Information acquisition device and information acquisition method

Abstract

The present invention provides an information acquisition device and method for measuring information about a specific substance present in a flow channel while a fluid is flowing through the channel provided in a flow cell. [Solution] The information processing device forms a flow channel in the flow cell 804 by providing a transparent member 810 in the cell section 808 so as to close the opening 816 of the cell section 808, and also provides an adjustment section 818 in the cell section, which changes the cross-sectional area of ​​the flow channel perpendicular to the direction of fluid flow. By controlling the flow velocity of the fluid flowing through the flow channel of the flow cell, it becomes possible to measure information about a specific substance present in the flow channel.

Description

Technical Field

[0001] The present invention relates to an information acquisition device and an information acquisition method for measuring information on a specific substance present in a flow path while flowing a fluid through the flow path provided in a flow cell.

Background Art

[0002] A substrate processing apparatus that supplies a processing liquid such as a chemical solution or a rinse solution to a substrate for processing is known. For example, in the apparatus described in Patent Document 1, a silicon nitride film formed on a substrate is etched and removed using an aqueous phosphoric acid solution in a processing tank. Further, in order to circulate and use the aqueous phosphoric acid solution used for the etching process, the aqueous phosphoric acid solution is refluxed to the processing tank through a circulation line, and a concentration meter is attached to the circulation line in order to acquire the concentration of a specific substance contained in the aqueous phosphoric acid solution flowing through the circulation line (corresponding to an example of "information on a specific substance" in the present invention).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The concentration meter described above is an example of the information acquisition device of the present invention and is configured as follows. The concentration meter measures the concentration of a specific substance (e.g., silicon concentration) in a liquid by flowing an aqueous phosphoric acid solution through a flow cell and measuring the absorbance of light at a specific wavelength. As will be described in detail later, this measurement depends on the velocity of the aqueous phosphoric acid solution flowing through the flow cell. As a result, the following problems may occur. For example, when estimating the end of the etching process in a processing tank by monitoring changes in absorbance in a circulation line, if the flow velocity of the aqueous phosphoric acid solution in the flow cell differs significantly from the flow velocity of the aqueous phosphoric acid solution in the processing tank, the accuracy of the estimation will decrease. Here, it is conceivable to change the flow cell according to the process conditions in the processing tank. However, each time the flow cell is changed, the substrate processing must be temporarily interrupted, leading to a decrease in work efficiency.

[0005] Such challenges are not limited to measuring the concentration of specific substances in devices that circulate phosphoric acid aqueous solutions through a treatment tank, but are common to technologies that measure information about specific substances present in a flow channel while a fluid flows through it in a flow cell. However, no concrete configuration has existed to resolve these challenges until now.

[0006] This invention has been made in view of the above problems, and aims to provide an information acquisition device and information acquisition method that allows for the measurement of information about a specific substance present in a flow channel while a fluid is flowing through the flow channel provided in a flow cell, while controlling the fluid velocity in the flow channel. [Means for solving the problem]

[0007] A first aspect of this invention is an information acquisition device comprising: a flow cell having a channel for flowing a fluid; and a total reflection measuring unit for measuring information about a specific substance present in the channel through which the fluid flows; wherein the flow cell has an inlet for introducing the fluid and an outlet for discharging the fluid, and includes a cell section extending from the inlet to the outlet and constituting a part of the channel; and a transparent member having transparency in a wavelength range including the absorption spectrum of the specific substance, and provided in the cell section so as to close an opening provided in the cell section between the inlet and the outlet, thereby cooperating with the cell section to form the channel; wherein the total reflection measuring unit includes a light-emitting unit that irradiates the transparent member with directional light in the wavelength range so as to be totally reflected inside the transparent member, and a light-receiving unit that receives the light that has been totally reflected by the transparent member and has been emitted from the transparent member; and the cell section has an adjustment unit for adjusting the cross-sectional area of ​​the channel perpendicular to the direction of fluid flow.

[0008] Furthermore, a second aspect of the present invention is an information acquisition method comprising the steps of: preparing a flow cell having an inlet for introducing fluid and an outlet for discharging the fluid, extending from the inlet to the outlet and constituting a part of the flow path; and a transparent member having transparency in a wavelength range including the absorption spectrum of the specific substance, and provided in the cell so as to close an opening provided in the cell between the inlet and the outlet, thereby cooperating with the cell to form the flow path; flowing the fluid through the flow path of the flow cell; irradiating the transparent member with directional light in the wavelength range such that it is totally reflected inside the transparent member, and receiving the light that has been totally reflected by the transparent member and has been emitted from the transparent member to measure information about the specific substance present in the flow path through which the fluid is flowing; and adjusting the cross-sectional area of ​​the flow path perpendicular to the direction of fluid flow before measuring the information.

[0009] In this configuration, a transparent member is provided in the cell portion to close the opening of the cell portion, thereby forming a flow channel in the flow cell, and an adjustment section is provided in the cell portion. The adjustment section changes the cross-sectional area of ​​the flow channel perpendicular to the direction of fluid flow, thereby controlling the flow velocity of the fluid flowing through the flow channel of the flow cell. [Effects of the Invention]

[0010] As described above, according to the present invention, it is possible to measure information about a specific substance present in the flow channel while controlling the fluid velocity in the flow channel of the flow cell. [Brief explanation of the drawing]

