Measurement method and measurement system

Abstract

To provide a measurement method and measurement system, each enabling film thickness of copper oxide to be measured more simply and in shorter time.SOLUTION: In a measurement method according to one embodiment, a mathematical expression indicative of a relationship between a film thickness of copper oxide equal to or less than 15 nm and color information on the copper oxide are prepared; color of a surface of copper being a measurement object is measured, and the color-measurement result is applied to the mathematical expression, and thus the film thickness of the copper oxide formed on the surface is calculate. In a different another embodiment, the color of the copper oxide is measured based on a method complying with any of DIN5033 Teil7, JIS Z 8722 Condition c, ISO7724 / 1, CIE No.15(2004), or ASTM E 1164(SCI). In another measurement method, a mathematical expression is prepared which is indicative of a relationship between color information on copper oxide in which an L value is larger than 53 and less than 82, an a value is larger than 17 and less than 45, and a b value is larger than 24 and less than 43 and a film thickness of the copper oxide; a color of the surface of the copper oxide of the measurement object is measured; and a film thickness of the copper oxide formed on the surface is calculated by applying a color-measurement result to a mathematical expression.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a measurement method and a measurement system.

Background Art

[0002] When copper reacts with oxygen, copper oxide is formed. There is a need for a technique that can more easily measure the film thickness of the copper oxide film formed on the surface of a copper member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the present invention is to provide a measurement method and a measurement system capable of more easily and in a shorter time measuring the film thickness of copper oxide.

Means for Solving the Problems

[0005] In a measurement method according to an embodiment, a mathematical formula showing the relationship between the film thickness of copper oxide of 15 nm or less and the color information of the copper oxide is created. In the measurement method, the surface color of the copper to be measured is measured, and the film thickness of the copper oxide formed on the surface is calculated by applying the color measurement result to the mathematical formula.

[0006] In another measurement method according to an embodiment, copper oxide is colorimetrically measured by a method compliant with any of DIN5033 Teil7, JIS Z 8722 condition c, ISO7724 / 1, CIE No.15 (2004), or ASTM E 1164 (SCI). In the measurement method, a mathematical formula showing the relationship between the color information of copper oxide where the L value is greater than 53 and less than 82, the a value is greater than 17 and less than 45, and the b value is greater than 24 and less than 43, and the film thickness of the copper oxide is created. In the measurement method, the surface of the copper to be measured is colorimetrically measured, and the film thickness of the copper oxide formed on the surface is calculated by applying the colorimetric result to the mathematical formula.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0008] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationships between the thickness and width of each part, the size ratios between parts, etc. are not necessarily the same as those in reality. Also, even when representing the same part, the dimensions and ratios may be represented differently in the drawings. In this specification and each figure, the same reference numerals are given to elements similar to those already described, and detailed descriptions will be omitted as appropriate.

[0009] On the surface of the copper member, copper oxide is formed by the reaction of copper and oxygen. The embodiment of the present invention is used to more simply obtain the film thickness of this copper oxide.

[0010] FIG. 1 is a flowchart showing the measurement method according to the embodiment. As shown in FIG. 1, the measurement method M1 according to the embodiment includes model construction (step S10) and film thickness measurement (step S20). In model construction, a mathematical formula (model) showing the relationship between the film thickness of copper oxide and the color information of copper oxide is created. In film thickness measurement, the surface color of the target copper is measured, and the film thickness of copper oxide is calculated using the mathematical formula and the color measurement result. Hereinafter, each step will be specifically described.

[0011] In model construction, first, while changing the film thickness of copper oxide, the copper oxide is color-measured (step S11). As a result, a plurality of measurement data are obtained. Each measurement data includes the film thickness of copper oxide and the color information corresponding to that film thickness. As the color information, numerical values (color values) indicating colors are used. Colors are quantified in the XYZ color system or the Lab color system. Here, the case where colors are quantified using the Lab color system will be described.

[0012] For color measurement, a colorimeter is used. As the colorimeter, a spectrophotometer, a color difference meter, etc. are used. Alternatively, a general-purpose camera including a CCD image sensor or a CMOS image sensor may be used as the colorimeter. For example, a color image is taken by the image sensor, and the RGB pixel values at each pixel are converted into the XYZ color system or the Lab color system.

