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

Abstract

This system accurately acquires information regarding the concentration and quantity of specific substances present on the upper surface of a substrate, with high temporal resolution. [Solution] This invention comprises: a light irradiation unit that irradiates a 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 that the light is 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 from the absorption spectrum of the specific substance included in the measurement information.

Description

[Technical Field]

[0001] This invention relates to an information acquisition technology for acquiring information such as 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. [Background technology]

[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). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 7312656 [Overview of the project] [Problems that the invention aims to solve]

[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. [Means for solving the problem]

[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. [Effects of the Invention]

[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. [Brief explanation of the drawing]

[0011] [Figure 1] This 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. [Figure 2A] This figure shows the configuration of the first embodiment of the substrate processing apparatus according to the present invention. [Figure 2B] This is a plan view of the central part of Figure 2A, seen from above. [Figure 2C] Figure 2A is an exploded and assembled perspective view showing the structure for adsorbing and holding a substrate in the substrate processing apparatus. [Figure 3A]It is a schematic diagram showing the irradiation path of the irradiation light to the prism and the propagation of the irradiation light. [Figure 3B] It is a schematic diagram showing the propagation of the total reflection light and the emission path from the prism. [Figure 4] It is a flowchart showing the operation of the substrate processing apparatus shown in FIG. 2A. [Figure 5A] It is a graph showing an example of the absorption spectrum obtained when 10% IPA and DIW are supplied to the upper surface of the substrate. [Figure 5B] It is a graph showing the relationship between the ratio of the absorption peak of a specific substance obtained from the measurement information and the absorption peak of pure water and the concentration of the specific substance. [Figure 6] It is a flowchart showing the operation of the second embodiment of the substrate processing apparatus according to the present invention. [Figure 7A] It is a diagram showing the configuration of the third embodiment of the substrate processing apparatus according to the present invention. [Figure 7B] It is a plan view of the central part of FIG. 7A seen from above. [Figure 8] It is a schematic diagram showing the irradiation path of the irradiation light to the prism in the third embodiment, the propagation of the irradiation light, the propagation of the total reflection light, and the emission path from the prism. [Figure 9] It 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. [[ID=Z9]] [Figure 10] It is a diagram showing the configuration of the fifth embodiment of the substrate processing apparatus according to the present invention. [Figure 11] It is a diagram schematically showing the configuration and operation of the light irradiation unit and the light receiving unit in the sixth embodiment of the substrate processing apparatus according to the present invention. [Figure 12] It is a diagram schematically showing the configuration and operation of the light irradiation unit and the light receiving unit in the seventh embodiment of the substrate processing apparatus according to the present invention. [Figure 13] It is a diagram schematically showing the configuration and operation of the light irradiation unit and the light receiving unit in the eighth embodiment of the substrate processing apparatus according to the present invention. [Figure 14] It is a diagram showing the configuration of the ninth embodiment of the substrate processing apparatus according to the present invention. [Figure 15A]This is a schematic diagram showing the irradiation path and propagation of the irradiation light to the bevel portion of the substrate in the ninth embodiment. [Figure 15B] This is a schematic diagram showing the propagation of total reflected light and the emission path from the bevel portion of the substrate in the ninth embodiment. [Modes for carrying out the invention]

[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 illustrates 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 vertically. 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 glass substrate for a photomask, a glass substrate for a liquid crystal display, a glass substrate for a plasma display, a substrate for a Field Emission Display (FED), a substrate for an optical disk, a substrate for a magnetic disk, or a substrate for a magneto-optical disk. The following explanation will primarily use a substrate processing apparatus 10 used for processing semiconductor wafers as an example, with reference to the drawings, 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 and store processed substrates S in the containers C. Each container C contains multiple substrates S in a nearly horizontal position.

[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 so that substrates S from the indexer robot 122 can 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 drawings, 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 a circular horizontal surface that is smaller than the diameter of the substrate S and has the same outer diameter as the outer diameter of the spin base 21, allowing it to be mounted on the upper surface of the spin base 21. Although not shown in the drawing, four through holes extend from the bottom surface of the groove 532 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 in the spin base 21 corresponding to the above 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 above 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 via 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, enabling the receipt of 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 activated 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 horizontally by suction on 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 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 also 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 light irradiated onto the prism. The prism 53 guides the irradiation 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 irradiation light L0 near the lower peripheral edge Sbs so that after the irradiation, the irradiation 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 irradiation 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 solution), the irradiation light L1 is totally reflected. Also, because the refractive index of the processing solution 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 solution. 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 described above. 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 described above. 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 a 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 a specific substance SS on or near the upper surface Sf of the substrate S. 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 on the inclined surface 534 of the prism 53, that is, the exit region, 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 (specific substance SS) of the chemical solution 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, valves 35 and 37 provided in the processing liquid supply unit 30 are both closed until the chemical solution processing is started.