[0011] [Figure 1] This is a plan view showing the schematic configuration of a substrate processing system equipped with an information acquisition device according to the present invention. [Figure 2] This figure shows the configuration of a first embodiment of a substrate processing apparatus equipped with an information acquisition device according to the present invention. [Figure 3] This is a perspective view showing one embodiment of the information acquisition device according to the present invention. [Figure 4A] Figure 3 schematically shows the cross-sectional structure and operation of the information acquisition device. [Figure 4B] Figure 3 schematically shows the cross-sectional structure and operation of the information acquisition device. [Figure 5] This diagram schematically shows the configuration and operation of the total reflection measurement unit. [Figure 6] Figure 2 is a flowchart showing the operation of the substrate processing apparatus. [Figure 7] This diagram schematically shows the change in chemical solution flow velocity and the flow velocity dependence of the concentration value when the concentration of a specific substance is measured by an information acquisition device in parallel with the chemical solution treatment. [Figure 8] This diagram schematically shows the change in the flow velocity of the chemical solution and the flow velocity dependence of the concentration value when the concentration of a specific substance is measured by an information acquisition device in parallel with the rinsing process. [Figure 9]This figure shows the configuration of a second embodiment of a substrate processing apparatus equipped with an information acquisition device according to the present invention. [Figure 10] This figure shows the configuration of a third embodiment of a substrate processing apparatus equipped with an information acquisition device according to the present invention. [Modes for carrying out the invention]

[0012] Figure 1 is a plan view showing the schematic configuration of a substrate processing system equipped with the information acquisition device 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, on which circuit patterns, etc. (hereinafter referred to as "patterns") are formed only on one main surface. Substrate processing is performed using a processing liquid in a processing unit equipped in the substrate processing system 100. In this specification, of the two main surfaces of the substrate, the pattern-forming surface (one main surface) on which a pattern is formed is referred to as the "front surface," and the other main surface on the opposite side on which no pattern is formed is referred to as the "back surface." Also, the surface facing downwards is referred to as the "bottom surface," and the surface facing upwards is referred to as the "top surface." In this specification, "pattern-forming surface" means a surface on the substrate on which an uneven pattern is formed in an arbitrary area.

[0013] 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 used for processing semiconductor wafers as an example, with reference to the drawings, but the method can also be similarly applied to processing the various substrates exemplified above.

[0014] As shown in FIG. 1, the substrate processing system 100 has a substrate processing area 110 for processing a disk-shaped substrate S. An indexer unit 120 is provided adjacent to this substrate processing area 110. The indexer unit 120 has a container holding part 121 that can hold a plurality of containers C (such as a FOUP (Front Opening Unified Pod), SMIF (Standard Mechanical Interface) pod, OC (Open Cassette), etc. that house a plurality of substrates S in a sealed state). Further, the indexer unit 120 includes an indexer robot 122 for accessing the container C held by the container holding part 121 to take out an unprocessed substrate S from the container C or store a processed substrate S in the container C. A plurality of substrates S are housed in each container C in a substantially horizontal posture.

[0015] The indexer robot 122 includes a base part 122a fixed to the apparatus housing, an articulated arm 122b provided rotatable about a vertical axis with respect to the base part 122a, and a hand 122c attached to the tip of the articulated arm 。The hand 122c is structured to be able to place and hold the substrate S on its upper surface. Since an indexer robot having such an articulated arm and a hand for holding a substrate is well-known, a detailed description thereof will be omitted.

[0016] In the substrate processing area 110, a mounting table 112 is provided so as to be able to mount the substrate S from the indexer robot 122. Also, in a plan view, a substrate transfer robot 111 is arranged substantially at the center of the substrate processing area 110. Further, a plurality of processing units 1 are arranged so as to surround the substrate transfer robot 111. The substrate transfer robot 111 randomly accesses these processing units 1 to transfer the substrate S. On the other hand, each processing unit 1 executes a predetermined process on the substrate S. In the present embodiment, one of these processing units 1 corresponds to the substrate processing apparatus 1 equipped with the information acquisition apparatus according to the present invention.

[0017] FIG. 2 is a diagram showing the configuration of a first embodiment of a substrate processing apparatus equipped with an information acquisition apparatus according to the present invention. The substrate processing apparatus 1 is a single wafer type apparatus that processes substrates S one by one. The substrate processing apparatus 1 includes a box-shaped chamber 2, a spin chuck 3 that rotates the substrate S around a vertical rotation axis A1 passing through the central portion of the substrate S while holding the substrate S horizontally within the chamber 2, a processing liquid supply unit 4 that discharges a processing liquid toward the substrate S held by the spin chuck 3, and a cylindrical cup 5 that receives the processing liquid discharged from the substrate S.

[0018] The spin chuck 3 has a disk-shaped spin base 31 held in a horizontal posture, a plurality of chuck pins 32 that hold the substrate S in a horizontal posture above the spin base 31, a spin shaft 33 that extends downward from the central portion of the spin base 31, and a spin motor 34 that rotates the substrate S and the spin base 31 around the rotation axis A1 by rotating the spin shaft 33. The spin chuck 3 is not limited to a clamping type chuck that brings the plurality of chuck pins 32 into contact with the peripheral end surface of the substrate S, and may be a vacuum type chuck that holds the substrate S horizontally by adsorbing the back surface (lower surface) of the substrate S, which is a non-device formation surface, to the upper surface of the spin base 31.

[0019] The processing liquid supply unit 4 includes a chemical liquid supply system for supplying a chemical solution to the substrate S and a rinse liquid supply system for supplying a rinse liquid to the substrate S. The chemical liquid supply system includes a chemical liquid nozzle 41 that discharges the chemical solution downward toward the upper surface of the substrate S held by the spin chuck 3, a nozzle moving unit 42 that moves the chemical liquid nozzle 41 between a processing position (a position shown by a solid line in Figure 2) and a retracted position (a position shown by a dotted line in Figure 2), and a bottomed cylindrical standby pot 43 positioned below the retracted position of the chemical liquid nozzle 41. The chemical liquid nozzle 41 and the standby pot 43 are located inside the chamber 2. The processing position is the position where the chemical solution discharged from the chemical liquid nozzle 41 lands on the upper surface of the substrate S, and the retracted position is the position where the chemical liquid nozzle 41 is retracted so that the chemical liquid nozzle 41 and the substrate S do not overlap in a plan view. The chemical solution is, for example, BHF (Buffered Hydrogen Fluoride), and a chemical solution supply source (not shown) that supplies it is connected to the chemical solution nozzle 41 by piping 44. Therefore, when the valve 61 provided in the fluid box 6 is opened, the chemical solution is sent to the chemical solution nozzle 41 and discharged from the chemical solution nozzle 41.