[0013] To enable color measurement of the copper surface, the surface is illuminated with light. The surface may be illuminated by a light source or by natural light. For example, in order to suppress changes in the color of the reflected light due to the light source, color measurement is preferably performed by a method compliant with any of DIN5033 Teil7, JIS Z 8722 condition c, ISO7724 / 1, CIE No.15(2004), or ASTM E 1164(SCI).

[0014] Figure 2 is a schematic diagram showing the state of thin film interference. When a thin layer of copper oxide is formed on the surface of copper, as shown in Figure 2, thin film interference occurs between the light L1 reflected from the surface of the oxide film and the light L2 reflected at the interface between Cu and the oxide film. Due to this thin film interference, the color of the copper oxide changes according to the film thickness of the copper oxide. This thin film interference is represented by the following equation. In the equation, n is the refractive index of the oxide film. d is the film thickness of the copper oxide. θ is the refractive angle. λ is the wavelength of the incident light. 2nd(cosθ)=(m+1 / 2)λ

[0015] The measurement method of this embodiment measures the film thickness of copper oxide by utilizing the thin film interference of copper oxide. Thin film interference occurs when the film thickness of copper oxide is 15 nm or less. Therefore, the measurement method of this embodiment is suitable for measuring a film thickness of 15 nm or less.

[0016] The composition of copper oxide mainly includes CuO and Cu2O. The refractive index of Cu is 1.2. The refractive index of CuO is 2.6. The refractive index of Cu2O is 2.7. Since the refractive indices of CuO and Cu2O are almost the same, the sum of the film thicknesses of CuO and Cu2O can be used as one parameter.

[0017] Note that since the color of copper oxide changes according to its film thickness, it is also possible to specify the object of the measurement method of the embodiment according to the range of color values. For example, in the colorimetric results conforming to any of DIN5033 Teil7, JIS Z 8722 condition c, ISO7724 / 1, CIE No.15 (2004), or ASTM E 1164 (SCI), when the L value is greater than 53 and less than 82, the a value is greater than 17 and less than 45, and the b value is greater than 24 and less than 43, the copper oxide can be the object of the measurement method of the embodiment.

[0018] After step S11, using a plurality of measurement data, the relationship between the film thickness of copper oxide and the color values is modeled (step S12). The model is represented by a mathematical formula. More specifically, as the mathematical formula, one or more selected from a first formula showing the relationship between the film thickness of copper oxide and the L value, a second formula showing the relationship between the film thickness of copper oxide and the a value, and a third formula showing the relationship between the film thickness of copper oxide and the b value are created. For example, in any of the first to third formulas, the film thickness and the color values are represented by a linear relationship. The response surface method can be used for modeling.

[0019] After model construction, film thickness measurement is performed. First, using a colorimeter, the surface of the copper to be measured is colorimetrically measured (step S21). In order to accurately measure the film thickness, it is preferable that the conditions of the light source used in the collection of measurement data and the conditions of the light source used in the measurement of the film thickness are common.

[0020] Next, it is determined whether each numerical value of the color information obtained by colorimetry is within the target range of the model (step S22). More specifically, it is determined whether the L value of the color information obtained by colorimetry is included in the range from the lower limit to the upper limit of the L value used for creating the first formula. It is determined whether the a value of the color information is included in the range from the lower limit to the upper limit of the a value used for creating the second formula. It is determined whether the b value of the color information is included in the range from the lower limit to the upper limit of the b value used for creating the third formula. If any of the L value, a value, and b value of the color information are outside the range, the film thickness calculated using the color information may deviate from the actual film thickness. Therefore, such color information is not used for calculating the film thickness. For example, when the film thickness of copper oxide exceeds 15 nm, each numerical value of the color information may be outside the range. When each numerical value of the color information is outside the range, the process ends without calculating the film thickness of copper oxide.

[0021] When at least any one of the numerical values of the color information is within the target range of the model, the film thickness of copper oxide is calculated using the mathematical formula created in step S12 and the colorimetry result obtained in step S21 (step S23). Specifically, the measured L value is substituted into the first formula regarding the L value to calculate the film thickness. Or, the measured a value is substituted into the second formula regarding the a value to calculate the film thickness. Or, the measured b value is substituted into the third formula regarding the b value to calculate the film thickness.

