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 indices _i,i+1 , r ^(S) _i,i+1 can be expressed as follows.

Here, φ _i is the incident angle in the i layer. This angle of incidence _φi can be calculated from the angle of incidence of the measurement light 22 in the air layer 40 of the uppermost layer according to the following Snell's law.

N ₀ sinφ ₀ = N _i sinφ _i

In a layer having a film thickness in which light can interfere, light reflected with an amplitude reflectance represented by the above equation travels through the layer many times. Therefore, since the optical path lengths are different between the light reflected directly at the interface with the adjacent layer and the light after multiple reflection in the layer, the phases are different from each other, and light interference occurs on the surface of the coating layer 41. this happens In order to express such an interference effect of light in each layer, introducing the phase angle β _i of light in the i-layer layer can be expressed as follows.

Here, d _i represents the film thickness of the i layer, and λ represents the wavelength of the incident light.

For further simplification, when light is irradiated perpendicularly to the sample 4, that is, when the incident angle φ _i = 0, the distinction between P polarized light and S polarized light disappears, and the amplitude reflectance and The phase angle β ₁ of the film thickness is as follows.

In addition, the reflectance R with respect to the sample 4 shown in FIG. 20 is as follows.

In the above equation, considering the frequency transformation (Fourier transform) for the phase angle β ₁ , the phase factor cos2β ₁ becomes nonlinear with respect to the reflectance R. Therefore, conversion into a function having linearity is performed for this phase factor cos2β ₁ . As an example, this reflectance R is converted according to the following formula, and a unique variable wavenumber conversion reflectance R' is defined.

This wavenumber conversion reflectance R' becomes a linear expression for the phase factor cos2β ₁ and has linearity. Here, R _a in the formula is an intercept in the wave number conversion reflectance R', and R _b is a slope in the wave number conversion reflectance R'. That is, this wavenumber conversion reflectance R' is a function for linearizing the value of reflectance R at each wavelength with respect to the phase factor cos2β ₁ related to frequency conversion. Also, as a function for linearizing such a phase factor, a function of 1/(1-R) may be used.

Therefore, the wave number K ₁ in the target coating layer 41 can be defined as follows.

Here, propagation characteristics of electromagnetic waves in the coating layer 41 depend on the wave number K ₁ . That is, since the speed of light of light having a wavelength λ in a vacuum decreases within the layer, it is understood that the wavelength also increases from λ to λ/n ₁ . Considering this wavelength dispersion phenomenon, the wave number conversion reflectance R' is defined as follows.

From this relationship, when the wave number transform reflectance R' is subjected to frequency transformation (Fourier transform) with respect to the wave number K, a peak appears in the period component corresponding to the film thickness d ₁ of the coating layer 41, and by specifying the position of this peak, The film thickness d ₁ of the coating layer 41 can be calculated.

That is, the correspondence relationship between the spectral reflectance measured from the sample 4 and the reflectance at each wavelength is the correspondence relationship between the wavenumber calculated from each wavelength and the wavenumber conversion reflectance R' calculated according to the above-described relational expression (wavenumber distribution characteristics ), the function of the wavenumber conversion reflectance R' including the wavenumber K is frequency-converted with respect to the wavenumber K to calculate a spectrum, and based on the peak appearing in the calculated spectrum, the coating layer constituting the sample 4 The film thickness d ₁ of (41) is calculated. This means that the amplitude value of each wavenumber component included in the wavenumber distribution characteristics is acquired, and the film thickness d ₁ of the coating layer 41 is calculated based on the wavenumber component having the largest amplitude value among them.

As a method of analyzing the wavenumber component having a large amplitude value from the wavenumber distribution characteristics, an FFT method using a discrete Fourier transform such as FFT or a method using an optimization method such as the Maximum Entropy Method can be adopted. can

<C. Measurement Reliability >

Next, 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 capable of measuring at an arbitrary position while held by a user. In addition, in the spectroscopic interference method using the reflected light observation system employed by the optical measurement system 1, the measurement light 22 emitted from the probe 200 transmits the observation light 24 that may be generated from the sample 4 to the probe ( 200) needs to be received. Therefore, measurement may become unstable depending on the user's holding state. Hereinafter, several factors that make film thickness measurement unstable will be described.

Fig. 21 is a diagram for explaining factors that cause film thickness measurement instability in the optical measurement system 1 according to the present embodiment. 21 shows an example in which the angle of incidence of the measurement light 22 to the measurement surface of the sample 4 is inappropriate.

