Inspection method, inspection device, and substrate processing device

Abstract

To determine the arrangement state of a substrate from a spectrum indicating the characteristics of absorption or reflection of light obtained by irradiating the substrate with the light.SOLUTION: A method includes: a step of irradiating a measurement area set on a substrate with light to measure a characteristic spectrum such as a reflectance spectrum; and a step of, by using a learning model that is generated by learning the characteristic spectrum for a plurality of substrates when the characteristic spectrum changes according to the structure of the substrate within the measurement area, in association with a film thickness when a film is formed on the surface of the substrate or the thickness of the substrate, determining the arrangement state of the substrate in the measurement area, from the structure of the substrate identified by comparing a spectrum to be inspected that is the characteristic spectrum measured in the step of measuring the characteristic spectrum, and a spectrum for collation that is the characteristic spectrum obtained from the learning model.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to an inspection method, an inspection apparatus, and a substrate processing apparatus. [Background technology]

[0002] In a substrate processing apparatus, after a film is formed on a substrate such as a wafer, the film may be inspected to see if it has a preset film thickness and if there are any abnormalities such as voids inside the film. Patent Document 1 describes that in a film thickness measurement unit for measuring the film thickness of a thin film or the like, a laser beam is irradiated toward the wafer, and the light reflected from the wafer is used to evaluate the thin film by a spectroscopic ellipsometry method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-56336 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can determine the arrangement state of a substrate based on a spectrum indicating the absorption or reflection characteristics obtained by irradiating the substrate with light. [Means for solving the problem]

[0005] The method of the present disclosure comprises: a step of irradiating a measurement area set on the substrate with light and measuring a characteristic spectrum showing the absorption or reflection characteristics for the wavelength of the light; When the characteristic spectrum changes depending on the structure of the substrate in the measurement area, the characteristic spectrum is associated with a film thickness when a film is formed on the surface of the substrate or with a thickness of the substrate, using a learning model generated by learning about a plurality of substrates, and the characteristic spectrum is compared with a target spectrum for inspection, which is the characteristic spectrum measured in the step of measuring the characteristic spectrum, and a reference spectrum, which is the characteristic spectrum obtained from the learning model based on the film thickness or substrate thickness identified from the substrate from which the target spectrum for inspection was obtained, to determine the arrangement state of the substrate in the measurement area from the structure of the substrate identified. Effect of the Invention

[0006] According to the present disclosure, the arrangement state of a substrate can be determined from a spectrum indicating the absorption or reflection characteristics obtained by irradiating the substrate with light. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a structural diagram showing an inspection device according to a first embodiment. [Diagram 2] FIG. 2 is a configuration diagram showing a control device in the first embodiment. [Diagram 3] 13 is a partial plan view showing the positioning of a measurement area in a comparative example. FIG. [Figure 4] 10 is a vertical sectional side view of substrate W showing the process of moving a measurement region to an inspection region. FIG. [Diagram 5] 5 is a graph illustrating the reflectance spectra in (a) to (c) of FIG. 4. [Figure 6] 13 is a graph showing a change in wavelength of a singular point with respect to the thickness of a SiN film. [Figure 7] FIG. 4 is a partial plan view showing the positioning of a measurement region in the first embodiment. [Figure 8] 13 is a flowchart showing a generating operation. [Figure 9] 13 is a flowchart showing a determination operation and a movement operation. [Figure 10]FIG. 13 is a vertical cross-sectional side view illustrating a substrate with another film. [Figure 11] 11 is a graph showing reflectance spectra at each measurement position shown in FIG. 10. [Figure 12] FIG. 2 is a vertical cross-sectional side view illustrating a substrate on which a taper is formed. [Figure 13] 13 is a graph showing the reflectance spectrum at each measurement position shown in FIG. 12. [Figure 14] FIG. 11 is a partial plan view showing positioning in a modified example of the first embodiment. [Figure 15] 13 is a flowchart showing a generation operation of a modified example. [Figure 16] 13 is a flowchart showing a determination operation and a movement operation of a modified example. [Figure 17] FIG. 1 is a plan view showing a film forming system. [Figure 18] FIG. 2 is a vertical sectional side view showing a film forming module. [Figure 19A] 13 is a plan view showing a state in which a measurement region is positioned on an alignment mark in the second embodiment. FIG. [Figure 19B] 13 is a plan view showing a state in which a measurement region is shifted from an alignment mark in the second embodiment. FIG. [Figure 20] 11 is a vertical sectional side view illustrating positioning to an alignment mark. FIG. [Figure 21] FIG. 2 is a vertical sectional side view of the substrates, showing the upper and lower substrates in a state before they are bonded together. [Figure 22] 1 is a vertical sectional side view showing an upper substrate and a lower substrate bonded together in an aligned state; [Diagram 23] FIG. 2 is a vertical cross-sectional side view showing an upper substrate and a lower substrate bonded together in a misaligned state. [Figure 24] FIG. [Diagram 25] FIG. 13 is a structural diagram showing an inspection device according to a fourth embodiment. [Figure 26] FIG. 1 is an explanatory diagram showing the principle of spectroscopic measurement using HSC. [Figure 27]FIG. 13 is a partial plan view showing a measurement area where spectroscopic measurement is performed in a fourth embodiment. [Figure 28] 13 is a graph showing a characteristic spectrum by spectroscopic measurement according to the fourth embodiment. [Figure 29] 1 is a graph showing reflectance spectra when spectroscopically measured at different illuminance intensities. [Diagram 30] 1 is a vertical sectional side view showing an example of a film forming module provided with an inspection device using an HSC. [Diagram 31] FIG. 2 is a cross-sectional plan view showing the film forming module. [Diagram 32] 1 is a reflectance spectrum showing the results of Experiment 1. [Diagram 33] 13 is a table summarizing the conditions of spectroscopic measurement in Experiment 2. [Diagram 34] 1 is a first graph showing the results of Experiment 2. [Diagram 35] 2 is a second graph showing the results of Experiment 2. [Diagram 36] FIG. 13 is a top perspective view showing a turntable on which a substrate to be subjected to spectroscopic measurement in Experiment 3 is placed. [Figure 37] 13 is a first graph showing the experimental results of Experiment 3. [Figure 38] 2 is a second graph showing the experimental results of Experiment 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (First embodiment) The inspection device 1 according to the first embodiment will be described in detail below with reference to the drawings. The inspection device 1 according to the first embodiment has a function of guiding measurement light for performing spectroscopic measurement of the substrate W to a correct irradiation position. FIG. 1 is a structural diagram showing the inspection device 1 according to this embodiment. FIG. 2 is a configuration diagram showing a control device 100 in this embodiment. The inspection device 1 in this embodiment is disposed, for example, in a film formation system 10 that performs a film formation process described later, and inspects the substrate W after film formation together with the control device 100 that controls the film formation process of the film formation system 10.

[0009] As shown in FIG. 3 as a plan view and FIG. 4(a) as a vertical cross section, the substrate W to be inspected has an uneven pattern 32 formed by etching or the like on an underlayer 31 constituting the surface of a semiconductor wafer, for example. A surface film 33 is formed on the uneven pattern 32 by a film formation process in the film formation processing system 10. The diagonal lines on the inspection area T1 in FIG. 3 are a simplified representation of the uneven pattern 32. The underlayer 31 is made of, for example, silicon (Si) constituting the substrate W. The surface film 33 is, for example, a silicon nitride (SiN) film or a silicon oxide (SiO) film. The inspection device 1 performs a film thickness inspection, for example, by measuring the film thickness of the surface film 33 and judging whether the film thickness is within a preset range. This film thickness inspection is performed on the inspection area T1 where the surface film 33 is formed on the uneven pattern 32, and inspects whether the surface film 33 is formed to an appropriate thickness without including, for example, voids (air gaps).

[0010] As shown in FIG. 1, the inspection device 1 includes a measurement unit (inspection unit) 11 for performing spectroscopic measurement, a stage 21 on which a substrate W is placed, and a control device 100. The inspection device 1 irradiates an inspection area T1 of the substrate W on the stage 21 with measurement light, and performs a film thickness inspection of the surface film 33 by an optical method using reflected light, which will be described later. Furthermore, as will be described later, when the irradiation of the measurement light and the reception of the reflected light are performed from a common position, the measurement area R for the film thickness inspection is an area on the substrate W irradiated with the measurement light, and is a range in which the reflected light from the substrate W can be detected. The measurement area R is an area on the substrate W where spectroscopic measurement for the film thickness inspection is effectively performed, and if the entire area is not located within the inspection area T1, accurate film thickness measurement cannot be performed. In other words, it is necessary to irradiate the measurement light so that the non-inspection area T2 adjacent to the inspection area T1 is not included within the measurement area R. Otherwise, if data indicating a film thickness outside the allowable range is obtained in the film thickness inspection, it is not possible to determine whether the data is due to a defect in the surface film or due to a positional deviation of the measurement area R, and an accurate inspection result cannot be obtained. Therefore, the inspection apparatus 1 performs positioning in advance for disposing the measurement region R in the inspection region T1 before the film thickness inspection.

[0011] Hereinafter, "the entire range of the measurement region R is placed in the inspection region T1" may also be expressed as, for example, "the measurement region R is properly placed in the inspection region T1." "At least a part of the measurement region R is not placed in the inspection region T1" such that an accurate inspection result is not output may also be expressed as, for example, "the measurement region R is not properly placed in the inspection region T1."

[0012] The measurement unit 11 of the inspection device 1 includes a collimator lens 12, a coaxial probe 13 that irradiates measurement light via the collimator lens 12 and receives the reflected light, an illuminator 14, and a measurement instrument 15 for spectroscopic measurement. The measurement unit 11 also includes a moving mechanism (not shown) that displaces the positions of the collimator lens 12 and the coaxial probe 13. The height direction distance of the coaxial probe 13 and the collimator lens 12 relative to the substrate W is adjusted so that the measurement region R can be positioned without protruding from the inspection region T1.

[0013] The illuminator 14 incorporates a light source for emitting measurement light in the wavelength range from visible light to ultraviolet light used for positioning the measurement region R, and optical elements such as mirrors and lenses. The coaxial probe 13 is composed of a center portion for emitting light and an outer periphery for receiving light, and the center portion is connected to the illuminator 14 and the outer periphery is connected to the measuring instrument 15 by optical fibers 16. The measurement light irradiated from the coaxial probe 13 irradiates the measurement region R, which is at least a part of the inspection region T1 on the substrate W that is the target of film thickness inspection, and the light reflected from the measurement region R is detected by the measuring instrument 15 via the outer periphery of the coaxial probe 13 and the optical fiber 16.

[0014] Fig. 2 is a diagram showing an example of a schematic configuration of the control device 100 according to this embodiment. The control device 100 is, for example, an information processing device such as a computer. The control device 100 has an external I / F (interface) unit 111, a display unit 112, an input unit 113, a storage unit 114, and a control unit 115. Note that the control device 100 may have various functional units that a known computer has in addition to these functional units shown in Fig. 2.

[0015] The external I / F unit 111 is an interface for inputting and outputting information to and from other devices. For example, the external I / F unit 111 is an interface for controlling communication with other devices. One aspect of the external I / F unit 111 is a network interface card such as a LAN card. For example, the external I / F unit 111 transmits and receives various data to and from the film forming processing system 10 and other devices via a network. The external I / F unit 111 may be an interface such as a Universal Serial Bus (USB) port. The external I / F unit 111 may be an interface such as a Universal Serial Bus (USB) port.

[0016] The display unit 112 is a display device that displays various information. Examples of the display unit 112 include a liquid crystal display (LCD) and a cathode ray tube (CRT). The display unit 112 displays various information. The input unit 113 is an input device that inputs various information, such as a mouse or a keyboard. The input unit 113 accepts an operation input from an operator or the like, and inputs operation information indicating the content of the accepted operation to the control unit 115.

[0017] The storage unit 114 is a storage device that stores various data. For example, the storage unit 114 is a storage device such as a hard disk, a solid state drive (SSD), an optical disk, etc. Note that the storage unit 114 may be a semiconductor memory in which data can be rewritten, such as a random access memory (RAM), a flash memory, or a non-volatile static random access memory (NVSRAM).

[0018] The storage unit 114 stores an OS (Operating System) and various programs executed by the control unit 115. For example, the storage unit 114 stores a program in which commands (step groups) for executing each operation of film thickness inspection and positioning and a film forming process are written. Furthermore, the storage unit 114 stores various data used in the programs executed by the control unit 115. For example, the storage unit 114 stores processing condition data 120, learning data 121, and model data 122. Note that the storage unit 114 can also store other data in addition to the data exemplified above. Also, the various programs and data may be stored in a computer-readable computer recording medium (for example, a hard disk, an optical disk such as a DVD, a flexible disk, a semiconductor memory, etc.) or the like. Also, the various programs and data can be transmitted from other devices at any time and used online.

[0019] The control unit 115 is a device that controls the control device 100. Specifically, the control unit 115 is an electronic circuit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 115 has an internal memory for storing programs and data, reads out various programs stored in the storage unit 114, and executes the processing of the read programs. The control unit 115 functions as various processing units by the operation of the programs. Specifically, the control unit 115 has a system control unit 130 that controls each unit of the film forming system 10 and controls the film forming process, a first measurement control unit 131, a second measurement control unit 132, a generating unit 133, and a determining unit 134. Note that, in this embodiment, the control unit 115 is described as having the above-mentioned system control unit 130 to determining unit 134, but the functions of the system control unit 130 to determining unit 134 may be distributed and realized by a plurality of control units.

[0020] Before describing the configuration of the control device 100 with respect to film thickness inspection and positioning, the positioning of this embodiment will be briefly touched upon. In recent years, as semiconductor devices have become increasingly miniaturized, miniaturization has already progressed to the nm (nanometer) range in the semiconductor manufacturing process of, for example, VLSI (Very Large Scale Integration). For this reason, higher accuracy is also required for the positioning of the measurement region R to the inspection region T1. In order to clearly explain the positioning of this embodiment with high accuracy, a comparative form of positioning different from this embodiment will first be described.

[0021] Positioning in the comparative embodiment is performed using image processing. Specifically, the inspection device in the comparative embodiment includes an imaging unit such as a CCD (Charge Coupled Devices) that captures a surface image of the substrate W, and a signal control unit that processes an image signal from the imaging unit. The signal processing unit is connected to a control device 100, which has an image processing program. As shown in FIG. 3, which illustrates the positioning of the measurement region R in the comparative embodiment, the image processing program first identifies a reference point RP from the surface image of the substrate W, and positions the measurement region R at the reference point. Then, based on a preset moving distance L from the reference point RP to the inspection region T1, the coaxial probe 13 is moved to properly position the measurement region R in the inspection region T1.

