KR20230058376A - Optical measuring systems and probes - Google Patents

Abstract

An optical measurement system for measuring the spectral reflectance of a sample is provided. The optical measurement system includes a light source for generating measurement light, a light receiving unit for receiving light generated by irradiating the measurement light on a sample as observation light, optically connected to the light source and the light receiving unit, and a probe that can be placed at an arbitrary position; and an arithmetic processing unit that measures the spectral reflectance of the sample based on a detection result by the light receiving unit and calculates a measurement result based on the measured spectral reflectance. The probe includes a body portion that is held by a user and a flexible portion that is bendable so that measurement light can be perpendicularly incident to the sample.

Description

Optical measuring systems and probes

The present invention relates to a portable optical measurement system and a probe used in the optical measurement system.

There is a need to control the quality 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. Further, Japanese Unexamined Patent Publication No. 2007-198771 (Patent Document 5) discloses a film thickness measurement method capable of measuring the film thickness of a light-transmitting film formed on a support substrate with good accuracy in a film thickness measurement method of a light-transmitting film. Initiate.

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 Japanese Unexamined Patent Publication No. 2007-198771

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.

Further, the film thickness measurement method disclosed in Patent Literature 5 is based on the premise of measuring the distance between the lens and the surface of the coating film at a constant level, but how to maintain the distance is not taught.

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 a sample.

According to one aspect of the present invention, an optical measurement system for measuring the spectral reflectance of a sample is provided. The optical measurement system includes a light source for generating measurement light, a light receiving unit for receiving light generated by irradiating the measurement light on a sample as observation light, optically connected to the light source and the light receiving unit, and a probe that can be placed at an arbitrary position; and an arithmetic processing unit that measures the spectral reflectance of the sample based on a detection result by the light receiving unit and calculates a measurement result based on the measured spectral reflectance. The probe includes a body portion that is held by a user and a flexible portion that is bendable so that measurement light can be perpendicularly incident to the sample.

The probe may further include a contact portion formed at the tip of the flexible portion and brought into contact with the sample.

A bendable light guide path may be disposed inside the probe.

The flexible part may be made of a material having flexibility.

The flexible portion may include a spring connected to the main body portion.

The flexible part may include an axial mechanism each capable of rotating around two axes orthogonal to each other.

The flexible portion may include a bellows connected to the body portion.

The flexible part may include a ball joint rotatably connected to the body part.

According to another aspect of the present invention, a probe constituting an optical measurement system for measuring the spectral reflectance of a sample is provided. The optical measurement system includes a light source for generating measurement light, a light receiving unit for receiving light generated by irradiating the measurement light onto a sample as observation light, and measuring the spectral reflectance of the sample based on a detection result by the light receiving unit, and measuring the and an arithmetic processing unit that calculates a measurement result based on the spectral reflectance. The probe includes a body portion that is held by a user and a flexible portion that is bendable so that measurement light can be perpendicularly incident to the sample. The probe is optically connected to the light source and the light receiving unit, and is configured to be dispositionable at an arbitrary position.

According to any embodiment of the present invention, a 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.
4 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.
5 is a schematic diagram showing an example of a cross-sectional structure of a probe for a curved surface used in the optical measurement system according to the present embodiment.
Fig. 6 is a schematic diagram showing a configuration example of a probe for a curved surface used in the optical measurement system according to the present embodiment.
Fig. 7 is a schematic diagram showing a configuration example of a probe for a curved surface used in the optical measurement system according to the present embodiment.
Fig. 8 is a schematic diagram showing a configuration example of a probe for a curved surface used in the optical measurement system according to the present embodiment.
Fig. 9 is a schematic diagram showing a configuration example of a probe for a curved surface used in the optical measurement system according to the present embodiment.
10 is a schematic diagram showing an example of a cross-sectional structure of a sample to be measured by the optical measuring system according to the present embodiment.
11 is a diagram for explaining an example of a method for calculating measurement reliability in the optical measurement system according to the present embodiment.
12 is a diagram for explaining another example of a method for calculating measurement reliability in the optical measurement system according to the present embodiment.
13 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. 14 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.
15 is a schematic diagram showing an example of a functional configuration provided by the optical measurement system according to the present embodiment.
16 is a flow chart showing the processing procedure of the optical measuring 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 measuring system 1 is an optical measuring device that measures the spectral reflectance of a sample using light. That is, the optical measurement system 1 measures the spectral reflectance of the sample and calculates a measurement result based on the measured spectral reflectance.

