Substrate processing apparatus and substrate processing method

Abstract

The present disclosure explains a substrate treatment device and a substrate treatment method with which the state of coverage of a substrate surface by a treatment liquid can be detected, and while doing so, the surface condition of the substrate and the quality of the state of the substrate treatment device can be evaluated.　The substrate treatment device executes: a process of controlling a rotary holding part to rotate the substrate; a process of controlling a supply part to supply a treatment liquid to the surface of the rotating substrate; a process of detecting an arrival of the treatment liquid at a first irradiation site on the basis of a change in the intensity of reflected light obtained by a first light sensor at the first irradiation site; a process of detecting an arrival of the treatment liquid at a second irradiation site on the basis of a change in the intensity of reflected light obtained by a second light sensor at the second irradiation site; a process of calculating a diffusion speed of the treatment liquid on the surface of the substrate on the basis of a time difference between the arrival time of the treatment liquid at the first irradiation site and the arrival time of the treatment liquid at the second irradiation site; and a process of determining the suitability of the treatment of the substrate on the basis of the calculated diffusion speed.

Description

[Technical Field]

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

[0002] Currently, when manufacturing semiconductor devices by microfabrication of substrates (e.g., semiconductor wafers), there are known substrate processing systems that perform substrate processing by discharging various processing liquids onto the substrate. Patent Document 1 discloses a substrate processing method that detects the discharging state of a coating liquid by comparing the difference between laser reflected light from the substrate before the coating liquid is discharged onto the substrate and laser reflected light from the substrate during the discharging of the coating liquid onto the substrate with a threshold value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-258658 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure describes a substrate processing apparatus and a substrate processing method that are capable of evaluating the quality of the substrate surface condition and the state of the substrate processing apparatus while detecting the coating state of the substrate surface with a processing liquid. [Means for solving the problem]

[0005] An example of a substrate processing apparatus includes a rotary holder configured to hold and rotate a substrate, a supply unit configured to supply a processing liquid to the surface of the substrate, a first optical sensor configured to irradiate light toward a first irradiation point set to overlap with the surface of the substrate held by the rotary holder and receive the reflected light, a second optical sensor configured to irradiate light toward a second irradiation point set to overlap with the surface of the substrate held by the rotary holder and located radially outward of the substrate from the first irradiation point and receive the reflected light, and a control unit. The control unit is configured to perform a first process of controlling the rotation holding unit to rotate the substrate, a second process of controlling the supply unit to supply processing liquid to the surface of the rotating substrate, a third process of detecting the arrival of processing liquid at a first irradiation location based on a change in the intensity of reflected light acquired by a first optical sensor at the first irradiation location, a fourth process of detecting the arrival of processing liquid at a second irradiation location based on a change in the intensity of reflected light acquired by a second optical sensor at the second irradiation location, and a fifth process of calculating the diffusion rate of the processing liquid on the surface of the substrate based on the time difference between the arrival of the processing liquid at the first irradiation location and the arrival of the processing liquid at the second irradiation location. [Effects of the Invention]

[0006] According to the substrate processing apparatus and substrate processing method of the present disclosure, it is possible to detect the state of coating of the surface of the substrate with the processing liquid, while evaluating the quality of the surface state of the substrate and the state of the substrate processing apparatus. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view schematically illustrating an example of a substrate processing system. [Figure 2] FIG. 2 is a side view schematically illustrating an example of the liquid processing unit. [Figure 3] FIG. 3 is a top view showing an example of the irradiation position of the optical sensor. [Figure 4] FIG. 4 is a block diagram showing an example of a main part of a substrate processing system. [Figure 5]FIG. 5 is a schematic diagram illustrating an example of a hardware configuration of the controller. [Figure 6] FIG. 6 is a flowchart illustrating an example of a substrate processing procedure. [Figure 7] FIG. 7 is a side view for explaining an example of a procedure for calculating the diffusion rate. [Figure 8] FIG. 8 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using a hydrophilic substrate. [Figure 9] FIG. 9 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using a hydrophilic substrate. [Figure 10] FIG. 10 is a graph showing the coating speed of the processing liquid under the processing conditions in FIGS. [Figure 11] FIG. 11 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using hydrophobic and hydrophilic substrates. [Figure 12] FIG. 12 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using hydrophobic and hydrophilic substrates. [Figure 13] FIG. 13 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using hydrophobic and hydrophilic substrates. [Figure 14] FIG. 14 is a graph showing the coating speed of the processing liquid under the processing conditions in FIGS. [Figure 15] FIG. 15 is a top view showing another example of the irradiation position of the optical sensor. [Figure 16] FIG. 16 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using hydrophobic and hydrophilic substrates. [Figure 17] FIG. 17 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using hydrophobic and hydrophilic substrates. [Figure 18] FIG. 18 is a graph showing the results of measuring the intensity of reflected light at irradiation points P1 to P3 using hydrophobic and hydrophilic substrates. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the following description, the same elements or elements having the same functions will be designated by the same reference numerals, and redundant explanations will be omitted. Note that in this specification, when referring to the top, bottom, right, and left of a figure, the directions of the reference numerals in the figure will be used as the reference.

[0009] [Configuration of substrate processing system] 1, a substrate processing system 1 (substrate processing apparatus) configured to process a substrate W will be described. The substrate processing system 1 includes a loading / unloading station 2, a processing station 3, and a controller Ctr (controller). The loading / unloading station 2 and the processing station 3 may be aligned in a horizontal line, for example.

[0010] The substrate W may be disk-shaped or may be a non-circular plate-shaped such as a polygon. The substrate W may have a cutout portion cut out of a portion. The cutout portion may be, for example, a notch (a U-shaped, V-shaped groove, or the like) or a linear portion extending linearly (so-called orientation flat). The substrate W may be, for example, a semiconductor substrate (silicon wafer), a glass substrate, a mask substrate, an FPD (Flat Panel Display) substrate, or any other type of substrate. The diameter of the substrate W may be, for example, approximately 200 mm to 450 mm.

[0011] The loading / unloading station 2 includes a mounting section 4 (acquisition section), a loading / unloading section 5, and a shelf unit 6. The mounting section 4 includes a plurality of mounting tables (not shown) arranged in the width direction (the vertical direction in FIG. 1). Each mounting table is configured to be able to mount a carrier 7 thereon. When a carrier 7 is placed on the mounting section, the mounting section 4 is configured to read data relating to the type of substrate W stored in a memory section 7a (described later) of the carrier 7, and to transmit the data to the controller Ctr.

[0012] The carrier 7 is configured to accommodate at least one substrate W in a sealed state. The carrier 7 includes an opening / closing door (not shown) for inserting and removing the substrate W. The carrier 7 includes a memory unit 7a that stores data regarding the type of substrate W accommodated in the carrier 7. Substrates W of the same type may be accommodated in one carrier 7. Examples of information indicating the type of substrate W include the surface energy of the substrate W, the warpage of the substrate W, and the arrangement of patterning formed on the surface of the substrate W. The surface energy of the substrate W is an index indicating the wettability of the surface of the substrate W, and depending on its magnitude, it is possible to determine whether the substrate W is hydrophobic or hydrophilic. In this specification, the "surface of the substrate W" refers to the upper surface Wa or lower surface Wb of the substrate W (see FIG. 2).

[0013] The loading / unloading section 5 is disposed adjacent to the mounting section 4 in the direction in which the loading / unloading stations 2 and the processing stations 3 are lined up (the left-right direction in FIG. 1). The loading / unloading section 5 includes an opening / closing door (not shown) provided for the mounting section 4. When the carrier 7 is placed on the mounting section 4, the opening / closing door of the carrier 7 and the opening / closing door of the loading / unloading section 5 are both opened, thereby connecting the inside of the loading / unloading section 5 and the inside of the carrier 7.