[0022] The positioning accuracy of such a comparison form depends on the accuracy of identifying the reference point RP identified from the surface image. For example, when the reference point RP is set at the intersection of the contour line F (thick line in FIG. 3) of the scribe line constituted by the flat pattern 34, the reference point RP is identified by identifying the contour line F from the surface image. The contour line F is identified by acquiring a difference signal such as the brightness of adjacent pixels among the many pixels that constitute the surface image, and by the boundary between adjacent pixels where the difference is maximum. For this reason, the accuracy of identifying the reference point depends on the adjacent pixels that are part of the many pixels that constitute the surface image.

[0023] In accordance with the miniaturization of semiconductor devices as described above, it is necessary to further increase the resolution of the surface image. In addition, since the highly confidential pattern of the substrate W is reflected in the surface image, the handling of the acquired surface image may be problematic. In contrast to the above-mentioned comparative inspection apparatus, the inspection apparatus 1 of this embodiment performs highly accurate positioning using, for example, either the absorbance or reflectance spectrum acquired by spectroscopic measurement of reflected light in the entire measurement region R, without using such image processing. In this embodiment, in addition to the absorbance spectrum or reflectance spectrum, the intensity spectrum and absorbance intensity spectrum of reflected light from the measurement region R can also be used. In this disclosure, a spectrum showing the characteristics of absorbance or reflection for the wavelength of the measurement light irradiated to the measurement region R is called a "characteristic spectrum". In the following description, a case in which a reflectance spectrum is used will be described.

[0024] Next, the characteristics appearing in the reflectance spectrum of the reflected light used in the positioning of this embodiment will be described. (a) to (c) of FIG. 4 are longitudinal side views of the substrate W showing the process of moving the measurement region R from the non-inspection region T2 adjacent to the inspection region T1 toward the inspection region T1. The non-inspection region T2 shown in the figure can be exemplified by a region on a flat pattern 34 such as a scribe line, and the surface film 33 is formed with a substantially uniform thickness on the surface of the underlayer 31 of the substrate W. In FIG. 4(a), the measurement region R is disposed at a measurement position I on the non-inspection region T2, and in FIG. 4(b), the measurement region R is disposed at a measurement position II which is the boundary between the inspection region T1 and the non-inspection region T2. ​​And in FIG. 4(c), the measurement region R is disposed at a measurement position III on the inspection region (measurement region where spectroscopic measurement is performed) T1. Furthermore, FIG. 4(d) shows a case where the surface film 33 formed on the concave-convex pattern 32 contains voids 35 when the measurement region R is disposed at the measurement position III. FIG. 5 is a graph illustrating the reflectance spectra when the measurement region R is arranged as shown in FIG. 4(a) to FIG. 4(c).

[0025] In each reflectance spectrum (characteristic spectrum) shown in FIG. 5, it can be confirmed that there is an intersection point at which the same reflectance (value) is obtained at the same wavelength regardless of the arrangement (measurement position) of the measurement region R. As shown in FIG. 4(a) to FIG. 4(c), the wavelength at which the multiple reflectance spectra obtained by changing the surface pattern (substrate structure) of the substrate W corresponding to the measurement region R intersect is hereinafter referred to as a "singular point". Meanwhile, the reflectance spectra of the inspection region T1, the non-inspection region T2, and the boundary region thereof are generally different from each other except for the singular points P1 and P2. Therefore, by measuring the reflectance spectrum, it can be determined whether the object is located in the inspection region T1, the non-inspection region T2, or the boundary region between the inspection region T1 and the non-inspection region T2.

[0026] At least one of the singular points P1 and P2, including singular points other than the intersection points described below, appeared in the reflectance spectra measured on substrates W having different shapes of the concave-convex pattern 32 and different film properties and thicknesses of the surface film 33. The inventors therefore made the following inference and came up with the idea of ​​using the singular points to position the measurement region R.

[0027] The measurement light includes, for example, light of multiple wavelengths, and when it is generally reflected by the patterns 32, 34 under the surface film 33, the optical characteristics of the reflected light, such as the reflectance, change for each wavelength. In other words, it can be said that the reflectance spectrum changes according to the shape of the patterns 32, 34. On the other hand, in the film formation process performed by the film formation processing system 10, the film thickness of the surface film 33 is formed to be generally the same on the upper end faces 32a, 34a of the patterns 32, 34 that effectively reflect the measurement light. The reflected light due to the reflection of the measurement light is also an interference wave that causes reflection and interference depending on the wavelength, and the interference wave changes depending on the interference factor and the light absorption factor. Both of these interference factors and light absorption factors have the refractive index, etc., and the film thickness due to the composition of the film as common factors. Therefore, it can be assumed that even if the waveform, etc., differs depending on the shape of the patterns 32, 34, a singular point will appear in the reflectance spectrum that has the same reflectance at at least one wavelength if the composition and film thickness of the surface film 33 are generally the same.

[0028] 5, the reflectance spectra of surface films 33 of approximately the same thickness formed on different pattern shapes have mutually different waveforms in the wavelength ranges before and after singular points P1 and P2. Hereinafter, the adjacent wavelength ranges before and after each of the singular points P1 and P2 may be referred to as adjacent wavelength ranges.

[0029] Among the adjacent wavelength ranges, the wavelength ranges outside the singular points that do not include the wavelength of the singular point as shown in FIG. 5 are Δλ1, Δλ2, and Δλ3. In the wavelength ranges Δλ1 and Δλ3, the reflectances at the measurement positions I to III are different, that is, the waveforms of the reflectance spectra are different. In the wavelength range Δλ2, the reflectances at the measurement positions I and II are approximately the same, that is, the waveforms of the reflectance spectra are approximately the same. On the other hand, even in the same wavelength range Δλ2, the reflectances at the measurement positions I and II and the measurement position III are different, and the waveforms of the reflectance spectra are different. In this way, the difference in the waveforms of the reflectance spectra caused by the difference in the pattern shape provided in the measurement region R can be clearly seen from the reflectance of one wavelength and the waveform of the reflectance spectrum in the wavelength range outside the singular point.

[0030] Therefore, when the measurement region R is displaced in such a surface film 33 with the same thickness and a spectroscopic measurement is performed, even if the waveform of the reflectance spectrum changes with the displacement, it can be said that a singular point with the same reflectance at a predetermined wavelength appears. And, the wavelength of such a singular point changes according to the film thickness of the surface film 33 when the composition of the surface film 33 is common. For example, FIG. 6 is a graph showing the change in the wavelength of the singular point with respect to the film thickness of a SiN film. As illustrated in FIG. 6, the film thickness of the surface film 33 with the same composition and the wavelength of the singular point are, for example, in a proportional relationship, and the wavelength of the singular point increases as the film thickness increases. In this embodiment, the measurement region R is positioned using the characteristics of such a singular point and the measurement result of the reflectance spectrum in the inspection region T1. Hereinafter, data showing the correspondence relationship between the film thickness and the wavelength of the singular point as shown in FIG. 6 may also be called film thickness singular point correlation data.

[0031] In this embodiment, the positioning of the measurement region R is performed by a generation operation for generating a prediction model (learning model) based on learning data of the film thickness and the reflectance spectrum of the inspection region T1, and a determination operation for determining whether or not the measurement region R is located in the inspection region T1 based on the prediction model. If it is determined in the determination operation that the measurement region R is not located in the inspection region T1, the measurement region R is moved and the determination operation is performed again, and these operations are repeated to position the measurement region R. The measurement of the reflectance spectrum for generating the prediction model is performed using a learning substrate W1 formed in the same manner as the substrate W to be inspected.

[0032] Returning to the description of the control device 100, the learning data 121 in the storage unit 114 is learning data used to generate a prediction model. The learning data 121 is a plurality of sets of corresponding data stored in association with each other, including the reflectance spectrum measured in the inspection region T1 in the learning substrate W1, which is described later and calculated by the second measurement control unit 132, the singular point information of the reflectance spectrum, and the film thickness of the surface film 33 of the learning substrate W1. As a specific example, the reflectance spectrum is a reflectance spectrum in an adjacent wavelength range as described above. The adjacent wavelength range of the reflectance spectrum used as learning data cannot be generally stated because various waveforms appear in the reflectance spectrum, but for example, a wavelength range including the wavelength before (short wavelength) and after (long wavelength) of the singular point, or a wavelength range before or after the singular point is appropriately set. The width of the adjacent wavelength range can be exemplified as about 50 nm to 200 nm, and it is preferable that the width is as narrow as possible in order to improve the efficiency of the generation operation and the judgment operation. For example, the lower limit of the adjacent wavelength range Δλm illustrated in FIG. 5 is a wavelength at which the difference in reflectance between waveforms is large enough to allow the waveforms to be sufficiently distinguished, for example, the wavelength λm at which the reflectance at measurement positions I and II is at its maximum value. The upper limit λn of the adjacent wavelength range Δλm is set to "λn=λt×2-λm" so that the difference in wavelength from the wavelength λt of the singular point P1 to the upper limit λn is the same as the difference from the wavelength λt to the lower limit wavelength λm. When multiple singular points P1 and P2 exist as in FIG. 5, the width of the adjacent wavelength range Δλm can be set to approximately 50 nm. In this case, the difference in reflectance spectrum becomes clear, and the generation operation and the determination operation can be performed effectively and efficiently.

[0033] Here, a plurality of sets of corresponding data constituting the learning data 121 used to generate the prediction model are stored, each set being different in thickness of the surface film 33. Furthermore, taking into consideration fluctuations in the reflectance spectrum and singular points due to film formation, a plurality of corresponding data points of the same thickness may be acquired. The corresponding data is acquired by acquiring the reflectance spectrum measured by the measuring instrument 15 via the external I / F unit 111, and manually inputting the film thickness and singular points by the operator via the input unit 113, and is stored in the memory unit 114 as the learning data 121.

[0034] The generating unit 133 performs machine learning on the learning data 121, and stores a prediction model of the characteristic spectrum in association with the film thickness of the surface film 33 in the storage unit 114 as model data 122. For example, the generating unit 133 performs machine learning on the learning data 121 using a linear regression algorithm, and generates a prediction model that learns the relationship between a plurality of sets of corresponding data of the learning data 121. For example, the generating unit 133 generates a prediction model that learns the film thickness of each corresponding data and the reflectance spectrum of the adjacent wavelength range as linear regression. Incidentally, the film thickness included in each corresponding data of the learning data 121 has a one-to-one correspondence with the wavelength of the singular point as shown in FIG. 6, and therefore can be replaced with the singular point information. Therefore, the technical scope of the present disclosure also includes a case where a prediction model is generated from singular point information including at least the wavelength and the reflectance spectrum. Moreover, the singular point information in such correspondence data is the wavelength and reflectance of the singular point, and may be only the wavelength without including the reflectance.

[0035] In this embodiment, a linear regression algorithm is used as machine learning to generate a prediction model so as to prevent overfitting in the learning data 121. However, it is also possible to use a more advanced machine learning algorithm such as a neural network or a more advanced regression analysis than linear regression. Note that the learning model in this disclosure is not limited to a learning model created based on the results of machine learning of the learning data 121. For example, the "learning" in this disclosure also includes a case where singular points and reflectance spectra are obtained for multiple learning substrates W1 for each film thickness, and a prediction model is generated that indicates the correspondence between the film thickness and the singular points or reflectance spectrum (reflectance at each wavelength) by arithmetic averaging.

[0036] The second measurement control unit 132 controls spectroscopic measurement of the substrate W and the learning substrate W1 to calculate the reflectance spectrum of the substrate W and the learning substrate W1, respectively. Specifically, the second measurement control unit 132 controls the irradiator 14 and the measuring instrument 15 to irradiate measurement light from the irradiator 14 and detect reflected light from the measurement region R, which is the irradiated region, with the measuring instrument 15. The measuring instrument 15 outputs data on the signal intensity of the detected light to the external I / F unit 111. The second measurement control unit 132 performs spectroscopic analysis such as Fourier transform on the signal intensity data output by the measuring instrument 15 to calculate the reflectance spectrum.

[0037] In the positioning determination operation, the determination unit 134 determines whether the measurement region R is disposed in the inspection region T1 by using a prediction model from the reflectance spectrum measured for the substrate W to be inspected for the film thickness. Specifically, the determination unit 134 first derives the reflectance spectrum of the adjacent wavelength range in the inspection region T1 corresponding to the film thickness from the model data 122, using the film thickness as an explanatory variable and the reflectance spectrum of the adjacent wavelength range as an objective variable. Then, in the reflectance spectrum measured for the substrate W to be inspected, the reflectance at the wavelength of the singular point corresponding to the film thickness of the surface film 33 is acquired and set as the singular point information. By determining whether the singular point information acquired from the substrate W to be inspected matches the singular point information derived from the reflectance spectrum of the prediction model, it is determined whether the arrangement state of the measurement region R can be determined by the determination operation of this embodiment.

[0038] If it is determined that they match, the determining unit 134 compares the derived reflectance spectrum with the measured reflectance spectrum to determine whether they match, and determines the arrangement state of the measurement region R with respect to the inspection region T1. Specifically, if it is determined that the derived reflectance spectrum and the measured reflectance spectrum generally match, it determines that the measurement region R is arranged in the inspection region T1, and if it is determined that they do not match, it determines that the measurement region R is not arranged in the inspection region T1. An example of the compared reflectance spectra generally matching is a case where the reflectance is, for example, 80% or more, preferably 90% or more, with respect to the wavelength. In addition, the determination of whether the reflectance spectra match is not limited to a case where the reflectance is strictly matched at each wavelength and the "reflectance spectra match" is determined. For example, when the reflectance is displayed as a percentage, if the measured reflectance spectrum is within a range of ±5% of the reflectance in the derived reflectance spectrum at each wavelength, it may be determined that these reflectance spectra match.

[0039] A first measurement control unit 131 that performs measurement control of the film thickness inspection detects an interference intensity spectrum of light reflected by the upper and lower surfaces of the surface film 33, for example, with a measuring instrument 15, and calculates the film thickness using the refractive index of the surface film 33 and parameters related to the substrate W stored in the memory unit 114 (spectral interference film thickness measurement). A determination unit 134 determines whether the calculated film thickness of the surface film 33 is within a preset allowable film thickness range.

