Substrate Processing Equipment

Abstract

To improve the yield of substrates.SOLUTION: A substrate processing apparatus according to an embodiment includes a liquid amount detection unit that detects the amount of liquid in a liquid film formed on a substrate, a coating detection unit that detects the coating state of the substrate with the liquid film, a drying unit that performs a drying process on the substrate on which the liquid film has been formed, and a load cell that measures the weight of the substrate. The drying unit includes a main body with an opening formed on the side for loading and unloading the substrate, and a lifter that is provided outside the main body, and receives the substrate on which the liquid film has been formed from a substrate transport device, and also transfers the substrate after drying process to the substrate transport device. A load cell is provided on the lifter.SELECTED DRAWING: Figure 10A

Description

[Technical field]

[0001] The disclosed embodiments relate to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a substrate processing apparatus that performs a drying process by forming a liquid film on the surface of a substrate to prevent drying, and then contacting the substrate on which the liquid film has been formed with a supercritical fluid (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-12538 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned substrate processing apparatus, the drying process may be performed in a state in which a liquid film is not properly formed on the substrate, which may result in a decrease in the yield of substrates after the drying process.

[0005] An object of one aspect of the embodiment is to provide a substrate processing apparatus and a substrate processing method that improve the yield of substrates. [Means for solving the problem]

[0006] A substrate processing apparatus according to one aspect of the embodiment includes a liquid amount detection unit that detects the amount of liquid in a liquid film formed on a substrate, a coating detection unit that detects a coating state of the substrate with the liquid film, a drying unit that performs a drying process on the substrate on which the liquid film has been formed, and a load cell that measures the weight of the substrate. The drying unit has a main body having an opening formed on a side surface for loading and unloading the substrate, and a lifter that is provided outside the main body and receives the substrate on which the liquid film has been formed from the substrate transport device and transfers the substrate after drying to the substrate transport device. The load cell is provided on the lifter. Effect of the Invention

[0007] According to one aspect of the embodiment, the yield of substrates can be improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a substrate processing system according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic configuration of the transfer section. [Diagram 3] FIG. 3 is a cross-sectional view showing a schematic configuration of the cleaning processing unit. [Figure 4] FIG. 4 is an external perspective view showing the configuration of the dry processing unit. [Figure 5A] FIG. 5A is a schematic cross-sectional view showing a part of the dry processing unit at the transfer position. [Figure 5B] FIG. 5B is a schematic cross-sectional view showing a part of the dry processing unit at the standby position. [Figure 6] FIG. 6 is a schematic block diagram of the control device according to the first embodiment. [Figure 7A] FIG. 7A is a schematic diagram showing a state in which no defective portion occurs in the liquid film of the IPA liquid. [Figure 7B] FIG. 7B is a schematic diagram showing a state in which a defective portion occurs in the liquid film of the IPA liquid. [Figure 8] FIG. 8 is a flowchart illustrating the substrate processing in the first embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a schematic configuration of a substrate processing system according to the second embodiment. [Figure 10A] FIG. 10A is a schematic cross-sectional view showing a part of the dry processing unit according to the second embodiment. [Figure 10B] FIG. 10B is a schematic cross-sectional view of the dry processing unit showing a state in which a wafer is placed on a holding plate. [Figure 11] FIG. 11 is a schematic block diagram of a control device according to the second embodiment. [Figure 12] FIG. 12 is a flowchart illustrating the substrate processing according to the second embodiment. [Figure 13] FIG. 13 is a schematic plan view of the dry processing unit according to the third embodiment. [Figure 14] 14 is a schematic cross-sectional view showing a part of the dry processing unit taken along the line XIV-XIV in FIG. [Figure 15] FIG. 15 is a schematic diagram showing the state of reflection of laser light on a wafer on which a liquid film of IPA liquid has been formed. [Figure 16A] FIG. 16A is a schematic diagram showing reflected light in a state where no defective portion occurs in the liquid film of the IPA liquid. [Figure 16B] FIG. 16B is a schematic diagram showing reflected light in a state where a defective portion occurs in the liquid film of the IPA liquid. [Figure 17] FIG. 17 is a schematic block diagram of a control device according to the third embodiment. [Figure 18] FIG. 18 is a schematic plan view of the dry processing unit according to the fourth embodiment. [Figure 19] FIG. 19 is a schematic cross-sectional view showing a part of the dry processing unit taken along the line XIX-XIX in FIG. [Figure 20] FIG. 20 is a diagram for explaining the principle of occurrence of interference fringes. [Figure 21A] FIG. 21A is a schematic diagram of a wafer in a state where no defective portion occurs in the liquid film of the IPA liquid, as viewed obliquely from above. [Figure 21B] FIG. 21B is a schematic diagram of a wafer in a state where no defective portion occurs in the liquid film of the IPA liquid, as viewed obliquely from above. [Figure 22] FIG. 22 is a schematic plan view of a dry processing unit of a substrate processing system according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, with reference to the attached drawings, an embodiment of the substrate processing apparatus and the substrate processing method disclosed in the present application will be described in detail. Note that the present invention is not limited to the following embodiment. In each of the drawings referred to below, in order to make the description easier to understand, an orthogonal coordinate system is shown in which the X-axis direction, the Y-axis direction, and the Z-axis direction are defined as being orthogonal to each other, and the positive direction of the Z-axis is the vertically upward direction.

[0010] (First embodiment) <Outline of Substrate Processing System 1> A substrate processing system 1 according to a first embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing a general configuration of the substrate processing system 1 according to the first embodiment.

[0011] The substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other. The substrate processing system 1 corresponds to a substrate processing apparatus.

[0012] The carry-in / out station 2 includes a carrier placement section 11 and a transport section 12. On the carrier placement section 11, a plurality of carriers C are placed, each of which accommodates a plurality of semiconductor wafers W (hereinafter referred to as wafers W) in a horizontal state.

[0013] The transfer section 12 is provided adjacent to the carrier placement section 11, and includes a substrate transfer device 13 and a transfer section 14 therein. The substrate transfer device 13 includes a wafer holding mechanism for holding a wafer W. The substrate transfer device 13 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the carrier C and the transfer section 14 using the wafer holding mechanism. An example of the configuration of the transfer section 14 will be described later.

[0014] The processing station 3 is provided adjacent to the transport section 12. The processing station 3 includes a transport section 15, a plurality of cleaning processing units 16, and a plurality of drying processing units 17. The plurality of cleaning processing units 16 and the plurality of drying processing units 17 are provided side by side on both sides of the transport section 15. Note that the arrangement and the number of the cleaning processing units 16 and the drying processing units 17 shown in FIG. 1 are merely an example, and are not limited to those shown in the figure.

[0015] The transfer section 15 includes therein a substrate transfer device 18. The substrate transfer device 18 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 18 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the delivery section 14, the cleaning processing unit 16, and the drying processing unit 17 using the wafer holding mechanism.

[0016] The cleaning processing unit 16 performs a predetermined cleaning process on the wafer W transferred by the substrate transfer device 18. An example of the configuration of the cleaning processing unit 16 will be described later.

[0017] The drying processing unit 17 performs a predetermined drying process on the wafer W cleaned by the cleaning processing unit 16. An example of the configuration of the drying processing unit 17 will be described later.

[0018] The substrate processing system 1 also includes a control device 4. An example of the configuration of the control device 4 will be described later.

[0019] In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 in the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement part 11, and places the taken-out wafer W on the transfer part 14. The wafer W placed on the transfer part 14 is taken out of the transfer part 14 by the substrate transfer device 18 in the processing station 3, and is carried into the cleaning processing unit 16.

[0020] The wafer W carried into the cleaning processing unit 16 is subjected to cleaning processing by the cleaning processing unit 16, and then carried out from the cleaning processing unit 16 by the substrate transfer device 18. The wafer W carried out from the cleaning processing unit 16 is carried into the drying processing unit 17 by the substrate transfer device 18, and is subjected to drying processing by the drying processing unit 17.