[0014] The loading / unloading section 5 incorporates a transport arm A1 and a shelf unit 6. The transport arm A1 is configured to be able to move horizontally in the width direction of the loading / unloading section 5, move up and down in the vertical direction, and rotate about a vertical axis. The transport arm A1 is configured to take out a substrate W from a carrier 7 and pass it to the shelf unit 6, and also to receive a substrate W from the shelf unit 6 and return it to the carrier 7. The shelf unit 6 is located near the processing station 3 and is configured to store substrates W.

[0015] The processing station 3 includes a transport section 8 and a plurality of liquid processing units U (substrate processing apparatuses). The transport section 8 extends horizontally, for example, in the direction in which the loading / unloading station 2 and the processing stations 3 are lined up (the left-right direction in FIG. 1). The transport section 8 incorporates a transport arm A2 (transport section). The transport arm A2 is configured to be able to move horizontally in the longitudinal direction of the transport section 8, move up and down in the vertical direction, and pivot about a vertical axis. The transport arm A2 is configured to remove substrates W from the shelf unit 6 and pass them to the liquid processing units U, and to receive substrates W from the liquid processing units U and return them to the shelf unit 6.

[0016] The liquid processing units U are arranged on both sides of the transport section 8, aligned in a row along the longitudinal direction of the transport section 8 (the left-right direction in FIG. 1). The liquid processing units U are configured to perform a predetermined process (e.g., etching process, cleaning process, etc.) on the substrates W. Details of the liquid processing units U will be described later.

[0017] The controller Ctr is configured to partially or entirely control the substrate processing system 1. The controller Ctr will be described in detail later.

[0018] [Details of the liquid processing unit] 2 and 3, the liquid processing unit U will be described in detail. As illustrated in FIG. 2, the liquid processing unit U includes a spin holder 10, supply units 20 and 30, an imaging unit 40, and a plurality of optical sensors 50.

[0019] The rotation holding unit 10 includes a drive unit 11, a shaft 12, and a holding unit 13. The drive unit 11 is configured to operate based on an operation signal from the controller Ctr and rotate the shaft 12. The drive unit 11 may be a power source such as an electric motor.

[0020] The holder 13 is provided at the tip of the shaft 12. The holder 13 is configured to suction-hold the lower surface Wb of the substrate W, for example, by suction. That is, the rotation holder 10 may be configured to rotate the substrate W around a rotation center axis Ax that is perpendicular to the surface of the substrate W while the substrate W is in a substantially horizontal position.

[0021] The supply unit 20 is configured to supply the chemical liquid L1 to the upper surface Wa of the substrate W. Although not shown, the supply unit 20 may also be configured to supply the chemical liquid L1 to the lower surface Wb of the substrate W. The chemical liquid L1 may be, for example, an acid-based chemical liquid, an alkaline-based chemical liquid, or an organic-based chemical liquid. The acid-based chemical liquid may include, for example, SC-2 liquid (a mixture of hydrochloric acid, hydrogen peroxide, and pure water), SPM (a mixture of sulfuric acid and hydrogen peroxide), HF liquid (hydrofluoric acid), DHF liquid (dilute hydrofluoric acid), HNO3 + HF liquid (a mixture of nitric acid and hydrofluoric acid), etc. The alkaline-based chemical liquid may include, for example, SC-1 liquid (a mixture of ammonia, hydrogen peroxide, and pure water), hydrogen peroxide, etc.

[0022] The supply unit 20 includes a liquid source 21, a pump 22, a valve 23, a nozzle 24, a pipe 25, and a drive source 26. The liquid source 21 is a supply source of the chemical liquid L1. The pump 22 operates based on an operation signal from the controller Ctr, and is configured to suck in the chemical liquid L1 from the liquid source 21 and send it to the nozzle 24 via the pipe 25 and the valve 23.

[0023] The valve 23 operates based on an operation signal from the controller Ctr, and is configured to transition between an open state that allows the fluid to flow through the pipe 25 and a closed state that prevents the fluid from flowing through the pipe 25. The nozzle 24 is disposed above the substrate W so that its discharge outlet faces the upper surface Wa of the substrate W. The nozzle 24 is configured to discharge the chemical liquid L1 delivered from the pump 22 from the discharge outlet toward the upper surface Wa of the substrate W. Because the substrate W is rotated by the rotary holder 10, the chemical liquid L1 discharged onto the upper surface Wa of the substrate W spreads from the center of the substrate W toward the peripheral edge at a predetermined diffusion speed, and is thrown off outward from the peripheral edge of the substrate W.

[0024] The pipe 25 connects, in order from the upstream side, the liquid source 21, the pump 22, the valve 23, and the nozzle 24. The drive source 26 is directly or indirectly connected to the nozzle 24. The drive source 26 is configured to operate based on an operation signal from the controller Ctr and move the nozzle 24 horizontally or vertically above the substrate W. Therefore, the chemical liquid L1 can be discharged not only toward the center of the upper surface Wa of the substrate W, but also toward any position on the upper surface Wa of the substrate W. For example, while the nozzle 24 continues to discharge the chemical liquid L1, the nozzle 24 may move from the periphery of the substrate W toward the center (a so-called scan-in operation). Alternatively, while the nozzle 24 continues to discharge the chemical liquid L1, the nozzle 24 may move from the center of the substrate W toward the periphery (a so-called scan-out operation).

[0025] The supply unit 30 is configured to supply a rinse liquid L2 to the substrate W. The rinse liquid L2 is a liquid for removing (rinsing away) from the substrate W, for example, the chemical liquid L1 supplied to the upper surface Wa of the substrate W, components of a film dissolved by the chemical liquid L1, etching residues, etc. The rinse liquid L2 may contain, for example, pure water (DIW: deionized water), ozone water, carbonated water (CO2 water), ammonia water, etc.

[0026] The supply unit 30 includes a liquid source 31, a pump 32, a valve 33, a nozzle 34, a pipe 35, and a drive source 36. The liquid source 31 is a supply source of the rinse liquid L2. The pump 32 operates based on an operation signal from the controller Ctr, and is configured to suck in the rinse liquid L2 from the liquid source 31 and send it to the nozzle 34 via the pipe 35 and the valve 33.

[0027] The valve 33 operates based on an operation signal from the controller Ctr, and is configured to transition between an open state that allows the fluid to flow through the pipe 35 and a closed state that prevents the fluid from flowing through the pipe 35. The nozzle 34 is disposed above the substrate W so that its outlet faces the upper surface Wa of the substrate W. Like the nozzle 24, the nozzle 34 is configured to discharge the rinsing liquid L2 delivered from the pump 32 from its outlet toward the upper surface Wa of the substrate W. Because the substrate W is rotated by the spin holder 10, the rinsing liquid L2 discharged onto the upper surface Wa of the substrate W spreads from the center of the substrate W toward the peripheral edge at a predetermined diffusion speed, and is then thrown off outward from the peripheral edge of the substrate W.

[0028] The pipe 35 connects, in order from the upstream side, the liquid source 31, the pump 32, the valve 33, and the nozzle 34. The drive source 36 is directly or indirectly connected to the nozzle 34. The drive source 36 is configured to operate based on an operation signal from the controller Ctr and move the nozzle 34 horizontally or vertically above the substrate W. Therefore, the rinse liquid L2 can be discharged not only toward the center of the upper surface Wa of the substrate W, but also toward any position on the upper surface Wa of the substrate W. For example, while the nozzle 34 continues to discharge the rinse liquid L2, the nozzle 34 may move from the periphery of the substrate W toward the center (a so-called scan-in operation). Alternatively, while the nozzle 34 continues to discharge the rinse liquid L2, the nozzle 34 may move from the center to the periphery of the substrate W (a so-called scan-out operation).