In this specification, the "measurement result based on the spectral reflectance" includes any measurement result calculated using the measured spectral reflectance in addition to the measured spectral reflectance itself. Examples of measurement results calculated using the spectral reflectance include film thickness, reflectance characteristics, object color, and the like.

Hereinafter, for convenience, the configuration for measuring the film thickness of the sample will be mainly described.

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.

(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 probe 200 has a structure suitable for measurement of the sample 4 having an uneven measurement surface. In the example shown in FIG. 1 , the sample 4 includes a base 6 and a layer 8 as a target for film thickness measurement. At least a part of the probe 200 is bendable so as to closely adhere to the surface shape of the sample 4 . More specifically, the probe 200 includes a body portion 224 , a flexible portion 226 , and a contact portion 228 . In the example shown in FIG. 1 , a configuration in which the flexible portion 226 can be bent is realized.

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 measures the spectral reflectance based on the detection result by the spectral measuring unit 104 (the intensity of the observation light 24 for each wavelength), and the measurement result 128 based on the measured spectral reflectance yields The arithmetic processing unit 110 can measure the film thickness of the sample as the measurement result 128 based on the measured spectral reflectance. In addition, the arithmetic processing unit 110 has a reliability 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.

<B: Probe (200)>

Next, a configuration example of the probe 200 used in the optical measurement system 1 according to the present embodiment will be described. The probe 200 used in the optical measurement system 1 according to the present embodiment is suitable for measuring a sample 4 having an uneven measurement surface. Such a probe 200 is also referred to as a probe for curved surfaces.

In the optical measuring system 1, the film thickness of the sample 4 is measured in a state in which the user holds the probe 200 and brings the probe 200 into contact with the sample 4 (applied state). In order to perform proper measurement, it is necessary that the measurement light 22 irradiated from the light-transmitting part of the probe 200 is reflected from the sample 4 and the observation light 24 generated is incident on the light-transmitting part of the probe 200. there is. At this time, if the measurement light 22 irradiated from the probe 200 is not perpendicularly incident on the sample 4, the observation light 24 generated by reflection does not return to the probe 200, so that the sample The film thickness of (4) cannot be measured. In particular, when the surface of the sample 4 is curved, it is difficult to vertically apply the probe 200 to an arbitrary measurement position of the sample 4 .

Therefore, in the optical measurement system 1 according to the present embodiment, a probe for a curved surface can be used. The probe for curved surfaces is mainly used for measuring the film thickness and the like of a sample whose measuring position is a curved surface.

Hereinafter, several structural examples of the probe for a curved surface will be described.

Fig. 4 is a schematic diagram showing an example of a curved surface probe 200A used in the optical measurement system according to the present embodiment. Referring to Fig. 4, a bendable flexible portion 226 is formed at the tip of the probe 200A. The flexible portion 226 is made of a soft material. When the user brings the probe 200A to an arbitrary measurement position of the sample 4, the flexible part 226 is deformed 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.

In the measurement state, the sample 4 is irradiated with the measurement light 22 in a state where the contact portion 228 of the probe 200A shown in FIG. 4 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.

Fig. 5 is a schematic diagram showing an example of a cross-sectional structure of a curved surface probe 200A used in the optical measurement system according to the present embodiment. Referring to Fig. 5, a light guide path 204 optically connected to an optical fiber 20 (see Fig. 4) is formed inside the probe 200A. 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 .

The light guide path 204 is made of a bendable material such as an optical fiber. Further, the flexible portion 226 of the probe 200A is made of a material having flexibility such as rubber. A terminal mechanism 206 is formed at one end of the light guide path 204, and the terminal mechanism 206 communicates with a terminal mechanism 208 optically connected to the light-transmitting/receiving portion 202.