[0021] The wafer W that has been dried by the drying processing unit 17 is carried out from the drying processing unit 17 by the substrate transfer device 18, and placed on the delivery section 14. Then, the processed wafer W placed on the delivery section 14 is returned to the carrier C of the carrier placement section 11 by the substrate transfer device 13.

[0022] <Overview of Delivery Section 14> Next, the delivery section 14 will be described with reference to Fig. 2. Fig. 2 is a cross-sectional view showing a schematic configuration of the delivery section 14.

[0023] The transfer section 14 includes a case 40, a pedestal 41, a plurality of lifting members 42, and a load cell 43. The case 40 is formed with openings 40A and 40B through which the substrate transfer devices 13 and 18 load and unload the wafer W. The pedestal 41 is disposed within the case 40. The pedestal 41 is formed with an insertion hole into which the lifting members 42 are inserted.

[0024] The lifting member 42 is supported by the pedestal 41 so as to be liftable and lowerable by a lifting drive unit (not shown). When the wafer W carried in by the substrate transfer device 13 and the substrate transfer device 18 is placed on the tip of the lifting member 42, the lifting member 42 supports the underside of the wafer W. When the lifting member 42 is lowered by the lifting drive unit from a predetermined transfer position while supporting the wafer W, the wafer W is placed on the load cell 43. When the lifting member 42 is raised by the lifting drive unit while the wafer W is placed on the load cell 43, the lifting member 42 abuts against the underside of the wafer W to support the wafer W and raises the wafer W to the transfer position.

[0025] The load cell 43 measures the weight of the wafer W carried in from the carrier C or the wafer W dried by the drying unit 17, and outputs a signal relating to the weight of the wafer W to the control device 4.

[0026] <Overview of cleaning processing unit 16> Next, the cleaning processing unit 16 will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing a schematic configuration of the cleaning processing unit 16. The cleaning processing unit 16 is configured as a single-wafer type cleaning processing unit 16 that cleans wafers W one by one by spin cleaning, for example.

[0027] The cleaning processing unit 16 includes a wafer holding mechanism 25 , a nozzle arm 26 , and an infrared sensor 27 .

[0028] Wafer holding mechanism 25 includes a lifter 28 and a wafer holding part 29. Wafer holding mechanism 25 is disposed in outer chamber 23 that forms a processing space, and holds wafer W approximately horizontally by wafer holding part 29 and rotates wafer W by rotating it about a vertical axis.

[0029] The lifter 28 includes a plurality of lifter pins 28a, a support portion 28b that is connected to the lower ends of the lifter pins 28a and supports the lifter pins 28a, and a load cell 28c that is provided on the lower surface of the support portion 28b.

[0030] The lifter pins 28a are extended and retracted in the vertical direction by an extension / retraction drive unit (not shown). The lifter pins 28a transfer the wafer W between the substrate transport device 18 at an upper transfer position. The lifter pins 28a also transfer the wafer W between the wafer holding unit 29 at a lower transfer position. The lifter pins 28a abut against the underside of the wafer W to support the wafer W. When the lifter pins 28a further contract from the state in which the wafer W is held by the wafer holding unit 29, they move away from the underside of the wafer W.

[0031] The load cell 28c measures the weight of the wafer W in a state in which the wafer W is supported by the lifter pins 28a. The load cell 28c measures the weight of the wafer W before and after the cleaning process is performed on the wafer W. The load cell 28c outputs a signal related to the weight of the wafer W to the controller 4.

[0032] The lifter pin 28a may be a rod-like member that does not expand or contract. In this case, in the lifter 28, the lifter pin 28a, the support portion 28b, and the load cell 28c move vertically as a unit.

[0033] Wafer holding part 29 holds wafer W substantially horizontally. Wafer holding mechanism 25 rotates wafer W by rotating around a vertical axis while wafer holding part 29 holds wafer W.

[0034] The infrared sensor 27 measures the temperature of the wafer W after the cleaning process, and outputs a signal related to the temperature of the wafer W to the controller 4. The infrared sensor 27 measures the temperature of the wafer W in a state in which the wafer W is held by the wafer holder 29. Note that the infrared sensor 27 may measure the temperature of the wafer W in a state in which the wafer W is supported by the lifter pins 28a.

[0035] Also, there may be provided a plurality of infrared sensors 27. For example, even if one infrared sensor 27 cannot detect the temperature of the entire region of the wafer W, by providing a plurality of infrared sensors 27, the temperature of the entire region of the wafer W can be detected.

[0036] Nozzle arm 26 advances above the rotating wafer W and supplies a chemical liquid, a rinse liquid, an acidic chemical liquid, and IPA in a predetermined order from chemical liquid nozzle 26a provided at the tip of nozzle arm 26, thereby cleaning the surface of wafer W. A plurality of nozzle arms 26 may be provided. When measuring the temperature of wafer W with infrared sensor 27, nozzle arm 26 retracts so as not to interfere with the measurement by infrared sensor 27.

[0037] In the cleaning processing unit 16, a chemical liquid supply path 25a is also formed inside the wafer holding mechanism 25. The back surface of the wafer W is cleaned by the chemical liquid, rinsing liquid, and the like supplied from the chemical liquid supply path 25a.

[0038] The above-mentioned cleaning process of the wafer W includes, for example, first removing particles and organic contaminants with an alkaline chemical SC1 liquid (a mixture of ammonia and hydrogen peroxide), then rinsing with a rinse liquid deionized water (hereinafter referred to as DIW), then removing native oxide films with an acidic chemical solution dilution hydrofluoric acid (hereinafter referred to as DHF), and then rinsing with DIW.

[0039] The various chemical solutions described above are received in the outer chamber 23 or the inner cup 24 disposed within the outer chamber 23, and are discharged from a drainage outlet 23a provided in the bottom of the outer chamber 23 or a drainage outlet 24a provided in the bottom of the inner cup 24. Furthermore, the atmosphere within the outer chamber 23 is exhausted from an exhaust outlet 23b provided in the bottom of the outer chamber 23.

[0040] After the above-mentioned rinsing process of the wafer W, IPA in a liquid state (hereinafter referred to as "IPA liquid") is supplied to the front and back surfaces of the wafer W while rotating the wafer holding mechanism 25, replacing the DIW remaining on both sides of the wafer W. Then, the rotation of the wafer holding mechanism 25 is gradually stopped. As a result, a mound of IPA liquid is formed on the front surface of the wafer W, and a liquid film L (see FIGS. 7A and 7B) of the IPA liquid is formed. The liquid film L is formed so as to cover the entire pattern of the wafer W.

[0041] The wafer W which has been subjected to the cleaning process in this manner is transferred to the substrate transfer device 18 via the lifter 28 with the liquid film L of the IPA liquid still formed on its surface, and is then carried out from the cleaning process unit 16 .

[0042] The IPA liquid piled on the surface of the wafer W functions as an anti-drying liquid that prevents pattern collapse caused by evaporation (vaporization) of the liquid on the surface of the wafer W during transportation of the wafer W from the cleaning processing unit 16 to the drying processing unit 17 or during loading into the drying processing unit 17.

[0043] After the cleaning process in the cleaning process unit 16, the wafer W having the liquid film L of the IPA liquid formed on its surface is transferred to the drying process unit 17. Then, in the drying process unit 17, a process fluid of CO2 in a supercritical state (hereinafter also referred to as a "supercritical fluid") is brought into contact with the IPA liquid on the surface of the wafer W, whereby the IPA liquid is dissolved in the supercritical fluid and removed, and the wafer W is dried.

[0044] <Outline of Drying Processing Unit 17> Next, the configuration of the dry processing unit 17 will be described with reference to Fig. 4. Fig. 4 is an external perspective view showing the configuration of the dry processing unit 17.