[0029] The imaging unit 40 is disposed above the substrate W. The imaging unit 40 is configured to operate based on an operation signal from the controller Ctr and to capture an image of the upper surface Wa of the substrate W. Specifically, the imaging unit 40 may capture a still image or a moving image of the state of coverage of the upper surface Wa of the substrate W with the chemical liquid L1 or the rinse liquid L2 when the chemical liquid L1 or the rinse liquid L2 is supplied to the upper surface Wa of the substrate W.

[0030] The imaging unit 40 is configured to transmit the captured image to the controller Ctr. The imaging unit 40 may be, for example, a CCD camera or a CMOS camera. The location where the imaging unit 40 is installed is not particularly limited as long as it is within the liquid processing unit U. For example, when the chemical liquid L1 or the rinse liquid L2 is supplied to the lower surface Wb of the substrate W, the imaging unit 40 may be disposed below the substrate W.

[0031] The multiple optical sensors 50 are disposed above the substrate W. The multiple optical sensors 50 include an irradiation unit (not shown) and a light receiving unit (not shown). The irradiation unit is configured to operate based on an operation signal from the controller Ctr and to irradiate light onto the upper surface Wa of the substrate W being rotated by the rotation holder 10. The light receiving unit is configured to receive light reflected from the upper surface Wa of the substrate W (reflected light) and transmit the intensity of the reflected light (hereinafter referred to as "reflection intensity") to the controller Ctr.

[0032] The optical sensor 50 may be, for example, a laser sensor, a photoelectric sensor, or a color sensor. When the optical sensor 50 is a laser sensor, the irradiation unit may use, for example, a red laser (wavelength: 655 nm) as the laser light, or may use other types of laser light.

[0033] The irradiation section of the optical sensor 50 may irradiate light downward in a direction perpendicular to the upper surface Wa of the substrate W. The irradiation section of the optical sensor 50 may irradiate the upper surface Wa of the substrate W with light via a light reflecting member (e.g., a mirror), and the light receiving section of the optical sensor 50 may receive the reflected light via the mirror. In these cases, the irradiation section and light receiving section of the optical sensor 50 may be arranged in the same housing, or may be physically separated.

[0034] The irradiation section of the optical sensor 50 may irradiate light obliquely downward along a direction inclined with respect to the upper surface Wa of the substrate W. In this case, the irradiation section and the light receiving section of the optical sensor 50 may be physically separated, and may be disposed so that the point on the upper surface Wa of the substrate W that is irradiated with light is located between them.

[0035] 2, the multiple optical sensors 50 may include three optical sensors 51 to 53. The optical sensors 51 to 53 are configured to irradiate light toward irradiation points P1 to P3 set so as to overlap with the upper surface Wa of the substrate W held by the rotary holder 10, respectively, and to receive light reflected from the irradiation points P1 to P3. The irradiation points P1 to P3 are fixed positions that do not change even when the substrate W rotates.

[0036] The irradiation points P1 to P3 are set at different positions from one another, as illustrated in FIG. 2. That is, the irradiation points P1 to P3 may be aligned from the center toward the periphery of the substrate W. Specifically, the irradiation point P2 may be located closer to the periphery of the substrate W than the irradiation point P1, and the irradiation point P3 may be located closer to the periphery of the substrate W than the irradiation point P2. The irradiation points P1 to P3 may be aligned in a line in the radial direction of the substrate W, as illustrated in FIG. 3(a). Alternatively, the irradiation points P1 to P3 may not be aligned in the radial direction of the substrate W, but may be aligned with a shift in the circumferential direction of the substrate W, as illustrated in FIG. 3(b). That is, the irradiation points P1 and P2 do not have to be on a straight line connecting the irradiation point P3 and the center of the substrate W, and the irradiation points P2 and P3 do not have to be on a straight line connecting the irradiation point P1 and the center of the substrate W, and the irradiation points P1 and P3 do not have to be on a straight line connecting the irradiation point P2 and the center of the substrate W.

[0037] The intervals between the irradiation points P1 to P3 may be approximately equal or different. When the radius of the substrate W is approximately 150 mm, the irradiation point P1 may be located approximately 50 mm from the center of the substrate W, the irradiation point P2 may be located approximately 100 mm from the center of the substrate W, and the irradiation point P3 may be located approximately 147 mm from the center of the substrate W.

[0038] [Controller Details] 4, the controller Ctr has a reading unit M1, a memory unit M2, a processing unit M3, and an instruction unit M4 as functional modules. These functional modules are merely a division of the functions of the controller Ctr into a plurality of modules for convenience, and do not necessarily mean that the hardware constituting the controller Ctr is divided into such modules. Each functional module is not limited to being realized by the execution of a program, but may also be realized by a dedicated electric circuit (for example, a logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit) that integrates such circuits.

[0039] The reading unit M1 is configured to read a program from a computer-readable recording medium RM. The recording medium RM stores a program for operating each part of the substrate processing system 1, including the liquid processing unit U. The recording medium RM may be, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or a magneto-optical recording disk. In the following description, each part of the substrate processing system 1 may include a spinning holder 10, supply units 20 and 30, an imaging unit 40, and an optical sensor 50.

[0040] The memory unit M2 is configured to store various data. The memory unit M2 may store, for example, a program read from the recording medium RM by the reading unit M1, setting data input by an operator via an external input device (not shown), etc. The memory unit M2 may store image data captured by the imaging unit 40. The memory unit M2 may store reflection intensity data acquired by the optical sensor 50. The memory unit M2 may store data related to the type of substrate W accommodated in the carrier 7, which is read from the memory unit 7a of the carrier 7 by the mounting unit 4.

[0041] The memory unit M2 may store correspondence information that associates data on the type of substrate W with an allowable range R of the diffusion rate of the processing liquid (chemical liquid L1 or rinse liquid L2) on the upper surface Wa of the substrate W when the processing liquid is supplied to the upper surface Wa of the substrate W during rotation of the substrate W having that type. Here, the allowable range R can be defined as a diffusion rate included between an allowable lower limit Vmin and an allowable upper limit Vmax, for example.

[0042] This allowable range R may differ depending on the type of substrate W. For example, if the substrate W is hydrophobic, the diffusion rate tends to be low, and therefore the allowable lower limit Vmin and the allowable upper limit Vmax may be relatively small. On the other hand, if the substrate W is hydrophilic, the diffusion rate tends to be high, and therefore the allowable lower limit Vmin and the allowable upper limit Vmax may be relatively large. Furthermore, for example, if the substrate W is warped such that the central portion thereof is convex downward, the diffusion rate tends to be low, and therefore the allowable lower limit Vmin and the allowable upper limit Vmax may be relatively small. On the other hand, for example, if the central portion thereof is warped such that the central portion thereof is convex upward, the diffusion rate tends to be high, and therefore the allowable lower limit Vmin and the allowable upper limit Vmax may be relatively large. For example, if a large proportion of the patterning formed on the surface of the substrate W extends along the circumferential direction of the substrate W, the diffusion rate tends to be low, and therefore the allowable lower limit Vmin and the allowable upper limit Vmax may be relatively small. On the other hand, for example, if a large proportion of the patterning formed on the surface of the substrate W extends along the radial direction of the substrate W, the diffusion rate tends to be high, and therefore the allowable lower limit value Vmin and the allowable upper limit value Vmax can take relatively large values.