[0020] The rinse liquid supply system has a rinse liquid nozzle 45 that discharges rinse liquid downward toward the upper surface of the substrate S held by the spin chuck 3. The rinse liquid nozzle 45 is located inside the chamber 2. The rinse liquid supply system may also include a nozzle moving unit that moves the rinse liquid nozzle 45 between a processing position and a retracted position.

[0021] The rinse liquid nozzle 45 is connected to a rinse liquid supply source (not shown) by piping 46. When a valve 62 provided in the fluid box 6 is opened, the rinse liquid is sent to the rinse liquid nozzle 45 and discharged from the rinse liquid nozzle 45. The rinse liquid is, for example, pure water (deionized water). The rinse liquid is not limited to pure water, but may also be carbonated water, electrolyzed ionized water, hydrogen water, ozonated water, or hydrochloric acid water at a diluted concentration (for example, about 10 to 100 ppm).

[0022] Cup 5 is positioned inside Chamber 2. Cup 5 has a cylindrical inclined portion 51 that extends diagonally upward toward the rotation axis A1, a cylindrical guide portion 52 that extends downward from the lower end (outer end) of the inclined portion 51, and a liquid receiving portion 53 that forms an annular groove that opens upward. The inclined portion 51 has an annular upper end with an inner diameter larger than that of the substrate S and the spin base 31. The upper end of the inclined portion 51 corresponds to the upper end of Cup 5. In a plan view, the upper end of Cup 5 surrounds the substrate S and the spin base 31. When the processing liquid is supplied to the substrate S, the upper end of Cup 5 is positioned above the substrate S. Processing liquids such as chemicals and rinse liquids that are scattered outward from the substrate S are received by the inclined portion 51 and then collected in the liquid receiving portion 53 by the guide portion 52. Furthermore, the chemicals and the like are discharged through the piping 54. In other words, in this embodiment, the piping 54 corresponds to an example of the "drainage piping" of the present invention.

[0023] The chemical supply pipe 44, the rinse liquid supply pipe 46, and the drain pipe 54 pass through the inside of the fluid box 6 and are connected to the chemical supply source, the rinse liquid supply source, and the drain tank (not shown), respectively. Inside the fluid box 6, valves 61 and 62 are interposed in the pipes 44 and 46, respectively. When valve 61 is opened in response to a command from the control unit 7 which controls the entire apparatus, the chemical is sent to the chemical nozzle 41 and supplied from the chemical nozzle 41 to the upper surface of the substrate S. As a result, the chemical components in the chemical are applied to the upper surface of the substrate S, and a predetermined substrate processing such as etching is performed. Following the supply of the chemical, when valve 62 is opened in response to a command from the control unit 7, the rinse liquid is sent to the rinse liquid nozzle 45 and supplied from the rinse liquid nozzle 45 to the upper surface of the substrate S. As a result, the rinsing process is performed, and the amount of chemical components remaining on the upper surface of the substrate S decreases as time passes since the start of the rinse liquid supply, and the substrate processing is completely stopped when the chemical components are gone. Therefore, by monitoring the amount of chemical components while reproducing such chemical supply and rinse solution supply at a location away from the top surface of the substrate S, it becomes possible to estimate the process progress on the top surface of the substrate S. In this embodiment, an information acquisition device 8 equipped with the above monitoring function is installed in the fluid box 6.

[0024] Figure 3 is a perspective view showing one embodiment of the information acquisition device according to the present invention. Figures 4A and 4B are schematic diagrams showing the cross-sectional structure and operation of the information acquisition device shown in Figure 3. In these drawings, the direction in which fluids such as chemical solutions and rinsing solutions flow within the flow cell of the information acquisition device is referred to as the "X direction," the horizontal direction from the right side to the left side in each figure is referred to as the "+X direction," and the opposite direction is referred to as the "-X direction." Furthermore, the horizontal direction perpendicular to the X direction is referred to as the "Y direction," and the vertical direction is referred to as the "Z direction."

[0025] The information acquisition device 8 comprises a flow cell 804 having a flow channel 802 for flowing fluid, and a total reflection measuring unit 806 for measuring information about a specific substance (in this embodiment, a component of a chemical solution contained in a chemical solution) present in the flow channel 802. The flow cell 804 has a cell section 808 extending in the X direction and a transparent member 810 having the same composition as the substrate S. In the cell section 808, an inlet 812 for introducing fluid is provided on the side facing the (-X) direction, while an outlet 814 for discharging fluid is provided on the side facing the (+X) direction. Furthermore, the central part of the cell section 808, in cooperation with the transparent member 810, constitutes a part of the flow channel 802 extending from the inlet 812 to the outlet 814. That is, as shown in Figures 4A and 4B, an opening 816 is provided in the lower central part of the cell section 808 (hereinafter referred to as the "lower central part of the cell"). The transparent member 810 is attached to the lower central part of the cell so as to close the opening 816 from below. Furthermore, an adjustment section 818 is attached to the upper central part of the cell section 808 (hereinafter referred to as the "upper central part of the cell") so as to face the transparent member 810. As a result, a central flow path region 820 is formed in the central part of the cell section 808, sandwiched between the adjustment section 818 and the transparent member 810, and the fluid introduced from the inlet 812 is guided to the outlet 814 via the central flow path region 820. In addition, a pair of guide sections 822 are provided that hang down from the upper central part of the cell toward the transparent member 810, so that a recess 824 is provided in the upper central part of the cell so as to recede vertically upward from the flow path 802.