[0045] The dry processing unit 17 includes a main body 31, a holding plate 32, a lid member 33, and a lifter 39. An opening 34 for loading and unloading the wafer W is formed in the housing-like main body 31. The holding plate 32 holds the wafer W to be processed in a horizontal direction. The lid member 33 supports the holding plate 32 and seals the opening 34 when the wafer W is loaded into the main body 31.

[0046] The main body 31 is a container having a processing space formed therein capable of accommodating a wafer W, and its wall is provided with supply ports 35A, 35B and a discharge port 36. The supply port 35A is connected to a supply line 35C that supplies a supercritical fluid into the processing space. The supply port 35B is connected to a supply line 35D that supplies a supercritical fluid into the processing space. The discharge port 36 is connected to a discharge line 36A that discharges the supercritical fluid from the processing space.

[0047] Supply port 35A is connected to the side surface of housing-like main body 31 opposite opening 34. Supply port 35B is connected to the bottom surface of main body 31. Discharge port 36 is connected to the lower side of opening 34. Note that, although two supply ports 35A, 35B and one discharge port 36 are illustrated in FIG. 4, the numbers of supply ports 35A, 35B and discharge ports 36 are not particularly limited.

[0048] Furthermore, fluid supply headers 37A, 37B and a fluid discharge header 38 are provided inside the main body 31. Each of the fluid supply headers 37A, 37B and the fluid discharge header 38 has a large number of openings formed therein.

[0049] Fluid supply header 37A is connected to supply port 35A, and is provided adjacent to the side surface opposite opening 34 inside housing-like main body 31. Furthermore, a large number of openings formed in fluid supply header 37A face the opening 34 side.

[0050] The fluid supply header 37B is connected to the supply port 35B, and is provided at the center of the bottom surface inside the housing-like main body 31. Furthermore, a large number of openings formed in the fluid supply header 37B face upward.

[0051] The fluid discharge header 38 is connected to the discharge port 36 and is provided inside the housing-like main body 31 adjacent to the side surface on the opening 34 side and below the opening 34. In addition, a large number of openings formed in the fluid discharge header 38 face the fluid supply header 37A side.

[0052] The fluid supply headers 37A and 37B supply the supercritical fluid into the main body 31. The fluid discharge header 38 guides the supercritical fluid in the main body 31 to the outside of the main body 31 and discharges it. The supercritical fluid discharged to the outside of the main body 31 via the fluid discharge header 38 contains the IPA liquid dissolved in the supercritical fluid from the surface of the wafer W.

[0053] The lifter 39 includes a plurality of lifter pins 39a and a support portion 39b that supports the transfer member and is connected to the lower ends of the lifter pins 39a. The lifter 39 is raised and lowered by a lifting drive portion (not shown).

[0054] The lifter 39 moves up and down between a transfer position where the wafer W is transferred to and from the substrate transfer device 18, and a standby position. The standby position is a lower position where the cover member 33 can be opened and closed.

[0055] The lifter 39 receives the wafer W from the substrate transfer device 18 at the transfer position shown in Fig. 5A. The lifter 39 supports the lower surface of the wafer W with lifter pins 39a. With the wafer W supported by the lifter pins 39a, the lifter 39 moves down to the standby position shown in Fig. 5B to place the wafer W on the holding plate 32. Fig. 5A is a schematic cross-sectional view showing a portion of the dry processing unit 17 at the transfer position. Fig. 5B is a schematic cross-sectional view showing a portion of the dry processing unit 17 at the standby position.

[0056] 5B, the lifter 39 supports the lower surface of the wafer W with the lifter pins 39a and receives the wafer W from the holding plate 32. With the lower surface of the wafer W supported by the lifter pins 39a, the lifter 39 rises to the delivery position shown in FIG. 5A and delivers the wafer W to the substrate transfer device 18. The lifter pins 39a are provided so as to be insertable into the insertion holes 32a of the holding plate 32.

[0057] The drying processing unit 17 further includes a pressing mechanism (not shown). The pressing mechanism has a function of pressing the cover member 33 toward the main body 31 against the internal pressure caused by the supercritical fluid in a supercritical state supplied into the processing space inside the main body 31, thereby sealing the processing space. In order to keep the supercritical fluid supplied into the processing space at a predetermined temperature, a heat insulating material, a tape heater, or the like may be provided on the surface of the main body 31.

[0058] After the drying process in the drying process unit 17, the wafer W is transferred to the transfer section 14 by the substrate transfer device 18.

[0059] <Configuration of control device 4> Next, the configuration of the control device 4 will be described with reference to Fig. 6. Fig. 6 is a schematic block diagram of the control device 4 according to the first embodiment.

[0060] The control device 4 is, for example, a computer, and includes a control unit 19 and a storage unit 20.

[0061] The control unit 19 includes a microcomputer and various circuits having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), input / output ports, etc. The CPU of the microcomputer reads and executes programs stored in the ROM to realize control of the transport unit 12 (see FIG. 1), the transport unit 15 (see FIG. 1), the cleaning processing unit 16, the drying processing unit 17, etc.

[0062] Such a program may be recorded on a computer-readable recording medium and installed from the recording medium into the storage unit 20 of the control device 4. Examples of computer-readable recording media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0063] The storage unit 20 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk. The storage unit 20 stores the weight of the wafer W measured by the load cells 28c and 43.

[0064] The control unit 19 includes a liquid amount detection unit 19A, a coating state detection unit 19B, a determination unit 19C, a signal generation unit 19D, and an output unit 19E. Signals related to the weight of the wafer W are input from the load cells 28c and 43 to the control unit 19. A signal related to the temperature of the wafer W is input from the infrared sensor 27 to the control unit 19. The control unit 19 also outputs signals for controlling the cleaning processing unit 16, the drying processing unit 17, etc.

[0065] The liquid amount detection unit 19A detects the amount of the liquid film L of the IPA liquid formed on the wafer W by the cleaning process (hereinafter referred to as the "liquid amount of the liquid film L"). Specifically, the liquid amount detection unit 19A calculates the difference between the weight of the wafer W after the cleaning process measured by the load cell 28c and the weight of the wafer W before the cleaning process measured by the load cell 28c, and detects the amount of the liquid film L formed on the wafer W based on the calculated difference.

[0066] Furthermore, the liquid amount detection unit 19A detects the dryness state of the wafer W after the drying process. Specifically, the liquid amount detection unit 19A calculates the difference between the weight of the wafer W after the drying process measured by the load cell 43 and the weight of the wafer W before the cleaning process measured by the load cell 28c, and detects the dryness state of the wafer W based on the calculated difference.

[0067] The coating state detection unit 19B detects the coating state of the wafer W on which the liquid film L of the IPA liquid is formed. Specifically, the coating state detection unit 19B detects a temperature distribution from the temperature of the wafer W measured by the infrared sensor 27. Then, the coating state detection unit 19B detects the coating state based on the temperature distribution.

[0068] When the temperature of the wafer W on which the liquid film L is formed is measured, the temperature differs between a location where the liquid film L is present and a location where there is no liquid film L. This is because the wafer W transmits infrared rays, and at a location where there is no liquid film L, the temperature of a member below the wafer W, for example, the wafer holding mechanism 25, is measured.

[0069] For example, when the liquid film L is properly formed on the wafer W, the temperature of the liquid film L is measured within a predetermined region on the wafer W, as shown by hatching in Fig. 7A. Fig. 7A is a schematic diagram showing a state in which no defective portion Wa (see Fig. 7B) is generated in the liquid film L of the IPA liquid. The predetermined region is a region that includes all regions in which a pattern is formed.