[0043] Based on the above, examples of correspondence information stored in the storage unit M2 are shown below. Substrate W type A: tolerance range R1 (tolerance lower limit Vmin1 to tolerance upper limit Vmax1) Type B of substrate W: Tolerance range R2 (lower limit Vmin2 to upper limit Vmax2) Type C of substrate W: Tolerance range R3 (lower limit Vmin3 to upper limit Vmax3) ...

[0044] The allowable range R may include an adjustment-free range Ra and an adjustment range Rb. The adjustment-free range Ra may be defined, for example, as a diffusion rate between the adjustment-free lower limit Vlow and the adjustment-free upper limit Vhigh. The adjustment-free lower limit Vlow is a value greater than the allowable lower limit Vmin, and the adjustment-free upper limit Vhigh is a value less than the allowable upper limit Vmax. That is, the adjustment-free range Ra is included in the allowable range R (Ra ⊂ R). On the other hand, the adjustment range Rb may be defined as a diffusion rate included in the range from the allowable lower limit Vmin to the adjustment-free lower limit Vlow and the range from the adjustment-free upper limit Vhigh to the allowable upper limit Vmax. That is, the lower limit of the adjustment range Rb is equal to the allowable lower limit Vmin and smaller than the adjustment-free lower limit Vlow, and the upper limit of the adjustment range Rb is equal to the allowable upper limit Vmax and larger than the adjustment-free upper limit Vhigh. The adjustment-free range Ra and the adjustment range Rb may also be set to values ​​according to the type of substrate W.

[0045] The processing unit M3 is configured to process various data, and may generate signals for operating each unit of the substrate processing system 1 based on the various data stored in the storage unit M2, for example.

[0046] The instruction unit M4 is configured to transmit the operation signal generated in the processing unit M3 to each unit of the substrate processing system 1.

[0047] The hardware of the controller Ctr may be configured, for example, by one or more control computers. As shown in Fig. 5, the controller Ctr may include a circuit C1 as a hardware configuration. The circuit C1 may be configured by electric circuit elements. The circuit C1 may include, for example, a processor C2, a memory C3, a storage C4, a driver C5, and an input / output port C6.

[0048] The processor C2 may be configured to execute a program in cooperation with at least one of the memory C3 and the storage C4 and to implement each of the above-mentioned functional modules by inputting and outputting signals via the input / output port C6. The memory C3 and the storage C4 may function as the storage unit M2. The driver C5 may be a circuit configured to drive each component of the substrate processing system 1. The input / output port C6 may be configured to mediate the input and output of signals between the driver C5 and each component of the substrate processing system 1.

[0049] The substrate processing system 1 may include one controller Ctr, or may include a controller group (controller) composed of multiple controllers Ctr. When the substrate processing system 1 includes a controller group, each of the above-mentioned functional modules may be realized by one controller Ctr, or may be realized by a combination of two or more controllers Ctr. When the controller Ctr is composed of multiple computers (circuits C1), each of the above-mentioned functional modules may be realized by one computer (circuit C1), or may be realized by a combination of two or more computers (circuits C1). The controller Ctr may include multiple processors C2. In this case, each of the above-mentioned functional modules may be realized by one processor C2, or may be realized by a combination of two or more processors C2.

[0050] [Substrate processing method] Next, a method for treating the substrate W with the treatment liquid will be described with reference to FIGS.

[0051] First, the carrier 7 is placed on the placement table of the placement unit 4. At least one substrate W of the same type is accommodated in the carrier 7. When the placement unit 4 detects that the carrier 7 has been placed on the placement table, it reads data relating to the type of substrate W stored in the memory unit 7a of the carrier 7 and transmits the data to the controller Ctr (see step S1 in FIG. 6). Based on the data relating to the type of substrate W, the controller Ctr searches for corresponding information stored in the memory unit M2 and obtains the allowable range R corresponding to the data relating to the type of substrate W (see step S2 in FIG. 6).

[0052] Next, the controller Ctr controls the transport arms A1 and A2 to take out one substrate W from the carrier 7 and transport it into one of the liquid processing units U. The substrate W transported into the liquid processing unit U is sucked and held by the holder 13 (see step S3 in FIG. 6).

[0053] Next, the controller Ctr controls the spin holder 10 to rotate the substrate W while suction-holding the lower surface Wb of the substrate W with the holder 13. In this state, the controller Ctr controls the supply unit 20 to supply the chemical liquid L1 from the nozzle 24 to the upper surface Wa of the substrate W for a predetermined time (see step S4 in FIG. 6). At this time, the nozzle 24 may perform a scan-in operation or a scan-out operation. The chemical liquid L1 supplied to the upper surface Wa of the substrate W spreads over the entire surface of the substrate W as the substrate W rotates, and is thrown off outward from the periphery of the substrate W. Therefore, while the supply of the chemical liquid L1 from the nozzle 24 continues, a liquid film of the chemical liquid L1 is formed on the upper surface Wa of the substrate W. In this way, the upper surface Wa of the substrate W is processed. At this time, the imaging unit 40 may capture an image of the state of coverage of the upper surface Wa of the substrate W with the chemical liquid L1 when the chemical liquid L1 is supplied to the upper surface Wa of the substrate W, and transmit the image data to the controller Ctr.

[0054] Next, the controller Ctr controls the spin holder 10 to rotate the substrate W while suction-holding the backside of the substrate W with the holder 13. In this state, the controller Ctr controls the supply unit 30 to supply the rinse liquid L2 from the nozzle 34 to the upper surface Wa of the substrate W for a predetermined time (see step S5 in FIG. 6). At this time, the nozzle 34 may perform a scan-in or scan-out operation. The rinse liquid L2 supplied to the upper surface Wa of the substrate W spreads over the entire surface of the substrate W as the substrate W rotates, and is thrown off outward from the periphery of the substrate W. Therefore, while the supply of the rinse liquid L2 from the nozzle 34 continues, a liquid film of the rinse liquid L2 is formed on the upper surface Wa of the substrate W. This cleans the upper surface Wa of the substrate W. At this time, the imaging unit 40 may capture an image of the state of coverage of the upper surface Wa of the substrate W with the rinse liquid L2 when the rinse liquid L2 is supplied to the upper surface Wa of the substrate W, and transmit the image data to the controller Ctr.

[0055] 7, before the rinse liquid L2 is supplied to the upper surface Wa of the substrate W, the optical sensors 51-53 irradiate the irradiation points P1-P3 with light, and the change in reflection intensity is acquired (see step S6 in FIG. 6). As the rinse liquid L2 spreads radially outward across the upper surface Wa of the substrate W, it passes through the irradiation points P1-P3 in this order. The reflection intensity from the upper surface Wa of the substrate W changes significantly before and after the rinse liquid L2 passes through the irradiation points P1-P3. This is presumably because the surface fluctuation of the liquid film of the rinse liquid L2 is severe, causing diffuse reflection of light. Other possible factors that may cause changes in reflection intensity include the type of processing liquid, the flow rate of the processing liquid, and the thickness of the liquid film of the processing liquid.

[0056] 8 and 9 show the results of measuring the reflection intensity at irradiation points P1 to P3 using a hydrophilic substrate W. Specifically, the hydrophilic substrate W is a substrate having a thermal oxide film (Th-Ox) formed on its surface.

