Information acquisition device, information acquisition method, and substrate processing device

Abstract

The present invention accurately acquires information pertaining to the concentration and amount of a specific substance present on the upper surface of a substrate with high temporal resolution. An information acquisition device according to the present invention comprises: a light irradiation unit that irradiates a substrate with irradiation light, which passes through the substrate and has directivity in a wavelength range including an absorption spectrum of a specific substance, so that the irradiation light is totally reflected inside the substrate; a light reception unit that receives the totally reflected light emitted from the substrate by propagating while being totally reflected inside the substrate, and outputs measurement information related to the totally reflected light; and an information acquisition unit that acquires information pertaining to the specific substance from the absorption spectrum of the specific substance included in the measurement information.

Description

Information acquisition device, information acquisition method, and substrate processing device.

[0001] This invention relates to an information acquisition technology for obtaining information regarding the concentration and amount of a specific substance present on the upper surface of a substrate, and a substrate processing technology for processing the substrate based on the above information. The disclosures in the specification, drawings, and claims of the Japanese application shown below are incorporated herein by reference in their entirety: Japanese Patent Application No. 2024-159977 (filed September 17, 2024).

[0002] In the manufacturing process of electronic devices such as semiconductor devices and liquid crystal displays, substrate processing equipment is known that supplies processing solutions such as chemical solutions and rinsing solutions to bulk substrates such as silicon wafers and GaAs wafers, or thin-film deposition substrates on which thin films are formed (hereinafter referred to as "substrates") (see, for example, Patent Document 1).

[0003] Patent No. 7312656

[0004] In substrate processing technology, it has been proposed to use a concentration meter, for example, to monitor the progress of substrate processing. For example, a concentration meter is inserted into a drainage pipe that discharges the processing liquid discharged during substrate processing, and the concentration of a specific substance contained in the drainage liquid is measured. The specific substance diffuses within the drainage pipe. The measurement results of the concentration meter do not accurately reflect information such as the concentration and amount of the specific substance on the substrate (hereinafter referred to as "in-situ information"). Moreover, since the progress of substrate processing changes moment by moment, it is necessary to measure the changes in in-situ information with high temporal resolution, but it has been difficult to satisfy this requirement with conventional technology.

[0005] This invention has been made in view of the above-mentioned problems, and aims to provide an information acquisition technology that can accurately acquire information regarding the concentration and amount of a specific substance present on the upper surface of a substrate with high temporal resolution, and a substrate processing apparatus that processes a substrate with high precision using this information acquisition technology.

[0006] A first aspect of this invention is an information acquisition device for acquiring information about a specific substance present on or near the upper surface of a substrate during the continuous supply of a processing liquid to the upper surface of the substrate, characterized in that it comprises: a light irradiation unit that irradiates the substrate with light that is transparent to the substrate and has directionality in a wavelength range including the absorption spectrum of the specific substance, so as to be totally reflected inside the substrate; a light receiving unit that receives the totally reflected light that propagates while being totally reflected inside the substrate and is emitted from the substrate, and outputs measurement information related to the totally reflected light; and an information acquisition unit that acquires information about the specific substance from the absorption spectrum of the specific substance included in the measurement information.

[0007] Furthermore, a second aspect of this invention is an information acquisition method for acquiring information about a specific substance present on or near the upper surface of a substrate during the continuous supply of a processing liquid to the upper surface of the substrate, characterized by comprising the steps of: irradiating the substrate with light that is transparent to the substrate and has directionality in a wavelength range including the absorption spectrum of the specific substance, such that the light is totally reflected inside the substrate; receiving the totally reflected light that propagates while being totally reflected inside the substrate and is emitted from the substrate, and outputting measurement information related to the totally reflected light; and acquiring information about the specific substance from the absorption spectrum of the specific substance included in the measurement information.

[0008] Furthermore, a third aspect of this invention is a substrate processing apparatus comprising: a processing liquid supply unit that supplies a processing liquid to the upper surface of a substrate held in a horizontal position; a light irradiation unit that, while continuously supplying the processing liquid to the upper surface of the substrate, irradiates the substrate with light that is transparent to the substrate and has directionality in a wavelength range including the absorption spectrum of a specific substance, so as to be totally reflected inside the substrate; a light receiving unit that receives the totally reflected light that propagates while being totally reflected inside the substrate and is emitted from the substrate, and outputs measurement information related to the totally reflected light; and an information acquisition unit that acquires information about a specific substance present on or near the upper surface of the substrate from the absorption spectrum of the specific substance included in the measurement information.

[0009] In the invention configured as described above, the light irradiation unit irradiates the substrate with light that is transparent to the substrate and has directionality in a wavelength range including the absorption spectrum of a specific substance, such that the light is totally reflected inside the substrate. Inside the substrate, the irradiated light is totally reflected and propagates as totally reflected light, which is then emitted from the substrate. The light receiving unit receives this totally reflected light, and information about the specific substance is obtained from the absorption spectrum of the specific substance included in the measurement information related to the totally reflected light.

[0010] As described above, according to the present invention, information regarding the concentration and amount of a specific substance present on the upper surface of a substrate can be obtained accurately and with high temporal resolution. Not all of the multiple components of each aspect of the present invention described above are essential, and in order to solve some or all of the above-described problems, or to achieve some or all of the effects described herein, it is possible to modify, delete, replace with other new components, or delete some of the limitations of some of the multiple components as appropriate. Furthermore, in order to solve some or all of the above-described problems, or to achieve some or all of the effects described herein, it is also possible to combine some or all of the technical features included in one aspect of the present invention described above with some or all of the technical features included in another aspect of the present invention described above to form an independent form of the present invention.

[0011] This is a plan view showing the schematic configuration of a substrate processing system equipped with one embodiment of the substrate processing apparatus according to the present invention. This is a diagram showing the configuration of the first embodiment of the substrate processing apparatus according to the present invention. This is a plan view of the central part of Figure 2A seen from above. This is an exploded and assembled perspective view showing the structure for adsorbing and holding a substrate in the substrate processing apparatus shown in Figure 2A. This is a schematic diagram showing the irradiation path of the light irradiated onto the prism and the propagation of the irradiated light. This is a schematic diagram showing the propagation of total reflected light and the exit path from the prism. This is a flowchart showing the operation of the substrate processing apparatus shown in Figure 2A. This is a graph showing an example of an absorption spectrum obtained when 10% IPA and DIW are supplied to the upper surface of the substrate. This is a graph showing the relationship between the ratio of the absorbance peak of a specific substance obtained from measurement information to the absorbance peak of pure water and the concentration of the specific substance. This is a flowchart showing the operation of the second embodiment of the substrate processing apparatus according to the present invention. This is a diagram showing the configuration of the third embodiment of the substrate processing apparatus according to the present invention. This is a plan view of the central part of Figure 7A seen from above. This is a schematic diagram showing the irradiation path of the light irradiated onto the prism, the propagation of the irradiated light, and the propagation of total reflected light and the exit path from the prism in the third embodiment. This is a plan view of the central part of the fourth embodiment of the substrate processing apparatus according to the present invention seen from above. This figure shows the configuration of the fifth embodiment of the substrate processing apparatus according to the present invention. This figure schematically shows the configuration and operation of the light irradiation unit and light receiving unit in the sixth embodiment of the substrate processing apparatus according to the present invention. This figure schematically shows the configuration and operation of the light irradiation unit and light receiving unit in the seventh embodiment of the substrate processing apparatus according to the present invention. This figure schematically shows the configuration and operation of the light irradiation unit and light receiving unit in the eighth embodiment of the substrate processing apparatus according to the present invention. This figure shows the configuration of the ninth embodiment of the substrate processing apparatus according to the present invention. This schematic diagram shows the irradiation path of the light irradiated onto the bevel portion of the substrate and the propagation of the irradiated light in the ninth embodiment. This schematic diagram shows the propagation of the totally reflected light and the emission path from the bevel portion of the substrate in the ninth embodiment.