[0070] On the other hand, when the liquid film L is not properly formed on the wafer W and a defective part Wa occurs where the liquid film L is not formed in a predetermined area as shown in Fig. 7B, for example, the temperature of the wafer holding mechanism 25 is measured at the defective part Wa. Fig. 7B is a schematic diagram showing a state where the defective part Wa occurs in the liquid film L of the IPA liquid.

[0071] In this manner, the coating state detection unit 19B detects the coating state of the wafer W based on the temperature distribution of the wafer W measured by the infrared sensor 27.

[0072] The determination unit 19C determines whether the amount of the liquid film L formed on the wafer W is normal. Specifically, the determination unit 19C determines whether the amount of the liquid film L is within a first predetermined range. The first predetermined range is a range set in advance, and is a range in which pattern collapse that would result in a defective wafer or particles are not generated on the wafer W after the drying process. If the amount of the liquid film L is within the first predetermined range, the determination unit 19C determines that the amount of the liquid film L is normal. If the amount of the liquid film L is outside the first predetermined range, the determination unit 19C determines that the amount of the liquid film L is not normal.

[0073] Furthermore, the determination unit 19C determines whether the drying state of the wafer W is normal. Specifically, the determination unit 19C determines whether the difference between the weight of the wafer W after the drying process and the weight of the wafer W before the cleaning process is within a second predetermined range. The second predetermined range is a preset range, and is a value by which it can be determined that the wafer W is dry. If the difference is within the second predetermined range, the determination unit 19C determines that the wafer W is dry and the drying state is normal. If the difference is outside the second predetermined range, the determination unit 19C determines that the wafer W is not dry and the drying state is not normal.

[0074] Furthermore, the determination unit 19C determines whether the coating state of the wafer W is normal or not. Specifically, the determination unit 19C determines whether or not there is a defective part Wa within the predetermined region. If there is no defective part Wa within the predetermined region, the determination unit 19C determines that the coating state of the wafer W is normal. If there is a defective part Wa within the predetermined region, the determination unit 19C determines that the coating state of the wafer W is not normal.

[0075] When the amount of the liquid film L is not normal or when the coating state is not normal, the signal generating unit 19D generates a signal for adjusting the liquid film L on the wafer W to the cleaning processing unit 16. For example, the signal generating unit 19D generates a signal for restarting the supply of the IPA liquid.

[0076] Furthermore, the signal generating unit 19D may generate a signal for adjusting the supply amount of IPA liquid so that the amount of the liquid film L and the covering state are normal in the subsequent cleaning process. For example, when the amount of the liquid film L is small, the signal generating unit 19D generates a signal for increasing the amount of IPA liquid supplied to the wafer W so that the amount of the liquid film L falls within a first predetermined range. This allows the amount of the liquid film L and the covering state to be normal in the subsequent cleaning process, and allows efficient substrate processing.

[0077] When the drying state of the wafer W is not normal, the signal generating unit 19D generates a signal to return the wafer W to the cleaning processing unit 16 and restart the processing from the cleaning processing. Furthermore, the signal generating unit 19D may generate a signal to adjust the drying processing so that the drying state of the wafer W becomes normal in the subsequent drying processing. For example, the signal generating unit 19D generates a signal to lengthen the drying processing.

[0078] The output section 19E outputs the signal generated by the signal generating section 19D to the cleaning processing unit 16, the drying processing unit 17, and the like.

[0079] <Substrate processing> Next, the substrate processing according to the first embodiment will be described with reference to Fig. 8. Fig. 8 is a flow chart illustrating the substrate processing according to the first embodiment.

[0080] The substrate processing system 1 performs a first transfer process (S10). The substrate processing system 1 uses the substrate transfer device 13 and the substrate transfer device 18 to transfer the wafer W from the carrier C to the cleaning processing unit 16 via the transfer section 14. The substrate processing system 1 places the wafer W on the lifter pins 28a of the lifter 28.

[0081] The substrate processing system 1 uses the load cell 28c to measure the weight of the wafer W before the cleaning process, that is, before the liquid film L of the IPA liquid is formed (S11).

[0082] The substrate processing system 1 performs a cleaning process (S12). After measuring the weight of the wafer W before the liquid film L of the IPA liquid is formed, the substrate processing system 1 transfers the wafer W from the lifter pins 28a to the wafer holding part 29 and has the wafer W held by the wafer holding part 29. After removing the contaminants, the substrate processing system 1 performs a rinse cleaning. Then, the substrate processing system 1 supplies the IPA liquid for a set time and flow rate to form a liquid film L of the IPA liquid on the surface of the wafer W.

[0083] The substrate processing system 1 detects the coating state (S13). The substrate processing system 1 measures the temperature of the wafer W using the infrared sensor 27, and detects the coating state based on the temperature distribution of the wafer W.

[0084] The substrate processing system 1 determines whether the coating state is normal or not (S14). If the coating state is normal (S14; Yes), the substrate processing system 1 measures the weight of the wafer W on which the liquid film L of the IPA liquid is formed using the load cell 28c (S15). The substrate processing system 1 transfers the wafer W from the wafer holder 29 to the lifter pins 28a, supports the wafer W by the lifter pins 28a, and measures the weight of the wafer W on which the liquid film L of the IPA liquid is formed.

[0085] The substrate processing system 1 determines whether the amount of the liquid film L is normal (S16). If the covering state is not normal (S14; No) or if the amount of the liquid film L is not normal (S16; No), the substrate processing system 1 adjusts the liquid film L of the IPA liquid formed on the wafer W (S17). After adjusting the liquid film L of the IPA liquid, the substrate processing system 1 detects the covering state (S13).

[0086] When the amount of the liquid film L is normal (S16; Yes), the substrate processing system 1 performs a second transfer process (S18). The substrate processing system 1 uses the substrate transfer device 18 to transfer the wafer W from the cleaning processing unit 16 to the drying processing unit 17, and loads the wafer W into the drying processing unit 17.

[0087] The substrate processing system 1 performs a drying process (S19), and after the drying process, performs a third transfer process (S20). The substrate processing system 1 uses the substrate transfer device 18 to transfer the wafer W from the drying process unit 17 to the transfer section 14, and loads the wafer W into the transfer section 14.

[0088] The substrate processing system 1 measures the weight of the wafer W after the drying process using the load cell 43 (S21).

[0089] The substrate processing system 1 determines whether the drying state of the wafer W is normal (S22). If the drying state of the wafer W is not normal (S22; No), the substrate processing system 1 performs the cleaning process again (S12). The substrate processing system 1 uses the substrate transfer device 18 to transfer the wafer W from the delivery section 14 to the cleaning processing unit 16, and forms a liquid film L of IPA liquid on the surface of the wafer W.

[0090] When the drying state of the wafer W is normal (S22; Yes), the substrate processing system 1 performs a fourth transfer process (S23). The substrate processing system 1 transfers the wafer W from the transfer section 14 to the carrier C using the substrate transfer device 13.

[0091] The substrate processing system 1 detects the amount of the liquid film L formed on the wafer W by the liquid amount detection unit 19A, and detects the coating state of the wafer W on which the IPA liquid film L is formed by the coating state detection unit 19B. This allows the substrate processing system 1 to detect whether the IPA liquid film L is properly formed on the wafer W, and improve the yield of the wafer W after the drying process.

[0092] The substrate processing system 1 uses the same load cell 28c to measure the weight of the wafer W before and after forming the liquid film L of the IPA liquid, and detects the amount of the liquid film L based on the measured weight. This makes it possible to suppress the influence of measurement errors in the load cell and accurately detect the amount of the liquid film L, compared to the case where a different load cell is used to detect the amount of the liquid film L.

[0093] The substrate processing system 1 performs a drying process on the wafer W on which the liquid film L of the IPA liquid has been formed. Specifically, the substrate processing system 1 performs the drying process when the coating state of the wafer W is normal and the liquid amount of the liquid film L is normal. In this way, the substrate processing system 1 can suppress the occurrence of pattern collapse on the wafer W after the drying process and the occurrence of particles on the wafer W after the drying process, thereby improving the yield of the wafer W.