[0057] Figure 8(a) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 1500 ml / min and the substrate W is rotated at 200 rpm. Figure 8(b) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 1500 ml / min and the substrate W is rotated at 500 rpm. Figure 8(c) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 1500 ml / min and the substrate W is rotated at 1000 rpm. Figure 8(d) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 1500 ml / min and the substrate W is rotated at 1500 rpm.

[0058] 9(a) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 2000 ml / min and the substrate W is rotated at 200 rpm. FIG. 9(b) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 2000 ml / min and the substrate W is rotated at 500 rpm. FIG. 9(c) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 2000 ml / min and the substrate W is rotated at 1000 rpm. FIG. 9(d) shows the change in reflection intensity at each of the irradiation locations P1 to P3 when the rinsing liquid L2 is discharged at a flow rate of 2000 ml / min and the substrate W is rotated at 1500 rpm.

[0059] 8 and 9, it can be seen that the reflection intensity increases rapidly (the reflection intensity rises) in the order of the irradiation points P1 to P3. That is, it can be determined that the treatment liquid has reached the irradiation points P1 to P3 at the time when the reflection intensity rises. Therefore, as shown in FIG. 10, by plotting the time when the reflection intensity rises and the positions of the irradiation points P1 to P3 on a graph and obtaining an approximate line, the diffusion rate can be calculated from the slope of the approximate line (i.e., the time difference between when the treatment liquid reaches the irradiation points P1 to P3) (see step S7 in FIG. 6).

[0060] 10(a) shows the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 1500 ml / min and the rotation speed of the substrate W is 200 rpm, and the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 2000 ml / min and the rotation speed of the substrate W is 200 rpm. FIG. 10(b) shows the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 1500 ml / min and the rotation speed of the substrate W is 500 rpm, and the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 2000 ml / min and the rotation speed of the substrate W is 500 rpm.

[0061] 10(c) shows the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 1500 ml / min and the rotation speed of the substrate W is 1000 rpm, and the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 2000 ml / min and the rotation speed of the substrate W is 1000 rpm. FIG. 10(d) shows the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 1500 ml / min and the rotation speed of the substrate W is 1500 rpm, and the rising time of the reflection intensity at each of the irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is 2000 ml / min and the rotation speed of the substrate W is 1500 rpm.

[0062] 11 to 13 show the results of measuring the reflection intensity at the irradiation locations P1 to P3 in the same manner as above using a hydrophobic substrate W, in comparison with the hydrophilic substrate W. FIGS. 11(a) to 11(c) show the change in reflection intensity at each of the irradiation locations P1 to P3 for a hydrophobic substrate W and a hydrophilic substrate W when the discharge flow rate of the rinsing liquid L2 is 1000 ml / min and the rotation speed of the substrate W is 1000 rpm. FIGS. 12(a) to 12(c) show the change in reflection intensity at each of the irradiation locations P1 to P3 for a hydrophobic substrate W and a hydrophilic substrate W when the discharge flow rate of the rinsing liquid L2 is 1500 ml / min and the rotation speed of the substrate W is 1000 rpm. Figures 13(a) to (c) show the change in reflection intensity at each of the irradiation points P1 to P3 for a hydrophobic substrate W and a hydrophilic substrate W when the discharge flow rate of the rinse liquid L2 is 2000 ml / min and the rotation speed of the substrate W is 1000 rpm.

[0063] Specifically, the hydrophobic substrate W is a silicon substrate (so-called "bare silicon") after the native oxide film has been removed by surface treatment using DHF (dilute hydrofluoric acid). As shown in FIGS. 11 to 13, even on the hydrophobic substrate W, the reflection intensity increases rapidly in the order of irradiation points P1 to P3 (the reflection intensity rises). However, it can be seen that the rise in reflection intensity at irradiation point P3 is slower than on the hydrophilic substrate W, particularly as the rotation speed of the substrate W decreases. Therefore, as shown in FIG. 14, it was confirmed that the diffusion rate of the hydrophobic substrate W is slower than that of the hydrophilic substrate W.

[0064] Next, the controller Ctr determines whether the diffusion rate calculated in step S7 is within the allowable range R acquired in step S2 (see step S8 in FIG. 6). If the determination by the controller Ctr shows that the diffusion rate calculated in step S7 is not within the allowable range R acquired in step S2 (see "NO" in step S8 in FIG. 6), the processing of the substrate W may be inappropriate. Therefore, the controller Ctr stores the image data of the substrate W during processing, captured by the imaging unit 40, or the processing conditions of the substrate W, together with the determination result that the diffusion rate is inappropriate, in the memory unit M2 (see step S9 in FIG. 6). At this time, the controller Ctr may issue an alarm indicating that the diffusion rate is not within the allowable range R from an alarm unit (not shown) (for example, an alarm may be displayed on a display, or an alarm sound or alarm guide may be issued from a speaker). After step S9, the processing of the substrate W is completed. Thereafter, the processing of the subsequent substrate W may be interrupted, or the processing of the subsequent substrate W may be carried out using a liquid processing unit U other than the liquid processing unit U in which the substrate W may have been inappropriately processed.

[0065] If the controller Ctr determines that the diffusion rate calculated in step S7 is within the allowable range R acquired in step S2 (see "YES" in step S8 of FIG. 6), the process proceeds to step S10. In step S10, the controller Ctr determines whether the diffusion rate calculated in step S7 is within the adjustment-free range Ra of the allowable range R acquired in step S2. If the controller Ctr determines that the diffusion rate calculated in step S7 is not within the adjustment-free range Ra of the allowable range R acquired in step S2 (see "NO" in step S10 of FIG. 6), there may be room for improvement in the processing conditions for the substrate W. Therefore, the controller Ctr changes the processing conditions for the subsequent substrate W (see step S11 of FIG. 6). Examples of the processing conditions that are changed here include the rotation speed of the subsequent substrate W and the flow rate of the processing liquid discharged onto the subsequent substrate W. At this time, similarly to step S9, the controller Ctr may store in the memory unit M2 the image data of the substrate W captured by the imaging unit 40 during processing or the processing conditions of the substrate W, along with the determination result that the diffusion rate is not within the adjustment-free range Ra. Furthermore, similarly to the above, the controller Ctr may issue an alarm indicating that the diffusion rate is not within the adjustment-free range Ra from an alarm unit (not shown). After step S11, the processing of the substrate W is completed. Thereafter, a subsequent substrate W may be processed under the changed processing conditions using a liquid processing unit U different from the liquid processing unit U for which the determination result that the diffusion rate is not within the adjustment-free range Ra is made. Alternatively, a subsequent substrate W may be processed under the changed processing conditions using the liquid processing unit U for which the determination result that the diffusion rate is not within the adjustment-free range Ra is made.

[0066] If the controller Ctr determines that the diffusion rate calculated in step S7 is within the adjustment-free range Ra in the allowable range R acquired in step S2 (see "YES" in step S10 of FIG. 6), it is assumed that the processing of the substrate W has been performed appropriately. Therefore, after step S9, the processing of the substrate W is completed. Thereafter, a subsequent substrate W may be processed using the same liquid processing unit U under the same processing conditions.