[0040] Various positioning operations in this embodiment will be described below. Fig. 7 is a plan view showing the substrate W, the inspection region T1 and the non-inspection region T2 of the learning substrate W1 in positioning the measurement region R in this embodiment. Fig. 8 is a flow chart showing the generating operation, and Fig. 9 is a flow chart showing the determining operation and the moving operation.

[0041] In the generation operation, first, a learning substrate W1 having the same pattern and surface film 33 as the substrate W to be inspected for film thickness is prepared (step S101). The learning substrate W1 is, for example, a substrate having the same pattern as the substrate W, and a film formation process is performed in a film formation processing system 10 described below to form a surface film 33. The surface film 33 of the learning substrate W1 does not include voids in the range where the measurement region R is located, and is not defective in film thickness, i.e., defective film formation.

[0042] The second measurement control unit 132 sets the thickness of the surface film 33 of the learning substrate W1 (step S102). The thickness is the average thickness of the surface film 33 on the inspection region T1 of the learning substrate W1 and the non-inspection region T2 in the peripheral region thereof, and is not limited to an actual value measured by film thickness measurement, but may be, for example, an estimated film thickness value. The estimated film thickness value is, for example, an estimated film thickness grasped from the film formation conditions of the film formation process of the film formation process system 10, or a target film thickness set in the film formation process, and can be regarded as the same as the average film thickness measured by actual measurement.

[0043] Next, the learning substrate W1 is placed on the stage 21, and the collimator lens 12 is moved by the moving mechanism to place the measurement area R in the inspection area T1 (FIG. 7). In the learning stage, the measurement area R can also be placed in the inspection area T1 by a hyperspectral camera or comparative image processing.

[0044] The measurement unit 11 and the second measurement control unit 132 measure the reflectance spectrum of the inspection area T1 and the non-inspection area T2 in the learning substrate W1 (step S103). For example, after measuring the reflectance spectrum of the inspection area T1, the collimator lens 12 (measurement area R) is moved to the non-inspection area T2 to measure a reflectance spectrum different from the reflectance spectrum of the inspection area T1.

[0045] Then, a singular point in the reflectance spectrum of the inspection area T1 is identified (step S104). The singular point can be identified, for example, from the intersection of the reflectance spectrum of the inspection area T1 and the reflectance spectrum of the non-inspection area T2. Alternatively, the singular point may be identified by identifying a wavelength from the film thickness of the learning substrate W1 using the film thickness singular point correlation data described above, and identifying the reflectance from the reflectance spectrum of the inspection area T1 measured based on that wavelength. In this case, it is not necessary to measure the reflectance spectrum of the non-inspection area T2 in step S103, and it is not necessary to identify the singular point (step S104).

[0046] The generation unit 133 stores the set film thickness of the learning substrate W1, the measured reflectance spectrum of the inspection region T1, and the identified singular point information in the learning data 121 as mutually corresponding data (step S105). In addition, the wavelength of the singular point is stored as the singular point information. Next, the learning data 121 is stored with the film thickness as an explanatory variable and the reflectance spectrum as an objective variable. The reflectance spectrum stored in the learning data 121 may be stored for the entire measured wavelength range, or may be stored only for adjacent wavelength ranges to reduce the amount of data.

[0047] Next, the generation unit 133 judges whether or not all of the planned learning data has been acquired (step S106). The planned learning data is a prediction model and a plurality of sets of corresponding data for the substrates W provided with the surface films 33 of each thickness required for generating the model data. The number of substrates W and the film thicknesses are determined in advance according to the number of substrates W and the film thicknesses of the surface films 33 required for generating the prediction model.

[0048] If it is determined that all of the planned learning data have not been acquired (No in step S106), the film thickness is changed (step S107) to prepare a substrate W (step S101), and the above steps S102 to S106 are similarly performed. By repeating the process until it is determined that all of the planned learning data have been acquired (Yes in step S106), learning data 121 is stored as a plurality of sets of data in which film thickness, reflectance spectrum, and singularity information are associated with each other for each substrate W including a surface film 33 with a different film thickness. Thereafter, the generation unit 133 performs machine learning on the learning data 121 to generate a prediction model (step S108), stores the prediction model as model data 122 in the storage unit 114, and ends the generation operation.

[0049] 9 is a flowchart showing an example of a determination operation and a movement operation in the method according to the embodiment. In the determination operation, first, a substrate W to be inspected on which a surface film 33 is formed is prepared (step S201), and the substrate W is placed on the stage 21 by a transport mechanism such as a transport arm. The second measurement control unit 132 sets the film thickness of the surface film 33 of the substrate W (step S202). The film thickness is set to be the same as the film thickness of the learning substrate W1 in the generation operation.

[0050] The determination unit 134 derives a reflectance spectrum corresponding to the set film thickness using the prediction model stored as the model data 122 (step S203). Specifically, the determination unit 134 acquires the reflectance spectrum of the adjacent wavelength range from the prediction model using the acquired film thickness as an explanatory variable and the reflectance spectrum of the adjacent wavelength range as an objective variable. Furthermore, the determination unit 134 reads out singularity information (wavelength of the singularity) stored in association with the film thickness as the learning data 121, and derives the reflectance at the singularity (model reflectance) using the reflectance spectrum acquired from the prediction model.

[0051] Next, the moving mechanism of the inspection device 1 moves the collimator lens 12 and the coaxial probe 13 to place the measurement region R at the first measurement position (step S204). The first measurement position is an arbitrary position among the inspection region T1 and the non-inspection region T2. ​​The measurement region R is placed at the first measurement position, for example, based on the pattern arrangement information of the substrate W known in advance, by visual estimation using an enlarged image captured by a camera to an extent that the pattern arrangement cannot be recognized, or a magnifying glass, with the inspection region T1 as the target. The placement at the first measurement position may also be performed by setting in advance an approximate relative movement amount from a reference position such as an alignment mark provided on the substrate W to the inspection region T1, and placing the inspection region T1 from the reference position based on the relative movement amount. The placement of these measurement regions R does not require high accuracy compared to the positioning performed by the judgment and movement operation of the present disclosure. The measurement region R placed in this way is placed in an area including the inspection region T1 or the non-inspection region T2, or outside the area.

[0052] The measurement unit 11 and second measurement control unit 132 measure the reflectance spectrum by spectroscopic measurement at the first measurement position (step S205, a step of measuring a characteristic spectrum). The determination unit 134 identifies a singular point in the measured reflectance spectrum. The singular point is identified, for example, by identifying the wavelength of the derived singular point information and the reflectance at that wavelength from the reflectance spectrum (measured reflectance). Then, the determination unit 134 determines whether the model reflectance at the wavelength that is the singular point matches the measured reflectance (step S206).

[0053] If the determination unit 134 determines that the difference between the model reflectance and the measured reflectance is equal to or greater than the preset tolerance and that the singular points do not match (No in step S206), the determination operation is terminated. If they do not match in this way, it is considered that there is an external factor, such as a poor film thickness of the surface film 33 at the initial position, a mistake in setting the measurement region R at the initial position, or an error in the inspection device 1 itself, and it is considered that the subsequent determination operation cannot be performed appropriately, so the determination operation is terminated. If the determination unit 134 determines that the identified model reflectance and the measured reflectance match (the singular points match) (Yes in step S206), it is considered that there is no such external factor and that the determination operation can be performed appropriately, so the determination operation is continued.

[0054] Next, the determination unit 134 compares the measured reflectance spectrum in the adjacent wavelength range (spectrum to be inspected) with the derived reflectance spectrum in the adjacent wavelength range of the inspection area T1 (verification spectrum) and determines whether they match (step S207). This step can be said to determine the arrangement state of the substrate W to be inspected relative to the measurement area R (step of determining the arrangement state). The comparison may be made by comparing the waveforms of the reflectance spectra in the adjacent wavelength ranges themselves, or by comparing the reflectance or the amount of change in reflectance at wavelengths other than the wavelength of the singular point in the adjacent wavelength range. Comparing the reflectance spectra in the adjacent wavelength ranges in this way makes it possible to clearly compare the reflectance spectra, and also reduces the data processing load of the determination unit 134, thereby speeding up the determination process.

[0055] When it is determined that the reflectance spectra in the adjacent wavelength ranges match each other (Yes in step S207), it can be determined that the measurement region R is placed in the inspection region T1, and the positioning of the measurement region R is completed, so the determination operation is terminated. When it is determined that the reflectance spectra in the adjacent wavelength ranges do not match each other (No in step S207), it can be determined that the measurement region R is not placed in the inspection region T1, and it is assumed that it is placed in the non-inspection region T2 or the boundary position between the inspection region T1 and the non-inspection region T2. ​​In this case, since the positioning of the measurement region R is not completed, a moving operation is performed. In the moving operation, for example, the moving mechanism of the inspection device 1 moves the collimator lens 12 and the coaxial probe 13 to move the measurement region R again (step S208, a process of moving the measurement region). The movement of the measurement region R is performed in the same manner as the placement at the first measurement position described above (step S204).

[0056] Then, the above-described steps S205 to S207 of the determination operation are performed. Such determination and movement operations are repeated until it is determined that the reflectance spectra in the adjacent wavelength ranges match (Yes in step S207) and it is determined that the measurement region R has been placed in the inspection region T1, thereby allowing the measurement region R to be placed in the inspection region T1. As described above, according to the positioning method of this embodiment, it is determined whether or not the measurement region R is positioned in the inspection region T1 based on the reflectance spectrum of the light reflected from the entire measurement region R. Therefore, the determination method of this embodiment uses an optical technique that is unlikely to involve measurement errors and uses the reflectance spectrum of the light reflected from the entire measurement region R, so that the position of the measurement region R can be determined with higher accuracy than the image processing of the comparative embodiment.

[0057] When the positioning of the measurement region R in the inspection area T1 is completed, the inspection device 1 performs a film thickness inspection. In the film thickness inspection, the first measurement control unit 131 calculates the film thickness using the reflectance spectrum measured in the positioned measurement region R and the parameters related to the refractive index of the surface film 33 and the substrate W stored in the memory unit 114. The determination unit 134 determines whether the calculated film thickness of the surface film 33 is within a preset allowable film thickness range, and inspects whether the surface film 33 has been appropriately formed.

[0058] Furthermore, such a film thickness inspection may be repeated at multiple positions within the inspection area T1. In this case, the measurement area R is moved by a preset displacement amount to repeatedly perform the film thickness inspection. The preset displacement amount is, for example, a length equal to or greater than the diameter of the measurement area R in one direction. Then, every time the measurement area R moves, the above-described judgment operation steps S205 to S207 are performed, and the film thickness inspection is performed after confirming that the measurement area R is placed within the inspection area T1. This allows the inspection area T1 to be inspected without going beyond the inspection area T1.

[0059] (Other examples of reflectance spectra) An example of a reflectance spectrum different from the example shown in Fig. 5 will be described. Fig. 10 is a vertical cross-sectional side view illustrating a substrate W having a film 36 that easily reflects light in an underlying portion of a surface film 33, and Fig. 11 is a graph showing the reflectance spectrum at each measurement position (I to III) shown in Fig. 10. Fig. 12 is a vertical cross-sectional side view illustrating a substrate W in which a taper is formed in the concave-convex pattern 32, and Fig. 13 is a graph showing the reflectance spectrum at each measurement position (I to III) shown in Fig. 12.

[0060] 10, a film 36 that easily reflects light may be formed between the underlayer 31 and the surface film 33, for example, in the non-inspection region T2. ​​In this case, as shown in Fig. 11, the reflectance of the spectroscopic measurement at measurement position I increases overall, so that the waveform of the reflectance spectrum deviates upward from the waveforms of the reflectance spectra at measurement positions II and III.

[0061] Therefore, unlike the example shown in FIG. 5, in the example shown in FIG. 12, the reflectance spectra at the measurement positions I to III do not intersect, and there is no intersection. In such a case, a singular point P3 is set at a position where the difference in reflectance values ​​of the reflectance spectra is minimum. The reflectance of the singular point P3 in this case is the reflectance of the reflectance spectra at the measurement positions I to III at the wavelength of the singular point P3. That is, the wavelength of the singular point P3 in this example is the same, but the reflectance is set for each of the reflectance spectra at the measurement positions I to III. In this case, for example, the reflectance is not included in the singular point information already described in this embodiment, and step S206 for comparing the singular points is not performed. As described above, the adjacent wavelength range when there is no intersection in the reflectance spectrum is set to, for example, a wavelength range extending before and after the wavelength of the singular point P3, and the width of the adjacent wavelength range is set to about 50 nm to 200 nm.

[0062] 12 includes convex portions that become wider toward the bottom, and the side surfaces of the concave-convex pattern 32 include inclined side surfaces 37. In this case, the measurement light tends to be diffused by the inclined side surfaces 37 and the reflected light tends to be incident from outside the range of the measurement positions I to III, and the reflectance spectra at the measurement positions I to III are generally similar to each other, as shown in FIG 13. However, even in this case, two singular points P4, which are the intersection points of the reflectance spectra, appear.

[0063] It has been confirmed that the wavelength of the singular point P3 described with reference to Fig. 11 is approximately equal to the wavelength of the singular point grasped from the film thickness of the surface film 33 by the correlation data as shown in Fig. 6. It has also been confirmed that, for the two singular points P4 described with reference to Fig. 13, the wavelength of the two singular points P4, for example the longer wavelength, is approximately equal to the wavelength of the correlation data as shown in Fig. 6. From the above-mentioned examples of the appearance of the singular points P3 and P4, even if a different film such as the film 36 or a pattern of a special shape is present at the measurement positions I to III, a singular point corresponding to the film quality and film thickness of the surface film 33 appears, and the generation operation and the determination operation of this embodiment can be efficiently performed by using the singular point.

[0064] (effect) According to the inspection apparatus 1 of the present embodiment, the arrangement state of the substrate W to be inspected relative to the measurement region R can be determined based on the reflectance spectrum (characteristic spectrum) obtained by irradiating the substrate W with the measurement light.

[0065] (Variations) In the above embodiment, in step S206 of FIG. 9, the reflectance at the singular point is compared to determine whether or not to continue the determination operation. In this case, an example has been described in which the reflectance at the singular point of the reflectance spectrum derived from the prediction model (model reflectance) is used as a comparison target with the reflectance at the singular point of the measured reflectance spectrum (measured reflectance). The method of identifying the model reflectance is not limited to this example. For example, in step S105 of FIG. 8, machine learning may be performed to create a prediction model in which the film thickness is used as an explanatory variable and the singular point information (the wavelength of the singular point and the reflectance at that wavelength) is used as an objective variable. In this case, in step S206 of FIG. 9, the singular point information (the reflectance at the singular point) obtained based on the result of inputting the film thickness into the prediction model may be used as the model reflectance to compare the reflectance.