[0094] The substrate processing system 1 detects the amount of the liquid film L before the wafer W is transported to the drying processing unit 17, specifically, while the wafer W is in the cleaning processing unit 16. This allows the substrate processing system 1 to adjust the liquid film L of the IPA liquid in the cleaning processing unit 16 when the amount of the liquid film L is not normal. Therefore, the substrate processing system 1 can adjust the liquid film L of the IPA liquid without transporting the wafer W from the cleaning processing unit 16, thereby shortening the adjustment time.

[0095] The substrate processing system 1 detects the coating state of the wafer W before the wafer W is transferred to the drying processing unit 17, specifically, while the wafer W is in the cleaning processing unit 16. This allows the substrate processing system 1 to adjust the liquid film L of the IPA liquid in the cleaning processing unit 16 when the coating state of the wafer W is not normal. Therefore, the substrate processing system 1 can adjust the liquid film L of the IPA liquid without transferring the wafer W from the cleaning processing unit 16, thereby shortening the adjustment time.

[0096] The substrate processing system 1 detects the coating state of the wafer W using the infrared sensor 27. Thereby, when a defective portion Wa occurs in the liquid film L of the IPA liquid, the occurrence of the defective portion Wa can be accurately detected.

[0097] Second embodiment <Outline of Substrate Processing System 1> Next, a substrate processing system 1 according to a second embodiment will be described with reference to Fig. 9. Fig. 9 is a schematic diagram showing a schematic configuration of the substrate processing system 1 according to the second embodiment. Here, differences from the substrate processing system 1 according to the first embodiment will be described, and a description of the same configuration as the first embodiment will be omitted.

[0098] The substrate processing system 1 includes an adjustment unit 50 that adjusts the liquid film L of the IPA liquid. The adjustment unit 50 adjusts the liquid film L of the IPA liquid when the liquid amount of the liquid film L is not normal or when the covering state is not normal.

[0099] The adjustment unit 50 is provided adjacent to the transfer section 15, and is configured so that the wafer W can be transferred by the substrate transfer device .

[0100] A load cell 43 (see FIG. 2) provided in the delivery section 14 measures the weight of the wafer W transferred from the carrier C. That is, the load cell 43 measures the weight of the wafer W before the cleaning process is performed.

[0101] Furthermore, the cleaning processing unit 16 of the substrate processing system 1 according to the second embodiment does not include the load cell 28c and the infrared sensor 27, unlike the cleaning processing unit 16 according to the first embodiment.

[0102] <Outline of Drying Processing Unit 17>

[0103] As shown in Fig. 10A, the drying processing unit 17 further includes a load cell 39c and an infrared sensor 60. Fig. 10A is a schematic cross-sectional view showing a part of the drying processing unit 17 according to the second embodiment.

[0104] 10A, the load cell 39c is provided on the lower surface of the support portion 39b of the lifter 39, and measures the weight of the wafer W in a state in which the wafer W is supported by the lifter pins 39a. The load cell 39c measures the weight of the wafer W on which the liquid film L of the IPA liquid is formed and the weight of the wafer W after the drying process.

[0105] The infrared sensor 60 is attached to the upper side of the main body 31 via a support arm 61. As shown in Fig. 10B, the infrared sensor 60 measures the temperature of the wafer W in a state in which the wafer W is placed on the holding plate 32. Fig. 10B is a schematic cross-sectional view of the drying processing unit 17 showing a state in which the wafer W is placed on the holding plate 32.

[0106] <Overview of control device 4> 11, signals related to the weight of the wafer W are input from the load cells 39c and 43 to the control unit 19 of the control device 4. In addition, a signal related to the temperature of the wafer W is input from the infrared sensor 60 to the control unit 19. Fig. 11 is a schematic block diagram of the control device 4 according to the second embodiment.

[0107] The liquid volume detection unit 19A calculates the difference between the weight of the wafer W after the cleaning process measured by the load cell 39c and the weight of the wafer W before the cleaning process measured by the load cell 43, and detects the volume of the liquid film L formed on the wafer W.

[0108] Furthermore, the liquid amount detector 19A calculates the difference between the weight of the wafer W after the drying process measured by the load cell 39c and the weight of the wafer W before the cleaning process measured by the load cell 43, and detects the dryness state of the wafer W.

[0109] In the substrate processing system 1 according to the second embodiment, after the liquid film L of the IPA liquid is formed and the wafer W is transferred to the drying processing unit 17 by the substrate transfer device , the liquid amount and coating state of the liquid film L are measured.

[0110] Next, the substrate processing according to the second embodiment will be described with reference to Fig. 12. Fig. 12 is a flow chart illustrating the substrate processing according to the second embodiment.

[0111] The substrate processing system 1 performs a first transfer process (S30). The substrate processing system 1 uses the substrate transfer device 13 to transfer the wafer W from the carrier C to the transfer section .

[0112] The substrate processing system 1 uses the load cell 43 to measure the weight of the wafer W before the cleaning process, that is, before the liquid film L of the IPA liquid is formed (S31).

[0113] The substrate processing system 1 performs a second transfer process (S32). The substrate processing system 1 transfers the wafer W from the delivery section 14 to the cleaning processing unit 16 using the substrate transfer device 18.

[0114] The substrate processing system 1 performs a cleaning process (S33). After removing the contaminants, the substrate processing system 1 performs a rinse process. Then, the substrate processing system 1 supplies the IPA liquid to the wafer W to form a liquid film L of the IPA liquid on the surface of the wafer W.

[0115] The substrate processing system 1 performs a third transfer process (S34). The substrate processing system 1 uses the substrate transfer device 18 to transfer the wafer W from the cleaning processing unit 16 to the drying processing unit 17. The substrate processing system 1 delivers the wafer W from the substrate transfer device 18 to the lifter pins 39a of the lifter 39.

[0116] The substrate processing system 1 uses the load cell 39c to measure the weight of the wafer W on which the liquid film L of the IPA liquid is formed (S35).

[0117] The substrate processing system 1 determines whether the amount of the liquid film L is normal (S36). If the amount of the liquid film L is normal (S36; Yes), the substrate processing system 1 detects the coating state (S37). The substrate processing system 1 measures the temperature of the wafer W using the infrared sensor 60, and detects the coating state based on the temperature distribution of the wafer W.

[0118] The substrate processing system 1 determines whether the coating state is normal or not (S38). If the coating state is normal (S38; Yes), the substrate processing system 1 performs a drying process (S39).

[0119] If the amount of IPA liquid is not normal (S36; No) or if the coating state is not normal (S38; No), the substrate processing system 1 transfers the wafer W to the adjustment unit 50 and adjusts the liquid film L of the IPA liquid formed on the wafer W (S40). The substrate processing system 1 transfers the adjusted wafer W to the drying processing unit 17 and measures the weight of the wafer W (S35).

[0120] After the drying process, the substrate processing system 1 measures the weight of the wafer W after the drying process by the load cell 39c (S41).

[0121] The substrate processing system 1 determines whether the drying state is normal or not (S42). If the drying state of the wafer W is not normal (S42; No), the substrate processing system 1 performs the cleaning process again (S33).

[0122] If the drying state of the wafer W is normal (S42; Yes), the substrate processing system 1 performs a fourth transfer process (S43). The substrate processing system 1 uses the substrate transfer device 18 to transfer the wafer W to the transfer section 14, and uses the substrate transfer device 13 to transfer the wafer W from the transfer section 14 to the carrier C.

[0123] The substrate processing system 1 detects the amount of the liquid film L after the wafer W on which the IPA liquid film L is formed is transported to the drying processing unit 17. This allows the substrate processing system 1 to detect the amount of the liquid film L immediately before the drying processing is performed. Therefore, it is possible to prevent the drying processing from being performed in a state where the amount of the liquid film L is small, for example, when the IPA liquid is spilled or volatilized while the wafer W is being transported to the drying processing unit 17 by the substrate transport device 18. Therefore, the substrate processing system 1 can prevent the occurrence of pattern collapse.