[0067] [Effect] According to the above example, it is possible to determine how quickly the processing liquid is spreading over the surface of the substrate W. The diffusion rate can vary depending on the surface condition of the substrate W, the state of the liquid processing unit U, and other factors. If the diffusion rate is extremely slow, it can be determined that the entire surface of the substrate W is not covered with the processing liquid. On the other hand, if the diffusion rate is extremely fast, it can be determined that there is a possibility of a malfunction in the liquid processing unit U or a malfunction in the surface condition of the substrate W. Therefore, by determining whether the substrate W is being processed properly based on the diffusion rate, it is possible to detect the state of coverage of the surface of the substrate W with the processing liquid and evaluate the quality of the surface condition of the substrate W and the state of the liquid processing unit U. Furthermore, compared to using a camera to acquire the surface condition of the substrate W, using the optical sensor 50 prevents the liquid processing unit U from becoming larger, reduces the amount of data handled, and simplifies calculations. Therefore, it is possible to detect the state of coverage of the surface of the substrate W with the processing liquid and evaluate the quality of the surface condition of the substrate W and the state of the liquid processing unit U at low cost.

[0068] According to the above example, the allowable range R is obtained based on the data relating to the type of substrate W read from the memory unit 7a of the carrier 7 and the corresponding information stored in the memory unit M2, and it is determined whether the calculated diffusion rate is within the allowable range R. In this case, the allowable range R of the diffusion rate of the processing liquid is appropriately set for each type of substrate W. This makes it possible to more accurately detect the state of coverage of the processing liquid on the upper surface Wa of the substrate W and evaluate the quality of the surface condition of the substrate W and the condition of the liquid processing unit U.

[0069] According to the above example, the allowable range R includes the adjustment-free range Ra and the adjustment range Rb, and it is determined whether the calculated diffusion rate is within the adjustment-free range Ra. In this case, even if the processing result of the substrate W is determined to be good, if the diffusion rate is within the adjustment range Rb, the rotation speed of the substrate W or the flow rate of the processing liquid is changed. In other words, the processing conditions for the substrate W are adjusted so that the processing result of the subsequent substrate W is improved. This makes it possible to process the substrate W more appropriately.

[0070] According to the above example, when it is determined that the coating state of the surface of the substrate W is inappropriate, the image data of the substrate W during processing, captured by the imaging unit 40, or the processing conditions of the substrate W, are stored in the memory unit M2 together with the determination result that the coating state is inappropriate. In this case, the operator can easily check the processing status of the substrate W when the determination result that the coating state is inappropriate is made.

[0071] [Variations] The disclosure in this specification should be considered to be illustrative in all respects and not restrictive. Various omissions, substitutions, modifications, etc. may be made to the above examples without departing from the scope and spirit of the claims.

[0072] (1) In the liquid processing unit U, the processing of the substrate W may be performed in a light-shielded space. For example, the housing constituting the liquid processing unit U may be made of a light-shielding material. In this case, since the optical sensor 50 is used, the diffusion rate can be calculated even when the substrate W is processed using a processing liquid whose properties may change depending on light. Therefore, compared to the case where a camera is used, it is possible to detect the coating state of the surface of the substrate W with the processing liquid for a wider variety of processing liquids, and evaluate the quality of the surface condition of the substrate W and the condition of the liquid processing unit U.

[0073] (2) In the above example, when the rinsing liquid L2 is supplied to the substrate W, the optical sensor 50 calculates the diffusion rate of the rinsing liquid L2 to determine whether the substrate W is being processed. However, when the chemical liquid L1 is supplied to the substrate W, the diffusion rate of the chemical liquid L1 may also be calculated to determine whether the substrate W is being processed.

[0074] (3) In the above example, the diffusion rate is calculated using three optical sensors 51 to 53, but the diffusion rate may be calculated using at least two optical sensors 50.

[0075] (4) Even when the processing liquid is supplied to the substrate W while the nozzles 24, 34 perform a scan-out operation from the center of the substrate W toward the periphery, the optical sensor 50 can calculate the diffusion rate of the processing liquid. Specifically, when the nozzles 24, 34 perform a scan-out operation, the processing liquid evaporates and dries from the center of the substrate W, resulting in a large change in reflection intensity before and after drying. Therefore, the evaporation rate of the processing liquid can be determined based on this change. The faster the diffusion rate of the processing liquid, the faster the evaporation rate of the processing liquid, and vice versa. Consequently, the evaporation rate of the processing liquid can be obtained by determining the evaporation rate of the processing liquid.

[0076] (5) However, as illustrated in FIG. 15, the processing liquid supplied to the substrate W may not spread uniformly in the radial direction of the substrate W. In this case, the uneven spreading of the processing liquid can be detected by using at least four optical sensors 50. Specifically, a plurality of irradiation points aligned in a first direction (three irradiation points P1 to P3 in the example of FIG. 15) and a plurality of irradiation points aligned in a second direction (three irradiation points P4 to P6 in the example of FIG. 15) are set. The first direction extends along the radial direction of the substrate W. The second direction extends along the radial direction of the substrate W but in a direction different from the first direction. The diffusion speed of the processing liquid when passing through the plurality of irradiation points aligned in the first direction and the plurality of irradiation points aligned in the second direction are calculated, and the difference between these diffusion speeds is calculated. If the difference is greater than a predetermined threshold, it can be determined that the processing liquid is spreading unevenly.

[0077] (6) The controller Ctr may arrange the calculated diffusion rates in chronological order and store them in the memory unit M2 as a log. The controller Ctr may predict when the diffusion rate is expected to fall outside the allowable range R in the future, based on the log information accumulated over time. For example, if multiple diffusion rates constituting the log gradually increase over time, the controller Ctr may calculate an approximation line for them to predict when the future diffusion rate will exceed the allowable range R.

[0078] (7) However, in the case of a hydrophobic substrate W, depending on the processing conditions, the surface of the substrate W may not be covered with the processing liquid. This point will be explained with reference to FIGS. 16 to 18, which show the results of processing a hydrophobic substrate W and a hydrophilic substrate W under various processing conditions.

[0079] 16(a) to 16(c) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 2000 ml / min and the rotation speed of the substrate W is set to 1000 rpm on a hydrophobic substrate W and a hydrophilic substrate W. 16(d) to 16(f) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 1500 ml / min and the rotation speed of the substrate W is set to 1000 rpm on a hydrophobic substrate W and a hydrophilic substrate W. 16(g) to 16(i) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 1000 ml / min and the rotation speed of the substrate W is set to 1000 rpm on a hydrophobic substrate W and a hydrophilic substrate W.

[0080] 17(a) to 17(c) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 2000 ml / min and the rotation speed of the substrate W is set to 500 rpm on a hydrophobic substrate W and a hydrophilic substrate W. 17(d) to 17(f) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 1500 ml / min and the rotation speed of the substrate W is set to 500 rpm on a hydrophobic substrate W and a hydrophilic substrate W. 17(g) to 17(i) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 1000 ml / min and the rotation speed of the substrate W is set to 500 rpm on a hydrophobic substrate W and a hydrophilic substrate W.

[0081] 18(a) to 18(c) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 2000 ml / min and the rotation speed of the substrate W is set to 200 rpm on a hydrophobic substrate W and a hydrophilic substrate W. 18(d) to 18(f) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 1500 ml / min and the rotation speed of the substrate W is set to 200 rpm on a hydrophobic substrate W and a hydrophilic substrate W. 18(g) to 18(i) are graphs showing changes in reflection intensity at the respective positions of irradiation locations P1 to P3 when the discharge flow rate of the rinsing liquid L2 is set to 1000 ml / min and the rotation speed of the substrate W is set to 200 rpm on a hydrophobic substrate W and a hydrophilic substrate W.

