JP2009200193A - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing apparatus which is small, and a substrate processing method which can process a substrate front surface promptly and satisfactorily. <P>SOLUTION: A dry nitrogen gas is simultaneously supplied to a processing space 162 by two lines, that is (1) a line supplying the dry nitrogen gas from a front surface perimeter portion of a substrate W, and (2) a line supplying the dry nitrogen gas from a front surface center portion of the substrate W, and consequently a humidity of the processing space 162 can be uniformly reduced. Moreover, while supplying the dry nitrogen gas to the processing space 162, since a gas discharge of the processing space 162 is suppressed rather than a gas discharge at the time of a wet processing, a humidity of the processing space 162 can be promptly reduced. Since a drying processing is thus carried out in the state where the humidity of the processing space 162 is reduced, the substrate can be dried, while suppressing an occurrence of a watermark or the like on the substrate front surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method for drying a substrate after supplying the processing liquid to the surface of the substrate and wet-treating the substrate with the processing liquid. The substrates to be processed include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, FED (Field Emission Display) substrates, optical disk substrates, and magnetic disks. And a magneto-optical disk substrate.

  In the manufacturing process of electronic components such as semiconductor devices and liquid crystal display devices, a chemical treatment with a chemical solution and a rinse treatment with a rinse solution such as pure water are performed, followed by a drying treatment to remove the rinse solution adhering to the substrate surface. Executed. For example, an apparatus described in Patent Literature 1 includes a base member that holds a substrate in a horizontal posture, a motor that rotates the base member, a blocking member that is provided to face the base member, and a motor that rotates the blocking member. And a cup surrounding the periphery of the substrate W held by the base member, and the chemical treatment, the rinse treatment and the drying treatment are performed as follows. In this apparatus, the unprocessed substrate is transferred to the base member and held by the transfer robot. Next, the blocking member is located near the base member so as to cover the upper part of the substrate, and the cup is positioned so as to surround the base member and the blocking member. Thereafter, the substrate is subjected to a chemical treatment with a chemical and a rinsing treatment with pure water while rotating the base member and the blocking member. Then, after the rinsing process with pure water is completed, the substrate is kept rotating as it is, and water droplets adhering to the substrate are shaken off by a centrifugal force (drying process). In this apparatus, an inert gas such as nitrogen gas is supplied between the substrate and the blocking member while the substrate surface is covered with the blocking member, and the drying process is performed in an inert gas atmosphere. It is possible to suppress the substrate processing satisfactorily.

  In addition, there are methods described in Patent Documents 2 and 3 as methods for suppressing the generation of watermarks. In the apparatuses described in the literatures 2 and 3, after the wafer (substrate) is delivered to the spin chuck, the spin chuck and the wafer are started to rotate, and the chemical treatment with the chemical and the rinse treatment with pure water are executed. After this rinsing process, an IPA (isopropyl alcohol) liquid film is formed on the wafer surface to replace pure water with the IPA liquid on the wafer surface, and then the drying nozzle arm is scanned along the wafer surface. Wafer drying. That is, a drying nozzle arm is provided so as to be able to reciprocate along the wafer surface above the wafer supported by the spin chuck, and a fluid nozzle and an inert gas nozzle are attached to the tip side of the drying nozzle arm. Yes. Then, the drying process is executed as follows. In a state where the fluid nozzle and the inert gas nozzle are arranged near the upper center of the wafer, supply of the IPA liquid from the fluid nozzle and supply of nitrogen gas from the inert gas nozzle are started. The drying nozzle arm is moved while supplying the IPA liquid and nitrogen gas while rotating the wafer by the spin chuck. As a result, the fluid nozzle and the inert gas nozzle move integrally with the drying nozzle arm to scan from the center to the periphery of the wafer. In this way, the substrate is dried by supplying the IPA liquid and nitrogen gas to the entire wafer surface.

  In the above-described conventional technology, an inert gas atmosphere is formed in the processing space in contact with the substrate surface to improve the drying performance. However, as a method for forming the inert gas atmosphere, a method using the above-described blocking member (Patent Document) In addition to 1) and nozzle scanning (Patent Documents 2 and 3), there is a method described in Patent Document 4. In Patent Document 4, a gas supply pipe is disposed at a position higher than the surface of the wafer placed on the spin chuck and outside the peripheral edge of the wafer, and is inert from the gas outlet of the gas supply pipe. Gas is blown out parallel to the wafer surface. In addition, the intake duct is disposed so as to face the gas supply pipe across the wafer, and the gas ejected from the gas ejection port is exhausted through the intake port of the intake duct. For this reason, a gas stream is formed in parallel with the wafer surface at a predetermined interval above the wafer surface.