[0124] The substrate processing system 1 detects the coating state of the wafer W after the wafer W on which the IPA liquid film L is formed is transported to the drying processing unit 17. This allows the substrate processing system 1 to detect the coating state of the wafer W immediately before the drying processing is performed. Therefore, it is possible to prevent the drying processing from being performed in a state in which a defective part Wa (see FIG. 7B) occurs in the liquid film L of the IPA liquid, for example, when the IPA liquid is spilled or volatilized while the wafer W is being transported to the drying processing unit 17 by the substrate transport device 18. Therefore, the substrate processing system 1 can prevent the occurrence of pattern collapse.

[0125] Third embodiment Next, a substrate processing system 1 according to a third embodiment will be described. Here, differences from the substrate processing system 1 according to the second embodiment will be mainly described, and a description of the same configuration as the substrate processing system 1 according to the second embodiment will be omitted. The substrate processing system 1 according to the third embodiment uses an imaging device 72 instead of the infrared sensor 60 to detect the coating state of the wafer W on which the liquid film L of the IPA liquid is formed.

[0126] <Outline of Drying Processing Unit 17> As shown in Figures 13 and 14, the dry processing unit 17 further includes a laser irradiation section 70, a screen 71, and an imaging device 72. Figure 13 is a schematic plan view of the dry processing unit 17 according to the third embodiment. Figure 14 is a schematic cross-sectional view showing a part of the dry processing unit 17 taken along the line XIV-XIV in Figure 13.

[0127] The laser irradiation unit 70 irradiates a laser beam toward the wafer W on which the liquid film L of the IPA liquid is formed and which is held by the holding plate 32. The laser irradiation unit 70 irradiates a plurality of laser beams toward the wafer W. The laser irradiation unit 70 irradiates the wafer W held by the holding plate 32 with the laser beams obliquely from above.

[0128] The screen 71 is disposed so as to face the laser irradiation unit 70 across the wafer W held by the holding plate 32. The wafer W and the laser light reflected by the holding plate 32 are projected onto the screen 71.

[0129] The imaging device 72 is disposed, for example, above the laser irradiation unit 70. The imaging device 72 is, for example, a digital camera, and captures the reflected light projected on the screen 71. Image data of the reflected light captured by the imaging device 72 is transmitted to the control device 4.

[0130] The laser irradiation unit 70, the imaging device 72, and the screen 71 are arranged side by side along the X-axis direction. Note that the positions of the laser irradiation unit 70, the imaging device 72, and the screen 71 are not limited thereto, and for example, the laser irradiation unit 70, the imaging device 72, and the screen 71 may be arranged along the Y-axis direction.

[0131] In the drying processing unit 17, the wafer W on which the IPA liquid film L is formed is placed on the holding plate 32 by a lifter 39 (see FIG. 10A, etc.), and then the laser irradiation section 70 irradiates the wafer W with laser light. Then, the drying processing unit 17 captures an image of the reflected light reflected on a screen 71 by an imaging device 72.

[0132] The dry processing unit 17 may irradiate the wafer W supported by the lifter 39 with laser light and capture an image of the reflected light.

[0133] When a wafer W on which a liquid film L of IPA liquid has been formed is irradiated with laser light from obliquely above, the laser light is refracted at the boundary between the IPA liquid and air and is reflected by the wafer W. The reflected light is then emitted from the IPA liquid as shown by the solid line in Fig. 15. Fig. 15 is a schematic diagram showing the state of reflection of the laser light from the wafer W on which a liquid film L of IPA liquid has been formed.

[0134] The laser light incident on the edge L1 of the liquid film L of the IPA liquid has various optical conditions, such as the angle of incidence and the angle of refraction, different from the laser light incident on the center side of the wafer W from the edge L1. Therefore, for example, the laser light incident from the edge L1 of the liquid film L of the IPA liquid on the laser irradiation unit 70 side is totally reflected at the boundary surface between the liquid film L of the IPA liquid and the air, as shown by the dashed line in FIG.

[0135] In this way, the reflected light of the laser light incident from the edge L1 of the liquid film L of the IPA liquid behaves differently from the reflected light of the laser light incident from the center side of the wafer W rather than from the edge L1. Therefore, the reflected light projected on the screen 71 has areas where the light intensity is low and areas where the reflected light is disturbed (hereinafter referred to as "disturbed areas") according to the edge L1 of the liquid film L of the IPA liquid.

[0136] For example, when no defective portion Wa occurs in the liquid film L of the IPA liquid, a substantially elliptical disturbance region is projected on the screen 71 in accordance with the circular edge portion L1 of the liquid film L of the IPA liquid, as shown by dots in Fig. 16A. Fig. 16A is a schematic diagram showing reflected light in a state in which no defective portion Wa occurs in the liquid film L of the IPA liquid. In Fig. 16A, the reflected light from the center side of the edge portion L1 of the liquid film L of the IPA liquid is shown by a dotted line, and the reflected light reflected by the holding plate 32 is shown by a solid line.

[0137] In contrast, when a defective portion Wa occurs in the liquid film L of the IPA liquid, the disturbed region does not have a substantially elliptical shape, but an uneven disturbed region corresponding to the defective portion Wa appears as circled in Fig. 16B. Fig. 16B is a schematic diagram showing reflected light in a state in which a defective portion Wa occurs in the liquid film L of the IPA liquid. In Fig. 16B, the disturbed region is shown by dots, the reflected light closer to the center than the edge portion L1 of the liquid film L of the IPA liquid is shown by a dotted line, and the reflected light reflected by the holding plate 32 or the wafer W is shown by a solid line.

[0138] In this manner, by irradiating the wafer W on which the liquid film L of the IPA liquid has been formed with laser light and photographing the reflected light reflected on the screen 71, it is possible to detect whether or not a defective portion Wa has occurred.

[0139] <Configuration of control device 4> 17, image data obtained by capturing an image of reflected light is input from an imaging device 72 to a control unit 19 of the control device 4. FIG 17 is a schematic block diagram of a control device 4 according to the third embodiment.

[0140] The coating state detection unit 19B detects the coating state of the wafer W based on the image data of the reflected light obtained by the imaging device 72. Specifically, the coating state detection unit 19B compares the image data of the reflected light captured in a state where no defective parts Wa are generated in the liquid film L of the IPA liquid with the image data of the reflected light captured in the current process, and detects the coating state of the wafer W. The image data of the reflected light captured in a state where no defective parts Wa are generated in the liquid film L of the IPA liquid is stored in advance in the storage unit 20.

[0141] The determining unit 19C determines whether or not the coating state of the wafer W is normal. Specifically, the determining unit 19C determines whether or not there is a defective part Wa in a predetermined region based on the detection result by the coating state detecting unit 19B.

[0142] <Substrate processing> Regarding the substrate processing according to the third embodiment, differences from the substrate processing according to the second embodiment will be described using the flowchart of FIG. 12, and a description of the same processes as in the substrate processing according to the second embodiment will be omitted.

[0143] In the substrate processing according to the third embodiment, when detecting the coating state (S37), the substrate processing system 1 detects the coating state based on image data of the reflected light captured by the imaging device 72.

[0144] In the substrate processing system 1, a laser irradiation unit 70 irradiates a wafer W on which a liquid film L of an IPA liquid has been formed with laser light, and an image capturing device 72 captures an image of the reflected light projected on a screen 71. Then, the substrate processing system 1 detects the coating state of the wafer W based on image data of the obtained reflected light.