Referring to FIG. 21 , when the probe 200 directly faces the measurement surface of the sample 4, the observation light 24 generated by the measurement light 22 emitted from the probe 200 , becomes 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 is properly directed to the probe 200. can't get in

In particular, when using a non-contact probe or a probe for a curved surface, since the user must hold the probe 200 during measurement, it is recommended to appropriately maintain the angle of incidence of the measurement light 22 with respect to the measurement surface of the sample 4. Since it is difficult, the measurement may become unstable.

In addition, similarly when the surface of the sample 4 is curved or has a complex shape, it is difficult to properly maintain the angle of incidence of the measurement light 22 with respect to the measurement surface of the sample 4, so measurement may become unstable. .

Fig. 22 is a diagram for explaining other factors that cause film thickness measurement instability in the optical measurement system 1 according to the present embodiment. 22 shows an example in which the focus of the measurement light 22 with respect to the measurement surface of the sample 4 is inappropriate.

Referring to FIG. 22 , when the distance between the probe 200 and the measurement plane of the sample 4 is appropriate, the measurement light 22 emitted from the probe 200 is focused on the measurement plane of the sample 4. Therefore, appropriate observation light 24 is generated from the sample 4 and enters the probe 200.

However, when 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 is positioned away from the measurement surface of the sample 4. Since it is focused at , it does not generate an appropriate observation light 24.

In particular, when using a non-contact probe or a probe for a curved surface, since the user must hold the probe 200 during measurement, it is difficult to properly maintain the distance between the probe 200 and the measuring surface of the sample 4. , the measurement may become unstable.

In addition, even when the surface of the sample 4 is curved or has a complex shape, it is difficult to properly maintain the distance between the probe 200 and the measurement surface of the sample 4, so measurement may become unstable.

Fig. 23 is a diagram for explaining another factor that makes film thickness measurement unstable in the optical measuring system 1 according to the present embodiment. 23 shows an example resulting from the microstructure of the sample 4.

Referring to FIG. 23 , assuming a sample 4 in which the coating layer 41 is formed on the substrate layer 42, the coating layer 41 may have fine irregularities. Alternatively, fine irregularities may also exist on the surface of the coating layer 41 . Also, a sample (4) having a structure in which only a part of the region can be measured is assumed.

Since the probe 200 needs to receive the observation light 24 that may occur in the sample 4, in such a sample 4, there are cases where the film thickness cannot be properly measured depending on the measurement position. there is.

Referring to FIG. 23, when the measurement surface of the sample 4 is substantially parallel to the cross section of the probe 200, the observation light 24 generated by the measurement light 22 emitted from the probe 200, It enters the probe 200.

However, when the measurement surface of the sample 4 is greatly inclined from the end face of the probe 200, the observation light 24 generated by the measurement light 22 emitted from the probe 200 cannot properly enter the

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

In this specification, "measurement reliability" means the degree to which a measured or calculated measurement result (eg, film thickness) is appropriately measured.

Although any method can be employed as a method for calculating the measurement reliability, some calculation methods will be described as typical examples.

(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.

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

Referring to Fig. 24, the spectral reflectance is calculated from the observation light 24 measured from the sample 4, converted into the wavenumber transformed reflectance R' as described above, and then frequency transformed (Fourier transform) with respect to the wavenumber K. By doing this, it is possible to calculate a spectrum (hereinafter also referred to as "power spectrum") in which the horizontal axis is the film thickness and the vertical axis is the power.

In this way, in the FFT method, the film thickness of the sample 4 is calculated based on a peak appearing in a spectrum calculated by frequency-converting the spectral reflectance or spectral transmittance.

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

For example, as shown in FIG. 24 , the area of a peak appearing at a position corresponding to the film thickness of sample 4 (peak area) and the area of other parts (noise area) are calculated and calculated. The area ratio may be regarded as the measurement reliability. Specifically, measurement reliability can be calculated according to the following formula.

Measurement Reliability = Peak Area/Noise Area

Alternatively, any formula shown below may be employed.

Measurement Reliability = Peak Area/(Peak Area + Noise Area)

Measurement Reliability = (Peak Area - Noise Area)/(Peak Area + Noise Area)

Alternatively, the measurement reliability may be calculated based on the height of the peak (magnitude of power). Specifically, measurement reliability can be calculated according to any formula shown below.