[0022] The film thickness may be calculated using any one of the first to third equations, or may be calculated using two or more of the first to third equations. For example, in step S22, if only one of the L value, a value, and b value of the color information is within the target range of the model, the film thickness is calculated using only the equation corresponding to that one value. When two or more of the L value, a value, and b value of the color information are within the target range of the model, the film thickness may be calculated using the equations corresponding to those two or more values. For example, the final film thickness is calculated by averaging the film thicknesses obtained from each equation. Or, one model may be selected from two or more models. For example, one model with the smallest error is selected from two or more models for the measurement data used in the measurement of the model. In that case, the film thickness is calculated using the selected model and the color information targeted by that model. For error comparison, the root mean square error (R 2 ) can be used.

[0023] Hereinafter, a specific example of the measurement method according to the embodiment will be described.

[0024] Figure 3 shows the experimental results illustrating the relationship between the film thickness of copper oxide and color information. In Figure 3, the horizontal axis represents the film thickness of copper oxide. The vertical axis represents the L value, a value, or b value. The round plots represent the L value. The triangular plots represent the a value. The square plots represent the b value. Also, in Figure 3, the approximate equations for the film thickness and L value, the film thickness and a value, and the film thickness and b value are shown by broken lines respectively. In the approximate equations in Figure 3, the film thickness is represented by "x", and the L value, a value, or b value is represented by "y".

[0025] The graph in Figure 3 shows the results of color measurement of copper oxide while changing the film thickness of copper oxide from 4 nm to 32.5 nm. The color measurement was performed by a method compliant with any of DIN5033 Teil7, JIS Z 8722 condition c, ISO7724 / 1, CIE No.15 (2004), ASTM E 1164 (SCI). A spectrocolorimeter (CM-25d) manufactured by Konica Minolta Inc. was used for the color measurement.

[0026] As can be seen from the experimental results shown in FIG. 3, when the film thickness is in the range of 4 nm to 14 nm, the film thickness and the color value are approximately linearly related. When the film thickness exceeds 20 nm, the relationship between the film thickness and the color value becomes non-linear. As described above, this is presumably because when the film thickness exceeds 15 nm, thin film interference by copper oxide hardly occurs on the surface of copper.

[0027] From the experimental results shown in FIG. 3, the first to third equations showing the relationship between the film thickness and the color value are created. The first equation is X L = k1×T + C1. The second equation is X a = k2×T + C2. The third equation is X b = k3×T + C3. T is the film thickness of copper oxide. C1, C2, C3, k1, k2, and k3 are constants. X L is the L value of the color measurement result. X a is the a value of the color measurement result. X b is the b value of the color measurement result.

[0028] Specifically, from the experimental results shown in FIG. 3, the following first to third equations are created. First equation: X L = -2.7974×T + 94.94 Second equation: X a = 2.6187×T + 3.9675 Third equation: X b = 1.7241×T + 18.967

[0029] The mean square error (R 2 ) between the measured L value and the film thickness calculated from the above first equation and the actual measured value of the film thickness was 0.951. The mean square error (R 2 ) between the measured a value and the film thickness calculated from the above second equation and the actual measured value of the film thickness was 0.9193. The mean square error (R 2 ) between the measured b value and the film thickness calculated from the above third equation and the actual measured value of the film thickness was 0.8732. It was confirmed that the film thickness of copper oxide could be accurately calculated regardless of which equation was used.

[0030] The advantages of this embodiment are explained. There is a need for a technique that can more easily measure the film thickness of copper oxide. For example, in the assembly of a power semiconductor device, a power semiconductor chip is joined to a substrate wiring or a lead frame. Solder is mainly used for the joining. When the joining surface is oxidized, the wettability of the solder decreases, making it difficult to form a joint. Generally, Cu is used for the substrate wiring. Therefore, the measurement of the film thickness of copper oxide becomes particularly important.

[0031] In solder joining, in recent years, the number of joining apparatuses using reducing formic acid gas has been increasing. When formic acid gas is used, there is a high possibility of joint failure due to a copper oxide film compared to joining using a conventional liquid flux. As a joining material having higher heat dissipation and higher reliability than solder, an Ag sintered material is also used. When the Ag sintered material is used, a joint is formed by solid-phase diffusion of Ag. Since Ag hardly forms a metal bond with a copper oxide, joint failure due to a copper oxide film is likely to occur.