[0012] Figure 1 is a plan view showing a schematic configuration of a substrate processing system equipped with one embodiment of the substrate processing apparatus according to the present invention. This does not show the external appearance of the substrate processing system 100, but is a schematic diagram that clearly shows its internal structure by excluding the outer wall panels and some other components of the substrate processing system 100. This substrate processing system 100 is a single-wafer type device that is installed, for example, in a clean room and processes substrates S one by one.

[0013] The substrate processing system 100 comprises multiple processing units (substrate processing devices) 1, each of which is responsible for processing the substrate S. Figure 1 shows four processing units 1 arranged horizontally, but each processing unit 1 can also be stacked in multiple layers in the vertical direction. For example, when the processing units 1 are stacked in six layers, the substrate processing system 100 will have a total of 24 processing units 1.

[0014] Each of the multiple processing units 1 equipped in the substrate processing system 100 receives a substrate S, removes foreign matter adhering to the upper surface of the substrate S, and cleans it, as will be described later. In other words, each processing unit 1 corresponds to an example of a substrate processing apparatus 10 capable of executing one embodiment of the substrate processing method according to the present invention.

[0015] In this embodiment, the "substrate" can be any type of substrate, such as a semiconductor wafer, a photomask glass substrate, a liquid crystal display glass substrate, a plasma display glass substrate, a Field Emission Display (FED) substrate, an optical disk substrate, a magnetic disk substrate, or a magneto-optical disk substrate. The following description will primarily use a substrate processing apparatus 10 used for processing semiconductor wafers as an example, but the method can be similarly applied to processing the various substrates exemplified above.

[0016] As shown in Figure 1, the substrate processing system 100 has a substrate processing area 110 for processing substrates S. An indexer unit 120 is provided adjacent to this substrate processing area 110. The indexer unit 120 has a container holding unit 121 that can hold multiple containers C for housing substrates S (such as FOUP (Front Opening Unified Pod), SMIF (Standard Mechanical Interface) pod, OC (Open Cassette), etc., which house multiple substrates S in a sealed state). The indexer unit 120 also includes an indexer robot 122 for accessing the containers C held by the container holding unit 121 to remove unprocessed substrates S from the containers C or to store processed substrates S in the containers C. Multiple substrates S are housed in a nearly horizontal position in each container C.

[0017] The indexer robot 122 comprises a base portion 122a fixed to the device housing, a multi-joint arm 122b rotatably mounted on the base portion 122a around a vertical axis, and a hand 122c attached to the tip of the multi-joint arm 122b. The hand 122c is structured to hold a substrate S placed on its upper surface. Since indexer robots having such a multi-joint arm and a hand for holding a substrate are well known, a detailed explanation will be omitted.

[0018] In the substrate processing area 110, a mounting table 112 is provided to allow substrates S from the indexer robot 122 to be placed on it. In a plan view, a substrate transfer robot 111 is positioned approximately in the center of the substrate processing area 110. Furthermore, multiple processing units 1 (substrate processing devices 10) are arranged to surround this substrate transfer robot 111. Specifically, multiple processing units 1 are positioned facing the space where the substrate transfer robot 111 is located. The substrate transfer robot 111 randomly accesses the mounting table 112 for these processing units 1 and transfers substrates S between them. In this embodiment, these processing units 1 (substrate processing devices 10) have the same function. Therefore, parallel processing of multiple substrates S is possible. Note that if the substrate transfer robot 111 can directly receive substrates S from the indexer robot 122, the mounting table 112 is not necessarily required.

[0019] Figure 2A is a diagram showing the configuration of a first embodiment of the substrate processing apparatus according to the present invention. Figure 2B is a plan view of the central part of Figure 2A seen from above. Figure 2C is an exploded perspective view showing the structure for adsorbing and holding a substrate in the substrate processing apparatus shown in Figure 2A. In Figures 2A, 2B, 2C, and later, the dimensions and number of each part are exaggerated or simplified for ease of understanding. The substrate processing apparatus 10 has a box-shaped chamber 11 with an internal space.

[0020] The side wall of the chamber 11 is provided with an inlet / outlet 14 through which the substrate S passes. A shutter 15 for opening and closing the inlet / outlet 14 is also attached to the side wall. For example, as shown in Figure 2A, with the shutter 15 open, the substrate S is loaded into the chamber 11 through the inlet / outlet 14. Inside the chamber 11, the spin base 21 of the spin chuck 20 holds a single substrate S horizontally via a ring-shaped prism 53 and rotates it around a vertical axis of rotation A1 passing through the center SC of the substrate S.

[0021] As shown in Figure 2C, the upper surface 531 of the prism 53 is an annular horizontal surface having the same outer diameter as the substrate S, and is capable of supporting the lower surface Sb of the substrate S from below. In addition, an annular groove 532 is provided on the upper surface 531 with an upward opening. Therefore, as shown in Figure 2A, when the substrate S is placed on the upper surface 531 of the prism 53, the substrate S is supported by the prism 53 with the groove 532 closed.

[0022] Furthermore, the lower surface 533 of the prism 53 is an annular horizontal surface having an outer diameter smaller than that of the substrate S and the same outer diameter as that of the spin base 21, and can be mounted on the upper surface of the spin base 21. Although not shown in the drawing, four through holes are provided on the bottom surface of the groove 532, extending down to the lower surface 533, forming a suction path connecting the upper surface 531 to the lower surface 533 of the prism 53. A total of four suction passages 211 are provided on the spin base 21 corresponding to the through holes. The prism 53 is then mounted on the upper surface of the spin base 21 with the through holes and suction passages 211 aligned in the vertical direction. Each suction passage 211 is in communication with a suction pipe 23. Therefore, the inside of the groove 532 is connected to the suction pump 22 via the through holes, suction passages 211 and suction pipe 23. A valve 24 is interposed in this suction pipe 23. Therefore, after the substrate S is transferred onto the prism 53 by the substrate transfer robot 111 and the opening of the groove 532 is closed, the suction force of the suction pump 22 is applied to the groove 532 through the communication path. As a result, the substrate S is attracted to the prism 53 and becomes able to rotate freely around the rotation axis A1 as an integral part of the prism 53 and the spin base 21.