Japanese Patent No. 3474055 (FIG. 1) JP 2007-36180 A (FIGS. 1 and 3) JP 2007-263485 A (FIGS. 1 and 6) JP-A-6-275506 (paragraph 0014, FIG. 1 and FIG. 3)

  In the invention described in Patent Document 1, since the base member and the blocking member rotate and the substrate is dried while the blocking member is close to the substrate, the driving motor for the blocking member and the driving of the motor are performed. A driving force transmission mechanism for transmitting force is required, which has been one of the factors increasing the manufacturing cost of the substrate processing apparatus. Further, in order to reduce the put print of the substrate processing system equipped with the substrate processing apparatus, a stack arrangement of the substrate processing apparatuses has been proposed, but the existence of a motor for driving the blocking member and a driving force transmission mechanism It became one of the obstruction factors. This is because the motor for driving the blocking member and the driving force transmission mechanism have to be disposed above the blocking member, and the device tends to increase in size in the vertical direction. Therefore, it has been studied to perform substrate processing without rotating the blocking member. However, if the substrate is processed while the blocking member is stationary, a watermark or the like is generated on the surface of the substrate, and the substrate cannot be processed satisfactorily.

  Further, in the method using no blocking member, that is, the inventions described in Patent Documents 2 to 4, the apparatus size in the vertical direction can be reduced, but an inert gas atmosphere of low humidity is provided in the processing space in contact with the substrate surface. It is difficult to form well and quickly, and it is difficult to dry the entire substrate surface well. That is, in the inventions described in Patent Documents 2 and 3, since the nozzle is scanned, in order to maintain the entire processing space in a low humidity state and improve the drying performance, the moving speed of the nozzle and the rotation of the wafer (substrate) It was necessary to control the number highly, and there was a problem in terms of controllability. Further, since the nozzle is scanned from the center to the periphery of the wafer, the humidity in the portion of the processing space in contact with the outer peripheral portion of the wafer surface tends to be higher than the humidity in the central portion, and poor drying remains in the outer peripheral portion. It was easy. Further, in the invention described in Patent Document 4, an inert gas is ejected from a gas outlet of a gas supply pipe, and the gas is exhausted through an intake port of an intake duct to form a gas flow in a processing space. There are only. Therefore, it is difficult to quickly reduce the humidity of the processing space, and there is a problem that a long time is required for the drying process.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a substrate processing apparatus and a substrate processing method that are small in size and can process a substrate surface quickly and satisfactorily.

  A substrate processing apparatus according to the present invention is a substrate processing apparatus for drying a substrate after supplying a treatment liquid to the surface of the substrate and subjecting the substrate surface to a predetermined wet process, and achieves the above object. Therefore, the substrate holding means for holding the substrate in a substantially horizontal posture, the first gas supply means for supplying the dry gas to the outer peripheral portion of the surface of the substrate held by the substrate holding means, and the surface of the substrate held by the substrate holding means A second gas supply means for supplying a dry gas to the central portion; an exhaust means for exhausting the processing space in contact with the substrate surface; and an exhaust adjustment means for adjusting the exhaust of the processing space. While supplying dry gas to the outer periphery of the surface and supplying dry gas from the second gas supply means to the center of the surface of the substrate, the exhaust adjustment means suppresses the exhaust of the process space from that during wet processing, thereby reducing the humidity of the process space. It is characterized in that the substrate is dried in a state of being lowered.

  Further, in order to achieve the above object, the substrate processing method according to the present invention supplies a processing liquid to the surface of the substrate to perform a predetermined wet process on the substrate surface, and a substrate processing method after the wet process. Humidity reduction process that supplies dry gas to each of the outer peripheral part of the surface and the central part of the surface and suppresses the exhaust of the processing space more than during wet processing to lower the humidity in the processing space, and drying that dries the substrate after the humidity reduction process And a process.