[0032] Conventionally, in order to determine the feasibility of joining, the film thickness of copper oxide has been measured. As methods for measuring the film thickness of copper oxide, there are a method of using Ar sputtering and surface analysis (AES or XPS) in combination, a method of observing a cross section with an electron microscope (TEM), a method of electrochemically measuring (SERA method), and a method of optically measuring (ellipsometry). There is also a measurement method using color tone as a non-destructive and simple measurement method.

[0033] When applying the film thickness measurement of copper oxide to the manufacturing line, it is desirable to be able to measure it non-destructively and in a short time. If the film thickness can be measured non-destructively and in a short time, all the copper members to be manufactured can be the measurement targets. Surface analysis, cross-sectional observation, and electrochemical measurement all require destroying the target and take a long time. Although the method using ellipsometry can be performed non-destructively and in a short time, the refractive index and other physical properties of the measurement target need to be accurately grasped. Also, if the composition of the measurement target is non-uniform or there are minute irregularities on the surface and interface, the measurement results are likely to contain errors. In the copper oxide film, it is common for both CuO and Cu2O to exist, and it is not easy to accurately grasp the physical properties of the measurement target in advance. Also, depending on the interface state between CuO and Cu2O, errors may occur in the measurement results. For this reason, a simpler measurement method is required.

[0034] Regarding these problems, in the embodiment of the present invention, the color information of copper oxide is used. Specifically, first, a mathematical formula showing the relationship between the film thickness of copper oxide of 15 nm or less and the color information of copper oxide is created. Next, the surface color of the copper of the measurement target is measured. Then, by applying the color measurement result to the mathematical formula, the film thickness of the copper oxide formed on the surface is calculated. Color measurement can be performed non-destructively and in a short time. Also, in the measurement method using color measurement, it is not necessary to accurately grasp the physical properties of the measurement target, and it is simpler than the method using ellipsometry. Even when the copper oxide contains both CuO and Cu2O, the film thickness of the copper oxide can be measured accurately. According to the embodiment, the film thickness of copper oxide can be measured more simply and in a shorter time.

[0035] For the quantification of color, the Lab color space system or the XYZ color space system can be used. The Lab color space system is more preferable than the XYZ color space system. In the Lab color space system, lightness is represented on the Z-axis, and chromaticity and saturation are represented on the ab plane. Since lightness is independent of chromaticity and saturation, even when an interaction is likely to occur between lightness and chromaticity or between lightness and saturation, those color information can be separated.

[0036] (Modification example) FIG. 4 is a flowchart showing a measurement method according to a modified example of the embodiment. The measurement method M2 according to the modified example shown in FIG. 4 includes step S11a instead of step S11 as compared with the measurement method M1 shown in FIG. 1. Further, the measurement method M2 includes step S12a instead of step S12 and step S23a instead of step S23 as compared with the measurement method M1.

[0037] In the measurement method M1, the film thickness of CuO and the film thickness of Cu2O are not distinguished, and the sum of the film thickness of CuO and the film thickness of Cu2O is used as one parameter. On the other hand, in the measurement method M2, the film thickness of CuO and the film thickness of Cu2O are used as separate parameters. Generally, the oxidation of copper proceeds sequentially from the surface to the inner side. For this reason, Cu2O is formed on the outermost surface of copper. CuO is formed at a position away from the outermost surface of copper. That is, it can be considered that a laminated film of CuO and Cu2O is formed on the surface of copper.

[0038] In step S11a, while changing the film thickness of CuO and the film thickness of Cu2O, the copper oxides are colorimetrically measured, and a plurality of measurement data are collected. As color information, the colorimetric result of the laminated film of CuO and Cu2O is obtained. Each measurement data includes the film thickness of CuO, the film thickness of Cu2O, and the color information corresponding to those film thicknesses.

[0039] In step S12a, using the plurality of measurement data, the relationships among the film thickness of CuO, the film thickness of Cu2O, and the color numerical values are modeled. As the mathematical formula of the model, one or more selected from a first formula showing the relationship between the film thickness of CuO and the film thickness of Cu2O and the L value, a second formula showing the relationship between the film thickness of CuO and the film thickness of Cu2O and the a value, and a third formula showing the relationship between the film thickness of CuO and the film thickness of Cu2O and the b value are created. The response surface method can be used for modeling.