[0026] The adjustment unit 818 includes a movable body 826 that is movable vertically in the Z direction while being guided by a pair of guide parts 822, and a positioning block 828 that positions the movable body 826 vertically in the Z direction. As shown in Figures 4A and 4B, the movable body 826 has an opposing part 830 that is movable vertically in the Z direction within the recess 824 with its lower surface facing the transparent member 810, and an upright part 832 that is erected vertically above the opposing part 830. The lower surface of the opposing part 830 faces the flow path 802, and the upper end of the upright part 832 protrudes vertically upward from the upper center of the cell through a through hole provided in the upper center of the cell. Therefore, for example, when an operator moves the upright part 832 vertically in the Z direction, the distance from the upper surface of the transparent member 810 to the lower surface of the opposing part 830 (corresponding to the "flow path height" which will be explained later) changes. As a result, the cross-sectional area of ​​the flow path perpendicular to the direction of fluid flow, that is, the direction X, is adjusted.

[0027] To facilitate adjustment of the cross-sectional area, in this embodiment, the positioning block 828 includes two hollow spacers 834, one connecting plate 836, two bolts 838, and two nuts 840. The two hollow spacers 834 are placed on the upper surface of the cell portion 808 so as to sandwich the upright portion 832 in the X direction. The connecting plate 836 is positioned so as to span the upper end of the upright portion 832, with the upright portion 832 being inserted through a through hole provided in the center of the connecting plate 836. The bolts 838 are inserted through the through holes drilled on the (-X) side of the hollow spacers 834 and into the hollow spacers 834 on the (-X) side, and screwed into the cell portion 808. The (+X) side is finished in the same way. In this way, the hollow spacers 834 and the connecting plate 836 are fixed to the cell portion 808 in a gate-like shape. Furthermore, the upper end of the upright portion 832 is connected to the connecting plate 836 using two nuts 840. A male thread is formed on the upper end of the upright portion 832, and it is possible to adjust the position of the nut 840 that screws onto the male thread below the connecting plate 836 and the nut 840 that screws onto the male thread above the connecting plate 836. In other words, the position of the movable body 826 can be changed by changing the height position of the movable body 826 in the vertical direction Z. Note that the configuration of the adjustment section 818 is not limited to the above, and for example, a height adjustment mechanism using a motor may be used.

[0028] Returning to Figure 2, let's continue the explanation of the configuration of the substrate processing apparatus 1. The inlet 812 of the information acquisition device 8 is connected to a pipe 63 that branches off from pipe 44 between valve 61 and chemical nozzle 41. Valve 64 is inserted into this pipe 63. Also, pipe 46 branches off between valve 62 and rinse nozzle 45, and this branched pipe 65 is connected to pipe 63 between the branching point of pipe 63 from pipe 44 and valve 64. Furthermore, pipe 63 branches off between valve 64 and inlet 812, and this branched pipe 66 is connected to a nitrogen gas supply source. In addition, valve 67 is inserted into pipe 66. Therefore, in the fluid box 6, valves 61, 62, 64, and 67 can be individually opened and closed in response to opening and closing commands from the control unit 7 to switch the supply mode of chemical solution, rinse solution, and nitrogen gas. The outline is shown in the following table.

[0029] [Table 1]

[0030] In conventional devices, the supply method was substantially the same as that of switching position PS2 in Table 1, that is, the chemical solution was supplied only to the top surface of the substrate S, and then the supply method was substantially the same as that of switching position PS4, that is, the rinse solution was supplied only to the top surface of the substrate S. Therefore, it was impossible to monitor the processing status and surface condition on the top surface of the substrate S. In contrast, in this embodiment, after performing chemical treatment at switching position PS3, the system can be switched to switching position PS5 to perform rinse treatment. In this case, the same processing as the chemical treatment and rinse treatment performed on the top surface of the substrate S is performed in the flow cell 804 of the information acquisition device 8. Therefore, by measuring the chemical components on the top surface of the transparent member 810 and its vicinity as specific substances using the total reflection measuring unit 806, which will be described next, it is possible to monitor the chemical treatment and rinse treatment on the top surface of the substrate S and estimate the processing status and surface condition. In addition, by switching from switching position PS6 to switching position PS8 by the control unit 7, nitrogen purging is performed on the flow cell 804, making it possible to remove residue from the flow cell 804.

[0031] In Figure 2, reference numeral 68 denotes a discharge pipe connecting the discharge port 814 of the information acquisition device 8 to the pipe 54, and reference numeral 842 denotes an O-ring for preventing fluid leakage from the flow cell 804.

[0032] Next, the configuration and operation of the total reflection measuring unit 806 will be explained with reference to Figures 3, 4A, 4B, and 5.

[0033] Figure 5 is a schematic diagram showing the configuration and operation of the total internal reflection measurement unit. The total internal reflection measurement unit 806 acquires information on the concentration of a specific substance based on information on the absorption spectrum of the specific substance that absorbs evanescent light seeping out from the upper surface of the transparent member 810, which is totally reflected at or near the upper surface of the transparent member 810 having the same composition as the substrate S. As shown in Figures 4A and 4B, the total internal reflection measurement unit 806 comprises a light-emitting unit 844, a prism 846, and a light-receiving unit 848. The light-emitting unit 844 has a laser light source that generates laser light in a wavelength range corresponding to both the transparent member 810 and the specific substance (chemical component). Here, we will describe the case where the substrate S and the transparent member 810 are silicon wafers.