[0145] This allows the substrate processing system 1 to accurately detect the occurrence of a defective portion Wa when the defective portion Wa occurs in the liquid film L of the IPA liquid. Furthermore, the substrate processing system 1 can prevent the drying process from being performed in a state in which the defective portion Wa occurs in the liquid film L of the IPA liquid. Therefore, the substrate processing system 1 can prevent the occurrence of pattern collapse.

[0146] (Fourth embodiment) Next, a substrate processing system 1 according to a fourth embodiment will be described. Here, differences from the substrate processing system 1 according to the second embodiment will be mainly described, and a description of the same configuration as the substrate processing system 1 according to the second embodiment will be omitted. The substrate processing system 1 according to the fourth embodiment uses an imaging device 72 instead of the infrared sensor 60 to detect the coating state of the wafer W on which the liquid film L of the IPA liquid is formed.

[0147] <Outline of Drying Processing Unit 17> As shown in Figures 18 and 19, the dry processing unit 17 further includes a monochromatic light irradiation section 75 and an imaging device 72. Figure 18 is a schematic plan view of the dry processing unit 17 according to the fourth embodiment. Figure 19 is a schematic cross-sectional view showing a part of the dry processing unit 17 in the XIX-XIX cross section of Figure 19.

[0148] The monochromatic light irradiation unit 75 is, for example, a sodium lamp. The monochromatic light irradiation unit 75 irradiates monochromatic light onto the wafer W on which the IPA liquid film L is formed and which is held by the holding plate 32. The monochromatic light irradiation unit 75 irradiates the wafer W held by the holding plate 32 with monochromatic light from obliquely above.

[0149] The imaging device 72 is disposed to face the monochromatic light irradiation unit 75 across the wafer W held by the holding plate 32. The imaging device 72 captures an image of the wafer W on which the liquid film L of the IPA liquid is formed. Image data of the wafer W captured by the imaging device 72 is transmitted to the control device 4.

[0150] In the drying processing unit 17, the wafer W on which the IPA liquid film L is formed is placed on the holding plate 32 by the lifter 39 (see FIG. 10A, etc.), and then the monochromatic light irradiation section 75 irradiates the wafer W with monochromatic light. Then, the drying processing unit 17 photographs the wafer W with the imaging device 72.

[0151] The dry processing unit 17 may irradiate the wafer W supported by the lifter 39 with monochromatic light and photograph the wafer W.

[0152] When monochromatic light is irradiated obliquely from above onto the wafer W on which the IPA liquid film L is formed, interference fringes are generated due to interference between the light reflected from the surface of the IPA liquid film L and the light reflected by the wafer W and emitted from the IPA liquid film L. The imaging device 72 captures an image of the interference fringes generated by the IPA liquid film L.

[0153] For example, when the imaging device 72 is placed ahead of point E shown in Fig. 20, interference fringes occur according to the path difference (ACD-BD). Fig. 20 is a diagram for explaining the principle of the occurrence of interference fringes.

[0154] The optical path difference corresponding to the above-mentioned path difference is "2ndcosθ", where the film thickness of the liquid film L is "d", the refractive index of the liquid film L is "n", the refractive index of air is "1.0", and the angle of incidence is "θ".

[0155] When the optical path difference satisfies the condition of formula (1), a bright line is generated due to interference between the reflected light reflected from the surface of the IPA liquid film L and the reflected light reflected by the wafer W and emerging from the IPA liquid film L.

[0156] 2ndcosθ=(m+1 / 2)λ (1)

[0157] Here, "λ" is the wavelength of monochromatic light, and "m" is an integer.

[0158] On the other hand, when the optical path difference satisfies the condition of equation (2), a dark line occurs due to interference between the reflected light reflected from the surface of the IPA liquid film L and the reflected light reflected by the wafer W and exiting from the IPA liquid film L.

[0159] 2ndcosθ=mλ (2)

[0160] In this way, dark lines are generated where the optical path difference is an integer multiple of the wavelength λ of the monochromatic light, and bright lines are generated where the optical path difference is a half wavelength away from the wavelength λ of the monochromatic light. This results in interference fringes. The interference fringes are generated according to the film thickness d of the IPA liquid formed on the wafer W.

[0161] Therefore, when no defective portion Wa occurs in the liquid film L of the IPA liquid, irradiating the IPA liquid formed on the circular wafer W with monochromatic light produces a substantially elliptical interference fringe as shown by the dashed line in Fig. 21A. Fig. 21A is a schematic diagram of a wafer W in a state in which no defective portion Wa occurs in the liquid film L of the IPA liquid, as viewed obliquely from above.

[0162] In contrast, when a defective portion Wa occurs in the liquid film L of the IPA liquid, irradiating the IPA liquid formed on a circular wafer W with monochromatic light generates an interference pattern in which a portion is depressed toward the center of the wafer W in accordance with the defective portion Wa, as shown by the dashed-dotted line in Fig. 21B. Fig. 21B is a schematic diagram of a wafer W in a state in which no defective portion Wa occurs in the liquid film L of the IPA liquid, viewed obliquely from above.

[0163] In this manner, the wafer W on which the IPA liquid film L is formed is irradiated with monochromatic light, and the resulting interference fringes are photographed, thereby making it possible to detect the presence or absence of defective parts Wa.

[0164] <Configuration of control device 4> Regarding the configuration of the control device 4 in the fourth embodiment, the block diagram of FIG. 17 will be used to explain the points that differ from the control device 4 in the third embodiment, and explanations of the configuration that is the same as the control device 4 in the third embodiment will be omitted.

[0165] Image data obtained by photographing the wafer W is input from the imaging device 72 to the control unit 19 of the control device 4.

[0166] The coating state detection unit 19B detects the coating state of the wafer W based on the image data of the wafer W obtained by the imaging device 72. Specifically, the coating state detection unit 19B compares the image data of the wafer W photographed in a state where no defective parts Wa are generated in the liquid film L of the IPA liquid with the image data of the wafer W photographed in the current process, and detects the coating state of the wafer W. The image data of the wafer W photographed in a state where no defective parts Wa are generated in the liquid film L of the IPA liquid is stored in advance in the storage unit 20.

[0167] The substrate processing system 1 irradiates the wafer W on which the liquid film L of the IPA liquid is formed with monochromatic light from a monochromatic light irradiation unit 75 such as a sodium lamp, and captures an image of the wafer W with the imaging device 72. Then, the substrate processing system 1 detects the coating state of the wafer W based on the obtained image data.

[0168] This allows the substrate processing system 1 to accurately detect the occurrence of a defective portion Wa when the defective portion Wa occurs in the liquid film L of the IPA liquid. Furthermore, the substrate processing system 1 can prevent the drying process from being performed in a state in which the defective portion Wa occurs in the liquid film L of the IPA liquid. Therefore, the substrate processing system 1 can prevent the occurrence of pattern collapse.

[0169] <Modification> The substrate processing system 1 according to the modified example may determine that pattern collapse has occurred on the wafer W and process the wafer W as a defective wafer when the amount of the liquid film L is too small, when the defective parts Wa generated in the liquid film L of the IPA liquid are large, or when there are many defective parts Wa generated in the liquid film L of the IPA liquid. For example, the substrate processing system 1 according to the modified example determines the occurrence of pattern collapse by comparing with each set threshold value. This makes it possible to suppress adjustment of the IPA liquid for the wafer W with the pattern collapse, and to efficiently process the substrate.

[0170] In the substrate processing system 1 according to the modified example, for example, when the amount of the liquid film L is larger than the upper limit value of the first predetermined range, the amount of supercritical fluid exhausted from the drying processing unit 17 may be increased. This allows the substrate processing system 1 according to the modified example to suppress the generation of particles without adjusting the IPA liquid.