[0040] For example, the first formula to the third formula are expressed as follows. (First formula) X L =k1×T1 + k2×T2 + k3×(T1 - C1)×(T2 - C2) + C3 (Equation 2) X a = k4×T1 + k5×T2 + k6×(T1 - C4)×(T2 - C5) + C6 (Equation 3) X b = k7×T1 + k8×T2 + k9×(T1 - C7)×(T2 - C8) + C9

[0041] T1 is the film thickness of CuO. T2 is the film thickness of Cu2O. C1, C2, C3, C4, C5, C6, C7, C8, C9, k1, k2, k3, k4, k5, k6, k7, k8, and k9 are constants. X L is the L value of the color measurement result. X a is the a value of the color measurement result. X b is the b value of the color measurement result.

[0042] In step S23a, using the color values determined to be within the target range of the model in step S22, the film thickness of CuO and the film thickness of Cu2O are calculated.

[0043] Figure 5 shows the experimental results illustrating the relationship between the film thickness of CuO and color information. Figure 6 shows the experimental results illustrating the relationship between the film thickness of Cu2O and color information. In Figure 5, the horizontal axis represents the film thickness of CuO. In Figure 6, the horizontal axis represents the film thickness of Cu2O. In Figures 5 and 6, the vertical axis represents the L value, a value, or b value. The round plots represent the L value. The triangular plots represent the a value. The square plots represent the b value. In the graphs of Figures 5 and 6, the color measurement results are shown when the film thickness of CuO varies within the range of 2.8 nm to 29.2 nm and the film thickness of Cu2O varies within the range of 0.3 nm to 3.3 nm. The color measurement was performed in accordance with any of DIN5033 Teil7, JIS Z 8722 condition c, ISO7724 / 1, CIE No.15 (2004), ASTM E 1164 (SCI). A spectrophotometer (CM - 25d) manufactured by Konica Minolta Inc. was used for the color measurement.

[0044] In FIG. 5, the approximate expressions for the film thickness of CuO and the L value, the approximate expression for the film thickness of CuO and the a value, and the approximate expression for the film thickness of CuO and the b value are each indicated by a dashed line. Similarly, in FIG. 6, the approximate expressions for the film thickness of Cu2O and the L value, the approximate expression for the film thickness of Cu2O and the a value, and the approximate expression for the film thickness of Cu2O and the b value are each indicated by a dashed line. In the approximate expressions in FIGS. 5 and 6, the film thickness is represented by "x", and the L value, a value, or b value is represented by "y".

[0045] Specifically, from the experimental results shown in FIGS. 5 and 6, the following first to third equations are created. (First Equation) X L =-1.8127×T1 - 3.6257×T2 + 91.931 (Second Equation) X a =1.4488×T1 + 1.0634×T2 + 0.0979×(T1 - 3.3939)×(T2 - 3.3939)+11.766 (Third Equation) X b =2.6551×T1 + 1.9630×T2 - 0.1312×(T1 - 3.3939)×(T2 - 3.3939)+ 14.785

[0046] From the graph of FIG. 5, it can be seen that within the range where the film thickness of CuO is from 2.8 nm to 11.3 nm, the relationship between the color measurement results and each color value can be accurately approximated. Also, from the graph of FIG. 6, it can be seen that within the range where the film thickness of Cu2O is from 1.7 nm to 2.9 nm, the relationship between the color measurement results and each color value can be accurately approximated. Note that when the film thickness of Cu2O is 0.3 nm, the color value deviates from the approximate expression indicated by the dashed line. This is presumably because when the film thickness of Cu2O is 0.3 nm, the film thickness of CuO is 20.3 nm, and the sum of their film thicknesses exceeds 15 nm. If the sum of the film thicknesses does not exceed 15 nm, even if the film thickness of Cu2O is less than 1.7 nm, the film thickness of Cu2O can be accurately measured.