  In the invention thus configured (substrate processing apparatus and substrate processing method), the dry gas is supplied to the outer peripheral portion of the surface of the substrate that has undergone the wet process, and the dry gas is supplied to the center of the surface of the substrate. The entire processing space in contact with the surface is filled with dry gas, and the humidity of the processing space is uniformly reduced. Moreover, in the present invention, since the exhaust of the processing space is suppressed as compared with the exhaust during the wet processing together with the supply of the dry gas, the dry gas is efficiently stored in the entire processing space, and the humidity of the processing space is rapidly reduced. To do. And a drying process is performed in the state which reduced the humidity of the process space in this way. As a result, the substrate is dried while the generation of a watermark or the like on the substrate surface is suppressed.

  Here, a low surface tension solvent whose surface tension is lower than that of the treatment liquid is supplied to the surface of the substrate, and a solvent supply means for replacing the treatment liquid on the substrate surface with the low surface tension solvent is provided. Later, the substrate surface may be dried by removing the low surface tension solvent from the substrate surface. Thus, drying performance can be improved by using a low surface tension solvent. In this way, when the processing liquid on the substrate surface is replaced with a low surface tension solvent, as will be described later, it tends to cause poor drying due to heat of vaporization generated when the low surface tension liquid is dried. By starting the supply of the dry gas from the first gas supply means later and before the replacement with the low surface tension solvent, it is possible to prevent defective drying during the replacement. Then, defective drying can be effectively suppressed by starting the supply of the dry gas from the second gas supply means after the completion of the replacement and before the drying process.

  When exhausting the processing space through the exhaust pipe, the exhaust adjusting means may be configured as follows. That is, the exhaust adjustment means has a smaller diameter than the exhaust pipe, and the bypass pipe branched from the exhaust pipe and communicated with the exhaust pipe again, the branch position where the bypass pipe branches from the exhaust pipe, and the bypass pipe communicates with the exhaust pipe. An open / close valve inserted in the exhaust pipe between the communication position and the communication position may be provided. Then, by opening the on-off valve at the time of wet processing, the processing space can be exhausted with a relatively large exhaust amount, and the processing liquid atmosphere generated in the processing space at the time of wet processing is efficiently discharged from the processing space. On the other hand, the humidity of the processing space can be reduced in a short time by closing the on-off valve during the humidity lowering process and suppressing the exhaust amount of the processing space as compared with the wet processing.

  In addition, when the humidity inside the apparatus at the time of starting wet processing is relatively high, the humidity of the processing space is not sufficiently reduced even by supplying dry gas to the processing space, and a desired drying performance can be obtained. It may not be possible. In order to cope with this, the start of the wet process may be controlled based on the humidity inside the apparatus. That is, when the first humidity detection means for detecting the humidity inside the apparatus is provided and the initial humidity detected by the first humidity detection means before the start of the wet processing exceeds the first specified humidity, the wetness is determined. The start of processing may be regulated.

  In addition, when the humidity of the processing space is not sufficiently decreased even by supplying the dry gas to the processing space, it is desirable to regulate the drying process. That is, in the case where the second humidity detecting means for detecting the humidity of the processing space is provided and the humidity of the processing space before the start of the drying process detected by the second humidity detecting means exceeds the second specified humidity The start of the drying process may be regulated.

  Further, in order to satisfactorily perform substrate processing from wet processing to drying processing, clean air may be sent from the fan filter unit toward the substrate held by the substrate holding means. It is desirable to use one having a lower humidity than clean air.

  In addition, when clean air is sent from the fan filter unit in this way, an air volume adjusting means for adjusting the air volume of the clean air is provided, and the air volume of the clean air is adjusted by the air volume adjusting means after the wet process and before the drying process. It is desirable to suppress the air volume of the air, and the humidity of the processing space can be effectively reduced by adjusting the air volume.

  Furthermore, as described above, the humidity inside the apparatus at the start of the wet process may be relatively high. However, the humidity inside the apparatus may be lowered by adjusting the humidity of clean air. In other words, a humidity control mechanism for adjusting the humidity of the clean air is provided, and first humidity detection means for detecting the humidity inside the apparatus is provided, and the initial humidity detected by the first humidity detection means before the start of the wet processing is determined. If the humidity exceeds the first specified humidity, the humidity control mechanism may be configured to reduce the humidity of the clean air, thereby suppressing the initial humidity to be equal to or lower than the first specified humidity and performing the substrate drying satisfactorily. be able to.