[0023] To facilitate the smooth placement of the substrate S onto the prism 53 by the substrate transport robot 111, a lifting pin 28 is provided on the spin base 21 so as to be able to move up and down. In other words, when receiving the substrate S, as shown by the dotted line in Figure 2C, the lifting pin 28 rises up the hollow portion 535 of the prism 53, making it possible to receive the substrate S. Subsequently, as shown by the solid line in Figure 2C, the lifting pin 28 descends below the upper surface of the spin base 21, so that the substrate S is supported by the prism 53 and can be held in place by the suction force of the suction pump 22. In this way, the spin base 21, prism 53, and substrate S are integrated.

[0024] As shown in Figure 2A, the spin chuck 20 has a spin shaft 25 extending downward from the center of the spin base 21, a spin motor (rotating part) 26 that rotates the spin shaft 25, the spin base 21 and the prism 53 around the rotation axis A1, and a motor housing 27 that houses the spin motor 26. Therefore, when the spin motor 26 is operated in response to a command from the control unit 90 that controls each part of the substrate processing apparatus 10, the substrate S, which is held in a horizontal position by suction to the spin base 21 via the prism 53, rotates integrally with the spin base 21 around the rotation axis A1.

[0025] A processing liquid supply unit 30 is provided to supply processing liquid to the upper surface of a rotating substrate S. The processing liquid supply unit 30 has a nozzle 31 with its discharge port (not shown) facing downwards. The nozzle 31 is connected to a nozzle moving unit 32 and is movable between a position above the center of the upper surface of the substrate S, i.e., a processing position P1 (Figure 2B), and a position P2 (Figure 2B) spaced away from the substrate S. That is, in response to a command from the control unit 90, the nozzle moving unit 32 moves the nozzle 31 to the processing position P1 and positions it, so that the discharge port of the nozzle 31 faces the center of the upper surface of the substrate S, as shown in Figure 2A. In this state, the nozzle 31 can selectively discharge chemical solution or rinse solution toward the substrate S. That is, a pipe 33 extends from the nozzle 31, and its tip is branched into two branch pipes. One of these branch pipes 34 is connected to a chemical solution supply source (not shown), and a valve 35 is interposed in its middle section. Furthermore, the other branch pipe 36 is connected to a rinse liquid supply source (not shown), and a valve 37 is interposed in the middle of it. Therefore, when valves 35 and 37 are opened and closed respectively in response to a command from the control unit 90, the chemical solution is discharged downward from the discharge port of the nozzle 31 and supplied to the upper surface of the substrate S. This performs the chemical solution treatment. Conversely, when valves 35 and 37 are closed and opened respectively, the rinse liquid is discharged downward from the discharge port of the nozzle 31 and supplied to the upper surface of the substrate S. This performs the rinsing treatment.

[0026] During the chemical treatment and rinsing process, the treatment liquid is shaken off the substrate S. Therefore, a guard section 40 is provided to surround the rotating substrate S. The guard section 40 includes a cylindrical guard 41 that receives the chemical and rinsing liquid discharged outward from the substrate S as the substrate S rotates, a cup 42 that receives the treatment liquid guided downward by the guard 41, and an outer ring 43 that surrounds the guard 41 and the cup 42.

[0027] The guard 41 is movable vertically relative to the bottom of the chamber 11. On the other hand, the cup 42 is fixed to the bottom of the chamber 11. A lifting unit 44 is connected to the guard 41, as shown in Figure 2A. The lifting unit 44 moves the guard 41 vertically up and down between an upper position (indicated by a dashed line) and a lower position (indicated by a solid line) in response to a command from the control unit 90, and stops the guard 41 at any position between the upper and lower positions. Here, in the upper position, the upper end of the guard 41 is located above the support position where the substrate S held by the spin chuck 20 is placed. In the lower position, the upper end of the guard 41 is located below the support position.

[0028] In this embodiment, a light irradiation unit 50 and a light receiving unit 60 are provided in the substrate processing apparatus 10, and information regarding the concentration and amount of a specific substance (in this embodiment, a solute component contained in the chemical solution) present on the upper surface of the substrate S during chemical treatment and rinsing is acquired as in-site information using the so-called ATR (Attenuated Total Reflection) method. The configuration of the light irradiation unit 50 and the light receiving unit 60 will be described below.

[0029] As shown in Figure 2A, the light irradiation unit 50 includes a light source 51, an irradiation head 52, a prism 53, an optical fiber 54 that guides the irradiation light generated by the light source 51 to the irradiation head 52, and a support member 55 that supports the irradiation head 52. The light source 51 generates irradiation light (laser light) that is transparent to the substrate S and has directionality in a wavelength range that includes the absorption spectrum of a specific substance. The irradiation light L0 is guided to the irradiation head 52 by the optical fiber 54 and incident from the irradiation head 52 onto the inclined surface 534 of the prism 53 (Figure 2C).

[0030] Figure 3A is a schematic diagram showing the irradiation path and propagation of the irradiated light to the prism. The prism 53 guides the irradiated light L0 to the lower peripheral edge Sbs and causes it to enter the interior of the substrate S, and adjusts the path of the irradiated light L0 near the lower peripheral edge Sbs so that after the incident, the irradiated light L1 propagates through the interior of the substrate S while undergoing total internal reflection. Thus, the region of the lower peripheral edge Sbs into which the irradiated light L0 is incident corresponds to an example of the "incident region" of the present invention. Furthermore, as shown in Figure 3A, the light that propagates through the interior of the substrate S while undergoing total internal reflection (hereinafter sometimes referred to as "total internal reflection light Ltr") is stably guided into the interior of the substrate S while ensuring an angle θ of θc or greater with respect to the direction Dv (dashed line direction in the figure) perpendicular to both main surfaces of the substrate S (upper surface Sf, lower surface Sb). It is irradiated onto the upper surface Sf of the substrate S at the above angle θ with respect to direction Dv. At this irradiation position Pf1 (the boundary between the upper surface Sf of the substrate S and the processing liquid), the irradiation light L1 is totally reflected. Also, because the refractive index of the processing liquid is lower than that of the substrate S, at the totally reflected position, evanescent light Lef1 seeps out from the upper surface Sf of the substrate S towards the processing liquid. After the evanescent light Lef1 has been generated once, the totally reflected light L1a travels through the interior of the substrate S toward the center SC of the substrate S (Figure 2A) due to totally reflected at irradiation position Pf1, and is irradiated onto the lower surface Sb of the substrate S at the angle θ. At this irradiation position Pb1 (the boundary between the lower surface Sb of the substrate S and the air layer), the totally reflected light L1a is totally reflected, and evanescent light Leb1 seeps out from the lower surface Sb of the substrate S towards the air layer. After the evanescent light Leb1 has been generated once, the totally reflected light L1b travels through the interior of the substrate S toward the center SC of the substrate S due to totally reflected at irradiation position Pb1, and is irradiated onto the upper surface Sf of the substrate S at the angle θ. This total internal reflection is repeated, generating multiple evanescent light spots Lef1, Lef2, ... on the upper surface Sf of the substrate S. These spots of evanescent light Lef1, Lef2, ... are formed at regular intervals in the radial direction D. For example, as shown in Figure 3A, if a specific substance SS is attached to the upper surface Sf of the substrate S at the irradiation position Pf3, or if the specific substance SS is present near the irradiation position Pf3, the specific substance SS will absorb the evanescent light Lef3.