Measurement Reliability = Peak Height/Noise Height

Measurement Reliability = Peak Height/(Peak Height + Noise Height)

Measurement Reliability = (Peak Height − Noise Height)/(Peak Height + Noise Height)

In this way, when the film thickness of the sample is calculated by the FFT method, the measurement reliability can be calculated based on the size of the peak appearing in the calculated power spectrum.

(c2: Calculation method of measurement reliability by optimization method)

Next, a method suitable for calculating the film thickness by the optimization method will be described.

The optimization method is a method of fitting the parameters of a model representing the spectral reflectance to match the actually measured spectral reflectance (or the wavenumber converted reflectance R' obtained by converting the actually measured spectral reflectance).

In this way, in the optimization method, the film thickness of the sample is calculated by fitting the parameter of the model representing the spectral reflectance or spectral transmittance to match the spectral reflectance or spectral transmittance calculated based on the observation light 24 .

To what extent the spectral reflectance (theoretical value) calculated by the model defined by the parameters determined by the optimization method agrees with the actually measured spectral reflectance (i.e., the degree of agreement with the actually measured spectral reflectance, or from the actually measured spectral reflectance) Based on the degree of deviation), measurement reliability can be calculated.

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

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

In this way, when the film thickness of the sample is calculated by the optimization method, the measurement reliability can be calculated based on the degree of agreement between the spectral reflectance calculated by the model defined by the determined parameters and the actually measured spectral reflectance. . 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: Calculation method of measurement reliability based on reflectance)

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

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

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.

Moreover, you may make it calculate measurement reliability from the value of reflectance (amplitude reflectance). For example, the reflectance may be output as measurement reliability as it is, or the measurement reliability may be calculated by inputting the reflectance into a predetermined function (for example, a function in which the output monotonically increases with respect to the reflectance).

When the angle or distance of the probe 200 relative to the sample is not appropriate, or when light diffusion on the surface of the sample is large, the calculated reflectance (amplitude reflectance) becomes small, which means that the measurement reliability is low.

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.

Alternatively, the measurement reliability may be calculated from the variation in 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 a fine film thickness distribution exists on the sample surface, the calculated reflectance ( amplitude reflectance) becomes large, which means that the measurement reliability is low.

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

Fig. 26(A) shows an example of the reflectance when the measurement is unstable, and Fig. 26(B) 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 the deviation is relatively small. For this reason, the measurement reliability may be calculated based on the size of the variation in reflectance.

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

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

(c4: Calculation method of measurement reliability based on reference signal)

Measurement reliability may be calculated based on a reference signal that is the observation light 24 measured in a state where the reference cap 30 is attached to the probe 200.

For example, when the light source 102 is degraded due to use, the amount of measurement light generated by the light source 102 decreases. In such a state, it can be considered that the reliability of measurement is degraded. Therefore, the measurement reliability may be calculated based on the magnitude of the reference signal before product shipment or immediately after 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 during actual measurement to the magnitude of the reference signal before product shipment or immediately after product shipment may be calculated as measurement reliability.

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

(c5: Calculation method of measurement reliability based on deviation of measurement results)

Measurement reliability may be calculated from variations in measurement results (eg, film thickness). 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 a fine film thickness distribution exists on the sample surface, measurement or calculation The deviation of the measurement results becomes large, which means that the measurement reliability is low.

Similar to Fig. 26(A) and Fig. 26(B) described above, when the measurement is stable, the measured or calculated measurement result is also stable, so the deviation is relatively small. For this reason, the measurement reliability may be calculated based on the size of the deviation of the measured or calculated measurement results.

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 most recent measurement.

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

(c6: method using multiple types of measurement reliability)

As described above, measurement reliability can be calculated by a plurality of methods. Therefore, it may be calculated as the final measurement reliability by combining a plurality of measurement reliability calculated by different methods. In this case, the final measurement reliability may be calculated by simple averaging after normalizing a plurality of measurement reliability of the target.

Alternatively, the final measurement reliability may be calculated by multiplying a plurality of target measurement reliability by a respective corresponding weighting factor. Alternatively, the weighting coefficient may be changed according to conditions.

In this way, by determining the final measurement reliability using a plurality of types of measurement reliability, the accuracy of the measurement reliability can be increased.

<D. Film thickness measurement mode>

In the optical measurement system 1 according to the present embodiment, the following measurement modes may be implemented using the above-described measurement reliability.