[0082] Under the processing conditions in FIG. 16, the reflection intensity changes to a similar extent for both the hydrophobic substrate W and the hydrophilic substrate W. On the other hand, under the processing conditions in FIGS. 17 and 18, the rotation speed of the substrate W is slower than that under the processing conditions in FIG. 16, and therefore an extremely low reflection intensity was detected on the peripheral edge of the hydrophobic substrate W (see FIGS. 17(h) and (i) and FIGS. 18(c), (e), (f), (h), and (i)). That is, by acquiring the change in reflection intensity using the optical sensor 50, it is possible to determine whether the surface of the substrate W is covered with the processing liquid. In other words, the controller Ctr may be configured to determine the coverage state of the surface of the substrate W with the processing liquid based on the reflection intensity received from the optical sensor 50. In this case, it is possible to automatically determine whether the surface of the substrate W is covered with the processing liquid without relying on visual inspection by an operator.

[0083] 16, when the flow rate of the processing liquid or the rotation speed of the substrate W is high, the surface of the substrate W tends to be adequately covered with the processing liquid. However, the processing conditions for the substrate W are generally determined in advance depending on the type of substrate W, and it may not be possible to set a high flow rate of the processing liquid or a high rotation speed of the substrate W for all substrates W. In particular, when the flow rate of the processing liquid or the rotation speed of the substrate W is high, there is a concern that the processing liquid may be splashed to the surroundings or the air flow near the surface of the substrate W may be disturbed, resulting in the generation of particles on the surface of the substrate W. Therefore, by automatically detecting the coverage state of the processing liquid on the surface of the substrate W after the fact, it is possible to process the substrate W under the processing conditions set in advance as much as possible.

[0084] [Other examples] Example 1. An example of a substrate processing apparatus includes a rotary holder configured to hold and rotate a substrate, a supply unit configured to supply a processing liquid to the surface of the substrate, a first optical sensor configured to irradiate light toward a first irradiation point set to overlap with the surface of the substrate held by the rotary holder and receive the reflected light, a second optical sensor configured to irradiate light toward a second irradiation point set to overlap with the surface of the substrate held by the rotary holder and located radially outward of the substrate than the first irradiation point and receive the reflected light, and a control unit. The control unit is configured to execute a first process of controlling the rotation holder to rotate the substrate, a second process of controlling the supply unit to supply the processing liquid to the surface of the rotating substrate, a third process of detecting the arrival of the processing liquid at the first irradiation location based on a change in the intensity of reflected light acquired by the first optical sensor at the first irradiation location, a fourth process of detecting the arrival of the processing liquid at the second irradiation location based on a change in the intensity of reflected light acquired by the second optical sensor at the second irradiation location, a fifth process of calculating the diffusion rate of the processing liquid on the surface of the substrate based on the time difference between the arrival of the processing liquid at the first irradiation location and the arrival of the processing liquid at the second irradiation location, and a sixth process of determining whether the substrate is being processed based on the diffusion rate calculated in the fifth process. In this case, it is possible to determine how quickly the processing liquid is spreading over the surface of the substrate. The diffusion rate may vary depending on the surface condition of the substrate and the state of the substrate processing apparatus. If the diffusion rate is extremely slow, it may be determined that the entire surface of the substrate is not covered with the processing liquid, for example. On the other hand, if the diffusion rate is extremely fast, it can be determined that there is a possibility of a malfunction in the substrate processing apparatus or a malfunction in the surface condition of the substrate. Therefore, by determining whether the substrate is being processed based on the diffusion rate, it is possible to detect the state of coating of the substrate surface with the processing liquid and evaluate the quality of the substrate surface condition and the state of the substrate processing apparatus. Furthermore, compared to using a camera to obtain the surface condition of the substrate, using an optical sensor prevents the apparatus from becoming large, reduces the amount of data to be handled, and simplifies the calculation process.Therefore, it is possible to detect the state of coating of the substrate surface with the processing liquid and to evaluate the quality of the substrate surface state and the state of the substrate processing apparatus at low cost.

[0085] Example 2. The apparatus of Example 1 further includes a memory unit configured to store correspondence information associating data regarding the type of substrate with an allowable range of the diffusion rate of the processing liquid on the surface of the substrate when the processing liquid is supplied to the surface of the substrate while the substrate is rotating, and an acquisition unit configured to acquire the type of substrate. The control unit is further configured to perform a seventh process of acquiring the allowable range for the substrate based on the type of substrate acquired by the acquisition unit and the correspondence information stored in the memory unit. The sixth process may include determining whether the diffusion rate calculated in the fifth process is within the allowable range acquired in the seventh process. In this case, the allowable range of the diffusion rate of the processing liquid is appropriately set for each type of substrate. This makes it possible to more accurately detect the coating state of the processing liquid on the surface of the substrate and evaluate the quality of the surface condition of the substrate and the state of the substrate processing apparatus.

[0086] Example 3: In the apparatus of Example 2, the allowable range may include an adjustment-free range and an adjustment range, the upper limit of the adjustment range being greater than the upper limit of the adjustment-free range and the lower limit of the adjustment range being smaller than the lower limit of the adjustment-free range. The control unit may further be configured to execute an eighth process in which, when it is determined in the sixth process that the diffusion rate calculated in the fifth process is within the adjustment range, the control unit controls at least one of the spin holder and the supply unit to change at least one of the rotation speed of the subsequent substrate and the flow rate of the processing liquid dispensed onto the subsequent substrate. In this case, even if the processing result of the substrate is determined to be good, if the diffusion rate is within the adjustment range, the rotation speed of the substrate or the flow rate of the processing liquid is changed. In other words, the processing conditions for the substrate are adjusted to improve the processing result of the subsequent substrate. This enables more appropriate processing of the substrate.

[0087] Example 4: The apparatus of any one of Examples 1 to 3 may further include an imaging unit configured to capture an image of the supply of the processing liquid to the surface of the substrate, and the control unit may be configured to further execute a ninth process in which, if it is determined in the sixth process that the coating state of the surface of the substrate is inappropriate, image data captured by the imaging unit during the processing of the substrate or the processing conditions of the substrate are stored in the storage unit together with the determination result that the substrate is inappropriate. In this case, it becomes possible for an operator to easily check the status of the substrate processing when the determination result that the substrate is inappropriate is made.

[0088] Example 5: In any of the apparatuses of Examples 1 to 4, the first optical sensor and the second optical sensor may both be laser sensors, and the second to fourth processes may be performed in a light-shielded space. In this case, since a laser sensor is used, the diffusion rate can be calculated even when a substrate is processed using a processing liquid whose properties can be changed by light. Therefore, compared to the case where a camera is used, it is possible to detect the coating state of the substrate surface with the processing liquid for a wider variety of processing liquids, and evaluate the quality of the substrate surface state and the state of the substrate processing apparatus.

[0089] Example 6. An example of a substrate processing method includes a first step in which a supply unit supplies a processing liquid to a surface of the substrate while a rotation holder holds and rotates the substrate; a second step in which a first optical sensor irradiates a first irradiation point on the rotating substrate with light and detects the arrival of the processing liquid at the first irradiation point based on a change in the intensity of the reflected light acquired by the first optical sensor; a third step in which a second optical sensor irradiates a second irradiation point on the rotating substrate with light and detects the arrival of the processing liquid at the second irradiation point based on a change in the intensity of the reflected light acquired by the second optical sensor, where the second irradiation point is located radially outward of the first irradiation point; a fourth step in which a diffusion rate of the processing liquid on the surface of the substrate is calculated based on the time difference between the arrival of the processing liquid at the first irradiation point and the arrival of the processing liquid at the second irradiation point; and a fifth step in which the appropriateness of substrate processing is determined based on the diffusion rate calculated in the fourth step. In this case, the same effects as those of the apparatus of Example 1 can be obtained.