[0031] The totally reflected light Ltr propagates with absorption of evanescent light by the upper surface Sf of the substrate S or a specific substance SS near the upper surface. Then, as shown in Figures 2A and 2B, the totally reflected light Ltr passes through the prism 53 and is emitted from the region opposite the incident region, i.e., the exit region, on the inclined surface 534 of the prism 53, with the center SC of the substrate S in between. The substrate processing apparatus 10 has a light receiving unit 60 to receive this totally reflected light Ltr.

[0032] Figure 3B is a schematic diagram showing the propagation of total internal reflection light and the exit path from the prism. As shown in Figure 2A, the light receiving unit 60 includes a lens 61, a light receiving head 62, an optical fiber 63, a light receiving element 64, and a support member 65. The lens 61 is positioned opposite the exit region to collect the total internal reflection light Ltr that has been emitted from the exit region. The light receiving head 62 is configured to capture the total internal reflection light Ltr at the point where it is collected. The optical fiber 63 guides the total internal reflection light Ltr captured by the light receiving head 62 to the light receiving element 64. The light receiving element 64 receives the total internal reflection light Ltr, and measurement information related to the total internal reflection light Ltr is output to the control unit 90. The support member 65 is responsible for supporting the lens 61, the light receiving head 62, and the optical fiber 63.

[0033] The control unit 90 is composed of a computer having a CPU (= Central Processing Unit) and RAM (= Random Access Memory), and controls each part of the substrate processing apparatus 10 as follows according to a program stored in the memory unit (not shown), and performs chemical treatment and rinsing treatment. In addition, in this embodiment, in parallel with the chemical treatment and rinsing treatment, the control unit 90 controls the light irradiation unit 50 and the light receiving unit 60 to receive measurement information related to total reflected light Ltr, and acquires information on the specific substance SS from the absorption spectrum of the specific substance SS contained in the measurement information. Thus, in this embodiment, the control unit 90 functions as the "information acquisition unit" of the present invention, and the control unit 90, the light irradiation unit 50 and the light receiving unit 60 constitute the "information acquisition device" of the present invention.

[0034] Figure 4 is a flowchart showing the operation of the substrate processing apparatus shown in Figure 2A. The control unit 90 acquires the process conditions to be executed by the substrate processing apparatus 10 (step S1). Then, the control unit 90 acquires the absorption wavelengths of the components constituting the chemical solution and the rinse solution from the process conditions (step S2). In this embodiment, an aqueous solution obtained by dissolving a solute component in pure water is used as the chemical solution, and pure water is used as the rinse solution. Therefore, the solute component corresponds to the specific substance SS. In addition, pure water includes DIW (=De-ionized Water) used in semiconductor manufacturing, carbonated water, electrolyzed ionized water, hydrogen water, ozone water, etc. Therefore, in step S2, the absorption wavelength of the solute component of the chemical solution (specific substance SS) and the absorption wavelength of the pure water are acquired and temporarily stored in the memory unit of the control unit 90. As will be explained later, until the chemical solution processing is started, both valves 35 and 37 provided in the processing liquid supply unit 30 are closed.

[0035] Once the preparation for acquiring in-site information is complete, the control unit 90 requests the substrate transport robot 111 to load the substrate S. In response, the substrate S is placed on the lifting pin 28, which is in the raised position, as shown by the dotted line in Figure 2C. Subsequently, the control unit 90 controls the pin lifting unit (not shown) to lower the lifting pin 28 below the upper surface of the spin base 21, thereby placing the substrate S on the upper surface 531 of the prism 53. After that, the valve 24 is opened, and the substrate S is held in place by the suction force of the suction pump 22. Once the loading of the substrate S is complete, the substrate transport robot 111 moves away from the substrate processing device 10 (step S3).

[0036] Once the preparation for chemical treatment is complete, the control unit 90 issues a movement command to the nozzle movement unit 32, moving the nozzle 31 to the treatment position P1. The control unit 90 then starts the rotation of the spin chuck 20, which holds the substrate S via the prism 53, by the spin motor 26 (step S4). Subsequently, the control unit 90 issues a lighting command to the light source 51, starting the irradiation of light L0 from the light source 51 to the prism 53 (step S5). The control unit 90 also opens the valve 35 while maintaining the closed state of the valve 37. As a result, the chemical solution is discharged from the nozzle 31 toward the upper surface Sf of the substrate S, and the chemical treatment begins (step S6).

[0037] In this embodiment, the total internal reflection light Ltr emitted from the prism 53 is received by the light-receiving element 64 of the light-receiving unit 60 in parallel with the chemical treatment, and measurement information related to the total internal reflection light Ltr is output to the control unit 90. This measurement information reflects the absorption of evanescent light by the specific substance SS on or near the upper surface Sf of the substrate S. The control unit 90 then obtains the concentration and amount of the specific substance SS (solute component in the chemical solution) from the absorption spectrum included in the measurement information (step S7). Here, the method for measuring the concentration when 10% IPA is used as the chemical solution will be explained with reference to Figures 5A and 5B.

[0038] Figure 5A is a graph showing an example of an absorption spectrum obtained when 10% IPA and DIW are supplied to the upper surface of a substrate. Figure 5B is a graph showing the relationship between the ratio of the absorbance peak of a specific substance obtained from the measurement information to the absorbance peak of pure water, and the concentration of the specific substance. Note that the graph for DIW in Figure 5A (dotted line) is attached as reference information. When measurement information related to total reflected light Ltr is obtained by the ATR method while 10% IPA is continuously supplied as the processing liquid, an absorption spectrum shown by the solid line in Figure 5A is obtained, for example. The absorption spectrum of 10% IPA shows the absorption wavelength (3380 cm) corresponding to the (O-H) bond that indicates the presence of DIW, which is an example of pure water. －１ The O-H peak value at ) and the absorption wavelength (2977 cm) corresponding to the (C-H) bond indicating the presence of IPA. －１It includes the C-H peak value at ( ). And since (O-H peak value) / (C-H peak value) and the IPA concentration have the relationship shown in FIG. 5B, the O-H / C-H peak ratio (= (O-H peak value) / (C-H peak value)) can be obtained from the measurement information, and the IPA concentration can be acquired from the relationship shown in FIG. 5B. Also, the amount of the specific substance SS can be obtained from the supply amount of 10% IPA and the IPA concentration.

[0039] Here, immediately after the start of the chemical solution treatment, although the (C-H peak value) is relatively low, as the elapsed time from the start of the chemical solution treatment increases, the (C-H peak value) rapidly approaches the value shown in FIG. 5A and reaches a constant value. After that, the desired chemical solution treatment proceeds steadily. Therefore, in the present embodiment, measurement information is continuously acquired, and by sequentially acquiring the information on the elapsed time after the solute component of the chemical solution, that is, the concentration of the specific substance SS reaches a constant value, the progress of the chemical solution treatment is accurately and precisely grasped.