[0047] According to the modification example, the film thickness of copper oxide can be measured by separating it into the film thickness of CuO and the film thickness of Cu2O. For example, after the film thickness of copper oxide is calculated, a reduction treatment is performed on the copper. For the reduction treatment, hydrogen gas, formic acid, or the like is used. The film thickness of copper oxide becomes smaller due to the reduction treatment. When the reduction treatment is performed, the film thickness of CuO and the film thickness of Cu2O are separated and measured, so that the equipment for performing the reduction treatment can be appropriately selected according to those film thicknesses. Further, the conditions of the reduction treatment can be adjusted according to the measured film thickness of CuO and the film thickness of Cu2O.

[0048] FIG. 7 is a schematic diagram showing a measurement system according to the embodiment. The measurement system 10 shown in FIG. 7 includes a light source 1, a colorimeter 2, a measurement device 3, and a storage device 4. The light source 1 applies light L to the surface of the copper member 5 to be measured and illuminates the surface. For example, the light source 1 includes an LED. The colorimeter 2 detects the reflected light from the surface of the copper member 5 and measures the color of the surface of the copper member 5. The measurement device 3 controls the operations of the light source 1 and the colorimeter 2. Further, the measurement device 3 receives the color measurement result from the colorimeter 2. The storage device 4 stores a previously created model (mathematical formula). When the measurement device 3 receives the color measurement result, it acquires the mathematical formula from the storage device 4. The measurement device 3 measures the film thickness of the copper oxide formed on the surface of the object using the mathematical formula and the color measurement result.

[0049] The measurement device 3 may further determine the quality of the copper member 5 based on the measured film thickness. For example, the measurement device 3 compares the measured film thickness with a preset threshold value. When the film thickness exceeds the threshold value, the measurement device 3 determines that the copper member 5 is defective.

[0050] The measurement system 10 enables the film thickness of the copper oxide formed on the surface of the copper member 5 to be measured more simply and in a shorter time. For example, by using the measurement system 10, it becomes possible to inspect all of the manufactured copper members 5.

[0051] The measurement system 10 can also be used when building a model. By illuminating the surface of copper with the light source 1 and measuring the color of the surface with the colorimeter 2, measurement data can be collected. Using the collected measurement data, a model is created. The model may be created by the measuring device 3 or by another processing device.

[0052] Figure 8 is a schematic diagram showing the hardware configuration. As the measuring device 3, for example, the computer 90 shown in Figure 8 is used. The computer 90 includes a CPU 91, a ROM 92, a RAM 93, a storage device 94, an input interface 95, an output interface 96, and a communication interface 97.

[0053] The ROM 92 stores a program for controlling the operation of the computer 90. The ROM 92 stores the programs necessary for the computer 90 to implement each of the above-described processes. The RAM 93 functions as a storage area where the programs stored in the ROM 92 are expanded.

[0054] The CPU 91 includes a processing circuit. The CPU 91 uses the RAM 93 as a work memory and executes a program stored in at least one of the ROM 92 or the storage device 94. During the execution of the program, the CPU 91 controls each component via the system bus 98 and executes various processes.

[0055] The storage device 94 stores the data necessary for the execution of the program and the data obtained by the execution of the program.

[0056] The input interface (I / F) 95 can connect the computer 90 and the input device 95a. The input I / F 95 is, for example, a serial bus interface such as USB. The CPU 91 can read various data from the input device 95a via the input I / F 95.

[0057] Output interface (I / F) 96 can connect computer 90 and output device 96a. The output I / F 96 is, for example, a video output interface such as Digital Visual Interface (DVI) or High-Definition Multimedia Interface (HPMI (registered trademark)). The CPU 91 can transmit data to the output device 96a via the output I / F 96 and cause the output device 96a to display an image.

[0058] Communication interface (I / F) 97 can connect server 97a outside computer 90 and computer 90. The communication I / F 97 is, for example, a network card such as a LAN card. The CPU 91 can read various data from the server 97a via the communication I / F 97.

[0059] The storage device 94 includes one or more selected from a Hard Disk Drive (HDD) and a Solid State Drive (SSD). The input device 95a includes one or more selected from a mouse, a keyboard, a microphone (voice input), and a touch pad. The output device 96a includes one or more selected from a monitor, a projector, a printer, and a speaker. A device having both functions of the input device 95a and the output device 96a, such as a touch panel, may be used.

[0060] Each process executed by the measuring device 3 may be realized by one computer 90 or may be realized by the cooperation of a plurality of computers 90.