[0035] Once preparations for acquiring in-site information are 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 top 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. 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 (OH) bond that indicates the presence of DIW, which is an example of pure water. -1 The OH peak value at ) and the absorption wavelength (2977 cm) corresponding to the (CH) bond indicating the presence of IPA. -1The CH peak value is included in the measurement. Furthermore, the relationship between (OH peak value) / (CH peak value) and the IPA concentration is as shown in Figure 5B. Therefore, the OH / CH peak ratio (=(OH peak value) / (CH peak value)) can be determined from the measurement information, and the IPA concentration can be obtained from the relationship shown in Figure 5B. In addition, the amount of specific substance SS can also be obtained from the supply amount of 10% IPA and the IPA concentration.

[0039] Here, although the (CH peak value) is relatively low immediately after the start of chemical treatment, as time elapses from the start of chemical treatment, the (CH peak value) rapidly approaches the value shown in Figure 5A and reaches a constant value. After that, the desired chemical treatment proceeds steadily. Therefore, in this embodiment, measurement information is continuously acquired, and information on the elapsed time after the concentration of the solute component of the chemical solution, i.e., the specific substance SS, reaches a constant value is sequentially acquired, thereby accurately and precisely understanding the progress of the chemical treatment.

[0040] Returning to Figure 4, the explanation continues. In this embodiment, in step S7, measurement information is continuously acquired, and in step S8, the control unit 90 determines when the chemical treatment is complete. While the determination in step S8 is NO, the control unit 90 returns to step S7 to monitor the progress of the chemical treatment. On the other hand, when the end of the chemical treatment is detected, 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).

[0041] Immediately after the start of rinse solution supply, the concentration of the specific substance SS decreases only slightly from the concentration during chemical treatment, but as the rinse treatment progresses, the concentration of the specific substance SS gradually decreases. As is clear from the explanation based on Figure 5A, the decrease in the concentration of the specific substance SS is due to the absorption wavelength of the specific substance SS (2977 cm in the case of IPA). -1 ) and the absorption wavelength of pure water (3380 cm in the case of DIW) -1It can be monitored based on the peak ratio with ). In other words, by continuously acquiring measurement information, it is possible to accurately and precisely determine when the rinsing process is complete, i.e., when the concentration of the solute component of the chemical solution, i.e., the specific substance SS, becomes zero.

[0042] Therefore, in this embodiment, while continuously acquiring measurement information in step S11, the control unit 90 determines the completion of the rinsing process in step S12. While the determination in step S12 is NO, the control unit 90 returns to step S11 to monitor the progress of the rinsing process. On the other hand, when the completion of the rinsing process is detected, the control unit 90 closes the valve 37 to stop the supply of rinse from the nozzle 31 and moves the nozzle 31 to position P2 (step S13). The control unit 90 also gives a command to the light source 51 to turn off the light, stopping the irradiation of the light source 51 to the prism 53 with the light L0 (step S14). Subsequently, the control unit 90 gives a command to the spin motor 26 to rotate at high speed, spin-drying the substrate S (step S15).

[0043] Subsequently, the control unit 90 issues a rotation stop command to the spin motor 26, stopping the rotation of the substrate S. Furthermore, the control unit 90 requests the substrate transfer robot 111 to unload the substrate S, and the processed substrate S is discharged from the substrate processing device 10 by the reverse operation of the loading process (step S16).

[0044] As described above, according to this embodiment, the substrate processing apparatus 10 has an information acquisition device composed of a control unit 90, a light irradiation unit 50, and a light receiving unit 60. This information acquisition device is capable of accurately acquiring the concentration and amount of specific substances SS present on or near the upper surface Sf of the substrate S by the ATR method while flowing a processing liquid (chemical solution, rinsing liquid) onto the upper surface Sf of the substrate S, with high temporal resolution.

[0045] 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.

[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 propagates throughout the entire interior of the substrate. Consequently, it is possible to acquire the concentration and amount of the specific substance SS across 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 liquid) 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 while the treatment liquid is continuously supplied to the upper surface Sf of the substrate S as actual measurement information, information on 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 chemical supply, the control unit 90 receives measurement information output from the photodetector 64, which is a photodetector for 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 memory 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 the third embodiment of the substrate processing apparatus according to the present invention. Figure 7B is a plan view of the center of Figure 7A seen from above. Figure 8 is a schematic diagram showing the irradiation path of the irradiated light to 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 at which the efficiency of capturing the irradiated light L0 in the gap between the prism 56 and the substrate S can be maintained is λ / 8, then the spacing d1 is given by the following inequality: d1 < λ / 8 × cosθ = 212.5 nm You just need to satisfy that condition.