[0090] Example 7. The method of Example 6 may further include a sixth step of acquiring the type of substrate, and a seventh step of acquiring an allowable range for the substrate based on the type of substrate acquired in the sixth step and correspondence information, where the correspondence information is information that associates data on the type of substrate with an allowable range of the diffusion rate of the processing liquid on the surface of the substrate when the processing liquid is supplied to the surface of the substrate having that type while rotating, and the fifth step may include determining whether the diffusion rate calculated in the fourth step is within the allowable range acquired in the seventh step. In this case, the same effects as those of the device of Example 2 can be obtained.

[0091] Example 8: In the method of Example 7, the allowable range includes an adjustment-free range and an adjustment range, the upper limit of the adjustment range is set to be greater than the upper limit of the adjustment-free range and the lower limit of the adjustment range is set to be smaller than the lower limit of the adjustment-free range, and the method may further include an eighth step of changing at least one of the rotation speed of the subsequent substrate and the flow rate of the processing liquid discharged onto the subsequent substrate when it is determined in the fifth step that the diffusion rate calculated in the fourth step is within the adjustment range. In this case, the same effects as those of the apparatus of Example 3 can be obtained.

[0092] Example 9: Any of the methods of Examples 6 to 8 may further include a ninth step of storing, in a storage unit, image data of the substrate during processing taken by the imaging unit or processing conditions of the substrate, together with the determination result that the coating state of the surface of the substrate is inappropriate, if the coating state of the surface of the substrate is determined to be inappropriate in the fifth step. In this case, the same effects as those of the device of Example 4 can be obtained.

[0093] Example 10: In any of the methods of Examples 6 to 9, the first optical sensor and the second optical sensor may both be laser sensors, and the first to third steps may be performed in a light-shielded space. In this case, the same effects as those of the device of Example 5 can be obtained. [Explanation of symbols]

[0094] 1...substrate processing system (substrate processing apparatus), 4...placement section (acquisition section), 7...carrier, 7a...memory section, 10...rotating holding section, 20, 30...supply section, 40...imaging section, 50...optical sensor, Ctr...controller (control section), M2...memory section, P1 to P3...irradiation area, R...tolerable range, Ra...range not requiring adjustment, Rb...adjustable range, U...liquid processing unit (substrate processing apparatus), W...substrate, Wa...upper surface (surface), Wb...lower surface (surface).

Claims

1. a rotation holder configured to hold and rotate the substrate; a supply unit configured to supply a treatment liquid to a surface of the substrate; a first optical sensor configured to irradiate light toward a first irradiation point set to overlap with the surface of the substrate held by the rotary holder and to receive the reflected light; a second optical sensor configured to irradiate light toward a second irradiation location that is set to overlap with the surface of the substrate held by the rotary holder and be located radially outward of the substrate relative to the first irradiation location, and to receive reflected light; a control unit; The control unit a first process of controlling the rotation holder to rotate the substrate; a second process of controlling the supply unit to supply a processing liquid to the surface of the substrate while the processing liquid is being rotated; a third process of detecting arrival of the treatment liquid at the first irradiation location based on a change in the intensity of the reflected light acquired by the first optical sensor at the first irradiation location; a fourth process of detecting arrival of the treatment liquid at the second irradiation location based on a change in the intensity of the reflected light acquired by the second optical sensor at the second irradiation location; a fifth process of calculating a diffusion rate of the processing liquid on the surface of the substrate based on a time difference between the arrival of the processing liquid at the first irradiation location and the arrival of the processing liquid at the second irradiation location; and a sixth process of determining whether the substrate processing is appropriate based on the diffusion rate calculated in the fifth process.

2. a storage unit configured to store correspondence information in which data relating to the type of substrate is associated with an allowable range of a diffusion rate of the processing liquid on the surface of the substrate when the processing liquid is supplied to the surface of the substrate having the type while rotating; an acquisition unit configured to acquire the type of the substrate; The control unit a seventh process is further performed to acquire an allowable range for the substrate based on the type of the substrate acquired by the acquisition unit and the correspondence information stored in the storage unit, The apparatus according to claim 1 , wherein the sixth step includes determining whether the diffusion rate calculated in the fifth step is within the tolerance range obtained in the seventh step.

3. The allowable range includes an adjustment-free range and an adjustment range, an upper limit of the adjustment range is set to be greater than an upper limit of the adjustment-free range, and a lower limit of the adjustment range is set to be smaller than the adjustment-free range, 3. The apparatus of claim 2, wherein the control unit is configured to further perform an eighth process in which, when it is determined in the sixth process that the diffusion rate calculated in the fifth process is within the adjustment range, the control unit controls at least one of the rotation holding unit and the supply unit to change at least one of the rotation speed of the subsequent substrate and the flow rate of the processing liquid ejected onto the subsequent substrate.

4. an imaging unit configured to capture an image of a state in which a processing liquid is supplied to the surface of the substrate; The apparatus according to any one of claims 1 to 3, wherein the control unit is configured to further execute a ninth process in which, if it is determined in the sixth process that the coating state of the surface of the substrate is inappropriate, image data of the substrate during processing taken by the imaging unit or processing conditions of the substrate is stored in a memory unit together with the determination result that the coating state is inappropriate.

5. the first optical sensor and the second optical sensor are both laser sensors; The apparatus according to claim 1 , wherein the second process to the fourth process are performed in a light-shielded space.

6. a first step in which a supply unit supplies a processing liquid to a surface of the substrate while a rotation holder holds and rotates the substrate; a second step of irradiating a first irradiation point on the rotating substrate with light by a first optical sensor, and detecting arrival of the processing liquid at the first irradiation point based on a change in intensity of the reflected light acquired by the first optical sensor; a third step of irradiating light toward a second irradiation point on the substrate during rotation by a second optical sensor, and detecting arrival of a processing liquid at the second irradiation point based on a change in intensity of reflected light acquired by the second optical sensor, wherein the second irradiation point is located radially outward of the substrate relative to the first irradiation point; a fourth step of calculating a diffusion rate of the processing liquid on the surface of the substrate based on a time difference between the arrival of the processing liquid at the first irradiation location and the arrival of the processing liquid at the second irradiation location; a fifth step of determining whether the substrate is suitable for processing based on the diffusion rate calculated in the fourth step.

7. a sixth step of acquiring the type of the substrate; a seventh step of acquiring an allowable range for the substrate based on the type of the substrate acquired in the sixth step and the correspondence information, the correspondence information is information in which data on the type of the substrate is associated with an allowable range of a diffusion rate of the processing liquid on the surface of the substrate when the processing liquid is supplied to the surface of the substrate having the type while rotating, The method of claim 6 , wherein the fifth step includes determining whether the diffusion rate calculated in the fourth step is within the acceptable range obtained in the seventh step.

8. The allowable range includes an adjustment-free range and an adjustment range, an upper limit of the adjustment range is set to be greater than an upper limit of the adjustment-free range, and a lower limit of the adjustment range is set to be smaller than the adjustment-free range, The method according to claim 7, further comprising an eighth step of changing at least one of the rotation speed of the subsequent substrate and the flow rate of the processing liquid ejected onto the subsequent substrate when it is determined in the fifth step that the diffusion rate calculated in the fourth step is within the adjustment range.

9. 9. The method according to claim 6, further comprising: a ninth step of, when it is determined in the fifth step that the coating state of the surface of the substrate is inappropriate, storing in a storage unit image data of the substrate during processing taken by an imaging unit or processing conditions of the substrate together with the determination result that the coating state is inappropriate.

10. the first optical sensor and the second optical sensor are both laser sensors; 7. The method according to claim 6, wherein the first to third steps are performed in a light-shielded space.

Images