[0040] Returning to FIG. 4, the description will be continued. In the present embodiment, while continuously acquiring measurement information in step S7, the control unit 90 determines the end of the chemical solution treatment in step S8. While it is determined as NO in step S8, the control unit 90 returns to step S7 to monitor the progress of the chemical solution treatment. On the other hand, when detecting the end of the chemical solution treatment, the control unit 90 closes the valve 35 to stop the supply of the chemical solution from the nozzle 31 (step S9), and then opens the valve 37 to start the supply of the rinse liquid from the nozzle 31 (step S10).

[0041] Immediately after the start of the rinse liquid supply, the concentration of the specific substance SS decreases slightly from the concentration during the chemical solution treatment, but as the rinse treatment progresses, the concentration of the specific substance SS gradually decreases. The decrease in the concentration of the specific substance SS can be monitored based on the peak ratio between the absorption wavelength of the specific substance SS (in the case of IPA, 2977 cm －１ ) and the absorption wavelength of pure water (in the case of DIW, 3380 cm －１ ). That is, by continuously acquiring measurement information, it is possible to accurately and precisely grasp that the rinse treatment is completed when the concentration of the solute component of the chemical solution, that is, the concentration of the specific substance SS becomes zero.

[0042] Therefore, in the present embodiment, while continuously acquiring measurement information in step S11, the control unit 90 determines the end of the rinse process in step S12. While determining NO in step S12, the control unit 90 returns to step S11 to monitor the progress of the rinse process. On the other hand, when detecting the end of the rinse process, the control unit 90 closes the valve 37 to stop the rinse supply from the nozzle 31 and moves the nozzle 31 to the position P2 (step S13). Further, the control unit 90 gives a light-off command to the light source 51 to stop the irradiation of the irradiation light L0 from the light source 51 to the prism 53 (step S14). Subsequently, the control unit 90 gives a high-speed rotation command to the spin motor 26 to spin-dry the substrate S (step S15).

[0043] After that, the control unit 90 gives a rotation stop command to the spin motor 26 to stop the rotation of the substrate S. Further, the control unit 90 issues an unloading request for the substrate S to the substrate transfer robot 111, and the processed substrate S is unloaded from the substrate processing apparatus 10 by an operation reverse to the loading process (step S16).

[0044] As described above, according to the present embodiment, the substrate processing apparatus 10 includes an information acquisition device including the control unit 90, the light irradiation unit 50, and the light receiving unit 60. This information acquisition device can accurately and with high time resolution acquire the concentration and amount of a specific substance SS present on or near the upper surface Sf of the substrate S by the ATR method while flowing a processing liquid (chemical solution, rinse solution) on the upper surface Sf of the substrate S.

[0045] In addition, based on the concentration of the specific substance SS and the like, the end of the chemical solution treatment and the rinse treatment can be accurately and quickly grasped, and the supply of excessive chemical solutions and rinse solutions can be suppressed. Thereby, the environmental load can be reduced.

[0046] Furthermore, the substrate processing apparatus 10 is configured to rotate a ring-shaped prism 53 integrally with the substrate S and spin base 21 around a rotation axis A1, while irradiating the substrate S with illumination light L0 from one end of the substrate S and emitting total internal reflection light Ltr from the other end of the substrate S, with the rotation axis A1 in between. As a result, measurement information can be continuously acquired while the total internal reflection light Ltr is propagated throughout the entire interior of the substrate. Consequently, it is possible to acquire the concentration and amount of the specific substance SS over the entire upper surface of the substrate S.

[0047] Thus, in this first embodiment, the prism 53 corresponds to an example of the "first prism" of the present invention and functions as the "prism section" of the present invention. Also, the spin chuck 2 corresponds to an example of the "substrate holding section" of the present invention. The suction pump 22 corresponds to an example of the "suction section" of the present invention.

[0048] Figure 6 is a flowchart showing the operation of the second embodiment of the substrate processing apparatus according to the present invention. There are two main differences between the second embodiment and the first embodiment. The first is that, before chemical treatment, the absorption spectrum included in the measurement information obtained by receiving total reflected light Ltr when irradiation light L0 is irradiated onto the substrate S in a so-called dry state without supplying the treatment liquid (chemical solution, rinse solution) to the upper surface Sf of the substrate S is stored as reference information. The second is that, after acquiring measurement information obtained by receiving total reflected light Ltr when irradiation light L0 is irradiated onto the upper surface Sf of the substrate S during continuous supply of the treatment liquid, information regarding the specific substance SS is obtained from the corrected information obtained by correcting the actual measurement information with the reference information. Other configurations and operations are the same as in the first embodiment. Therefore, the following will focus on the differences, and the same configurations and operations will be denoted by the same reference numerals and their explanations will be omitted.

[0049] The control unit 90 performs the same steps as in the first embodiment: acquiring process conditions (step S1), acquiring absorption wavelength (step S2), loading the substrate S (step S3), starting rotation of the substrate S (step S4), and starting irradiation with irradiation light L0 (step S5). Before starting the supply of chemical solution, the control unit 90 receives measurement information output from the photodetector 64, which is a photodetector that receives total reflected light Ltr emitted from the substrate S while it is still in a dry state, acquires an absorption spectrum from this measurement information, and temporarily stores it in the storage unit of the control unit 90 (not shown) (step S20). In this specification, the absorption spectrum thus acquired is referred to as the dry absorption spectrum, and this corresponds to an example of the "reference information" of the present invention. The substrate S used at this time corresponds to an example of the "reference substrate" of the present invention. In this embodiment, the control unit 90 performs step S20 each time. However, if the chemical treatment is to be repeated for each substrate S of the same composition, the substrate processing apparatus 10 may be configured such that the control unit 90 executes step S20 only for the first substrate S, and skips step S20 for subsequent substrates S. Alternatively, the reference information may be measured and stored in advance using a reference substrate having the same composition as the substrate S, and when the chemical treatment is actually performed on the substrate S, the reference information may be read from the storage unit instead of step S20.

[0050] Once the acquisition of reference information is complete, the control unit 90 opens the valve 35. As a result, the chemical solution is discharged from the nozzle 31 toward the upper surface Sf of the substrate S, and the chemical solution treatment begins (step S6). In parallel with the chemical solution treatment, the total internal reflection light Ltr emitted from the prism 53 is received by the light-receiving element 64 of the light-receiving unit 60, and measurement information related to the total internal reflection light Ltr is output to the control unit 90. This measurement information not only reflects the absorption of evanescent light by the specific substance SS on or near the upper surface Sf of the substrate S, but also includes the above-mentioned reference information, which can become a noise component. Therefore, in the second embodiment, the control unit 90 acquires measurement information obtained by receiving the total internal reflection light Ltr when irradiation light L0 is irradiated during the continuous supply of the chemical solution to the upper surface Sf of the substrate S as actual measurement information, and measures the concentration and amount of the specific substance SS from the corrected information obtained by correcting the actual measurement information based on the reference information (step S21). More specifically, correction information is obtained by subtracting the dry absorption spectrum (reference information) from the absorption spectrum included in the actual measurement information mentioned above.