[0066] In addition, it is preferable that the density of the uneven pattern 32 is substantially the same in the entire inspection area T1. As a result, the density of the uneven pattern 32 is the same regardless of the position of the measurement area R arranged in the inspection area T1, and the reflectance spectrum can be obtained regardless of the position of the measurement area T1. Then, by comparing the reflectance spectrum of the prediction model with the measured reflectance spectrum, it is possible to determine with high accuracy whether or not the measurement area is in the inspection area T1. In addition, in this embodiment, since the measurement unit 11 can also be used for spectroscopic measurement for positioning, the film thickness inspection is performed by the spectroscopic interference film thickness measurement, but this is not limited to this, and for example, the film thickness inspection may be performed by the reflectance spectroscopy method or the spectroscopic ellipsometry method. The positioning of the present disclosure is not limited to being performed by an inspection device for film thickness inspection, and may be performed by another inspection device for in-line inspection of the substrate W.

[0067] In the inspection device 1 of this embodiment, positioning is performed using either the absorbance or reflectance spectrum as the characteristic spectrum, but the characteristic spectrum available for positioning is not limited to this. For example, even if the intensity spectrum of reflected light or the absorbance intensity spectrum (FIG. 28) which is the difference between the intensity spectrum of irradiated light and the intensity spectrum of reflected light is used, a singular point similarly appears, so it can be treated in the same way as the reflectance spectrum.

[0068] (Modification of the first embodiment) Positioning in this modified example will be described with reference to Fig. 14 to Fig. 16. In the description of this modified example, differences from the first embodiment will be mainly described, and the description of the same configuration as the first embodiment will be omitted. Fig. 14 is a plan view showing the substrate W, the inspection region T1 and the non-inspection region T2 of the learning substrate W1 in the positioning of the measurement region R in this modified example. Fig. 15 is a flow chart showing the generation operation of this modified example, and Fig. 16 is a flow chart showing the judgment operation and the movement operation of this modified example.

[0069] 14, in positioning the measurement region R in this modification, there are adjacent regions Ta, Tb, Tc, and Td each including a different pattern formed on the base layer 31 in the non-inspection region T2. ​​Then, the different reflectance spectra of the adjacent regions Ta to Td are measured, and data in which each reflectance spectrum is associated with region information indicating each of the adjacent regions Ta to Td is stored in the learning data 121 to generate model data 122. In the determination operation, the model data 122 thus generated is used to determine in which region T1, Ta to Td the measurement region R is located, and the measurement region R is quickly positioned toward the inspection region T1 based on the relative positional relationship of each of the adjacent regions Ta to Td with respect to the inspection region T1.

[0070] 14 and 15, the operation of generating a prediction model in this modified example will be described. In the non-inspection region T2 of the substrate W and the learning substrate W1, various uneven patterns or flat patterns different from the uneven pattern 32 of the inspection region T1 are formed around the inspection region T1. Since these adjacent patterns each include a different pattern, reflectance spectra of different waveforms are measured by irradiation of the measurement light by the measurement unit 11. The regions in which the adjacent patterns are provided are set as adjacent regions Ta to Td, respectively. The ranges of the inspection region T1 and the adjacent regions Ta to Td and the relative positions of the adjacent regions Ta to Td may be grasped in advance from design information of the substrate W, etc., and can be acquired in the generation operation described later.

[0071] As in the first embodiment, first, a first learning substrate W1 is prepared (step S301), the thickness of the surface film 33 is set for the learning substrate W1 (step S302), and the reflectance spectrum in the inspection area T1 is measured (step S303). Next, for example, the measurement area R is moved toward the adjacent area Ta, and the reflectance spectrum of the adjacent area Ta is measured (step S304). When the relative position of the adjacent area Ta is not grasped by design information or the like, for example, the measurement area R is moved from the inspection area T1 to the positive direction of the Y axis shown in FIG. 14 while measuring the reflectance spectrum. Then, when the reflectance spectrum clearly changes from the reflectance spectrum of the inspection area T1, the area where the measurement area R is arranged is set as the adjacent area Ta, and the movement to the adjacent area Ta is completed. In this case, a movement amount vector A of the measurement area R may be specified, and the movement amount vector A may be set as the relative position of the adjacent area Ta.

[0072] Next, singular points are identified from the reflectance spectrum of the inspection region T1 and the reflectance spectrum of the adjacent region Ta (step S305). Next, the singular point information, each measured reflectance spectrum, film thickness, and each region information are stored in the learning data 121 as mutually corresponding data (hereinafter, also referred to as relative data) (step S306). Specifically, the region information indicating the inspection region T1, the reflectance spectrum of the inspection region T1, the singular point information, and the film thickness are mutually corresponding, and the region information indicating the adjacent region Ta, the reflectance spectrum of the adjacent region Ta, the singular point information, and the film thickness are mutually corresponding and stored in the learning data 121, respectively. These film thicknesses and singular point information generally match, but the reflectance of the singular point information may differ as described above.

[0073] The above operation will be described in detail below. The film thickness is learned as an explanatory variable, and the reflectance spectrum and the region information are learned as objective variables, and stored in the learning data 121. The relative position may be stored in the learning data 121 together with the region information or in place of the region information, as data corresponding to the region information, or may be stored in the storage unit 114.

[0074] Next, the generating unit 133 judges whether or not all of the adjacent regions Ta to Td have been measured (step S307). When the relative positions of the adjacent regions Ta to Td are not known by design information or the like, the generating unit 133 judges whether or not it is possible to determine that the relative data of each adjacent region required for positioning has been acquired based on, for example, the accumulated contents of the relative data of the learning data 121. When it is determined that all of the planned learning data has not been acquired (No in step S307), the measuring region R is moved to another adjacent region, for example, the adjacent region Tb, and the reflectance spectrum of the adjacent region Tb is measured (step S308). The measuring region R is moved to the adjacent region Tb in the same manner as the movement from the inspection region T1 to the adjacent region Ta in the above-mentioned step S304, and the relative position of the adjacent region Tb can also be grasped by the movement amount vector B.

[0075] As was done for adjacent region Ta in step S306, data in which the reflectance spectrum, region information, and film thickness measured for adjacent region Tb are correlated with each other is stored in training data 121 (step S306). The above steps S308, S306, and S307 are also performed for the other adjacent regions Tc and Td. When it is determined that measurements have been made for all adjacent regions Ta to Td (step S307), multiple sets of data for inspection region T1 and adjacent regions Ta to Td for the first training substrate W1 are stored in training data 121.

[0076] Next, the generating unit 133 judges whether the learning substrate W1 with all the planned thicknesses has been measured (step S309). If it is judged that the learning substrate W1 with all the planned thicknesses has not been measured (No in step S309), a second substrate W with a changed thickness is prepared (steps S310, S301). Then, the reflectance spectrum is measured for each region T1, Ta to Td in the same manner as the first learning substrate W1, and data in which the regions T1, Ta to Td are associated with each other is stored in the learning data 121 (steps S302 to S308). By repeating the above until it is judged that the learning substrate W1 with all the thicknesses has been measured (Yes in step S309), the learning data 121 stores a plurality of sets of data in which the regions T1, Ta to Td are associated with each other for a plurality of learning substrates W1 with different thicknesses. The generation unit 133 performs machine learning on the learning data 121 to generate a prediction model (step S311), stores the prediction model as the model data 122 in the storage unit 114, and ends the generation operation.

[0077] The judgment operation and the movement operation of this modification will be described with reference to FIG. 16, which is a flow chart showing an example of the judgment operation and the movement operation in the method according to the present embodiment. First, the substrate W to be inspected on which the surface film 33 is formed is prepared on the stage 21 (step S401), and the film thickness of the surface film 33 is set (step S402). Next, the reflectance spectrum of each of the regions T1 and Ta to Td corresponding to the set film thickness is derived using the prediction model stored as the model data 122 (step S403). Specifically, the judgment unit 134 acquires the reflectance spectrum of each of the regions T1 and Ta to Td from the prediction model using the set film thickness as an explanatory variable, the mutually corresponding region information, and the reflectance spectrum as an objective variable. Furthermore, the judgment unit 134 reads out the singular point information (wavelength of the singular point) stored in association with the film thickness as the learning data 121, and derives the reflectance at the singular point (model reflectance) using the reflectance spectrum acquired from the prediction model.

[0078] Next, the measurement region R is placed at the first measurement position on the substrate W (step S404), and the reflectance spectrum is measured at the first measurement position (step S405, a step of measuring a characteristic spectrum). Then, it is determined whether the reflectance of a specific point identified from the measured reflectance spectrum (measured reflectance) matches with the reflectance of a specific point of the reflectance spectrum derived from the prediction model (model reflectance) (step S406). If it is determined that these reflectances match (Yes in step S406), it is determined whether the derived reflectance spectrum of the inspection region T1 matches with the measured reflectance spectrum (step S407).

[0079] If it is determined that these reflectance spectra do not match (No in step S407), a movement operation is performed. First, the determination unit 134 identifies the region information and relative position of the measurement region R (step S408). The region information and relative position are identified, for example, by identifying the reflectance spectrum that matches or is most similar to the measured reflectance spectrum among the derived reflectance spectra of the adjacent regions Ta to Td, and then identifying the region information and relative position associated with the identified reflectance spectrum. The region information and relative position may be identified by identifying only the relative position without identifying the region information.

[0080] Based on the identified relative position, the movement mechanism of the measurement unit 11 moves the measurement region R towards the inspection region T1 (step S409). To give a specific example using Fig. 14, for example, when the measured reflectance spectrum matches the region information indicating the adjacent region Tc and the reflectance spectrum linked to the relative position (movement amount vector C), the measurement region R is moved by a vector C' in the opposite direction of the movement amount vector C indicating the relative position. According to the method of this modified example configured to repeatedly perform such a movement operation and the determination operation of steps S405 to S407, the measurement region R can be positioned in the inspection region T1 efficiently and with high accuracy.

[0081] (Film forming processing system 10) The film forming processing system 10 in which the inspection apparatus 1 of this embodiment and its modified example is installed will be briefly described below. Fig. 17 is a plan view showing the film forming processing system 10. The film forming processing system 10 includes a loader module 61, a load lock module 65, a vacuum transfer module 66, and first to third processing modules 7A to 7C.

[0082] The loader module 61, the load lock module 65, and the vacuum transfer module 66 are arranged in this order in the front-rear direction.

[0083] The loader module 61 includes a housing whose interior is at atmospheric pressure, a transport mechanism 62 for the substrate W provided in the housing, and four load ports 63, and the inspection apparatus 1 according to this embodiment is disposed in the housing. A transport container 64 for storing the substrate W, called a FOUP (Front Opening Unified Pod), is placed on each load port 63. The transport mechanism 62 includes, for example, a multi-joint arm that can move left and right, and is capable of transporting the substrate W between the transport container 64 on each load port 63, each load lock module 65, and the inspection apparatus 1.

[0084] In this example, there are three load lock modules 65. Each load lock module 65 has a housing, and the housing is connected to the loader module 61 and the vacuum transfer module 66 via gate valves G provided in the front and rear of the housing, respectively.

[0085] Each load lock module 65 is configured such that the pressure inside the housing can be freely changed between atmospheric pressure and vacuum pressure when the gate valves G at the front and rear of the housing are closed. A stage (not shown) is provided inside the housing, and the stage can carry a substrate W thereon and deliver the substrate W to the transport mechanism 62 and a vacuum transport mechanism 67 (described later) that access the load lock module 65, respectively.

[0086] The vacuum transfer module 66 includes a housing 66a and a vacuum transfer mechanism 67 provided in the housing 66a. The housing 66a is connected to an exhaust mechanism (not shown), such as a turbo molecular pump, via an exhaust pipe, and the inside of the housing 66a is maintained in a vacuum atmosphere by exhausting air from the exhaust mechanism.

[0087] The first to third processing modules 7A to 7C are arranged side by side on both left and right sides of a housing 66a of a vacuum transfer module 66 when viewed from the front side. The substrate W is transferred between the first to third processing modules 7A to 7C and the load lock module 65 by a vacuum transfer mechanism 67 including, for example, an articulated arm.

[0088] The correspondence between the processes performed in each of the first to third process modules 7A to 7C and the series of processes described above is shown. The first process module 7A performs a COR process to alter an oxide film formed on the surface of the underlayer 31 of the substrate W to generate a reaction product, and the second process module 7B performs a PHT process to sublimate and remove the reaction product. The third process module 7C performs a film formation process to form a surface film 33. Each of the process modules 7A to 7C includes a process chamber 71 that is evacuated to create a vacuum atmosphere inside, and a mounting table 72 that is provided in the process chamber 71 and on which the substrate W is placed, and each process step is performed in the process chamber 71.

[0089] The system control unit 130 of the control device 100 outputs control signals to each part of the film forming system 10 according to each program stored in the storage unit 114, and controls the operation of each part. Specifically, the system control unit 130 controls the operation of the first to third process modules 7A to 7C, the opening and closing of the gate valves G and G1, the transfer mechanism 62, the vacuum transfer mechanism 67, etc.

[0090] The transport path of the substrate W in the film forming processing system 10 is first transported in the order of the transport container 64 → the loader module 61 → the load lock module 65 → the vacuum transport module 66 → the first processing module 7A → the second processing module 7B → the third processing module 7C. In this transport process, the oxide film on the surface of the underlayer 31 of the substrate W is removed, and then the surface film 33 is formed on the substrate W. Next, the substrate W is transported in the order of the third processing module 7C → the vacuum transport module 66 → the load lock module 65 → the loader module 61 → the inspection device 1. In this transport process, the substrate W on which the surface film 33 is formed is subjected to a film thickness inspection by the inspection device 1. The substrate W that passes the film thickness inspection is transported to the transport container 64, and is transported to the next processing device together with the transport container 64 by a transport device not shown. The substrate W that fails the film thickness inspection is stored in a failed substrate W storage area (not shown) provided in the loader module 61, for example.

[0091] (Deposition module) Next, the third process module 7C, which is a film forming module, will be described as a representative of the process modules 7A to 7C, with reference to the vertical cross-sectional side view of FIG. 18. The case where film formation is performed as the substrate processing will be mainly described as an example. The third process module 7C is configured to be airtight, and the process container 71 is cylindrical. A mounting table 72 is provided within the process container 71.