[0034] The wavelength range that the silicon wafer transmits is 1.2 μm to 6 μm, and it is preferable that this wavelength range includes the absorption wavelength range of the chemical solution component. In other words, the transparent member 810 must satisfy the relationship that it is transparent to light emitted from the light-emitting unit 844 in a wavelength range that includes the absorption spectrum of a specific substance. Therefore, in this embodiment, the light-emitting unit 844 uses a directional infrared laser as its light source. The laser light L0 emitted from the emission surface of the light-emitting unit 844 is incident on the transparent member 810 via the prism 846. The prism 846 guides the light to the lower surface region on the (-X) side of the lower surface of the transparent member 810 and causes it to enter the interior of the transparent member 810, and adjusts the path of the laser light L0 near the lower surface region on the (-X) side so that after the incident, the laser light L1 propagates through the interior of the transparent member 810 while undergoing total internal reflection. Furthermore, the prism 846 adjusts the path of the laser beam L0 so that, after incidence, the laser beam L1 undergoes total internal reflection inside the transparent member 810 and travels in the (+X) direction. In other words, the prism 846 has the function of stably guiding the laser beam L0 into the transparent member 810 while ensuring an angle θ greater than or equal to the total internal reflection angle with respect to the direction Dv (dashed line direction in the figure) perpendicular to both main surfaces (top and bottom surfaces) of the transparent member 810, which is necessary for the laser beam L0 to undergo total internal reflection at the top and bottom surfaces of the transparent member 810. The external shape and type of the prism 846 are arbitrary as long as this function can be achieved, and for example, a triangular prism may be used. In addition, in this embodiment, the laser beam is configured to travel inside the transparent member 810 parallel to the flow direction X of the fluid (chemical solution and rinse solution), but the laser beam may be configured to travel in any direction as long as it is parallel to the top and bottom surfaces of the transparent member 810.

[0035] Furthermore, the distance d1 between the transparent member 810 and the prism 846 is set to be less than or equal to the diffraction limit of the laser light L0. For example, if the central wavelength λ of the laser light L0 and the angle θ are 3.4 μm and 60°, respectively, and the optical distance at which the efficiency of laser light L0 capture in the gap between the prism 846 and the transparent member 810 can be maintained is λ / 8, then the distance d1 is given by the following inequality: d1 < λ / 8 × cosθ = 212.5 nm You just need to satisfy that condition.

[0036] As shown in Figure 5, the laser light L0 from the light-emitting unit 844 sequentially passes through the prism 846 and the lower surface of the transparent member 810, and is irradiated into the interior of the transparent member 810 as laser light L1. In this way, the laser light L1 that has entered the interior of the transparent member 810 is irradiated onto the upper surface of the transparent member 810 via the lower surface at the angle θ with respect to the direction Dv. At this irradiation position Pf1 (the boundary position between the upper surface of the transparent member 810 and the fluid flowing in the central flow channel region 820), the laser light L1 is totally internalized. Also, because the refractive index of the fluid is lower than that of the transparent member 810, evanescent light Lef1 seeps out from the upper surface of the transparent member 810 into the fluid at the totally internalized position. After the evanescent light Lef1 has been generated once, the laser light L1a travels through the interior of the transparent member 810 in the (+X) direction due to totally internalized at the irradiation position Pf1, and is irradiated onto the lower surface of the transparent member 810 at the angle θ. At the irradiation position Pb1 (the boundary between the lower surface of the transparent member 810 and the air layer), the laser light L1a is totally reflected, and the evanescent light Leb1 seeps out from the lower surface of the transparent member 810 towards the air layer. After the evanescent light Leb1 is generated, the laser light L1b, due to total reflection at the irradiation position Pb1, travels through the interior of the transparent member 810 in the (+X) direction and is irradiated onto the upper surface of the transparent member 810 at the angle θ. This total reflection is repeated, and multiple evanescent light spots Lef1, Lef2, ... are generated on the upper surface of the transparent member 810. These spots of evanescent light Lef1, Lef2, ... are formed with a constant interval W in the radial direction D. For example, as shown in Figure 3, if a chemical component is attached to the upper surface of the transparent member 810 at the irradiation position Pf3, the chemical component absorbs the evanescent light Lef3. Furthermore, evanescent light is attenuated to 1 / e in intensity at several hundred nanometers from the surface of the transparent material 810, and exists as a local field that is enhanced to approximately four times the incident light intensity at its maximum. This so-called surface enhancement effect allows nano-sized chemical components to be efficiently absorbed.

[0037] The laser light that has passed through the transparent member 810 while undergoing total internal reflection is received by the light receiving unit 848, and information corresponding to the amount of light received, that is, information regarding the absorption spectrum of the specific substance that absorbed the evanescent light, is obtained, and a signal containing this information is sent from the light receiving unit 848 to the control unit 7. Upon receiving this, the control unit 7 can determine the concentration of the specific substance in the fluid flowing through the flow cell 804 and the residual status of the specific substance on the upper surface of the transparent member 810 (residual chemical concentration), etc.

[0038] The control unit 7 is composed of a computer having a CPU (Central Processing Unit), RAM (Random Access Memory), etc., and controls each part of the substrate processing apparatus 1 according to a program stored in the memory unit (not shown) to perform chemical treatment and rinsing. In this embodiment, in parallel with the chemical treatment and rinsing, the residual chemical concentration on the upper surface of the substrate S is measured by an information acquisition device 8 located outside the chamber 2. Moreover, the fluid flow rate in the flow cell 804 is controlled according to various conditions in the chemical treatment and rinsing, so-called process conditions. The operation of the substrate processing apparatus 1 will be described below with reference to Figures 6 to 8.

[0039] Figure 6 is a flowchart showing the operation of the substrate processing apparatus shown in Figure 2. The control unit 7 acquires the process conditions to be executed by the substrate processing apparatus 1 (step S1), determines the flow path height that conforms to the process conditions (i.e., the distance from the upper surface of the transparent member 810 to the opposing part 830 of the movable body 826), and informs the operator. Here, the technical significance of this will be explained based on Figures 7 and 8 before describing the chemical treatment and rinsing treatment.