The flexible part 226 is made of a flexible material and the bendable light guide path 204 is placed therein to obtain a probe 200A suitable for measuring the sample 4 having an uneven measurement surface. It can be realized.

As shown in FIGS. 4 and 5 , the probe 200A is configured such that the part applied to the sample 4 moves flexibly. By employing such a configuration, even if the measurement position of the sample 4 is a curved surface, the user can apply the probe 200A to the sample 4, thereby generating the observation light 24 at an arbitrary measurement position of the sample 4. can be appropriately irradiated, whereby the film thickness of the sample 4 can be measured simply and reliably.

Fig. 6 is a schematic diagram showing a configuration example of a curved surface probe 200B used in the optical measurement system according to the present embodiment. 6 shows an example in which the flexible part 226 is configured using a spring.

Referring to FIG. 6(A), the bendable flexible part 226 of the probe 200B is configured using a spring 232 connected to the body part 224. The body portion 224 and the flexible portion 226 are held in a predetermined relative relationship by the restoring force of the spring 232 . However, when a force exceeding the restoring force of the spring 232 is applied, the flexible portion 226 can take an arbitrary angle with respect to the body portion 224 . That is, the flexible portion 226 is oriented diagonally with respect to the longitudinal direction of the body portion 224 so as to suit the surface shape of the sample 4 .

Referring to FIG. 6(B), inside the probe 200B, an optical fiber 20 (see FIG. 4) 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 .

The light guide path 204 is made of a bendable material such as an optical fiber. A terminal mechanism 206 is formed at one end of the light guide path 204, and the terminal mechanism 206 communicates with a terminal mechanism 208 optically connected to the light-transmitting/receiving portion 202.

The light guide path 204 is arranged so as to pass through the inside of the spring 232 . Since the inner diameter of the spring 232 is sufficiently larger than the outer diameter of the light guide passage 204, even when the flexible portion 226 is diagonal to the longitudinal direction of the body portion 224, the light guide passage 204 and the Spring 232 does not contact.

In addition, the structure of the contact part 228 of probe 200B is the same as that of the contact part 228 of probe 200A shown in FIG.

As shown in FIG. 6 , the probe 200B adopts a structure in which a body portion 224 held by the user and a contact portion 228 applied to the sample 4 are connected by a spring 232. By employing such a structure, the user can apply the contact portion 228 at an angle corresponding to an arbitrary measurement position of the sample 4 without being aware of the angle of the body portion 224 . This makes it possible to measure the film thickness of the sample 4 simply and reliably.

Fig. 7 is a schematic diagram showing a configuration example of a curved surface probe 200C used in the optical measurement system according to the present embodiment.

Referring to Fig. 7(A), the bendable flexible portion 226 of the probe 200C is configured using an axis mechanism capable of rotating about two mutually orthogonal axes. More specifically, the probe 200C includes a plate 234 rotating along the first rotational axis 235 and a plate 236 rotating along the second rotational axis 237 . Also, two plates 234 are formed to face each other, and similarly, two plates 236 are formed to face each other.

One end of the plate 234 is connected to the main body 224, and the other end of the plate 234 is connected to the link member 238. In addition, one end of the plate 236 is connected to the link member 238, and the other end of the plate 236 is connected to a member including the contact portion 228.

Since the first rotation shaft 235 of the plate 234 and the second rotation shaft 237 of the plate 236 are each freely rotatable, the flexible part 226 is moved by the external force applied by the user. It can take any angle with respect to (224). That is, the flexible portion 226 is oriented diagonally with respect to the longitudinal direction of the body portion 224 so as to suit the surface shape of the sample 4 .

Referring to FIG. 7(B), inside the probe 200C, an optical fiber 20 (see FIG. 4) 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 .

The light guide path 204 is made of a bendable material such as an optical fiber. A terminal mechanism 206 is formed at one end of the light guide path 204, and the terminal mechanism 206 communicates with a terminal mechanism 208 optically connected to the light-transmitting/receiving portion 202.