  According to the present invention, while supplying a dry gas to the outer peripheral portion of the surface of the substrate subjected to the wet process and supplying a dry gas to the center of the surface of the substrate, the exhaust of the processing space in contact with the substrate surface is exhausted during the wet process. Since the humidity of the processing space is rapidly reduced and the drying process is performed in the low humidity state by suppressing the exhaust gas rather than the exhaust, the substrate surface can be processed quickly and satisfactorily. Further, it is not necessary to rotate the blocking member, and the device size in the vertical direction can be reduced.

  FIG. 1 is a diagram showing a substrate processing system to which the present invention can be preferably applied. More specifically, FIG. 1A is a top view of the substrate processing system, and FIG. 1B is a side view of the substrate processing system. This substrate processing system is a processing system including a plurality of processing units as single-wafer type substrate processing apparatuses for performing processing with a processing liquid, processing gas, or the like on a disk-shaped substrate W such as a semiconductor wafer. The substrate processing system includes a substrate processing unit PP for processing a substrate W, an indexer unit ID coupled to the substrate processing unit PP, and a configuration for supplying / discharging a processing fluid (liquid or gas). The processing fluid boxes 11 and 12 are accommodated.

The indexer unit ID includes a cassette C for storing substrates W (FOUP (Front Opening Unified Pod) for storing a plurality of substrates W in a sealed state), SMIF (Standard
(Machine Interface) Pod, OC (Open Cassette), etc.) and a cassette holder 21 that holds a plurality of unprocessed substrates W. And an indexer robot 22 for taking out processed substrates and storing processed substrates in the cassette C.

  In each cassette C, a plurality of substrates W are accommodated in one unit called “lot”. A plurality of substrates W are transferred between various substrate processing apparatuses in units of lots, and the same type of processing is performed on each substrate W constituting the lot by each substrate processing apparatus. Each cassette C is provided with a plurality of shelves (not shown) for stacking and holding a plurality of substrates W in the vertical direction with minute intervals, and one substrate W is placed on each shelf. Can be held. Each shelf is configured to contact the peripheral edge of the lower surface of the substrate W and hold the substrate W from below. The substrate W has the front surface (pattern forming surface) facing upward and the back surface facing downward. The cassette C is accommodated in a substantially horizontal posture.

  The substrate processing unit PP includes a substrate transfer robot (substrate transfer device) 13 disposed substantially in the center in plan view, and a frame 30 to which the substrate transfer robot 13 is attached. As shown in FIG. 1A, a plurality (four in this embodiment) of processing units 1A, 2A, 3A, and 4A are mounted on the frame 30 so as to surround the substrate transfer robot 13. ing. In this embodiment, as the processing units 1 </ b> A to 4 </ b> A, processing units that perform predetermined processing on a substantially circular substrate W such as a semiconductor wafer are mounted on the frame 30. Further, as shown in FIG. 1B, another processing unit is installed at the lower stage of each processing unit. That is, the processing units 1B to 4B are respectively provided in the lower stage of the processing units 1A to 4A, and a two-tiered stacked structure is adopted.

  The substrate transport robot 13 can receive an unprocessed substrate W from the indexer robot 22 and can deliver the processed substrate W to the indexer robot 22. More specifically, for example, the substrate transfer robot 13 includes a base unit fixed to the frame 30 of the substrate processing unit PP, a lift base attached to the base unit so as to be lifted and lowered, A rotation base attached so as to be able to rotate about a vertical axis with respect to the base, and a pair of hands attached to the rotation base are provided. Each of the pair of substrate holding hands is configured to advance and retract in a direction approaching / separating from the rotation axis of the rotation base. With such a configuration, the substrate transport robot 13 can direct the substrate holding hand to any one of the indexer robot 22 and the processing units 1A to 4A and 1B to 4B, and can advance and retract the substrate holding hand in that state. Thereby, the delivery of the substrate W can be performed.

  The indexer robot 22 takes out the unprocessed substrate W from the cassette C designated by the control unit that controls the entire apparatus and delivers it to the substrate transfer robot 13, and also receives the processed substrate W from the substrate transfer robot 13 to receive the cassette. C. The processed substrate W may be stored in the cassette C that is stored when the substrate W is in an unprocessed state. In addition, the cassette C that stores the unprocessed substrate W and the cassette C that stores the processed substrate W are separated, and the cassette C is stored in a different cassette C from the cassette C stored in the unprocessed state. You may comprise so that the processed board | substrate W may be accommodated.