[0051] The control unit 90 repeats step S21 until it determines in step S8 that the chemical treatment is complete. By correcting the actual measurement information with reference information in this way, the progress of the chemical treatment can be grasped more accurately and precisely than in the first embodiment.

[0052] When the end of the chemical treatment is determined in step S8, the control unit 90 closes valve 35 to stop the supply of chemical from nozzle 31 (step S9), and then opens valve 37 to start supplying rinse liquid from nozzle 31 (step S10). In parallel with the rinse treatment, the total reflected light Ltr emitted from prism 53 is received by the light-receiving element 64 of light-receiving unit 60, and measurement information related to the total reflected light Ltr is output to the control unit 90. Since this measurement information is actual measurement information including reference information, similar to step S21, the control unit 90 measures the concentration and amount of the specific substance SS from the corrected information obtained by correcting the actual measurement information based on the reference information (step S22). The control unit 90 then repeats step S22 until it determines in step S12 that the rinse treatment is complete. By correcting the actual measurement information with reference information in this way, the progress of the rinse treatment can be grasped more accurately and precisely than in the first embodiment.

[0053] After the rinsing process is complete, the control unit 90 performs the following actions, similar to the first embodiment: stopping the supply of rinsing liquid (step S13), stopping the irradiation of the irradiation light (step S14), spin drying (step S14), stopping the rotation of the substrate S (step S15), and unloading the substrate S (step S16).

[0054] In the first and second embodiments described above, the substrate S is supported by a prism 53, which is a component of the information acquisition device, and the substrate S and spin base 21 are configured to rotate integrally. To perform this function, the prism 53 has a ring shape, and the incidence of irradiating light L0 onto the prism 53 and the emission of totally reflected light Ltr from the prism 53 occur in parallel. Here, as will be described below, the substrate processing device 10 may support the substrate S with only the spin base 21, and the prism 53 may be fixedly positioned facing the lower peripheral edge of the substrate S (third embodiment).

[0055] Figure 7A shows the configuration of a third embodiment of the substrate processing apparatus according to the present invention. Figure 7B is a plan view of the central part of Figure 7A seen from above. Figure 8 is a schematic diagram showing the irradiation path of the light irradiated onto the prism, the propagation of the irradiated light, and the propagation of the totally reflected light and the exit path from the prism. In the third embodiment, the spin base 21 directly supports and holds the lower surface of the substrate S by suction. The spin base 21 rotates around the rotation axis A1 while holding the substrate S by suction. The prism 56 is positioned at a certain distance from the lower peripheral edge Sbs of the substrate S so as not to interfere with the rotating substrate S. More specifically, the light irradiation unit 50 and the light receiving unit 60 are configured as follows. The other configurations and operations are basically the same as in the first embodiment (or second embodiment).

[0056] As shown in Figures 7A and 8, the light irradiation unit 50 has a prism 56 that is inverted trapezoidal in side view. This prism 56 is held by a prism holding mechanism 57 (Figure 7A) in a position where its horizontal upper surface 561 is separated from the lower peripheral edge Sbs of the substrate S by a certain distance d1 (Figure 8), and its inclined surface 562 faces the emission surface 521 of the irradiation head 52.

[0057] As shown in Figure 2A, the prism holding mechanism 57 has two columnar members 571 erected above the support member 55, and a spring member attached to the top of each columnar member 571. The horizontal lower surface 563 of the prism 56 is placed on the spring member 572, so that the prism 56 is held stably without interfering with the rotating substrate S. The prism 56 has the function of stably guiding the irradiated light L0 into the interior of the substrate S while ensuring an angle θ greater than or equal to the total reflection angle with respect to the direction Dv (dashed line direction in the figure) perpendicular to both main surfaces of the substrate S (upper surface Sf, lower surface Sb), which is necessary for the irradiated light L0 to be totally reflected by the upper surface Sf and lower surface Sb of the substrate S.

[0058] Furthermore, the spacing d1 is set to be less than or equal to the diffraction limit of the irradiated light L0. For example, if the central wavelength λ of the irradiated light L0 and the angle θ are 3.4 μm and 60°, respectively, and the optical distance that can maintain the efficiency of capturing the irradiated light L0 in the gap between the prism 56 and the substrate S is λ / 8, then the spacing d1 should satisfy the following inequality: d1 < λ / 8 × cosθ = 212.5 nm.

[0059] On the other hand, the light-receiving unit 60 includes a lens 61 positioned opposite the other inclined surface 564 of the prism 56, a light-receiving head 62, an optical fiber 63, and a light-receiving element 64. In the third embodiment, the lens 61, the light-receiving head 62, and the optical fiber 63 are supported by a support member 55.

[0060] In this third embodiment, as in the first and second embodiments, the information acquisition device, which consists of a control unit 90, a light irradiation unit 50, and a light receiving unit 60, is capable of accurately acquiring the concentration and amount of a specific substance SS present on or near the upper peripheral edge Sfs of the substrate S by the ATR method while flowing a processing liquid (chemical solution, rinse solution) onto the upper surface Sf of the substrate S, with high temporal resolution.

[0061] Furthermore, the completion of chemical treatment and rinsing can be accurately and quickly determined based on the concentration of specific substances such as suspended solids (SS), thereby suppressing the supply of excessive chemicals and rinsing solutions. This reduces the environmental burden.

[0062] In the third embodiment, since the combination of the light irradiation unit 50 and the light receiving unit 60 is provided corresponding to the lower peripheral edge Sbs of the substrate S, as described above, the measurement area for the concentration and amount of the specific substance SS is limited to the upper peripheral edge Sfs of the substrate S or its vicinity. Therefore, as shown in Figure 9, a plurality of combinations 70 may be dispersed below the lower surface Sb of the substrate S so as to be different from each other in the radial direction (fourth embodiment). This expands the range over which the concentration of the specific substance SS can be obtained. In this fourth embodiment, the prism 56 constituting the combination 70 located furthest out in the radial direction D corresponds to an example of the "second prism" of the present invention. Furthermore, the prism 56 constituting the combination 70 located closer to the rotation axis A1 than the above combination 70 in the radial direction D is provided opposite the lower intermediate part of the substrate S closer to the center than the lower peripheral edge Sbs, and corresponds to an example of the "third prism" of the present invention. These plurality of prisms 56 function as the "prism section" of the present invention.

[0063] Furthermore, as shown in Figure 10, the light irradiation unit 50 may be configured to have a prism 58 for the incident irradiation light L0, while the light receiving unit 60 may have a prism 66 for the emission of totally reflected light Ltr (fifth embodiment). These prisms 58 and 66 function as the "prism unit" of the present invention.