(d1: navigation assistance mode)

The search support mode is a measurement mode that makes it easy 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 a state where the film thickness measurement shown in FIGS. 27(A) and 27(C) is unstable, the amplitude of the measured spectral reflectance also decreases. On the other hand, in 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 in a state where the measurement light 22 is being irradiated from the probe 200 . The measuring device 100 calculates the spectral reflectance from the observation light 24 generated in the sample 4 and repeats the process of calculating the film thickness of the sample 4 through Fourier transform or the like. In addition, the measurement device 100 also calculates measurement reliability. In addition, the measurement device 100 sequentially notifies the user of the calculated measurement reliability.

Although any method may be used to notify the user of the measurement reliability, a notification sound indicating the measurement reliability may be used so that the user can easily recognize the measurement reliability while holding and scanning the probe 200 . For example, as follows, the height of the measurement reliability may be made to correspond to the generation period or frequency of notification sound.

Measurement Reliability: Low Beep (Silent) Beep

Measurement reliability: medium beep (silent) beep

Measurement Reliability: High beep beep beep (silent) beep beep beep

In this way, a notification sound corresponding to the height of measurement reliability may be generated. With such a notification sound, the user can grasp the measurement reliability in real time, so that 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 in an appropriate measurement state can be acquired.

In addition, the user may operate the operation unit 108 (eg, trigger switch) at the time of determining 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 processing in the search support mode of the optical measurement system 1 according to the present embodiment. Referring 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 measures the film thickness of the sample 4 by holding the probe 200 in a state where the reliability of the measurement is judged to be sufficiently high.

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

Fig. 29 is a flowchart showing the 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 when the processor 112 of the arithmetic processing unit 110 of the measurement device 100 executes the measurement program 124 .

Referring to FIG. 29 , the measurement device 100, when instructed to start measurement (YES in step S100), gives a drive command to the light source 102 to irradiate the measurement light 22 from the light source 102. is validated (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 which can be placed at any position.

Then, the measuring device 100 determines that the observation light 24 from the sample 4 enters the spectroscopic measurement unit 104 and outputs the detection result (the intensity of the observation light 24 for each wavelength), The film thickness of sample 4 is calculated (step S104). In this way, the measurement device 100 receives the reflected light (or transmitted light) generated by irradiating the sample 4 with the measurement light 22 as observation light in the spectroscopic measurement unit 104, and the spectroscopic measurement unit 104 ), the film thickness of the sample 4 is calculated from the spectral reflectance (or spectral transmittance) calculated based on the detection result.

In addition, the measurement device 100 calculates the reliability of the measurement 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 measurement reliability indicating how properly the calculated film thickness is measured. Then, the measuring device 100 generates a notification sound corresponding to the calculated measurement reliability level (step S108).

When the output of the measurement result by the trigger switch or the like is instructed (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 processing in step S112 is skipped.

The measuring device 100 ends the process of measuring the film thickness when end of measurement is instructed (Yes in step S114), and repeats the process from step S104 onwards if otherwise (No in step S114).

By using the above search support mode, 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 in a state where the measurement light 22 is being irradiated from the probe 200 . The measuring device 100 calculates the spectral reflectance from the observation light 24 generated in the sample 4 and repeats the process of calculating the film thickness of the sample 4 through Fourier transform or the like. In addition, 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, as a measurement result, a corresponding measurement reliability of which is high among the calculated film thicknesses.

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

As shown in Fig. 30, the maximum value of measurement reliability calculated between the start of measurement and the end of measurement (that is, one measurement reliability) may be extracted, or one or a plurality of measurement reliability values exceeding a predetermined threshold value may be extracted. you can do it In addition, even when extracting the maximum value of measurement reliability, it is good also as an additional condition that the maximum value of measurement reliability exceeds a predetermined threshold value.

In this way, any method may be employed to extract the measurement reliability.

Fig. 31 is a flowchart showing the 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 when processor 112 of arithmetic processing unit 110 of measurement apparatus 100 executes measurement program 124 .

Referring to FIG. 31 , when a measurement start is instructed (YES in step S200), the measurement device 100 issues a drive command to the light source 102, and irradiates measurement light 22 from the light source 102. is validated (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 which can be placed at any position.