The light guide path 204 is arranged so as to pass through a space formed in the central portion of the link member 238 . Since the inner diameter of the void of the link member 238 is sufficiently larger than the outer diameter of the light guide passage 204, even when the flexible portion 226 is diagonal to the longitudinal direction of the body portion 224, the light guide path ( 204) does not interfere with other members.

In addition, the structure of the contact part 228 of probe 200C is the same as that of the contact part 228 of probe 200A shown in FIG.

As shown in FIG. 7 , the probe 200C adopts a structure in which a main body portion 224 held by the user and a contact portion 228 applied to the sample 4 are connected by joints composed of two axes, there is. By employing such a structure, the user can apply the contact portion 228 at an angle corresponding to an arbitrary measurement position of the sample 4 without being aware of the angle of the body portion 224 . This makes it possible to measure the film thickness of the sample 4 simply and reliably.

Fig. 8 is a schematic diagram showing a configuration example of a curved surface probe 200D used in the optical measurement system according to the present embodiment.

Referring to FIG. 8(A), the bendable flexible portion 226 of the probe 200D is configured using a bellows 240 connected to the body portion 224. More specifically, the probe 200E includes a bellows 240 for connecting the body portion 224, the flexible portion 226, and the contact portion 228. Since the bellows 240 has a predetermined rigidity and flexibility, the body portion 224 and the flexible portion 226 are maintained in a predetermined relative relationship. However, when a force according to the flexibility of the bellows 240 is applied, the flexible portion 226 can take an arbitrary angle with respect to the main body portion 224 . That is, the flexible portion 226 is oriented diagonally with respect to the longitudinal direction of the body portion 224 so as to suit the surface shape of the sample 4 .

Referring to Fig. 8(B), inside the probe 200D, an optical fiber 20 (see Fig. 4) 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 .

The light guide path 204 is made of a bendable material such as an optical fiber. A terminal mechanism 206 is formed at one end of the light guide path 204, and the terminal mechanism 206 communicates with a terminal mechanism 208 optically connected to the light-transmitting/receiving portion 202.

The light guide passage 204 is arranged so as to penetrate the inner space of the bellows 240 . Since the inner diameter of the bellows 240 is sufficiently larger than the outer diameter of the light guide passage 204, even when the flexible portion 226 is diagonal to the longitudinal direction of the body portion 224, the light guide passage 204 It does not interfere with other members.

In addition, the structure of the contact part 228 of probe 200D is the same as that of the contact part 228 of probe 200A shown in FIG.

As shown in FIG. 8 , in the probe 200D, a body portion 224 held by the user and a contact portion 228 applied to the sample 4 are connected by a bellows 240 made of a normal flexible material. structure is adopted. By employing such a structure, the user can apply the contact portion 228 at an angle corresponding to an arbitrary measurement position of the sample 4 without being aware of the angle of the body portion 224 . This makes it possible to measure the film thickness of the sample 4 simply and reliably.

Fig. 9 is a schematic diagram showing a configuration example of a curved surface probe 200E used in the optical measurement system according to the present embodiment.

Referring to FIG. 9(A) , the bendable flexible portion 226 of the probe 200E is configured using a ball joint 242 rotatably connected to the main body portion 224 . More specifically, the probe 200E includes a ball joint 242 for connecting the body portion 224, the flexible portion 226, and the contact portion 228. Since the ball joint 242 has a predetermined resistance, the body portion 224 and the flexible portion 226 are maintained in a predetermined relative relationship. When a force exceeding the resistance of the ball joint 242 is applied, the flexible portion 226 can take an arbitrary angle with respect to the body portion 224 . That is, the flexible portion 226 is oriented diagonally with respect to the longitudinal direction of the body portion 224 so as to suit the surface shape of the sample 4 .

Referring to Fig. 9(B), inside the probe 200E, an optical fiber 20 (see Fig. 4) 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 .