[0064] As described above, in order to generate evanescent light by totally reflecting the irradiated light L0 inside the substrate S, it is necessary to adjust the angle θ of the irradiated light L1 with high precision. To achieve this, it is desirable to provide an angle adjustment unit 59 that adjusts the angle that the irradiated light L1 incident on the substrate S through the incident region and the totally reflected light Ltr emitted from the exit region make with the direction Dv perpendicular to the upper surface Sf of the substrate S, i.e., the exit angle. As the angle adjustment unit 59, the head attitude adjustment unit 59A shown in Figure 11 or the refractive index adjustment unit 59B shown in Figure 12 can be used.

[0065] Figure 11 is a schematic diagram showing the configuration and operation of the light irradiation unit and light receiving unit in the sixth embodiment of the substrate processing apparatus according to the present invention. As shown in the figure, a head attitude adjustment unit 59A is connected to the irradiation head 52 and the light receiving head 62, and adjusts the tilt of the irradiation head 52 and the head body (= lens 61 + light receiving head 62) in accordance with commands from the control unit 90. By adjusting the attitude of the light irradiation unit 50 and the light receiving unit 60 in this way, the incident angle of the irradiation light L0 incident on the prism unit and the emission angle of the total reflected light Ltr emitted from the substrate S are controlled.

[0066] Figure 12 is a schematic diagram showing the configuration and operation of the light irradiation unit and light receiving unit in the seventh embodiment of the substrate processing apparatus according to the present invention. As shown in the figure, in the seventh embodiment, a refractive index adjustment unit 59B is additionally equipped. The refractive index adjustment unit 59B supplies a gaseous component other than air (such as carbon dioxide) into the gap between the prism 56 and the substrate S in response to a command from the control unit 90, and fills the gap with the gaseous component. This makes it possible to change the refractive index of the gap and adjust the angle θ. The means for changing the refractive index of the gap is not limited to the substitution of the gaseous component mentioned above, but may also be configured to change the temperature, atmospheric pressure, humidity, etc.

[0067] Figure 13 is a schematic diagram showing the configuration and operation of the light irradiation unit and light receiving unit in the eighth embodiment of the substrate processing apparatus according to the present invention. The main differences between this eighth embodiment and the third embodiment are that the irradiation head 52 and the head body of the lens 61 and light receiving head 62 are provided to be movable in the radial direction D, and that the irradiation head 52 and the head body are connected to a movement adjustment unit 510. The movement adjustment unit 510 moves the irradiation head 52 in the radial direction D in response to a command from the control unit 90. Along with the movement of the irradiation head 52, the total reflection position also moves in the radial direction D, and the total reflected light Ltr also moves in the radial direction D. As a result, the concentration and amount of the specific substance SS can be obtained over a wide range. The technical matter of providing the movement adjustment unit 510 is also applicable to the fifth embodiment, and similar effects can be obtained by additional application.

[0068] FIG. 14 is a diagram showing the configuration of a ninth embodiment of a substrate processing apparatus according to the present invention. FIG. 15A is a schematic diagram showing the irradiation path of irradiation light to the bevel portion of the substrate and the propagation of the irradiation light. FIG. 15B is a schematic diagram showing the propagation of the total reflection light and the emission path from the bevel portion of the substrate. The main difference between this ninth embodiment and the first to eighth embodiments is that the irradiation light L0 is directly irradiated onto the substrate S without using a prism. As shown in FIGS. 15A and 15B, in a substrate S such as a semiconductor wafer, a bevel portion BV having an inclined surface is formed at its peripheral portion. The "bevel portion" as used herein refers to the entire edge region including a portion that is chamfered along the edge of the substrate S and finished into an inclined surface BV1 whose upper surface is inclined by an angle θB with respect to the horizontal plane when the substrate S is in a horizontal posture among the peripheral portions of the substrate S. In this specification, the angle θB is referred to as the "bevel cut angle θB".

[0069] In the first to eighth embodiments, without the presence of a prism, it is impossible to configure such that the irradiation light L0 directly irradiates the lower surface peripheral portion Sbs of the substrate S while the angle θ satisfies the total reflection condition. On the other hand, as shown in FIG. 14, when the substrate S has a bevel portion BV, the irradiation light L0 from the irradiation head 52 may irradiate the inside of the substrate S through the inclined surface BV1 (corresponding to an example of the "incident region" of the present invention). In this case, the incident angle of the irradiation light L0 to the inclined surface BV1 is (θ - θB). Therefore, the condition for the irradiation light L0 to pass through the inclined surface BV1 and be irradiated into the substrate S as the irradiation light L1 is the following formula: |θ - θB| < θc = sin －１ (n2 / n1) However, n1... refractive index of the substrate S, n2... refractive index of the air layer, θc... total reflection angle, is to be satisfied. Also, the condition for the irradiation light L1 to be totally reflected at the irradiation position Pf1 of the irradiation light L1 is the following formula: θ > θc = sin －１ (n2 / n1) is to be satisfied. Therefore, when θ ≧ θB, the following inequality: sin －１ (n2 / n1) < θ < sin －１ (n2 / n1) + θB is satisfied. On the other hand, when θ < θB, the following two inequalities: θ > θB - sin －１ (n2 / n1) θ > sin－１ It is sufficient to satisfy (n2 / n1) simultaneously. For example, if the substrate S (refractive index n1 = 3.44), the processing solution (in this case, the main component, water, has a refractive index n2 = 1.333), and the bevel cut angle θB = 30°, then the angle θ should be set within an angular range from 21.7° to 51.7°.

[0070] When set in this way, the irradiation light L0 passes through the inclined surface BV1 and is irradiated into the interior of the substrate S as irradiation light L1. At the irradiation position Pf1 (the boundary position between the upper surface Sf of the substrate S and the processing liquid), the irradiation light L1 is totally reflected, and evanescent light Lef1 seeps out from the upper surface Sf of the substrate S towards the processing liquid. After the evanescent light Lef1 has been generated, the totally reflected light L1a, due to totally reflected at the irradiation position Pf1, travels through the interior of the substrate S toward the center SC of the substrate S (Figure 14) and is irradiated onto the lower surface Sb of the substrate S at the angle θ. At this irradiation position Pb1 (the boundary position between the lower surface Sb of the substrate S and the air layer), the totally reflected light L1a is totally reflected, and evanescent light Leb1 seeps out from the lower surface Sb of the substrate S. After the evanescent light Leb1 is generated, the totally reflected light L1b travels through the interior of the substrate S toward the center SC of the substrate S due to total reflection at the irradiation position Pb1, and is irradiated onto the upper surface Sf of the substrate S at the angle θ. This total reflection is repeated, and multiple evanescent light rays Lef1, Lef2, ... are generated on the upper surface Sf of the substrate S. Furthermore, when the totally reflected light Ltr is emitted from the emission region, it is possible to emit the totally reflected light Ltr toward the lens 61 from the emission region by configuring it in the same way as the incidence region. Therefore, the same effects as in the first embodiment can be obtained.

[0071] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made to those described above without departing from the spirit of the invention. For example, although the information acquisition device and information acquisition method according to the present invention are applied to a substrate processing apparatus 10 that performs chemical treatment and rinsing treatment, the information acquisition device and information acquisition method according to the present invention can also be applied to other substrate processing apparatuses. The invention has been described above in accordance with specific embodiments, but this description is not intended to be interpreted in a restrictive sense. By referring to the description of the invention, various modifications of the disclosed embodiments will be apparent to those familiar with this art, as with other embodiments of the present invention. Therefore, the appended claims are considered to include such modifications or embodiments without departing from the true scope of the invention.