[0040] Figure 7 schematically shows the change in chemical solution flow velocity and the flow velocity dependence of the concentration value when the concentration of a specific substance is measured by the information acquisition device in parallel with the chemical solution treatment. When the switching position in Table 1 is set to PS3, the information acquisition device 8 performs concentration measurement of the specific substance in parallel with the chemical solution treatment. In this case, for example, as shown in Figure 4A, when the flow path height is relatively large, in the central flow path region 820, the cross-sectional area of ​​the flow path 802 perpendicular to the direction of chemical solution flow, i.e., direction X, becomes large, and the flow velocity of the chemical solution becomes small. Therefore, the concentration value measured by the information acquisition device 8 (hereinafter referred to as the "monitoring concentration value") gradually increases from the timing Tcs when the chemical solution treatment starts, and saturates at timing Tce after a relatively long time has elapsed. In contrast, for example, as shown in Figure 4B, when the flow path height is relatively small, in the central flow path region 820, the cross-sectional area of ​​the flow path 802 perpendicular to the direction of chemical solution flow, i.e., direction X, becomes small, and the flow velocity of the chemical solution becomes large. Therefore, the monitoring concentration value increases rapidly from the timing Tcs when the chemical treatment begins and saturates at timing Tce after a relatively short period of time has elapsed. While it is possible to estimate the chemical treatment status and surface condition on the top surface of the substrate S by referring to the monitoring concentration value, the estimation accuracy may decrease if there is a large difference between the flow rate of the chemical on the top surface of the substrate S and the flow rate of the chemical at the information acquisition device 8.

[0041] Figure 8 schematically shows the change in the flow velocity of the chemical solution and the flow velocity dependence of the concentration value when the concentration of a specific substance is measured by the information acquisition device in parallel with the rinsing process. When the switching position in Table 1 is set to PS5, the information acquisition device 8 performs concentration measurement of the specific substance in parallel with the rinsing process. In this case, for example, as shown in Figure 4A, when the flow path height is relatively large, the cross-sectional area of ​​the flow path 802 becomes large in the central flow path region 820, and the flow velocity of the rinsing liquid becomes small. Therefore, the monitoring concentration value gradually decreases from the start timing Trs of the rinsing process and saturates at timing Tre, after a relatively long time has elapsed. In contrast, for example, as shown in Figure 4B, when the flow path height is relatively small, the cross-sectional area of ​​the flow path 802 perpendicular to the flow direction of the rinsing liquid, i.e., direction X, is small in the central flow path region 820, and the flow velocity of the rinsing liquid becomes large. Therefore, the monitoring concentration value decreases rapidly from the start timing Tcs of the rinsing process and saturates at timing Tre, after a relatively short time has elapsed. While it is possible to estimate the rinsing status and surface condition on the top surface of the substrate S by referring to the monitoring concentration values, if there is a significant difference between the flow rate of the rinsing liquid on the top surface of the substrate S and the flow rate of the rinsing liquid in the information acquisition device 8, the accuracy of estimating the end of the rinsing process may decrease.

[0042] As described above, in order to accurately estimate the status of chemical treatment and rinsing treatment on the substrate S based on the monitoring concentration values, it is preferable to derive a flow path height that matches the process conditions and adjust it accordingly. If the fluid flow velocities differ between the chemical treatment and rinsing treatment, it is desirable to adjust the flow path height to match the process conditions of one of them. For example, if the priority is to monitor the completion of the rinsing treatment, it is preferable to adjust it to match the process conditions of the rinsing treatment.

[0043] In step S2, once the operator confirms that the flow path height has been adjusted to suit the process conditions, the control unit 7 requests the substrate transfer robot 111 to load the substrate S. Accordingly, the substrate S is placed on the spin chuck 3. Subsequently, the chuck pins 32 hold the substrate S, and the substrate transfer robot 111 retracts from the substrate processing apparatus 1 (step S3).

[0044] Once the preparation for chemical treatment is complete, the control unit 7 issues a movement command to the nozzle movement unit 42, moving the chemical nozzle 41 to the treatment position (the position shown by the solid line in Figure 2). The control unit 7 then starts the rotation of the spin chuck 3 holding the substrate S by the spin motor 34, and then switches the valves 61, 62, 64, and 65 from switching position PS1 to switching position PS3. As a result, the chemical solution is discharged from the chemical nozzle 41 toward the upper surface of the substrate S, and the chemical treatment begins (step S4). In this embodiment, the chemical solution is also sent to the information acquisition device 8 in parallel with the chemical treatment, and the monitoring concentration value is measured as an example of "information on specific substances" in the present invention and sent to the control unit 7 (step S5).

[0045] Upon receiving the monitoring concentration value, the control unit 7 estimates the surface state of the substrate S during chemical treatment based on this value (step S6). This acquisition of the monitoring concentration value (step S5) and estimation of the surface state (step S6) are repeated until the control unit 7 determines that the chemical treatment is complete ("YES" in step S7).

[0046] Once the chemical treatment is complete, the control unit 7 issues a movement command to the nozzle movement unit 42, moving the chemical nozzle 41 from the treatment position (indicated by a solid line in Figure 2) to the retracted position (indicated by a dotted line in Figure 2). Subsequently, the control unit 7 switches valves 61, 62, 64, and 65 to the switching position PS4. As a result, the rinsing liquid is discharged from the rinsing liquid nozzle 45 toward the upper surface of the substrate S, and the rinsing treatment begins (step S8). In this embodiment, the rinsing liquid is also sent to the information acquisition device 8 in parallel with the rinsing treatment, and the rinsing liquid is supplied to the upper surface of the transparent member 810 where the chemical treatment remains. As a result, the transparent member 810 is subjected to the same rinsing treatment as the substrate S, and the monitoring concentration value is measured as an example of "information on specific substances" in the present invention and sent to the control unit 7 (step S9).