The light guide path 204 is made of a bendable material such as an optical fiber. A terminal mechanism 206 is formed at one end of the light guide path 204, and the terminal mechanism 206 communicates with a terminal mechanism 208 optically connected to the light-transmitting/receiving portion 202.

The light guide path 204 is arranged so as to penetrate the inside of the ball joint 242 . The inner hole of the ball joint 242 is maintained regardless of the positional relationship between the body portion 224 and the flexible portion 226, so that the light guide passage 204 is not damaged.

In addition, the structure of the contact part 228 of probe 200E is the same as the contact part 228 of probe 200A shown in FIG.

As shown in FIG. 9 , the probe 200E adopts a structure in which a body portion 224 held by the user and a contact portion 228 applied to the sample 4 are connected by a ball joint 242. . By employing such a structure, the user can apply the contact portion 228 at an angle corresponding to an arbitrary measurement position of the sample 4 without being aware of the angle of the body portion 224 . This makes it possible to measure the film thickness of the sample 4 simply and reliably.

By employing the probe 200 having the structure as described above, the film thickness of the sample 4 having an uneven measurement surface can be measured. In addition, as long as the contact portion 228 can change an arbitrary direction with respect to the body portion 224 held by the user via the flexible portion 226, the structure is not limited to the above-described structure, and any structure The probe 200 of may be employed.

<C. 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.

10 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 description, FIG. 10 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. 10 , 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. 10 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

<D. 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. In particular, when using a probe for curved surfaces, since the user must hold the probe 200 during measurement, it is difficult to properly maintain the distance between the probe 200 and the measurement surface of the sample 4, so measurement is difficult. can become unstable.

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.

(d1: Calculation method of measurement reliability by FFT method)

First, a method suitable for calculating the film thickness by the FFT method will be described.

11 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. 11 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. 11, 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. 11, 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.

(d2: 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.

(d3: calculation method of measurement reliability based on reflectance)

12 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. 12(A) shows an example of the spectral reflectance when the measurement state is bad, and Fig. 12(B) shows an example of the spectral reflectance when the measurement state is appropriate. As shown in Fig. 12, 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 attached, a ratio to the reference amplitude may be calculated as the measurement reliability.

A reference cap is used for calibration of the optical measurement system 1 . Also, the reference cap can be used to prevent entry of dust or the like when the probe 200 is stored.

In the state where the reference cap is attached to the probe 200, a mirror is formed at a position facing the light transmitting/receiving portion 202 of the probe 200. The mirror 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 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.

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.

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

Fig. 13(A) shows an example of the reflectance when the measurement is unstable, and Fig. 13(B) shows an example of the reflectance when the measurement is stable. As shown in Fig. 13, 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.

(d4: Calculation method of measurement reliability based on reference signal)

The measurement reliability may be calculated based on the reference signal, which is the observation light 24 measured with the reference cap 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.

(d5: 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 the above-described FIGS. 13(A) and 13(B), 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.

(d6: 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.

(d7: method of notification)

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 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.

Fig. 14 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. 14(A) to 14(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 measuring device 100.

On the display 1060 of the measurement device 100 shown in FIG. 14(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. 14(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. 14(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. 14(A) to 14(C).

<E. Function block diagram>

15 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. 15 is typically realized when the processor 112 of the arithmetic processing unit 110 of the measurement apparatus 100 executes the measurement program 124 .

Referring to FIG. 15 , the measuring device 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 .

15 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. Processing order>

Fig. 16 is a flowchart showing the processing procedure of the optical measurement system 1 according to the present embodiment. Each step shown in FIG. 16 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. 16 , the measurement device 100, when instructed to start measurement (YES in step S100), gives a drive command to the light source 102, and irradiates 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).

In addition, the processing of steps S106 and S108 may be omitted. In this case, in step S110, it is determined whether or not the conditions for outputting the measurement result are satisfied.

<G. Modified example>

The above-described measuring device 100 may be implemented using a small personal computer. In this case, many components included in the measuring device 100 are included in the personal computer. Alternatively, the above-described measuring device 100 may be mounted using a smartphone, tablet, or the like.