[0092] The mounting table 72 is electrically at ground potential and is made of a metal such as nickel. The substrate W is placed on the upper surface of the mounting table 72, which supports the placed substrate W horizontally. The lower surface of the mounting table 72 is electrically connected to a support member 73 made of a conductive material. The mounting table 72 is supported by the support member 73. The support member 73 is supported by the bottom surface of the processing vessel 71, and the lower end of the support member 73 is electrically connected to the bottom surface of the processing vessel 71. Therefore, the processing vessel 71 is also grounded.

[0093] The mounting table 72 has a built-in heater 74, and can heat the substrate W mounted on the mounting table 72 to a predetermined temperature. The mounting table 72 is provided with lifter pins 75 for raising and lowering the substrate W. When the substrate W is loaded into the third processing module 7C, the lifter pins 75 are raised by a lifting mechanism (not shown) to receive the substrate W from the vacuum transfer mechanism 67 (FIG. 17), and after the vacuum transfer mechanism 67 leaves, the lifter pins 75 are lowered to place the substrate W on the mounting table 72.

[0094] A shower head 76 formed in a substantially disk shape is provided on the inner surface of the processing vessel 71 above the mounting table 72. The shower head 76 is supported on the upper part of the mounting table 72 via an insulating member 71a such as ceramics. This electrically insulates the processing vessel 71 from the shower head 76. The shower head 76 is made of a conductive metal such as nickel.

[0095] The shower head 76 includes a gas diffusion space 76a, has a shower plate 76b at its lower part facing the mounting table 72, and is provided so as to close the inside of the processing vessel 71 from above. The shower plate 76b has a large number of gas discharge holes 76c formed therein and opening toward the gas diffusion space 76a and the mounting table 72. A gas supply path 77a is connected to the upper part of the shower head 76 in order to introduce various gases into the gas diffusion space 76a. A gas supply unit 77 is connected to the gas supply path 77a.

[0096] The gas supply unit 77 has gas supply lines connected to gas supply sources of various gases used in forming the surface film 33, which is a SiN film. Each gas supply line branches appropriately according to the film formation process, and is provided with control devices for controlling the flow rate of the gas, such as valves such as an opening / closing valve and a flow rate controller such as a mass flow controller. The gas supply unit 77 supplies a purge gas, a source gas, and a reaction gas to the gas supply path 77a. For example, the purge gas is an inert gas, the source gas is SiH 4 (silane) gas, and the reactant gas is NH 3 (Ammonia) gas. These gases are diffused in the gas diffusion space 76a and discharged from each gas discharge hole 76c.

[0097] The space surrounded by the lower surface of the shower head 76 and the upper surface of the mounting table 72 forms a processing space where a film formation process is performed. The shower head 76 is paired with the mounting table 72 and functions as an electrode plate for forming, for example, a capacitively coupled plasma (CCP) in the processing space. A high-frequency power supply 78 is connected to the shower head 76 via a matching device 78a. When plasma is to be generated in the processing space, the high-frequency power supply 78 supplies high-frequency power (RF power) in accordance with the supply of gas from the gas supply unit 77. As a result, the high-frequency power is applied to the gas supplied from the shower head 76 to the processing space, and plasma is generated in the processing space.

[0098] An exhaust port connected to an exhaust pipe 79a is formed at the bottom of the processing vessel 71, and an exhaust device 79 having a vacuum pump and a pressure adjustment valve is connected to the exhaust pipe 79a. By the operation of the exhaust device 79, the inside of the processing vessel 71 is depressurized to a predetermined vacuum level.

[0099] Next, a flow of the third processing module 7C performing film formation on the substrate W under the control of the system control unit 130 that controls the film formation of the control device 100 will be briefly described. First, the substrate W is placed on the mounting table 72 by the vacuum transfer mechanism 67 of the film formation processing system 10. The substrate W that is carried in has the uneven pattern 32 exposed on the surface, and the surface film 33 is not formed. When performing film formation processing on such a substrate W, the system control unit 130 controls the exhaust device 79 to reduce the pressure inside the processing container 71 by the exhaust device 79. The system control unit 130 controls the gas supply unit 77 to supply various gases used for film formation from the gas supply unit 77 and introduce the processing gas into the processing container 71 from the shower head 76. Then, the system control unit 130 controls the high-frequency power source 78 to supply high-frequency power from the high-frequency power source 78 to generate plasma in the processing space, and perform film formation on the substrate W. In this manner, the surface film 33 is formed on the substrate W by the third processing module 7C. Then, the lifter pins 75 are caused to protrude from the stage 72 , the rear surface of the substrate W is supported by the lifter pins 75 , and the substrate W is lifted from the stage 72 and carried out by the vacuum transfer mechanism 67 .

[0100] Second embodiment The inspection device 1 of the second embodiment will be described below with reference to Figs. 19A, 19B, and 20. The inspection device 1 according to the second embodiment has a function of identifying the position of the alignment mark AM formed on the substrate W by utilizing a reflectance spectrum (characteristic spectrum) obtained by irradiating the substrate with measurement light. Fig. 19A is a plan view showing a state in which the measurement region R is positioned to the alignment mark in this embodiment, and Fig. 19B is a plan view showing a state in which the measurement region R is displaced from the alignment mark in this embodiment. In Figs. 19A and 19B, the measurement region R is shaded, and the periphery of the measurement region R is indicated by a dashed line. Fig. 20 is a vertical side view illustrating the positioning of the measurement region R to the alignment mark in a substrate having a resist layer and a hard mask layer provided on the surface.

[0101] The inspection device 1 in this embodiment uses the spectroscopic measurement of the measurement unit 11 to perform highly accurate positioning of the measurement region R to the alignment mark AM as mentioned in the comparative example shown in FIG. 3. As shown in FIG. 19A and FIG. 20, the alignment mark AM is, for example, a convex portion formed on the surface of the underlayer 31. The upper surface of the alignment mark AM forms a reference region AMa for indicating a reference position, and a characteristic concave-convex pattern AMb different from the various concave-convex patterns of the substrate W is formed in the reference region AMa. Therefore, by utilizing the positioning method described in the first embodiment, instead of the measurement positions II and III shown in FIG. 4(b) and (c), a comparison is made of the reflectance spectrum of the reference region AMa on the upper surface of the underlayer 31 and the surrounding region 31b around it as shown in FIG. 19A and FIG. 19B. This allows the measurement region R to be accurately positioned to the alignment mark AM.

[0102] Here, the measurement region R in this embodiment is set to have the same shape and area as the reference region AMa, for example. Therefore, when the measurement region R and the reference region AMa are arranged in a state where their respective center points overlap in a plan view, that is, when the measurement region R is aligned with the reference region AMa, the measurement region R is arranged in the reference region AMa without protruding from the reference region AMa. Then, in a positioning generation operation, the reflectance spectrum when the measurement region R is aligned is measured and learned, and stored in the model data 122. In a determination operation, the match between the measured reflectance spectrum and the reflectance spectrum when aligned by the prediction model is determined, and if they do not match, a movement operation is performed, so that the center position of the measurement region R can be positioned to the center of the alignment mark AM.

[0103] In addition, according to the determination operation of the present disclosure, it is possible to distinguish between the reflectance spectrum in the aligned arrangement of Fig. 19A and the reflectance spectrum in the case where the measurement region R is arranged protruding from the reference region AMa of Fig. 19B. Therefore, according to this embodiment, it is possible to determine the state where the measurement region R is aligned with the alignment mark AM, and to perform positioning with high accuracy.

[0104] 20, a hard mask layer 38 containing metal and enabling high selectivity etching and lacking transparency, and a resist layer 39 may be provided on the surface film 33n to be etched. In this case, the alignment mark AM cannot be recognized at the time of imaging in the positioning by image processing as shown in the comparative embodiment, and positioning becomes extremely difficult. However, in this embodiment, if a light source that emits measurement light in the wavelength range of infrared light is provided in the irradiator 14, positioning can be performed using spectroscopic measurement using infrared light that transmits through the hard mask layer 38 and the resist layer 39, and it can be used for a substrate W provided with various layers.

[0105] Note that the measurement area R may be set to a shape similar to the reference area AMa and slightly smaller than the reference area AMa, for example, so long as the positional deviation with respect to the alignment mark AM is within an allowable range.

[0106] Third embodiment The inspection apparatus 1A of the third embodiment performs an alignment inspection to check whether a laminated (bonded) substrate Wc formed by bonding the surfaces of an upper substrate Wa and a lower substrate Wb is aligned without misalignment. The substrates for which the alignment inspection is performed will be described below with reference to Figs. 21 to 23. Fig. 21 is a vertical sectional side view of the substrates showing the upper substrate and the lower substrate before they are bonded together, Fig. 22 is a vertical sectional side view showing the upper substrate and the lower substrate bonded together in an aligned state, and Fig. 23 is a vertical sectional side view showing the upper substrate and the lower substrate bonded together in a misaligned state.

[0107] First, the structure and bonding of the upper substrate Wa and the lower substrate Wb will be described with reference to FIG. 21. The upper substrate Wa and the lower substrate Wb have substantially the same configuration, and include a base substrate 31A, a calculation unit 20a, and a wiring layer 20b. Hereinafter, the surface of the upper substrate Wa and the lower substrate Wb that bonds to the other substrate Wa, Wb is referred to as a bonding surface SF. The calculation unit 20a is formed including a part of the base substrate 31A. The calculation unit 20a includes a semiconductor device such as a transistor. The base substrate 31A is, for example, a semiconductor wafer. The wiring layer 20b is, for example, a multi-layer wiring. The wiring layer 20b includes a wiring 22, a metal pad 23, a first insulating film 24, and a second insulating film 25.

[0108] The wiring 22 is provided in multiple layers. The wiring 22 is electrically connected to the arithmetic unit 20a. The metal pad 23 is provided on the bonding surface SF side of the wiring 22 located farthest from the base substrate 31A. The metal pad 23 is electrically connected to the wiring 22. The metal pad 23 is electrically connected to the arithmetic unit 20a via the wiring 22. The surface of the metal pad 23 is exposed. The first insulating film 24 is, for example, an interlayer insulating film filling the spaces between the wirings 22.

[0109] The second insulating film 25 is provided on the bonding surface SF side of the first insulating film 24. The surface of the second insulating film 25 is exposed. The exposed surface of the second insulating film 25 is flush with, for example, the exposed surface of the metal pad 23. The second insulating film 25 is, for example, a SiC film. In this manner, the upper substrate Wa and the lower substrate Wb each have, at the bonding surface SF, a region where the second insulating film 25 is exposed and a region where the metal pad 23 is exposed. Note that the second insulating film 25 is an example of an insulating film, and the metal pad 23 is an example of a conductive film.

[0110] The bonding of the upper substrate Wa and the lower substrate Wb will be described. First, the surfaces of the upper substrate Wa and the lower substrate Wb are planarized by chemical mechanical polishing (CMP) to form a bonding surface SF, and an adhesive film 26 is formed by applying, for example, an adhesive. As shown in FIG. 21, the upper substrate Wa is placed on the upper side and the lower substrate Wb is placed on the lower side of the upper substrate Wa, and the exposed pad surfaces 23a of the respective metal pads 23 are positioned so as not to be misaligned with each other, and the upper substrate Wa and the lower substrate Wb are bonded by applying pressure to form an overlapped substrate Wc. As shown in FIG. 22, it is preferable that the upper substrate Wa and the lower substrate Wb are not misaligned in a direction parallel to the bonding surface SF, and the pad surfaces 23a of the respective metal pads 23 are aligned without being misaligned in a direction parallel to the bonding surface SF. In detail, it is preferable that the portion of the pad surface 23a of one metal pad 23 on the upper substrate Wa or the lower substrate Wb that is shifted from the pad surface 23a of the other metal pad 23 and does not overlap with the other pad surface 23a is substantially zero.

[0111] However, as shown in Fig. 23, there may be a slight occurrence during manufacturing where the bonding surfaces SF of the upper substrate Wa and the lower substrate Wb are misaligned, resulting in the formation of an overlapped substrate Wc in which the substrates are bonded together with the pad surfaces 23a of the metal pads 23 misaligned. Therefore, the alignment inspection of the inspection device 1A according to this embodiment makes it possible to detect such an unaligned overlapped substrate Wc with high accuracy and ease. Below, the alignment inspection of this embodiment will be described by clearly indicating the differences from the first embodiment.

[0112] The measurement unit 11 (FIG. 1) in the matching inspection of this embodiment irradiates infrared light, particularly infrared light in a wavelength range of 1000 nm or more, as measurement light to measure the internal structure of the overlapped substrate Wc. The thickness of the overlapped substrate Wc and the learning overlapped substrate Wc1 in the generating operation correspond to the film thickness of the surface film 33 in the substrate W and learning substrate W1 of the first embodiment. Therefore, the singular point can be identified from the thickness of the overlapped substrate Wc and learning overlapped substrate Wc1.

[0113] In this embodiment, in order to prevent the inclusion of noise from the stage 21, it is preferable to provide an infrared absorbing sheet between the stage 21 and the substrate W. In addition, for example, the coaxial probe 13 may not have a coaxial structure, but may be provided separately as a probe connected to the irradiator 14 side and a probe connected to the measuring instrument 15 side, and a through hole penetrating the stage 21 from top to bottom may be formed. Then, the probe on the irradiator 14 side may be arranged below the through hole of the stage, and the probe on the measuring instrument 15 side may be arranged above the through hole, and the infrared light irradiated to the substrate W may be received, thereby preventing the inclusion of noise from the stage 21. In this case, the measurement region R is placed in the inspection region T3 described later by shifting the substrate W placed on the stage 21. As the characteristic spectrum when the measurement light is transmitted through the substrate W, for example, the intensity spectrum of the transmitted light transmitted through the substrate W received by the probe on the measuring instrument 15 side, or the absorbance intensity spectrum, absorbance spectrum, or transmittance spectrum, which is the difference between the intensity spectrum of the irradiated light and the intensity spectrum of the transmitted light and the intensity spectrum of the reflected light, may be used. Since the transmitted light is the difference between the light irradiated to the measurement region R and the light reflected and absorbed by the substrate W, it can be said that the intensity spectrum and transmittance spectrum of the transmitted light measure the characteristics corresponding to the reflection and absorption for the wavelength of the measurement light. Therefore, the intensity spectrum and transmittance spectrum of the transmitted light also correspond to the characteristic spectrum of the present disclosure.

[0114] In the matching inspection, for example, the pad surfaces 23a of the upper substrate Wa and the lower substrate Wb of the overlapped substrate Wc and the overlapped substrate Wc1 correspond to a pattern such as the concave-convex pattern 32 described in the first embodiment and its modified examples. According to this correspondence, in this embodiment, a matching state or a mismatching state of the metal pads 23 bonded to each other on the overlapped substrates Wc and Wc1 appears as a change in the reflectance spectrum excluding the singular points, and therefore the matching state or the mismatching state can be determined from the reflectance spectrum.