Then, the measuring device 100 determines that the observation light 24 from the sample 4 enters the spectroscopic measurement unit 104 and outputs the detection result (the intensity of the observation light 24 for each wavelength), The film thickness of the sample 4 is calculated (step S204). In this way, the measurement device 100 receives the reflected light (or transmitted light) generated by irradiating the sample 4 with the measurement light 22 as observation light in the spectroscopic measurement unit 104, and the spectroscopic measurement unit 104 ), the film thickness of the sample 4 is calculated from the spectral reflectance (or spectral transmittance) calculated based on the detection result.

In addition, the measuring device 100 calculates the reliability of the measurement 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 measurement reliability indicating how properly the calculated film thickness is measured.

The measuring device 100 executes the processing below step S210 when the end of measurement is instructed (YES in step S208), and repeats the processing below step S204 if otherwise (NO in step S208).

In step S208, the measurement device 100 extracts one or a plurality of measurement reliability values that satisfy a predetermined condition from among the measurement reliability values calculated from the measurement start to the measurement end (step S210). Then, the measuring device 100 outputs, as a measurement result, film thicknesses respectively corresponding to one or more of the extracted measurement reliability values (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 aware of measurement reliability or the like.

(d3: automatic measurement mode with navigation assistance)

The automatic measurement mode with search support is a measurement mode that automatically extracts measurement results with high measurement reliability from the start of measurement 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 in a state where the measurement light 22 is being irradiated from the probe 200 . The measuring device 100 calculates the spectral reflectance from the observation light 24 generated in the sample 4 and repeats the process of calculating the film thickness of the sample 4 through Fourier transform or the like. In addition, the measuring device 100 also calculates the measurement reliability corresponding to each film thickness. In addition, the measurement 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 of whether or not the measurement reliability is in the direction of improvement, but the height of the measurement reliability is such that it is easy to recognize the improvement in the measurement reliability in a state where the user is scanning while holding the probe 200. You may use a notification sound indicating. For example, a notification sound may be generated only when the measurement reliability changes in a direction higher than the previous measurement reliability. In addition, it is good also in accordance with the height of the calculated measurement reliability also for the notification sound to generate|occur|produce.

Alternatively, by generating a notification sound when the measurement reliability is improved and generating another notification sound when the measurement reliability is lowered, the user can determine whether or not the measurement reliability is in the direction of improvement through his/her own adjustments. easily recognizable.

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

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

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

As shown in Fig. 32, a peak appearing in measurement reliability calculated between the start of measurement and the end of measurement may be extracted, or one or a plurality of measurement reliability values exceeding a predetermined threshold may be extracted. Also, when extracting a peak that appears in the measurement reliability, it is good as an additional condition that the value of the peak exceeds a predetermined threshold value.

In this way, any method may be employed to extract the measurement reliability.

Fig. 33 is a flowchart showing the 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 when the processor 112 of the arithmetic processing unit 110 of the measurement device 100 executes the measurement program 124.

Referring to FIG. 33 , the measurement device 100, when instructed to start measurement (YES in step S300), gives a drive command to the light source 102 to irradiate the measurement light 22 from the light source 102. is validated (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 which can be placed at any position.

Then, the measuring device 100 determines that the observation light 24 from the sample 4 enters the spectroscopic measurement unit 104 and outputs the detection result (the intensity of the observation light 24 for each wavelength), The film thickness of the sample 4 is calculated (step S304). In this way, the measurement device 100 receives the reflected light (or transmitted light) generated by irradiating the sample 4 with the measurement light 22 as observation light in the spectroscopic measurement unit 104, and the spectroscopic measurement unit 104 ), the film thickness of the sample 4 is calculated from the spectral reflectance (or spectral transmittance) calculated based on the detection result.

In addition, the measuring device 100 calculates 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 measurement reliability indicating how properly the calculated film thickness is measured.

If the calculated measurement reliability is in the improvement direction (YES in step S308), the measurement 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 improvement direction (NO in step S308), the process of step S310 may be skipped.

Then, the measurement device 100 executes the processing below step S314 when the end of measurement is instructed (YES in step S312), and repeats the processing below step S304 if otherwise (NO in step S312).

In step S310, the measurement apparatus 100 extracts one or a plurality of measurement reliability values that satisfy a predetermined condition from among the measurement reliability values calculated from the measurement start to the measurement end (step S314). Then, the measurement device 100 outputs, as a measurement result, a film thickness corresponding to one or more of the extracted measurement reliability values, respectively (step S316). Then, the process ends.