Although the configuration example in which the measurement device 100 of the optical measurement system 1 executes necessary processing has been described, it is not limited to this, and the processing may be divided among a plurality of processing devices, for example, and some of the processing may be performed. The probe 200 may be in charge. 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.

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.

Moreover, it is not limited to the probe 200 mentioned above, You may employ|adopt the probe 200 of any shape. For example, according to the sample 4, the probe 200 may be 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) liquid probe, (9) oil film probe, (10) multi-angle probe and the like.

Further, although a configuration example in which the measuring device 100 and the probe 200 are separate bodies has been shown, the measuring device 100 and the probe 200 may be connected, and the measuring device 100 and the probe 200 may be connected. can be unified. In addition, although the configuration example in which the measuring device 100 and the probe 200 were optically connected was shown, the measuring device 100 and the probe 200 may be made wireless.

<H. summary>

In the optical measurement system according to the present embodiment, by using a probe including a bendable flexible portion, an optical measurement value can be easily obtained even for a sample having a curved surface. A user holds the probe according to the present embodiment and brings the probe to an arbitrary measurement position on the sample, thereby measuring an optical measurement value at the measurement position. At this time, since the probe includes a bendable flexible portion, the contact portion applied to the sample moves flexibly. Thereby, even for a sample with a curved surface, the light from the light source can be perpendicularly incident to the sample, and more accurate optical measurement of the sample can be realized.

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: optical measuring system
4: sample
6: donation
8: layer
10, 20: optical fiber
12, 14: branch fiber
16: branch
22: measurement light
24 : observation light
28 : Coupler
30: reference cap
40: air layer
41: coating layer
42: substrate layer
100: 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
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, 200A, 200B, 200C, 200D, 200E: Probe
202: transmission/receiving unit
204: light guide
206, 208: terminal mechanism
224: main body
226: flexible part
228: contact
230: rubber packing
232: spring
234, 236: plate
235: first rotation axis
237: second rotation axis
238: no link
240: Velos
242: ball joint
1060: display
1062: measured value
1064: Status bar
1066: shame
1068: indicator

Claims (9)

An optical measurement system for measuring the spectral reflectance of a sample,
a light source for generating measurement light;
A light receiving unit configured to receive light generated by irradiating the sample with the measurement light as observation light;
a probe optically connected to the light source and the light receiving unit and capable of being disposed at an arbitrary position;
An arithmetic processing unit for measuring spectral reflectance of the sample based on a detection result by the light receiving unit and calculating a measurement result based on the measured spectral reflectance;
The probe includes a body portion held by a user and a flexible portion that is bendable so that the measurement light can be perpendicularly incident to the sample. According to claim 1,
The probe further comprises a contact portion formed at a tip of the flexible portion and contacting the sample, the optical measuring system. According to claim 1 or 2,
An optical measurement system, wherein a bendable light guide path is disposed inside the probe. According to any one of claims 1 to 3,
The optical measuring system, wherein the flexible part is made of a material having flexibility. According to any one of claims 1 to 3,
The flexible part includes a spring connected to the body part, the optical measuring system. According to any one of claims 1 to 3,
The flexible part includes an axis mechanism rotatable about two axes orthogonal to each other, respectively. According to any one of claims 1 to 3,
The flexible part includes a bellows connected to the body part, the optical measuring system. According to any one of claims 1 to 3,
The flexible part includes a ball joint rotatably connected to the main body part. A probe constituting an optical measurement system for measuring the spectral reflectance of a sample,
The optical measurement system,
a light source for generating measurement light;
A light receiving unit configured to receive light generated by irradiating the sample with the measurement light as observation light;
An arithmetic processing unit for measuring spectral reflectance of the sample based on a detection result by the light receiving unit and calculating a measurement result based on the measured spectral reflectance;
The probe includes a body portion held by a user and a flexible portion that is bendable so that the measurement light can be perpendicularly incident to the sample,
The probe is optically connected to the light source and the light receiving unit, and is configured to be dispositionable at an arbitrary position.

Images