[0115] In the matching inspection, for example, the same inspection area T3 in the overlapped substrate Wc and the learning overlapped substrate Wc1 is subjected to spectroscopic measurement in the generating operation and the judging operation to measure the reflectance spectrum. The inspection area T3 is, for example, a portion including the front and back surfaces of the overlapped substrate Wc that is arbitrarily set, and is a portion including an area in which the pad surfaces 23a of the same pattern are arranged in the upper substrate Wa and the lower substrate Wb. In the generating operation, the reflectance spectrum and the singular points measured for the inspection area T3 of the learning overlapped substrate Wc1 of different thicknesses are stored in the storage unit 114 as the learning data 121. Then, the learning data 121 is machine-learned to generate a prediction model of the reflectance spectrum in association with the thickness of the learning overlapped substrate Wc1, and stored in the storage unit 114 as the model data 122.

[0116] In the judgment operation, the reflectance spectrum of the inspection region T3 of the superposed substrate Wc to be inspected is measured, and the reflectance spectrum derived by inputting the thickness of the superposed substrate Wc into the prediction model is compared with the measured reflectance spectrum to judge whether they match. From this result, it is judged whether the superposed substrate Wc is in a matched state or otherwise, that is, in an unmatched state. As a result, the superposed substrate Wc judged to be matched is classified as a pass product, and the superposed substrate Wc judged to be unmatched is classified as a fail product with high accuracy.

[0117] Furthermore, in the matching test, the reflectance spectrum in the mismatched state changes according to a plurality of misalignment directions along the bonding surface SF and the misalignment amount, which is the amount of displacement from the matched state. For this reason, for example, the misalignment amount can be changed within a preset range in each of the misalignment directions in two directions along the bonding surface SF and perpendicular to each other, and the reflectance spectrum can be learned in the generation operation. In this case, the misalignment direction and the misalignment amount of the laminated substrate Wc to be inspected can be estimated by understanding the misalignment amount in each misalignment direction in association with the area information and the relative position in the modification of the first embodiment.

[0118] (Joining device 7D) Hereinafter, a brief description will be given of the bonding device 7D that is installed together with the inspection device 1A of this embodiment and bonds the upper substrate Wa and the lower substrate Wb. FIG. 24 is a vertical cross-sectional side view showing the bonding device 7D. The upper substrate Wa is loaded into the bonding device 7D through a substrate loading / unloading port (not shown) formed in the processing container 71A on the transfer region A1 side. The upper substrate Wa is then transported to a position adjustment mechanism 81 by a substrate transport body 80 that is movable in the Y and Z directions. The position adjustment mechanism 81 is configured to rotate each of the substrates Wa-Wc that it holds around its center to adjust the horizontal position. The upper substrate Wa that was previously loaded is adjusted in position by the position adjustment mechanism 81, and then transferred to a holding arm 82a of the inversion mechanism 82 with the upper substrate Wa facing upward with the bonding surface SF.

[0119] The inversion mechanism 82 inverts the holding arm 82a in the transfer region A1 to invert the front and back surfaces of the upper substrate Wa held therein, so that the bonding surface SF of the upper substrate Wa faces downward. The inversion mechanism 82 then passes through an inlet / outlet 83a provided in a partition wall 83 that separates the transfer region A1 from the processing region A2, and moves to the upper chuck 84 side of the processing region A2. The upper chuck 84 then adsorbs the back surface of the upper substrate Wa to hold the upper substrate Wa. The upper chuck 84 is then moved to a position above and facing the lower chuck 85 by a chuck drive unit 84a that is movable in the Y direction. The upper substrate Wa waits in this state until the lower substrate Wb is transferred to the bonding device 7D.

[0120] Next, the lower substrate Wb is carried into the bonding device 7D, and the lower substrate Wb is carried to the position adjustment mechanism 81 by the substrate transport body 80. Next, the nozzle arm 91, which is movable in the Y and Z directions and to which a nozzle 93 is attached, moves the nozzle 93 to above the center of the lower substrate Wb. Next, the position adjustment mechanism 81 rotates the lower substrate Wb, and an adhesive supply mechanism connected to the nozzle 93 applies adhesive to the surface of the lower substrate Wb by spin coating, and the horizontal orientation of the lower substrate Wb is further adjusted by the position adjustment mechanism 81.

[0121] Next, the lower substrate Wb is transported by the substrate transport body 80 to the lower chuck 85 in the processing region A2, and the back surface of the lower substrate Wb is adsorbed and held by the lower chuck 85 with the bonding surface SF facing upward. Next, the horizontal positions of the lower substrate Wb held by the lower chuck 85 and the upper substrate Wa held by the upper chuck 84 are adjusted while capturing an image of their bonding surface SF with, for example, a CCD camera. Specifically, the position adjustment is performed by adjusting the horizontal position of the upper substrate Wa by the upper chuck 84 based on the captured image so that a predetermined reference point (not shown) on the surface of the lower substrate Wb coincides with a reference point (not shown) on the surface of the upper substrate Wa (FIG. 21).

[0122] Next, the lower chuck 85 is raised by a chuck driving unit 85a configured to raise and lower the lower chuck 85, and the lower substrate Wb held by the lower chuck 85 and the upper substrate Wa held by the upper chuck 84 are pressed against each other by abutting their bonding surfaces SF (FIGS. 22 and 23). As a result, the upper substrate Wa and the lower substrate Wb are bonded via the adhesive to form a laminated substrate Wc. The formed laminated substrate Wc is carried out from the bonding device 7D in the reverse order to the order in which one of the upper substrates Wa, Wb was carried into the processing region A2, and is carried into the inspection device 1A.

[0123] The inspection apparatus 1A performs a matching inspection on the loaded laminated substrate Wc as a substrate to be inspected, and judges whether the substrate is in a matched state or a mismatched state. As described above, according to the judgment operation of the present disclosure, a defective laminated substrate Wc judged to be in a mismatched state can be detected with high accuracy and simply.

[0124] (Fourth embodiment) An inspection device 1B of the fourth embodiment will be described with reference to Figures 25 to 31. In these figures, structures similar to those of the first embodiment are given the same reference numerals, and duplicated explanations will be omitted, and differences from the first embodiment will be mainly described. Figure 25 is a structural diagram showing the inspection device 1B according to the fourth embodiment, and Figure 26 is an explanatory diagram showing the principle of spectroscopic measurement by a hyperspectral camera (hereinafter, HSC) 11B constituting the inspection device 1B.

[0125] As shown in FIG. 25 and FIG. 26, the HSC 11B includes a lens 12, a spectroscope 17, and a camera 18. In the fourth embodiment, the HSC 11B is configured to perform spectroscopic measurement by arranging, for example, 900 optical elements side by side. That is, the HSC 11B is configured to arrange a large number of measurement regions R in the inspection device 1 described with reference to FIG. 1 side by side to form an elongated rectangular measurement region RB. Then, by scanning the substrate W while moving this measurement region RB, it is possible to efficiently perform spectroscopic measurement of the entire surface of the substrate W. As a specific configuration, the HSC 11B introduces incident light from the elongated rectangular measurement region RB, which is incident through the lens 12, into the spectroscope 17 through a horizontal slit (not shown) to be dispersed, and then receives the light with an area sensor 19 provided in the camera 18.

[0126] As shown in FIG. 26, in the area sensor 19, for example, 900 optical elements are arranged in a row in the x' direction (horizontal direction) in the same manner as the measurement area RB described above. A plurality of rows of optical elements are arranged in the vertical direction intersecting with the horizontal direction in the area irradiated with the light dispersed by the spectroscope 17. With this configuration, the area sensor 19 receives the light of each wavelength after dispersion in a matrix form by each optical element arranged in an area of ​​vertical width (Y) in each area (measurement area R) obtained by dividing the horizontal width (X) of the measurement area RB by, for example, 900. With the HSC 11B configured in this way, the characteristic spectrum as described above can be constructed based on the result of measuring the luminous intensity of the light received by each light receiving element for each wavelength at multiple positions (900 positions in this example) in the horizontal direction of the measurement area RB in one scan. HSC11B performs spectroscopic measurement at short intervals while scanning the measurement area RB in a direction (e.g., the Y direction) intersecting the longitudinal direction of the measurement area RB (corresponding to the "lateral direction" mentioned above), thereby decomposing the surface of the substrate W into a high-density matrix and performing spectroscopic measurement.

[0127] A data set including a large number of reflectance spectra acquired by one scan has a data size of, for example, terabytes and is stored in a memory (not shown) in the control device 100. These data sets are used for each process of positioning and film thickness inspection by each part of the control unit 115. The above-mentioned operation of acquiring the data set is repeated in the subsequent scans.

[0128] Since the HSC 11B performs spectroscopic measurement simultaneously at each lateral position of the measurement area RB in one scan, there is no change in illuminance due to different measurement times. Since the illuminance is approximately the same at multiple adjacent positions in the X direction in the measurement area RB in one scan, it can be said that the illuminance of the light incident on the optical element at the corresponding multiple positions is approximately the same. Since the upper surface of the substrate W can be scanned in a short time and spectroscopic measurement can be performed in a high-density matrix, it is considered that there is almost no illuminance difference in the spectroscopic measurement of multiple adjacent positions along the Y direction as well as the X direction. Therefore, for each area consisting of multiple adjacent positions in the X direction and Y direction where there is almost no illuminance difference on the surface of the substrate W that is spectroscopically measured in a high-density matrix, it is not necessary to consider the influence of the illuminance difference of the light irradiated to the substrate W on the reflectance spectrum.

[0129] FIG. 27 is a partial plan view showing the measurement region RB where the spectroscopic measurement is performed in the fourth embodiment. FIG. 28 is a graph showing an example of characteristic spectra in the regions T1, T2a, and T2b shown in FIG. 27, and the vertical axis shows the absorption intensity spectrum, which is the difference between the intensity of the irradiated light and the intensity of the reflected light, among the various characteristic spectra described above. It is assumed that a surface film 33 with the same film thickness is formed in these regions T1, T2a, and T2b. In this example, the measurement region RB is moved on the substrate W while scanning, and a large number of absorption intensity spectra slightly shifted from each other are measured at each measurement position in the width direction of the measurement region RB in the measurement region RB. Therefore, when the absorption intensity spectra obtained by scanning the regions T1, T2a, and T2b with the measurement region RB are superimposed, a characteristic spectrum group (absorption intensity spectrum group) including a region with a range of intensity (light amount) values ​​is obtained, rather than a single linear characteristic spectrum with no range in the reflectance value in FIG. 5 (FIG. 28). However, even in such a group of absorbance intensity spectra with different intensity values, the intensity values ​​converge to almost one point at the wavelength where the spectra in the regions T1, T2a, and T2b intersect, and the above-mentioned singular points P7 and P8 appear. Note that even when other characteristic spectra are measured as described in the first and third embodiments, characteristic spectrum groups and singular points each having a certain width are obtained.

[0130] Therefore, according to the spectroscopic measurement of the fourth embodiment, the positioning of the present disclosure can be performed in the same manner as in the first embodiment. For example, based on the flowchart described with reference to FIG. 9, it is determined whether the measurement region RB is arranged in the inspection region T1, the non-inspection region T2b, or the boundary region between the regions T1 and T2b. In this case, even if the measurement region RB shown in FIG. 27 is fixed and arranged and scanned without moving, a large number of reflectance spectrum groups (for example, 900 light receiving elements, i.e., 900 pixels) can be obtained by the measurement in step S205 of FIG. 9 as described above. Therefore, in the subsequent step S206 of FIG. 9, it is determined whether or not the singular points of these reflectance spectrum groups are included that match the singular points according to the prediction model. Then, if a reflectance spectrum with a matching singular point is included (step S206: Yes), it is confirmed whether or not the reflectance spectrum matches the reflectance spectrum of the inspection region according to the prediction model (step S207). If the reflectance spectra do not match (step S207: No), the measurement region RB is moved (step S208), and the operations of steps S205 to S207 are repeated.

[0131] As described above, when using the HSC 11B capable of performing spectroscopic measurement of many points in a short time, it is not essential to determine the placement state of the substrate W based on the flowchart of Fig. 9. For example, it may be determined in a lump whether or not the reflectance spectrum group obtained by moving the measurement region RB and scanning the entire surface of the substrate W includes a spectrum that matches the singular point and the reflectance spectrum of the inspection region T1 by the prediction model. If there is a singular point and a spectrum that matches the reflectance spectrum of the prediction model, the position where the reflectance spectrum was acquired in the surface of the substrate W is identified. The acquisition position of the reflectance spectrum can be identified, for example, from the arrangement position of the measurement region RB where the reflectance spectrum was acquired during the scanning period and the position of the pixel (optical element) in the measurement region RB.

[0132] As will be described in detail in the examples below, according to the positioning and film thickness inspection according to the present disclosure, particularly the fourth embodiment, even if there is blurring or change in illuminance due to focus deviation, it is unlikely to affect the identification of singular points, reflectance spectrum, etc. Therefore, even when applied to in-line inspection incorporated in a processing module where focus deviation and illuminance changes are expected to occur frequently due to disturbances such as vibration generation and illuminance fluctuation, positioning, etc. can be performed almost unaffected by these disturbances.

[0133] An example of illuminance fluctuation, which is an example of this disturbance, will be described. FIG. 29 is a graph illustrating a reflectance spectrum when a measurement region RB is arranged across two adjacent regions (for example, regions T1 and T2b in FIG. 27) having the same film thickness and different patterns, and spectroscopic measurement is performed under different illuminances L1 to L3. The solid line in the figure indicates a representative reflectance spectrum for one of the regions T1 and T2b, and the dashed line indicates a representative reflectance spectrum for the other region. As described above, according to the spectroscopic measurement of the fourth embodiment, in a spectroscopic analysis of one scan, the illuminance may be considered to be approximately the same at multiple positions that are continuous in the horizontal direction within the measurement region RB. Therefore, according to the reflectance spectrum in each adjacent region measured in one scan, spectroscopic measurement is performed at approximately the same illuminance.