  Next, an embodiment of a processing unit mounted on the above substrate processing system will be described. In the substrate processing system of FIG. 1, eight processing units are mounted. However, these processing units can all have the same structure as the processing unit 100 described below.

<First Embodiment>
FIG. 2 is a view showing a first embodiment of a processing unit as a substrate processing apparatus according to the present invention. FIG. 2 (a) is a bottom view of the first gas supply nozzle as seen from below, and FIG. ) Is a schematic diagram showing a configuration of a processing unit. FIG. 3 is a block diagram showing an electrical configuration for controlling the processing unit of FIG. The processing unit 100 is a single-wafer type processing unit used for a cleaning process for removing unnecessary substances attached to the surface of a substrate W such as a semiconductor wafer. More specifically, the substrate surface is subjected to a chemical treatment with a chemical solution such as hydrofluoric acid and a rinsing treatment with pure water or DIW (deionized water), and the rinse solution on the substrate W This is an apparatus for drying the substrate W after the replacement with the IPA liquid.

  In the processing unit 100, a fan filter unit (FFU) 104 is disposed on the ceiling portion of the processing chamber 102. The fan filter unit 104 includes a fan 104a and a filter 104b. Air taken in from the outside by the fan 104a is cleaned by the filter 104b, and clean air is sent into the central space of the processing chamber 102. A spin chuck 106 is disposed in this central space. The spin chuck 106 rotates the substrate W while maintaining the substrate W in a substantially horizontal position with the substrate surface facing upward. In the spin chuck 106, the rotation support shaft 108 is connected to the rotation shaft of the chuck rotation mechanism 110 including a motor, and the spin chuck 106 can rotate around the rotation axis (vertical axis) by driving the chuck rotation mechanism 110. It has become. The rotating support shaft 108 and the chuck rotating mechanism 110 are accommodated in a cylindrical casing 114. Further, a disc-shaped spin base 116 is integrally connected to the upper end portion of the rotation support shaft 108 by a fastening component such as a screw. Therefore, the spin base 116 rotates around the rotation axis by driving the chuck rotation mechanism 110 in accordance with an operation command from the unit control unit 118 that controls the entire processing unit. The unit controller 118 also controls the chuck rotation mechanism 110 to adjust the rotation speed of the spin base 116.

  Near the periphery of the spin base 116, a plurality of chuck pins 120 for holding the periphery of the substrate W are provided upright. Three or more chuck pins 120 may be provided to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 116. Each of the chuck pins 120 includes a substrate support portion that supports the peripheral portion of the substrate W from below, and a substrate holding portion that holds the substrate W by pressing the outer peripheral end surface of the substrate W supported by the substrate support portion. Yes. Each chuck pin 120 is configured to be switchable between a pressing state in which the substrate holding unit presses the outer peripheral end surface of the substrate W and a released state in which the substrate holding unit is separated from the outer peripheral end surface of the substrate W.

  When the substrate W is delivered to the spin base 116, the plurality of chuck pins 120 are released, and when performing substrate processing to be described later on the substrate W, the plurality of chuck pins 120 are pressed. State. By setting the pressing state in this manner, the plurality of chuck pins 120 can grip the peripheral edge portion of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 116. As a result, the substrate W is supported with its front surface facing upward and the back surface facing downward. The substrate holding mechanism is not limited to the chuck pins 120, and a vacuum chuck that supports the substrate W by sucking the back surface of the substrate may be used.

  Two types of nozzle arms 122 and 124 are swingably provided in a horizontal plane above the substrate W held by the spin chuck 106. A chemical supply nozzle 126 and a rinsing liquid supply nozzle 128 are attached to the tip of one nozzle arm 122. An IPA liquid supply nozzle 130 and a second gas supply nozzle 132 are attached to the tip of the other nozzle arm 124.