By using the automatic measurement mode including 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 height of the measurement reliability is associated with the generation period or frequency of notification sound has been exemplified, but it is not limited to this, and any notification method can be adopted.

When the measurement reliability is notified by sound (ie, when the user recognizes the measurement reliability by hearing), one or more of volume, pitch, and timbre may be changed according to the height of the calculated measurement reliability. The user can easily recognize a change in measurement reliability by changing any of the volume, pitch, and timbre of the notification sound.

In addition, notification by vibration, light, image, etc. can also be adopted, not limited to notification by sound.

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

In addition, when the measurement reliability is notified by light or an image (that is, when the user recognizes the measurement reliability visually), forming an arbitrary light emitting device in the measuring device 100 and/or the probe 200; In addition, the light emitting state of the light emitting device may be changed according to the height of the calculated measurement reliability. That is, you may make it output from the output part 106 at least one of the light and image which represent measurement reliability. A user can easily recognize a change in measurement reliability based on light or an image entering the eye.

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

On the display 1060 of the measuring device 100 shown in FIG. 34(A), a measured value 1062 of the film thickness and a status bar 1064 indicating the reliability of the measurement 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), a measured value 1062 of the film thickness and a numerical value 1066 indicating the reliability of the measurement are displayed. By confirming the numerical value 1066 representing the measurement reliability, the user can obtain the measured value 1062 of the film thickness while recognizing the measurement reliability.

A measured value 1062 of the film thickness is displayed on the display 1060 of the measuring device 100 shown in FIG. 34(C), and an indicator 1068 indicating measurement reliability is provided in the measuring device 100. . Indicator 1068 is lit by the number corresponding to the height of the calculated measurement reliability. The user can obtain the measured value 1062 of the film thickness while recognizing the measurement reliability by confirming the indicator 1068 indicating the measurement reliability.

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

<E. Function block diagram>

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

Referring to FIG. 35 , the measurement apparatus 100 includes a buffer 150, a wave number transform unit 152, a Fourier transform unit 154, a peak search unit 156, and a film thickness determination as functional components. A unit 158, a measurement reliability calculation unit 160, and an output processing unit 162 are included.

The buffer 150 stores the detection result from the spectrometer 104 (the intensity of the observation light 24 for each wavelength).

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

The Fourier transform unit 154 Fourier transforms the wavenumber transform reflectance calculated by the wavenumber transform unit 152 .

The peak search unit 156 searches for a peak included in the power spectrum calculated by Fourier transform by the Fourier transform unit 154, and outputs a position (film 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 properly 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 Fourier transform by the Fourier transform unit 154 .

The film thickness determination unit 158 determines the film thickness output from the peak search unit 156 as a measurement result, if a predetermined condition is satisfied. The predetermined conditions may include that the user operated the operation unit 108, that the measurement reliability in a predetermined period reached a maximum value, that the measurement reliability exceeded a predetermined threshold value, and the like. In this way, the film thickness determination unit 158 typically determines, as a measurement result, the film thickness at the point in time when the measurement reliability satisfies a predetermined condition.

The output processing unit 162 determines 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 processing output from the output unit 106. The output processing unit 162 notifies the user of the measurement reliability calculated by the measurement reliability calculation unit 160 through the output unit 106 .

35 shows a configuration example in the case of calculating the film thickness by the FFT method as a typical example, but in the case of measuring the film thickness by the optimization method, a model including the film thickness of the sample as a parameter; A fitting portion for fitting the actually measured reflectance (or transmittance) may be provided.

<F. Modified example>

In the above description, a configuration example in which the measurement device 100 of the optical measurement system 1 executes necessary processing has been described, but it is not limited to this, and the processing is divided among a plurality of processing devices, for example. Alternatively, the probe 200 may be in charge of a part of the processing. Further, a computing resource (so-called cloud) on a network (not shown) may be in charge of all or part of necessary processing.

When many computing resources are available, machine learning is performed using measurement results obtained in the past and/or measurement results obtained by another optical measurement system 1, and learning obtained by machine learning is completed. The user may be notified of optimum conditions related to film thickness measurement using the model.

<G. summary>

In the optical measurement system according to the present embodiment, since the film thickness of the sample is optically calculated based on the observation light acquired through the probe that can be placed at any position, the measurement accuracy of the film thickness can be increased.

In addition, in the optical measuring system according to the present embodiment, since the measurement reliability indicating how properly the calculated film thickness is measured is also calculated, the film thickness of the sample can be more appropriately measured.