[0072] This invention can be applied to all information acquisition technologies for acquiring information such as the concentration and amount of a specific substance present on the upper surface of a substrate, and to all substrate processing technologies for processing a substrate based on the above information.

[0073] 10...Substrate processing unit 11...Chamber 14...Input / Output 15...Shutter 20...Spin chuck (substrate holding unit) 21...Spin base 22...Suction pump (suction unit) 26...Spin motor (rotating unit) 30...Processing liquid supply unit 50...Light irradiation unit 51...Light source 53...(First) prism 56...(Second, third) prisms 59...Angle adjustment unit 59A...Head attitude adjustment unit 59B...Refractive index adjustment unit 60...Light receiving unit 90...Control unit A1...Rotation axis BV1...Inclined surface D...Radial direction L0...Irradiated light Ltr...Total reflected light S...Substrate SS...Specific substance Sb...Bottom surface (of the substrate) Sbs...Bottom edge (of the substrate) Sf...Top surface (of the substrate) Sfs...Top edge (of the substrate)

Claims

An information acquisition device that acquires information about a specific substance present on or near the upper surface of a substrate while a processing liquid is continuously supplied to the upper surface of the substrate, A light irradiation unit that irradiates the substrate with light that is transparent to the substrate and has directionality in a wavelength range including the absorption spectrum of the specific substance, such that the light is totally reflected inside the substrate. A light receiving unit that receives totally reflected light that propagates while undergoing total internal reflection within the substrate and is emitted from the substrate, and outputs measurement information related to the totally reflected light, An information acquisition unit that acquires information about the specific substance from the absorption spectrum of the specific substance included in the measurement information, An information acquisition device characterized by comprising the following features. 　 An information acquisition device according to claim 1, The system includes a storage unit that stores the measurement information obtained by receiving the total reflected light when the reference substrate is irradiated with the irradiation light, while the reference substrate is composed of the same composition as the aforementioned substrate and the specific substance is not present on its upper surface, and the processing liquid is not supplied to the reference substrate. The information acquisition unit is an information acquisition device that, after acquiring the measurement information obtained by receiving the total reflected light when the irradiation light is irradiated while the processing liquid is continuously supplied to the upper surface of the substrate as actual measurement information, acquires information about the specific substance from the corrected information obtained by correcting the actual measurement information with the reference information. 　 An information acquisition method for acquiring information about a specific substance present on or near the upper surface of a substrate while a processing liquid is continuously supplied to the upper surface of the substrate, A step of irradiating the substrate with light that is transparent to the substrate and has directionality in a wavelength range including the absorption spectrum of the specific substance, such that the light is totally reflected inside the substrate. A step of receiving totally reflected light that propagates while undergoing total internal reflection within the substrate and is emitted from the substrate, and outputting measurement information related to the totally reflected light, A step of obtaining information about the specific substance from the absorption spectrum of the specific substance included in the measurement information, An information acquisition method characterized by comprising the following features. 　 A processing liquid supply unit that supplies processing liquid to the upper surface of a substrate held in a horizontal position, During the continuous supply of the processing liquid to the upper surface of the substrate, a light irradiation unit irradiates the substrate with light that is transparent to the substrate and has directionality in a wavelength range including the absorption spectrum of a specific substance, such that the light is totally reflected inside the substrate. A light receiving unit that receives totally reflected light that propagates while undergoing total internal reflection within the substrate and is emitted from the substrate, and outputs measurement information related to the totally reflected light, An information acquisition unit that acquires information about the specific substance present on or near the upper surface of the substrate from the absorption spectrum of the specific substance included in the measurement information, A substrate processing apparatus characterized by comprising: 　 A substrate processing apparatus according to claim 4, The light irradiation unit comprises a light source that generates the irradiation light and a prism unit that guides the irradiation light from the light source to the incident region of the substrate, in a substrate processing apparatus. 　 A substrate processing apparatus according to claim 5, A suction unit that generates suction force, The system includes a rotating part that rotates the substrate about a rotation axis passing through the center of the substrate, A substrate processing apparatus having a first prism that holds the substrate by supporting the lower peripheral edge of the substrate from below with the upper surface of the prism and applying the suction force to the lower peripheral edge via the suction path. 　 A substrate processing apparatus according to claim 5, The incident region is the lower peripheral edge of the substrate, The substrate processing apparatus comprises a prism portion having a second prism provided below the lower peripheral edge portion, which guides the irradiated light from the lower surface side of the substrate to the lower peripheral edge portion. 　 A substrate processing apparatus according to claim 5, The incident region includes the lower peripheral edge of the substrate and the lower intermediate portion of the substrate that is closer to the center than the lower peripheral edge. The substrate processing apparatus includes a prism portion comprising a second prism provided below the lower peripheral edge portion for guiding the irradiated light from the light source to the lower peripheral edge portion of the substrate, and a third prism provided below the lower middle portion for guiding the irradiated light from the light source to the lower middle portion of the substrate. 　 A substrate processing apparatus according to claim 4, The substrate has a beveled inclined surface along its edge, The light irradiation unit has a light source that generates the irradiation light, and irradiates the substrate held by the substrate holding unit such that the angle of incidence of the irradiation light into the incident region where the irradiation light is incident on the substrate is smaller than the total reflection angle, and the light incident on the substrate through the incident region is totally reflected inside the substrate at an angle greater than or equal to the total reflection angle with respect to the direction perpendicular to the upper surface of the substrate. A substrate processing apparatus wherein the light receiving unit receives the totally reflected light emitted from the inclined surface of the substrate. 　 A substrate processing apparatus according to any one of claims 5 to 9, A substrate processing apparatus having an angle adjustment unit that adjusts the angle that the light incident on the substrate through the incident region and the totally reflected light emitted from the substrate make with a direction perpendicular to the upper surface of the substrate. 　 A substrate processing apparatus according to claim 10, A substrate processing apparatus having a head attitude adjustment unit that controls the incident angle of the irradiated light on the substrate and the emission angle of the totally reflected light emitted from the substrate by adjusting the attitude of the light irradiation unit and the light receiving unit. A substrate processing apparatus according to claim 11, The prism portion is positioned at a distance from the substrate. A substrate processing apparatus having a refractive index adjustment unit that adjusts the incident angle of the irradiated light into the incident region and the emission angle of the totally reflected light emitted from the substrate by controlling the refractive index of the gap formed between the prism unit and the substrate. 　 A substrate processing apparatus according to claim 7 or 8, The substrate is equipped with a rotating part that rotates the substrate around a rotation axis passing through the center of the substrate, A substrate processing apparatus in which the prism portion is positioned at a distance from the rotating substrate. 　 A substrate processing apparatus according to claim 13, A substrate processing apparatus in which the prism portion is positioned such that the distance between the prism portion and the rotating substrate is less than or equal to the diffraction limit of the irradiated light.

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