[0134] On the other hand, while repeating scanning of a large number of substrates W, the illuminance of the irradiated light may change due to, for example, dirt on a window through which the irradiated light or reflected light passes. In this regard, FIG. 29 shows that even when reflectance spectra are acquired under different illuminances L1 to L3, the wavelength of the singular point where the reflectance spectra acquired in the regions T1 and T2b having different pattern shapes intersect does not change. Therefore, according to the spectroscopic measurement according to the fourth embodiment, even if an illuminance fluctuation that can be expected in an in-line inspection occurs, the arrangement state of the substrate W can be stably specified based on the wavelength of the singular point that is not easily affected by such an illuminance fluctuation. In the following modified example, an example of in-line inspection using a film forming module 7E equipped with an inspection device 1B will be described.

[0135] (Application example of the fourth embodiment) In the application example of the fourth embodiment, the inspection device 1B is attached to a semi-batch type film forming module 7E (substrate processing device) provided in place of the third processing module 7C where the film forming process is performed, and an in-line inspection is performed in the film forming module 7E immediately after the film forming process. FIG. 30 and FIG. 31 are a vertical side view and a horizontal plan view showing the semi-batch type film forming module 7E. As shown in these figures, the processing container 71B is, for example, a flat cylindrical vacuum container, and a horizontal rotating table (table) 72B forming a mounting table is provided inside the processing container 71B. The rotating table 72B rotates around a central axis (rotation axis) M by a rotating mechanism 73B provided at the center of the rotating table 72B. A plurality of substrates W are placed on the rotating table 72B, and the substrates W are revolved around the central axis M by the rotation of the rotating table 72B.

[0136] As shown in Fig. 31, a source gas nozzle 51 for supplying a source gas and a reaction gas nozzle 52 for supplying a reaction gas are provided in a region through which the substrate W passes during revolution. A purge gas nozzle 53 for supplying a purge gas is provided in each of two regions between the source gas nozzle 51 and the reaction gas nozzle 52. The source gas, reaction gas, and purge gas nozzles 51, 52, and 53 are arranged spaced apart from each other in the circumferential direction so as to extend horizontally from the sidewall of the processing vessel 71B toward the center of the processing vessel 71B. The source gas, reaction gas, and purge gas nozzles 51, 52, and 53 are provided with a large number of gas discharge holes 50 (Fig. 30) along the longitudinal direction for discharging the various gases supplied into the processing vessel 71B.

[0137] 31, by disposing partition members 56 in each of the two regions surrounded by the two purge gas nozzles 53, the space within the processing vessel 71B is partitioned into a region 54 to which source gas is supplied and a region 55 to which reactive gas is supplied. This prevents the source gas and reactive gas from mixing within the processing vessel 71B. The region 54 to which source gas is supplied and the region 55 to which reactive gas is supplied are connected to an exhaust device 79 (FIG. 30) via exhaust paths 57 and 58 equipped with valves V1 and V2, respectively.

[0138] The gas supply unit 77 (process gas supply unit) is composed of supply paths independent of each other, and includes source gas, reactive gas, and purge gas supply systems 77b, 77c, and 77d having their own gas supply sources. The source gas, reactive gas, and purge gas supply systems 77b, 77c, and 77d are each provided with a flow rate controller such as a valve or a mass flow controller, and are connected to the source gas, reactive gas, and purge gas nozzles 51, 52, and 53. As a result, the source gas, reactive gas, and purge gas nozzles 51 to 53 are continuously supplied with the source gas, reactive gas, and purge gas from each supply source.

[0139] In this film formation module 7E, as the turntable 72B rotates, the substrate W passes through the source gas supply region 54, whereby the source gas is adsorbed onto the wafer surface. Next, the substrate W passes through the reactive gas supply region 55, whereby the source gas and the reactive gas on the wafer surface react with each other to form a film. In this manner, the substrate W passes alternately through the source gas supply region 54 and the reactive gas supply region 55, whereby a surface film 33 is formed on the substrate W by the ALD method, as in the first embodiment.

[0140] The processing vessel 71B has an opening at a portion above the region 55 to which the reaction gas is supplied, and the opening is closed by a window 76B that transmits light for the above-mentioned spectroscopic measurement. In order to maintain the airtightness of the processing vessel 71B, the periphery of the window 76B is sandwiched between the processing vessel 71B and a top lid 76C attached to the top of the processing vessel 71B via an O-ring. The top lid 76C is open above the central region of the window 76B for transmitting light so as not to block the central region.

[0141] HSC 11B is disposed above window 76B and configured to receive light reflected from measurement region RB through a central region of window 76B. HSC 11B is installed with lens 12 facing so that measurement region RB is disposed within a range that includes the diameter of revolving substrate W (FIG. 36). Furthermore, in HSC 11B, the orientation of lens 12 is adjusted so that measurement region RB is disposed extending radially from the sidewall of processing vessel 71B toward the center of processing vessel 71B, i.e., toward central axis M, in a plan view, similar to each of nozzles 51-53.

[0142] After the surface film 33 is formed, each substrate W is scanned by the HSC 11B while revolving in the deposition module 7E. That is, after each revolving substrate W enters the area below the measurement area RB, its entire surface passes below the measurement area RB. The HSC 11B performs spectroscopic measurement of the moving measurement area RB at short intervals, thereby measuring the reflectance spectrum of the entire upper surface of the substrate W. According to such in-line inspection in the deposition module 7E, the measurement area RB can be positioned in the inspection area T1 efficiently and accurately to perform film thickness inspection.

[0143] Here, in the past, it was thought that it was difficult to use high-precision spectroscopic measurement such as HSC11B in in-line inspection of the film-forming module 7E because of the influence of various disturbances. Examples of disturbances include changes in illuminance over time due to clouding of the window 76B caused by various gases supplied during the film-forming process, and diagnostic failure due to the image becoming unclear. In addition, there are inclination of the turntable 72B from the center side toward the outside, and occurrence of focus deviation due to rotational vibration of the turntable 72B. With the conventional spectroscopic measurement using HRC11B, it was thought that such disturbances make it difficult to obtain accurate measurement results. In contrast, if a judgment is made using the reflectance spectrum or its singular points as in the present disclosure, positioning and film thickness inspection can be performed accurately and efficiently without being influenced by disturbances, as will be described in the following examples.

[0144] (Other variations) The HSC 11B of the fourth embodiment is not limited to one that scans the linear measurement region RB every minute period while moving. For example, the HSC 11B may be another type of HSC, such as one that performs spectroscopic measurement by changing multiple spectral filters corresponding to different bands while keeping the area-shaped measurement region RB fixed. In addition, instead of the HSC 11B, a large number of measurement units 11 as in the first embodiment may be prepared, and each coaxial probe 13 may be moved integrally, so that each measurement region R moves integrally like the measurement region RB and performs spectroscopic measurement at the same timing.

[0145] Furthermore, the inspection device 1B is not limited to being attached to the film formation module 7E, and may be attached to another processing module, or may be disposed in the film formation processing system 10 as a standalone inspection device as shown in the first embodiment without being attached to a processing module. In this case, the inspection device 1B is not limited to being attached to a rotating stage, and may be placed on a rail-shaped stage that moves in one direction and spectroscopic measurement may be performed while moving the substrate, or the measurement region RB may be moved relatively by moving the HSC 11B while the substrate is stationary. EXAMPLES

[0146] (Experiment 1) In order to confirm the effectiveness of the alignment inspection of the third embodiment, unbonded wafers were overlapped with an extremely small amount of misalignment, and the reflectance spectrum of a predetermined inspection area was measured.

[0147] A. Experimental conditions Two TEG (Test Element Group) wafers with the same L / S pattern formed on the surface layer with a thickness of 350 nm were prepared. The thickness of the part of these wafers that does not include the L / S pattern is 775 μm, and the part with the thickness is made of silicon oxide (SiO 2The structure includes a structure in which metal such as metal pads 23 are embedded in a concave-convex pattern of silicon nitride (SiN) or the like. These wafers were placed on a flat table, unbonded, with the surface layers facing upwards, with the L / S patterns overlapping without any misalignment. A small vibration was then applied to the table to create an extremely small amount of misalignment between the wafers that makes quantitative measurement difficult, and five experiments were performed to measure the reflectance spectrum (Experiments 1 to 5). Each experiment was measured five times, and it was confirmed that there was no change in the reflectance spectrum for all five times.

[0148] B. Experimental Results Fig. 32 shows reflectance spectra showing the results of Experiment 1. In Fig. 32, the reflectance spectra of Experiments 1 to 5 are displayed using different line types, but since some reflectance spectra overlap with other reflectance spectra, they are shown using a solid line, a dashed line, a dashed line, and a dashed line.

[0149] As shown in FIG. 32, no change was observed in the reflectance spectrum of each of the first to fifth experiments after five measurements. This confirmed that the reflectance spectrum corresponds to the shift direction and the shift amount, and that the shift direction and the shift amount can be estimated from the reflectance spectrum measured on the laminated substrate Wc to be inspected using a prediction model. In FIG. 32, it was confirmed that singular points P4 and P5 at which the five reflectance spectra intersect appeared, and that the wavelength of the singular point P4 corresponds to the wavelength corresponding to the thickness of the wafer. Therefore, it was confirmed that the singular points also have the characteristics as described above. Therefore, it was confirmed that the alignment inspection of the third embodiment can easily detect even extremely minute positional deviations of the laminated substrate Wc with high accuracy.

[0150] (Experiment 2) Under conditions where the focus deviation and illuminance difference expected in the in-line inspection described above occur, the trends of the singular points and reflectance spectrum identified by the spectroscopic measurement of the fourth embodiment were confirmed.

[0151] A. Experimental conditions A bare wafer with multiple sets of test patterns on its surface was prepared as the substrate W to be used in the experiment. In order to identify the singular points for each set of test patterns, two different pattern areas were provided, and a SiN film of the same thickness was formed thereon. In order to identify the singular points corresponding to the film thickness, the film thicknesses were made different between each set. The entire top surface of the substrate W was then scanned, and the two pattern areas of each set of test patterns were spectroscopically measured, and the reflectance spectra of the two different pattern areas were obtained for each set of test patterns, and the singular points corresponding to the film thickness of each set of test patterns were confirmed from the intersections of these spectra.

[0152] In order to reproduce an environment with focus deviation and illuminance difference, spectroscopic measurement was performed at a low resolution where the width of the measurement area RB on the substrate W was made relatively large by adjusting the height of the lens 12, and at a high resolution where the width was made relatively small and the resolution was about 110 times higher than the low resolution. The high resolution reproduced a state where the illuminance was relatively high and in focus, and the low resolution reproduced a state where the illuminance was relatively low and out of focus.

[0153] In addition, for the reflectance spectrum of each data set acquired by the high- and low-resolution scans, a data set was also prepared in which it was converted to absolute reflectance in order to cancel the illuminance difference. <1> ~ <5> This is a table summarizing each condition. <1> ~ <5> Prepare a data set for each condition, and <1> ~ <5> The trend of the singular points identified in the test pattern analysis was confirmed. Figure 33 shows the results of the test pattern analysis under the condition of one of the multiple test patterns. <1> ~ <4> The wavelengths of the singular points measured under the conditions are also shown. <5> is obtained by spectroscopic measurement in the first embodiment using a single measurement region R.

[0154] And each condition <1> ~ <5> It was confirmed whether the singular point wavelengths identified by the measurement of each set of test patterns in the above corresponded to the film thickness of each set of test patterns. As an additional test, the singular points in the test patterns with relatively large voids were also confirmed by low-resolution spectroscopic measurement.

[0155] B. Experimental Results FIG. 34 is a graph showing the wavelength of the singular point showing the result of Experiment 2. In the figure, the singular point wavelength of each set of test patterns is plotted for each of the above conditions, with the horizontal axis representing the condition. <1> The vertical axis shows the wavelengths of the singular points in the reflectance spectrum without absolute value conversion. <2> ~ <5> The singular wavelength [nm] of the reflectance spectrum is taken. <1> For each set of test patterns obtained in the singular wavelength (vertical axis), the same set of test patterns is applied under each condition. <2> ~ <5> The singularity wavelength (horizontal axis) measured by the method is plotted.

[0156] As shown in Figure 34, the condition <1> Each singular point wavelength and the condition <2> ~ <4> The plots of the singular wavelengths of and overlap on a line with a slope of 1. As shown by these plots, <1> ~ <4> It was confirmed that the wavelengths of the singular points measured by the method are the same wavelengths of the singular points according to the film thickness of each set of test patterns, regardless of whether they are low or high resolution, or whether they are converted to absolute reflectance, and that there is no difference. Therefore, it was confirmed that the spectroscopic measurement of the fourth embodiment allows positioning and the like to be performed based on the reflectance spectrum using the singular points of the present disclosure, without being affected by the focal length of the lens 12 or the fluctuation of illuminance. It was also confirmed that the exact singular points can be identified from the reflectance spectra of the relative values ​​as measured, without conversion to absolute reflectance to cancel the difference in illuminance.

[0157] And, under the conditions shown in Figure 34 <1> ~ <4> It was confirmed that the wavelengths of the singular points of each film thickness were consistent with those of the singular points of each film thickness. <3> ~ <5> The figure shows the relationship between the thickness and some of the singular wavelengths identified in . As shown in the figure, <3> , <4> As described above in the first embodiment, the singular point wavelength is proportional to the film thickness, and it was confirmed that there is a corresponding relationship between the film thickness and the singular point in the spectroscopic measurement in the fourth embodiment as well.

[0158] In the pattern region where the film thickness is 0 nm, i.e., where no SiN film is provided, a singular point appears, but the wavelength is a value that is not in a proportional relationship with the film thickness as seen in other singular point wavelengths for film thicknesses of 0 nm or more. <5> The wavelengths of the singular points are measured under the conditions of the spectroscopic measurement of the fourth embodiment, including the case where the film thickness is 0 nm. <1> ~ <4> The wavelengths of the singularities of the two conditions are about 5 nm shorter than those of the two conditions. <5> This is believed to be due to a deviation specific to the calibration of the spectrometer used in 1. Therefore, it was presumed that if this deviation is understood and corrected in advance, the spectroscopic measurement of the first embodiment would have the same level of accuracy as that of the fourth embodiment.

[0159] Furthermore, FIG. 35 shows the singular points identified by the spectroscopic measurement of the fourth embodiment for another test pattern in which a SiN film with voids is formed, as a result of an additional test. A singular point with a wavelength different from the singular point wavelength corresponding to the film thickness appeared. In this way, it was confirmed that accurate singular points appeared even by the spectroscopic measurement of the low resolution of the fourth embodiment, and the SiN film containing voids could be identified. And, it was inferred that the low resolution capable of spectroscopic measurement of a wide range in one scan makes it easy to find the reflectance spectrum of different pattern areas in one scan, and therefore the singular points can be quickly identified. It was also inferred that the spectroscopic measurement can be performed quickly in a high-density matrix on the substrate W, and therefore the spectroscopic measurement can be performed efficiently.