In addition, since the optical measurement system according to the present embodiment can measure a sample by arranging a probe that can be placed at an arbitrary position, the film thickness can be easily measured at a production site or a production line. Moreover, even if it is a sample with a curved surface or a sample with a complicated shape, it can measure simply.

Embodiment disclosed this time should be considered as an illustration and not restrictive at all points. The scope of the present invention is shown by the claims rather than the above description, and it is intended that all changes within the scope and meaning equivalent to the scope of the claims are included.

1, 1A, 1B: optical measurement system
4: sample
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 measurement unit
106: output unit
108: control panel
110: calculation processing unit
112: processor
114: main memory
116: internal interface
117: universal interface
118: network interface
120: storage
122: operating system
124: measurement program
126: detection result
128: measurement result
130: power supply
132: battery
134: communication department
136: communication processing unit
150: buffer
152: wave number conversion unit
154: Fourier transform unit
156: peak search unit
158 film thickness determining unit
160: measurement reliability calculation unit
162: output processing unit
200, 200C, 200D, 200E, 200F, 200G, 200H, 200I, 200J, 200K, 200L, 200M: probe
200B: Highly functional probe
202: transmission/receiving unit
204: light guide
210, 212: attachment
214, 218: support member
220, 222: lens
226: flexible part
228: contact
230: rubber packing
234: sleep
1060: display
1062: measured value
1064: Status bar
1066: shame
1068: indicator

Claims (12)

As an optical measurement system for measuring the film thickness, which is the thickness of the layer included in the sample,
a light source for generating measurement light;
A light receiving unit configured to receive 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 unit and can be disposed at an arbitrary position;
a film thickness calculation unit for calculating 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 a reliability calculation unit that calculates a measurement reliability indicating how appropriately the film thickness calculated by the film thickness calculation unit is measured. According to claim 1,
The optical measuring system further comprises an output unit for notifying the measurement reliability calculated by the reliability calculation unit. According to claim 2,
The output unit generates a notification sound corresponding to the height of the measurement reliability. According to claim 2 or 3,
The optical measurement system, wherein the output unit outputs at least one of light and an image representing the measurement reliability. According to any one of claims 1 to 4,
and a determination unit for determining, as a measurement result, a film thickness at a point in time when the measurement reliability satisfies a predetermined condition. According to any one of claims 1 to 5,
The film thickness calculator calculates the film thickness of the sample based on a peak appearing in a spectrum calculated by frequency-converting the spectral reflectance or the spectral transmittance,
Wherein the reliability calculation unit calculates the measurement reliability based on the size of a peak appearing in the spectrum. According to any one of claims 1 to 5,
The film thickness calculation unit calculates the film thickness of the sample by fitting a parameter of a model representing spectral reflectance or spectral transmittance to match the spectral reflectance or spectral transmittance calculated based on the observation light,
The optical measurement system of claim 1 , wherein the reliability calculation unit calculates measurement reliability based on a result of the fitting determined by the film thickness calculation unit. According to any one of claims 1 to 7,
The optical measuring system, wherein the probe is configured to be changeable into different types according to the sample. According to any one of claims 1 to 8,
At least the film thickness calculation unit and the reliability calculation unit are mounted in a casing independent of the probe. According to any one of claims 1 to 8,
The optical measuring system, wherein at least the probe, the light source and the light receiving unit are mounted in a single casing. As an optical measurement method for measuring the film thickness, which is the thickness of a layer included in a sample,
irradiating the sample with measurement light generated by a light source through a probe that can be placed at an arbitrary position;
Receiving reflected light or transmitted light generated by irradiating the sample with the measurement light as observation light at a light receiving unit, and calculating the film thickness of the sample from the spectral reflectance or spectral transmittance calculated based on the detection result by the light receiving unit; ,
An optical measuring method, comprising: a step of calculating a measurement reliability indicating how appropriately the calculated film thickness is measured. A measurement program for measuring a film thickness, which is the thickness of a layer included in a sample, in a computer,
From the spectral reflectance or spectral transmittance calculated based on the detection result obtained by receiving reflected light or transmitted light generated when the sample is irradiated with measurement light generated by a light source through a probe that can be placed at an arbitrary position, the film of the sample Steps for calculating the thickness;
A measurement program that executes a step for calculating a measurement reliability indicating how properly the calculated film thickness is measured.

Images