[0047] Upon receiving the monitoring concentration value, the control unit 7 estimates the surface state of the substrate S during the rinsing process, particularly the progress of the rinsing process, based on this value (step S10). This acquisition of the monitoring concentration value (step S9) and estimation of the surface state (step S10) are repeated until the control unit 7 determines that the rinsing process is complete ("YES" in step S11). This allows the control unit 7 to estimate the progress of the rinsing process on the substrate S with high accuracy from the monitoring concentration value. It can also accurately estimate the timing of the end of the rinsing process. As a result, the supply of excessive rinsing solution can be reduced, and the environmental burden can be reduced.

[0048] Once the rinsing process is complete, the control unit 7 switches valves 61, 62, 64, and 65 to the switching position PS1. This stops the supply of rinsing fluid to the substrate S and the information acquisition device 8. Subsequently, the control unit 7 issues a high-speed rotation command to the spin motor 34 to spin-dry the substrate S (step S12).

[0049] Subsequently, the control unit 7 issues a rotation stop command to the spin motor 34, stopping the rotation of the substrate S. Furthermore, the control unit 7 requests the substrate transfer robot 111 to unload the substrate S, and the processed substrate S is discharged from the substrate processing device 1 (step S13).

[0050] As described above, in this embodiment, the concentration of a specific substance present in the flow channel 802 of the flow cell 804, i.e., the monitoring concentration value, can be measured while controlling the flow velocity of the fluid (chemical solution and rinse solution) in the flow channel 802. In particular, since the monitoring concentration value is measured in parallel with the chemical solution treatment and rinse treatment at a flow channel height that matches the process conditions, the surface state of the substrate S can be estimated with high accuracy from the monitoring concentration value. This allows for appropriate control of the chemical solution treatment and rinse treatment, and reduces the waste of chemical solutions and rinse solutions. Furthermore, it reduces the environmental impact.

[0051] In the above-described embodiment, the upper surface of the transparent member 810 corresponds to an example of the "flow channel side main surface" of the present invention. Furthermore, the chemical solution supply system and the rinse solution supply system correspond to an example of the "fluid supply system" of the present invention.

[0052] Figure 9 shows the configuration of a second embodiment of a substrate processing apparatus equipped with an information acquisition device according to the present invention. The main difference between the second embodiment and the first embodiment (Figure 2) is the placement of the information acquisition device 8. In other words, in the first embodiment, a portion of the fluid (chemical solution, rinse solution) is taken from the fluid supply system and the monitoring concentration value is measured. In contrast, in the second embodiment, a portion of the wastewater (chemical solution, rinse solution, or a mixture of both) is taken from the fluid discharge system that discharges the fluid collected in the liquid receiving section 53 and the monitoring concentration value is measured.

[0053] In the second embodiment, as shown in Figure 9, a pipe 69 branching from pipe 54 is connected to the inlet 812 of the information acquisition device 8. A valve 70 is inserted in this pipe 69. Therefore, when valve 67 is closed and valve 70 is opened in response to an opening command from the control unit 7, a portion of the fluid flowing through pipe 54 is introduced into the information acquisition device 8 via pipe 69. For example, if valve 70 is opened in parallel with the rinsing process, it becomes possible to estimate the surface state of the substrate S during the rinsing process based on the monitoring concentration value measured during the rinsing process, similar to the first embodiment.

[0054] In the second embodiment, the chemical solution, the rinse solution, and the mixture of both are discharged through the piping 54 without separation. Therefore, it is difficult to recover and reuse the chemical solution. As shown in Figure 10, the chemical solution, the rinse solution, and the mixture of the chemical solution and the rinse solution may be separated and recovered, and an information acquisition device 8 may be equipped in such a substrate processing apparatus 1 (third embodiment). ).

[0055] Figure 10 shows the configuration of a third embodiment of a substrate processing apparatus equipped with an information acquisition device according to the present invention. The main difference between the third embodiment and the second embodiment is that the cup 5 is configured similarly to the double-cup structure described in, for example, Japanese Patent Application Publication No. 2003-264167. In other words, in the third embodiment, during chemical treatment, the chemical is collected in a cup 5A dedicated to the chemical and recovered via a pipe 54A for chemical recovery. On the other hand, during rinsing, the mixture of the chemical and rinsing liquid, or the rinsing liquid, is collected in a cup 5B dedicated to rinsing and discharged via a drain pipe 54B. Furthermore, in the third embodiment, the same configuration as in the second embodiment is adopted for the drain pipe 54B. That is, as shown in Figure 10, a pipe 69 branching from pipe 54B is connected to the inlet 812 of the information acquisition device 8. When the valve 67 is closed, and the valve 70 is opened in response to an opening command from the control unit 7, a portion of the fluid flowing through pipe 54B is introduced into the information acquisition device 8 via pipe 69. By opening the valve 70 in parallel with the rinsing process, it becomes possible to estimate the surface state of the substrate S during the rinsing process based on the monitoring concentration value measured during the rinsing process, similar to the first and second embodiments.

[0056] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, the flow path height is changed by manual operation by an operator, but the flow path height may be configured to be changeable by a motor or actuator. In this case, the control unit 7 may determine the optimal flow path height during chemical treatment from the process conditions before chemical treatment, adjust the flow path height by controlling the motor, etc., and measure the monitoring concentration value in parallel with the chemical treatment at the adjusted flow path height. The same applies to the rinsing treatment. That is, the control unit 7 may determine the optimal flow path height during the rinsing treatment from the process conditions after chemical treatment and before the rinsing treatment, adjust the flow path height by controlling the motor, etc., and measure the monitoring concentration value in parallel with the rinsing treatment at the adjusted flow path height. Furthermore, in the above embodiment, the laser light L0 is incident on the transparent member 810 via the prism 846, but the end of the transparent member 810 may be beveled so that the laser light L0 is incident directly on it from the beveled portion.