[0160] (Experiment 3) When performing positioning and film thickness inspection using spectroscopic measurement by the HSC 11B in the film forming module 7E shown in the modified example of the fourth embodiment, it is confirmed whether positions on the substrate W can be detected for a large number of reflectance spectra included in each data set.

[0161] A. Experimental conditions 36 is a top perspective view of multiple substrates W that are the subject of spectroscopic measurement in Experiment 3. In Experiment 3, spectroscopic measurement of multiple substrates W placed on a turntable 72B and revolving in a film forming module 7E was reproduced as shown in the modified example of the fourth embodiment. The position of the lens 12 was set under low-resolution conditions so that the width (X) of the measurement region RB was longer than the diameter of the substrate W. Then, the measurement region RB, which was arranged in an elongated state in the direction toward the central axis M, was revolved relative to the multiple substrates W, and spectroscopic measurement was performed every short period of time to obtain a large number of data sets.

[0162] B. Experimental Results 37 and 38 are graphs showing the experimental results of Experiment 3. FIG. 37 shows the intensity profile of one wavelength acquired at each position of the measurement region RB at time t1. The intensity range inside the two dashed lines in FIG. 37 is the intensity range used for positioning and film thickness inspection of the present disclosure. Each reflected light having an intensity within this intensity range can be determined to have been reflected on the substrate W and then incident on the HSC 11B, while the reflected light having an intensity weaker than this intensity range is considered to have been reflected outside the substrate W, for example, on the rotating table 72B. It can be seen that the boundary positions of these reflected lights with different intensities correspond to the black dot A and the white dot B on the periphery of the substrate W shown in FIG. 36.

[0163] FIG. 38 is a graph showing the change over time in the positions of points A and B in the measurement area RB, which are identified by using the correspondence between the position and the intensity in the measurement area RB as shown in FIG. 37. The times t0 to t5 in the figure correspond to the times t0 to t5 shown in FIG. 36. As shown in FIG. 38, the position where the solid line and the dashed line indicating the positions of points A and B intersect is the position where the substrate W first or last entered under the measurement area RB. Points A and B gradually move away from this entry position, and at time t2 when points A and B are the most distant, it is considered that the diameter of the substrate W is located under the measurement area RB. After time t2, points A and B gradually approach each other and become the same position, and the period during which points A and B are not detected is the period until the next substrate W arrives at the measurement area RB. The period during which point A is displaced from the inside to the outside near time t5 is the period during which the measurement area RB moves on the notch.

[0164] As shown in Fig. 38, by grasping the positions of points A and B in the measurement region RB, it is possible to identify the position on the substrate W of the measurement region RB that relatively revolves from the change in the measurement range in the measurement region RB from minimum width (initial entry position) → maximum width (substrate diameter position) → minimum width (final entry position) during that time. Then, by collating with data showing the peripheral position of the substrate W as shown in Fig. 37, it is possible to determine at which position in the measurement region RB an acquired reflectance spectrum was measured. As described above, according to the in-line inspection as shown in the modified example of the fourth embodiment, it is possible to identify the measurement position of a reflectance spectrum acquired in the positioning of the inspection region T1 or in the film thickness inspection.

[0165] Incidentally, the relative moving speed of the measurement area RB relative to the substrate W as shown in FIG. 36 is small inside the measurement area RB and large outside, and the displacement directions at these positions are not strictly parallel. Therefore, there is a concern that the difference in the amount of movement and the direction of movement inside and outside the measurement area RB may affect the reflectance spectrum at each position, and an error may occur in the positioning using the singular points of the present disclosure. In order to solve such a problem, a separate test pattern was moved irregularly on the substrate W that revolves or moves straight, and the spectroscopic measurement in the fourth embodiment was performed under various conditions such as low resolution, high resolution, and with or without absolute value conversion as shown in Experiment 3, and the trends of the singular points, etc. were confirmed. In such an experiment, as in Experiment 3, a singular point corresponding to the film thickness could be identified from the reflectance spectrum measured for the test pattern. From this, it has been confirmed that accurate positioning, etc. can be performed without errors even in in-line inspection such as the modified example of the fourth embodiment.

[0166] It should be noted that the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, modified, and combined in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0167] W substrate Wc polymerized substrate R measurement area 33 Surface film 121 Training Data

Claims

1. A method for inspecting a substrate by irradiating the substrate with light, comprising the steps of: a step of irradiating a measurement area set on the substrate with light and measuring a characteristic spectrum showing the absorption or reflection characteristics for the wavelength of the light; and when the characteristic spectrum changes depending on the structure of the substrate in the measurement area, the characteristic spectrum is associated with a film thickness if a film is formed on the surface of the substrate or with a thickness of the substrate, using a learning model generated by learning about a plurality of substrates, and determining the arrangement state of the substrate in the measurement area from the structure of the substrate identified by comparing the characteristic spectrum measured in the step of measuring the characteristic spectrum with a reference spectrum obtained from the learning model based on the film thickness or substrate thickness identified from the substrate from which the inspection spectrum was obtained.

2. The method of claim 1 , wherein the characteristic spectrum is any one of a reflected light intensity spectrum, an absorbance intensity spectrum, an absorbance spectrum, and a reflectance spectrum from the measurement region.

3. the light irradiated onto the measurement region is measurement light for performing spectroscopic measurement of a film on a surface of the substrate on which a concave-convex pattern that is a structure of the substrate is formed, In the step of determining the arrangement state of the substrate, the learning model is used, which is generated by learning the characteristic spectrum formed according to the concave-convex pattern in association with the film thickness of the film, and a determination is made as to whether or not the measurement region is located within the region in which the concave-convex pattern is formed, based on a comparison result between the inspection target spectrum obtained by specifying the film thickness and the comparison spectrum; 2. The method according to claim 1, wherein, when it is determined in the step of determining the placement state that the measurement area is not located within the area in which the concave-convex pattern is formed, the steps of moving the measurement area, measuring the characteristic spectrum, and determining the placement state are repeated.

4. The method according to claim 3 , wherein the uneven pattern is formed in a measurement area where the spectroscopic measurement is performed.

5. an adjacent region on the substrate, the adjacent region having a projection-projection pattern different from the projection-projection pattern of the measurement region; In the step of determining the arrangement state of the substrate, the learning model generated by learning the characteristic spectra formed in accordance with the unevenness patterns of the measurement region and the adjacent region is used to determine whether the measurement region is located in the measurement region or in the adjacent region based on a comparison result between the inspection target spectrum obtained by specifying the film thickness and the comparison spectrum; The method according to claim 4, wherein, when it is determined in the step of determining the placement state that the measurement area is located within the adjacent area, in the step of moving the measurement area, the measurement area is moved based on a direction and movement distance that are preset based on the placement relationship between the measurement area and the adjacent area.

6. The method according to claim 3 , wherein the uneven pattern is an alignment mark formed in a preset area on the surface of the substrate, the alignment mark being provided for adjusting the alignment of the substrate.

7. 4. The method according to claim 3, further comprising the step of specifying values ​​of the inspection object spectrum and the comparison spectrum at the singular point after the step of measuring the characteristic spectra, when the wavelength of the light at a position where the multiple types of characteristic spectra obtained by changing a structure of the substrate intersect, or the wavelength of the light at a position where a difference between values ​​of the multiple types of characteristic spectra is minimum when the multiple types of characteristic spectra do not intersect, is called a singular point, and when a difference between the value specified in the inspection object spectrum and the value specified in the comparison spectrum is equal to or greater than a preset tolerance, not executing the step of determining the arrangement state of the substrate.

8. The method according to claim 7 , wherein the singular point varies depending on a thickness of a film on the surface of the substrate, and the step of identifying a value at the singular point includes identifying the value at the singular point that corresponds to the film thickness.

9. the substrate is a bonded substrate formed by bonding a first substrate and a second substrate, and the light irradiated to the measurement area is infrared light for measuring an internal structure of the bonded substrate; 2. The method according to claim 1, wherein in the step of determining the arrangement state of the substrates, a learning model generated by learning the characteristic spectrum formed according to the bonding state between the first substrate and the second substrate in correspondence with a thickness of the bonded substrate is used, and whether or not the first substrate and the second substrate are bonded in an accurate position is determined based on a comparison result between the inspection target spectrum obtained by identifying the thickness of the substrates and the comparison spectrum.

10. The method according to claim 9 , wherein the bonding state is a misalignment of metal pads provided on the first substrate and the second substrate, respectively, which connect the first substrate and the second substrate to each other.

11. The method of claim 1 , wherein the step of measuring the characteristic spectrum includes measuring the characteristic spectrum with a hyperspectral camera.

12. The method according to claim 11, wherein the measurement area of ​​the characteristic spectrum measured by the hyperspectral camera is configured as an elongated rectangle whose longitudinal dimension is greater than the diameter of the substrate, and in the measurement by the hyperspectral camera, the measurement area is moved relative to a plurality of the substrates placed on a stage in a fixed direction, thereby causing the measurement area to scan the entire surface of the substrate.

13. An apparatus for inspecting a substrate, comprising: Stage and an inspection unit that irradiates light onto a measurement area set on the substrate placed on the stage and receives reflected light; A control unit; Equipped with The control unit is a device that outputs a control signal to execute the steps of: irradiating light onto the measurement area and measuring a characteristic spectrum that indicates the absorption or reflection characteristics for the wavelength of the light; and, when the characteristic spectrum changes depending on the structure of the substrate in the measurement area, correlating the characteristic spectrum with the film thickness if a film is formed on the surface of the substrate or the thickness of the substrate, using a learning model generated by learning about a plurality of substrates, and determining the arrangement state of the substrate in the measurement area from the structure of the substrate identified by comparing the inspection target spectrum, which is the characteristic spectrum measured in the step of measuring the characteristic spectrum, with a reference spectrum, which is the characteristic spectrum obtained from the learning model based on the film thickness or substrate thickness identified from the substrate from which the inspection target spectrum was obtained.

14. The apparatus of claim 13 , wherein the characteristic spectrum is one of a reflected light intensity spectrum, an absorbance intensity spectrum, an absorbance spectrum, and a reflectance spectrum from the measurement region.

15. the inspection unit is configured to be movable within the measurement area, and light irradiated onto the measurement area is measurement light for performing spectroscopic measurement of a film on a surface of the substrate on which a concave-convex pattern that is a structure of the substrate is formed, 14. The apparatus according to claim 13, wherein, in the step of determining the arrangement state of the substrate, the control unit uses the learning model generated by learning the characteristic spectrum formed according to the concave-convex pattern in correspondence with the film thickness of the film, and determines whether or not the measurement area is located within the area in which the concave-convex pattern is formed from a comparison result between the spectrum to be inspected obtained by identifying the film thickness and the comparison spectrum, and when, in the step of determining the arrangement state, it is determined that the measurement area is not located within the area in which the concave-convex pattern is formed, outputs a control signal for repeatedly executing a step of moving the measurement area, a step of measuring the characteristic spectrum, and a step of determining the arrangement state.

16. The apparatus according to claim 15 , wherein the uneven pattern is formed in a measurement area where the spectroscopic measurement is performed.

17. an adjacent region on the substrate, the adjacent region having a projection-projection pattern different from the projection-projection pattern of the measurement region; 17. The apparatus according to claim 16, wherein, in the step of determining the arrangement state of the substrate, the control unit uses the learning model generated by learning the characteristic spectrum formed in accordance with the unevenness patterns of the measurement region and the adjacent region, and determines whether the measurement region is located in the measurement region or the adjacent region from a comparison result between the inspection target spectrum obtained by specifying the film thickness and the comparison spectrum, and if, in the step of determining the arrangement state, it is determined that the measurement region is located within the adjacent region, in the step of moving the measurement region, outputs a control signal for moving the measurement region based on a direction and movement distance that are preset based on the arrangement relationship between the measurement region and the adjacent region.

18. 16. The apparatus according to claim 15, wherein the uneven pattern is an alignment mark formed in a preset area on the surface of the substrate, the alignment mark being provided for adjusting the alignment of the substrate.

19. When the wavelength of the light at a position where the plurality of types of characteristic spectra obtained by changing the structure of the substrate intersect, or when the plurality of types of characteristic spectra do not intersect, the wavelength of the light at a position where the difference between the values ​​of the plurality of types of characteristic spectra is minimum, is called a singular point, 16. The apparatus according to claim 15, wherein the control unit includes a step of specifying values ​​at the singular points of the inspection object spectrum and the comparison spectrum after the step of measuring the characteristic spectra, and outputs a control signal not to execute a step of determining the placement state of the substrate when a difference between the value specified in the inspection object spectrum and the value specified in the comparison spectrum is equal to or greater than a preset tolerance.

20. the singular point varies depending on the thickness of the film on the surface of the substrate, The apparatus according to claim 19 , wherein the step of identifying a value at the singular point comprises the step of: the control unit outputs a control signal for identifying the value at the singular point corresponding to the film thickness.

21. the substrate is a bonded substrate formed by bonding a first substrate and a second substrate, and the light irradiated to the measurement area is infrared light for measuring an internal structure of the bonded substrate; 14. The apparatus according to claim 13, wherein in the step of determining the arrangement state of the substrates, the control unit uses the learning model generated by learning the characteristic spectrum formed in accordance with the bonding state of the first substrate and the second substrate in correspondence with a thickness of the bonded substrate, and outputs a control signal for determining whether the first substrate and the second substrate are bonded in an accurate position based on a comparison result between the inspection target spectrum obtained by identifying the thickness of the substrate and the comparison spectrum.

22. The device according to claim 21 , wherein the bonding state is a misalignment of metal pads provided on the first substrate and the second substrate, respectively, that connect the first substrate and the second substrate to each other.

23. The apparatus of claim 13 , wherein the inspection unit comprises a hyperspectral camera that measures the inspection target spectrum.

24. The measurement area of ​​the hyperspectral camera is configured as an elongated rectangle whose longitudinal dimension is greater than the diameter of the substrate; The apparatus according to claim 23 , wherein the measurement region is moved in a fixed direction relative to the plurality of substrates placed on the stage, so that the measurement region scans the entire surface of the substrate.

25. 25. An apparatus according to claim 24; A rotation axis for rotating the stage; a processing vessel that accommodates the stage on which the plurality of substrates are placed and that revolves around the rotation axis; a process gas supply unit for supplying a process gas to the substrate; Equipped with the substrate processing apparatus supplies the processing gas to the substrate placed on the stage to process the substrate, and then inspects the substrate.

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