[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 specific substances SS present at or near the upper peripheral edge Sfs of the substrate S by the ATR method while flowing a processing liquid (chemical solution, rinsing liquid) 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, 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, multiple 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 multiple prisms 56 then 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 incidence of the irradiation light L0, while the light receiving unit 60 may be configured to have a prism 66 for the emission of the 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 irradiating light L0 inside the substrate S, it is necessary to adjust the angle θ of the irradiating light L1 with high precision. To achieve this, it is desirable to provide an angle adjustment unit 59 that adjusts the angle that the irradiating 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, the seventh embodiment is additionally equipped with a refractive index adjustment unit 59B. 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, filling the gap with the gaseous component. This changes the refractive index of the gap, making it possible to 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 bodies 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 head bodies 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 commands 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] Figure 14 shows the configuration of the ninth embodiment of the substrate processing apparatus according to the present invention. Figure 15A is a schematic diagram showing the irradiation path of the light irradiated onto the bevel portion of the substrate and the propagation of the irradiated light. Figure 15B is a schematic diagram showing the propagation of the totally reflected light and the exit 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 Figures 15A and 15B, some substrates S, such as semiconductor wafers, have a bevel portion BV with an inclined surface formed on their peripheral edge. The term "bevel portion" here refers to the entire edge region, including the part of the peripheral edge of the substrate S that is chamfered along the edge and whose upper surface is finished as an inclined surface BV1 that is tilted at an angle θB with respect to the horizontal plane when the substrate S is in a horizontal position. In this specification, the angle θB is referred to as the "bevel cut angle θB".

[0069] In the first to eighth embodiments, there is no prism, and it is impossible to configure the system so that the angle θ satisfies the total internal reflection condition while the irradiation light L0 directly irradiates the lower peripheral edge Sbs of the substrate S. On the other hand, as shown in Figure 14, if the substrate S has a bevel BV, the irradiation light L0 from the irradiation head 52 may irradiate the interior of the substrate S via an 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 irradiate the interior of the substrate S as irradiation light L1 is given by the following equation: |θ-θB|<θc=sin -1 (n2 / n1) However, n1...refractive index of substrate S, n2...refractive index of the air layer, θc...total reflection angle, The condition is that the following must be satisfied. Furthermore, the condition for total internal reflection of the irradiated light L1 at the irradiation position Pf1 is given by the following equation: θ > θc = sin -1 (n2 / n1) The condition is to satisfy the following. Therefore, when θ≧θB, the following inequality holds: sin -1(n2 / n1) < θ < sin -1 (n2 / n1) + θB While satisfying this, when θ < θB, the following two inequalities, θ > θB − sin -1 (n2 / n1) θ > sin -1 (n2 / n1) only need to be satisfied simultaneously. For example, for the substrate S (refractive index n1 = 3.44), the processing liquid (here, the refractive index of water, which is the main component, n2 = 1.333), and the bevel cut angle θB = 30°, the angle θ can be set within the range of 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 substrate S as the irradiation light L1. Then, 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 the evanescent light Lef1 leaks out from the upper surface Sf of the substrate S to the processing liquid side. After the evanescent light Lef1 is generated once, the total reflection light L1a advances inside the substrate S toward the center SC of the substrate S (FIG. 14) by total reflection at the irradiation position Pf1 and is irradiated onto the lower surface Sb of the substrate S at the above angle θ. At this irradiation position Pb1 (the boundary position between the lower surface Sb of the substrate S and the air layer), the total reflection light L1a is totally reflected, and the evanescent light Leb1 leaks out from the lower surface Sb of the substrate S. After the evanescent light Leb1 is generated once, the total reflection light L1b advances inside the substrate S toward the center SC of the substrate S by total reflection at the irradiation position Pb1 and is irradiated onto the upper surface Sf of the substrate S at the above angle θ. Such total reflection is repeated, and a plurality of evanescent lights Lef1, Lef2,... are generated on the upper surface Sf of the substrate S. Also, when the total reflection light Ltr exits from the exit region, by configuring it in the same way as the incident region side, it is possible to emit the total reflection light Ltr from the exit region toward the lens 61. Therefore, the same operational effects as in the first embodiment and the like 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. [Industrial applicability]

[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. [Explanation of Symbols]

[0073] 10... Circuit board processing equipment 11… Chamber 14…Loading / Unloading Exit 15...Shutter 20... Spin chuck (substrate holder) 21…Spin base 22... Suction pump (suction unit) 26…Spin motor (rotating part) 30... Processing liquid supply unit 50...Light-irradiating section 51...Light source 53…(1st) Prism 56…(2nd, 3rd) Prism 59…Angle adjustment section 59A...Head position adjustment section 59B...Refractive index adjustment section 60...Light receiving section 90... Control Unit A1... Axis of rotation BV1…Slope surface D...Radial direction L0…Irradiation light Ltr…Totally reflected light S... Circuit board SS…Specific substance Sb... (Underside of the circuit board) Sbs… (The lower edge of the circuit board) Sf... Top surface (of the circuit board) Sfs…(the upper peripheral edge of the circuit board)

Claims

1. 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.

2. 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.

3. 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.

4. 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:

5. 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.

6. 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.

7. 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.

8. 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.

9. 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. The light-receiving unit receives the totally reflected light emitted from the inclined surface of the substrate, in a substrate processing apparatus.

10. 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.

11. 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.

12. 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.

13. 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.

14. 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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