[0171] The substrate processing system 1 according to the modified example may be provided with a load cell and an infrared sensor in the cleaning processing unit 16 and the drying processing unit 17. In this way, the substrate processing system 1 according to the modified example can transport the wafer W from the cleaning processing unit 16 with the amount of liquid and the coating state of the liquid film L being normal. Therefore, if the amount of liquid or the coating state of the liquid film L is not normal after the wafer W is transported to the drying processing unit 17, it can be determined that a malfunction has occurred between the cleaning processing unit 16 and the drying processing unit 17. That is, the cause of the malfunction can be easily identified.

[0172] In the substrate processing system 1 according to the modified example, the load cell may be provided in the substrate transport device 18. This makes it possible to reduce the number of load cells used in the substrate processing system 1. In addition, in the substrate processing system 1 according to the modified example, the cleaning processing unit 16 may be provided with the infrared sensor 27, the imaging device 72, etc., and the drying processing unit 17 may be provided with the load cell 39c.

[0173] The substrate processing system 1 according to the modified example may determine whether the amount of the liquid film L is normal by comparing the weight of the wafer W on which the IPA liquid film L is formed with a first predetermined weight. The substrate processing system 1 according to the modified example may determine whether the drying state is normal by comparing the weight of the wafer W after the drying process with a second predetermined weight. This makes it possible to determine whether the amount of the liquid film L and the drying state are normal without providing the load cell 43 in the delivery unit 14, and therefore the number of load cells used in the substrate processing system 1 can be reduced.

[0174] In the substrate processing system 1 according to the modified example, for example, in the drying processing unit 17 of the second embodiment, the temperature of the wafer W may be measured by the infrared sensor 60 while the wafer W is accommodated in the main body 31. In this way, even if the temperature of the entire region of the wafer W cannot be measured in a state where the wafer W is placed on the holding plate 32, the temperature of the entire region of the wafer W can be measured by the single infrared sensor 60.

[0175] Furthermore, in the substrate processing system 1 according to the modification, for example, in the drying processing unit 17 of the third embodiment, while the wafer W is accommodated in the main body 31, the laser irradiation section 70 may irradiate the wafer W with laser light. In this case, the laser irradiation section 70 may be disposed so as to be able to irradiate one laser light onto the tip of the wafer W on the main body 31 side, as shown in Fig. 22. Fig. 22 is a schematic plan view of the drying processing unit 17 of the substrate processing system 1 according to the modification.

[0176] The substrate processing system 1 according to the modified example continuously captures the reflected light reflected on the screen 71 using the imaging device 72 while storing the wafer W in the main body 31. The substrate processing system 1 according to the modified example can obtain image data of the reflected light from the entire wafer W by connecting the image data thus obtained. This makes it possible to detect the coating state of the wafer W using the laser irradiation unit 70 that irradiates a single laser beam.

[0177] In addition, in the substrate processing system 1 according to the modified example, before the wafer W on which the IPA liquid film L has been formed is placed on the holding plate 32, for example while the wafer W is placed on the lifter 39 (see FIG. 10A, etc.), the imaging device 72 may capture, for example, reflected light reflected on a screen 71.

[0178] Furthermore, the substrate processing system 1 according to the modified example may detect the coating state in accordance with a change in the interference fringes in the drying processing unit 17 of the fourth embodiment. Since the IPA liquid formed on the wafer W evaporates over time, the film thickness d of the liquid film L of the IPA liquid becomes thinner over time. That is, the position of the interference fringes generated according to the film thickness d of the liquid film L of the IPA liquid changes over time. In contrast, the defective area Wa has no IPA liquid and no interference fringes are generated, so there is no change in the image even over time.

[0179] In this manner, the substrate processing system 1 according to the modified example may detect the coating state based on the change in the interference fringes, thereby enabling the substrate processing system 1 according to the modified example to detect the coating state of the wafer W.

[0180] Furthermore, the substrate processing system 1 according to the modified example may capture an image of the wafer W on which the IPA liquid film L is formed by the imaging device 72, and detect the coating state of the wafer W based on the image data obtained by capturing the image. Furthermore, the substrate processing system 1 according to the modified example may capture an image of the wafer W after the drying process by an imaging device such as a camera, and detect the surface state of the wafer W after the drying process based on the image data obtained by capturing the image. This allows the substrate processing system 1 to more accurately determine the surface state of the wafer W after the drying process, specifically, whether or not the wafer W is sufficiently dried.

[0181] Furthermore, the substrate processing system 1 according to the modified example may photograph the wafer W on which the liquid film L of the IPA liquid has been formed using a camera, and estimate the amount of the liquid film L on the wafer W based on the image data obtained by photographing the wafer W.

[0182] In the substrate processing system 1 according to the modified example, when the drying state of the wafer W is not normal, the wafer W having the abnormal drying state may be discarded as a defective wafer. In addition, in the substrate processing system 1 according to the modified example, when the drying state of the wafer W is not normal, for example, when the wafer W is not sufficiently dried, the substrate processing system 1 according to the modified example may perform the drying process again.

[0183] Furthermore, the application of the above-mentioned method for detecting the amount of liquid, the method for detecting the coating state, and the method for detecting the dry state of the wafer W is not limited to the substrate processing system 1 having the drying processing unit 17 using a supercritical fluid. The methods can be applied to various substrate processing systems that form a liquid film on the wafer W and dry it.

[0184] Furthermore, the configurations of the substrate processing system 1 according to the above embodiment and the substrate processing system 1 according to the modified example may be appropriately combined.

[0185] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0186] 1. Substrate processing system (substrate processing equipment) 16 Cleaning Processing Unit 17 Drying processing unit (drying section) 19 Control section 19A Liquid volume detector 19B Covering state detection unit (covering detection unit) 27 Infrared Sensor 28c Load Cell 39c Load Cell 43 Load Cell 60 Infrared Sensor 70 Laser irradiation unit 71 screens 72 Imaging Device 75 Monochromatic light irradiation unit

Claims

1. a main body having a processing space formed therein capable of accommodating a wafer and an opening formed on a side surface for loading and unloading the wafer; a holding plate having a cover member that comes into contact with the opening when the wafer is carried into the main body and that holds the wafer in a horizontal direction; a lifter that is installed outside the main body and moves up and down to separate the wafer from the holding plate or to bring the wafer into contact with the holding plate; A load cell to measure the weight of the wafer A substrate processing apparatus comprising: The lifter is a plurality of lifter pins that pass through holes formed in the holding plate, have upper ends that protrude upward from the holding plate and come into contact with a lower surface of the wafer, thereby supporting the wafer from below; A support portion to which lower ends of the plurality of lifter pins are connected; a lifting drive unit for lifting and lowering the lifter; Equipped with The lift drive unit is a transfer position in which the support portion is raised and the plurality of lifter pins penetrate the holding plate and contact a lower surface of the wafer, thereby separating the wafer from the holding plate; The support portion is lowered, and the lifter is raised and lowered between a standby position where upper ends of the plurality of lifter pins are positioned below the holding plate, and a waiting position where the lifter is raised and lowered. The load cell is provided on the lifter.

2. The substrate processing apparatus according to claim 1 , wherein the holding plate is horizontally movable between the inside and the outside of the main body.

3. The substrate processing apparatus according to claim 1 , wherein the holding plate opens and closes the opening of the main body by moving in a horizontal direction when the lifter is at the standby position.

4. The wafer having the liquid film formed on the upper surface is moved in a horizontal direction and carried into the main body.

4. The substrate processing apparatus according to claim 1, wherein the wafer carried into the main body is subjected to a drying process.

5. the main body is provided with a supply port for supplying a fluid to the processing space; 5. The substrate processing apparatus according to claim 1, wherein the supply port is provided in a lower wall of the main body.

6. The body is provided with a discharge port for discharging fluid from the processing space; 6. The substrate processing apparatus according to claim 1, wherein the discharge port is provided on a side wall surface of the main body and is located below the opening.

7. 7. The substrate processing apparatus according to claim 1, wherein the support portion approaches the holding plate when the lifter is at the transfer position.

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