[0057] Furthermore, although the above embodiment described an information acquisition device 8 applicable to a substrate processing apparatus 1 that performs chemical treatment and rinsing in this order, the information acquisition device and information acquisition method according to the present invention can also be applied to other substrate processing apparatuses or apparatuses different from substrate processing apparatuses.

[0058] Furthermore, in the above embodiment, the information acquisition device 8 performs the function of monitoring the surface state of the substrate S while chemical treatment or rinsing treatment is being performed on the substrate S, so the composition of the transparent member 810 is limited to being the same as that of the substrate S. If the information acquisition device 8 is limited to the function of measuring the concentration of a specific substance in a fluid, the transparent member 810 can be made of a material that is transparent in the wavelength range including the absorption spectrum of the specific substance. [Industrial applicability]

[0059] This invention can be applied to all information acquisition technologies that measure information about specific substances present in a flow channel while a fluid is flowing through the channel provided in a flow cell. [Explanation of symbols]

[0060] 1…Substrate processing equipment 7…Control Unit 8…Information acquisition device 802…flow channel 804...Flow Cell 806...Total reflection measuring section 808... Cell part 810…Transparent component 812... Inlet 814...Exhaust port 816…Aperture 818…Adjustment section 820...Central channel area 824…recess 826…Movable body 828...Positioning block S... Circuit board

Claims

1. A flow cell having a channel for flowing fluid, The system includes a total reflection measuring unit that measures information about a specific substance present in the flow path through which the fluid flows, The aforementioned flow cell is A cell section having an inlet for introducing the fluid and an outlet for discharging the fluid, extending from the inlet to the outlet and constituting a part of the flow path, A transparent member that is transparent in a wavelength range including the absorption spectrum of the specified substance, and is provided in the cell portion so as to close the opening provided in the cell portion between the inlet and the outlet, thereby cooperating with the cell portion to form the flow path, It has, The total internal reflection measuring unit is, A light-emitting unit that irradiates the transparent member with light having directionality in the wavelength range such that it is totally reflected inside the transparent member, A light receiving unit that receives light that has been totally reflected by the transparent member and then emitted from the transparent member, It has, The information acquisition device is characterized in that the cell portion has an adjustment portion for adjusting the cross-sectional area of ​​the flow path which is perpendicular to the direction of fluid flow.

2. An information acquisition device according to claim 1, The cell portion has a recess that is positioned to recede from the flow path in a first direction perpendicular to the flow direction, while facing the transparent member across the flow path. The adjustment unit comprises a movable body provided within the recess so as to be movable in a first direction with its tip surface facing the transparent member, and a positioning block for positioning the movable body in the first direction, and the information acquisition device adjusts the cross-sectional area of ​​the flow path by changing the distance from the transparent member to the tip surface of the movable body in the first direction by changing the position of the movable body by the positioning block.

3. An information acquisition device according to claim 1 or 2, The transparent member has a main surface facing the flow path through the opening, The total reflection measuring unit is an information acquisition device that measures the concentration of the specific substance on and near the main surface of the flow path as the information.

4. An information acquisition device according to claim 1, The flow cell is placed in a fluid supply system that supplies a chemical solution containing the specific substance to the substrate for chemical treatment of the substrate, and a portion of the chemical solution flows through the flow path as the fluid. The total reflection measuring unit is an information acquisition device that measures the concentration of the specific substance as the information.

5. An information acquisition device according to claim 1, The flow cell is placed in a fluid supply system that supplies a chemical solution containing the specific substance to the substrate for processing the substrate, and a rinsing solution for rinsing the substrate that has been chemically treated with the chemical solution, in this order, and a portion of the chemical solution and a portion of the rinsing solution are flowed into the flow path as the fluid, The total reflection measuring unit is an information acquisition device that measures the concentration of the specific substance as the information.

6. An information acquisition device according to claim 1, The flow cell is placed in a fluid discharge system that discharges a chemical solution containing the specific substance used to chemically treat the substrate and a rinsing solution used to rinse the chemically treated substrate, and flows at least a portion of the chemical solution and at least a portion of the rinsing solution as the fluid. The total reflection measuring unit is an information acquisition device that measures the concentration of the specific substance as the information.

7. An information acquisition device according to claim 1, The flow cell is positioned in a fluid discharge system that discharges the chemical solution containing the specific substance used to chemically treat the substrate and the rinsing solution used to rinse the chemically treated substrate through separate drainage pipes, and flows at least a portion of the rinsing solution as the fluid. The total reflection measuring unit is an information acquisition device that measures the concentration of the specific substance in the rinse solution as the information.

8. An information acquisition device according to any one of claims 4 to 7, The transparent member is made of the same composition as the substrate, and the information acquisition device.

9. A step of preparing a flow cell having an inlet for introducing fluid and an outlet for discharging the fluid, a cell portion extending from the inlet to the outlet and constituting a part of the flow path, and a transparent member having transparency in a wavelength range including the absorption spectrum of a specific substance, and provided in the cell portion so as to close an opening provided in the cell portion between the inlet and the outlet, thereby cooperating with the cell portion to form the flow path, A step of flowing the fluid through the flow channel of the flow cell, A step of irradiating the transparent member with light having directionality in the wavelength range such that it is totally reflected inside the transparent member, and receiving the light that has been totally reflected by the transparent member and has been emitted from the transparent member to measure information about a specific substance present in the flow path through which the fluid is flowing, A step of adjusting the cross-sectional area of ​​the flow path perpendicular to the direction of fluid flow before measuring the aforementioned information, An information acquisition method characterized by comprising the following features.

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