[0061] The processing of the above various data may be recorded as a program executable by a computer on a magnetic disk (such as a flexible disk and a hard disk), an optical disk (such as a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD±R, a DVD±RW), a semiconductor memory, or other non-transitory computer-readable storage medium.

[0062] For example, the information recorded on a recording medium can be read by a computer (or an embedded system). In the recording medium, the recording format (storage format) is arbitrary. For example, a computer reads a program from the recording medium and causes a CPU to execute instructions described in the program based on this program. In a computer, the acquisition (or reading) of a program may be performed through a network.

[0063] According to the embodiment described above, a measuring method and a measuring system are provided that can measure the film thickness of copper oxide more simply and in a shorter time.

[0064] As described above, some embodiments of the present invention have been illustrated. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope. Further, the above-described embodiments can be implemented in combination with each other.

Description of Reference Numerals

[0065] 1: Light source, 2: Colorimeter, 3: Measuring device, 4: Storage device, 5: Copper member, 10: Measuring system, M1, M2: Measuring method

Claims

1. Create a mathematical formula showing the relationship between the film thickness of copper oxide below 15 nm and the color information of the copper oxide, A measurement method of measuring the color of the surface of copper to be measured and applying the color measurement result to the mathematical formula to calculate the film thickness of copper oxide formed on the surface.

2. Measure the color of copper oxide by a method conforming to any of DIN 5033 Teil 7, JIS Z 8722 condition c, ISO 7724 / 1, CIE No. 15 (2004), or ASTM E 1164 (SCI), Create a mathematical formula showing the relationship between the color information of copper oxide where the L value is greater than 53 and less than 82, the a value is greater than 17 and less than 45, and the b value is greater than 24 and less than 43, and the film thickness of the copper oxide, A measurement method of measuring the color of the surface of copper to be measured and applying the color measurement result to the mathematical formula to calculate the film thickness of copper oxide formed on the surface.

3. The color information is represented in the Lab color space system, The mathematical formula is X Ｌ = k １ × T + C １ is represented by the first equation and, X ａ = k ２ × T + C ２ and the second equation represented by X ｂ = k ３ × T + C ３ The third equation represented by and including one or more selected from T is the film thickness of copper oxide, C １ , C ２ , C ３ , k １ , k ２ , and k ３ are constants, X Ｌ is the L value of the colorimetric result, X ａ is the a value of the colorimetric result, X ｂ is the b value of the colorimetric result. The measurement method according to claim 1 or 2.

4. The measurement method according to Claim 3, wherein the mathematical formula includes the first formula, the second formula, and the third formula.

5. The mathematical formula shows the relationship between the combination of the film thickness of CuO and the film thickness of Cu ２ O and the color information. By applying the colorimetric result to the mathematical formula, the film thickness of CuO formed on the surface and the film thickness of Cu ２ O are measured. The measuring method according to claim 1 or 2.

6. The color information is represented in the Lab color space system, The mathematical formula is X Ｌ = k １ × T １ + k ２ × T ２ + k ３ × (T １ - C １ )(T ２ - C ２ ) + C ３ represented by the first formula and X ａ = k ４ × T １ + k ５ × T ２ + k ６ × (T １ - C ４ )× (T ２ - C ５ )+ C ６ is represented by the second formula as follows, X ｂ = k ７ × T １ + k ８ × T ２ + k ９ × (T １ - C ７ )(T ２ - C ８ ) + C ９ is represented by the third formula, and including one or more selected from T １ is the film thickness of CuO, T ２ is Cu ２ O's film thickness, C １ , C ２ , C ３ , C ４ , C ５ , C ６ , C ７ , C ８ , C ９ , k １ , k ２ , k ３ , k ４ , k ５ , k ６ , k ７ , k ８ , and k ９ are constants, X Ｌ is the L value of the color measurement result, X ａ is the a value of the color measurement result, X ｂ is the b value of the color measurement result. The measurement method according to claim 5

7. A light source for illuminating the surface of copper to be measured, A colorimeter for measuring the color of the illuminated surface, A measurement device that measures the film thickness of copper oxide formed on the surface by applying the color measurement result by the colorimeter to a mathematical formula showing the relationship between the film thickness of copper oxide below 15 nm and the color information of copper oxide, A measurement system comprising the above.

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