  Of these four nozzles, the chemical supply nozzle 126 is connected to the chemical supply unit 134 (FIG. 3). The chemical solution supply unit 134 can supply a chemical solution suitable for substrate cleaning such as hydrofluoric acid or BHF (Buffered Hydrofluoric acid) to the nozzle 126 side. Then, when the chemical solution supply unit 134 pumps the chemical solution toward the chemical solution supply nozzle 126 in accordance with a command from the unit control unit 118, the chemical solution is discharged from the nozzle 126 toward the substrate W. Similarly to the chemical liquid supply nozzle 126, the rinsing liquid supply unit 136 (FIG. 3) is also connected to the rinsing liquid supply nozzle 128, and the rinsing liquid is discharged toward the substrate W that has been subjected to the chemical liquid treatment. It is executable. A nozzle arm moving mechanism 138 is connected to the nozzle arm 122 to which these nozzles 126 and 128 are attached, and the nozzle arm moving mechanism 138 is driven in accordance with an operation command from the unit control unit 118. The nozzles 126 and 128 are movable between a discharge area above the surface of the substrate W and a standby position retracted laterally from the discharge area. Further, also in the discharge region, the nozzles 126 and 128 can be reciprocated between the upper center portion and the upper peripheral portion of the substrate surface by the nozzle arm moving mechanism 138.

  The IPA liquid supply nozzle 130 is connected to the IPA liquid supply unit 140 (FIG. 3). The IPA liquid supply unit 140 can supply a 100% IPA liquid or an IPA liquid diluted with pure water to the nozzle 130 side. When the IPA liquid supply unit 140 pumps the IPA liquid toward the IPA liquid supply nozzle 130 in accordance with a command from the unit control unit 118, the IPA liquid is discharged from the nozzle 130 toward the substrate W. Thus, the IPA liquid supply nozzle 130 functions as the “solvent supply means” of the present invention, and can supply the IPA liquid to the center of the surface of the substrate W as a low surface tension solvent having a surface tension lower than that of the chemical liquid or the rinse liquid. It has become. Similarly to the IPA liquid supply nozzle 130, a dry gas supply unit 142 (FIG. 3) is connected to the second gas supply nozzle 132, and the dry nitrogen gas (having a lower humidity than clean air, for example, a relative humidity of 10%). Nitrogen gas) can be discharged toward the substrate W. A nozzle arm moving mechanism 144 is connected to the nozzle arm 124 to which the nozzles 130 and 132 are attached, and the nozzle arm moving mechanism 144 is driven in accordance with an operation command from the unit control unit 118. The nozzles 130 and 132 are movable between a discharge area above the surface of the substrate W and a standby position retracted laterally from the discharge area.

  In this embodiment, the rotary support shaft 108 has a hollow tube structure, and is supplied to the upper end portion of the nozzle that is supplied from the rinse liquid supply unit 136 and is disposed in the internal space of the rotary support shaft 108. It is possible to discharge the rinse liquid from the formed nozzle hole (not shown) toward the back surface of the substrate.

  A receiving member 146 is fixedly attached around the casing 114. Three cylindrical partition members are erected on the receiving member 146. Then, three spaces are formed as drainage tanks 148a to 148c by the combination of these partition members and the casing 114. A splash guard (cup) 150 is placed above the drain tanks 148a to 148c along the rotation axis of the spin chuck 106 so as to surround the periphery of the substrate W held in a horizontal posture by the spin chuck 106. It can be moved up and down. The splash guard 150 has a substantially rotationally symmetric shape with respect to the rotation axis, and includes two guards arranged concentrically with the spin chuck 106 from the radially inner side to the outer side. Then, the splash guard 150 is lifted and lowered stepwise by driving the guard lifting mechanism 152, whereby the chemical liquid and the rinse liquid scattered from the rotating substrate W can be separated and discharged.

  In addition, one end of an exhaust pipe 160 is connected to the drainage tank 148a as shown in FIG. The other end of the exhaust pipe 160 is connected to an exhaust device (not shown). Therefore, the drainage tank 148a and the processing space 162 can be exhausted through the exhaust pipe 160. In addition, in this embodiment, the exhaust adjustment mechanism 164 is inserted in the exhaust pipe 160, and the exhaust adjustment mechanism 164 can adjust the exhaust amount from the processing space 162 in accordance with a command from the unit control unit 118. Yes. Thus, in this embodiment, the exhaust pipe 160 functions as the “exhaust means” of the present invention. Here, as the exhaust device, the power of the factory where the substrate processing system of FIG. 1 is installed may be used, or an exhaust unit such as a vacuum pump or an exhaust pump may be provided in the system. Regardless of which exhaust system is used, the processing space 162 can be reliably exhausted through the exhaust pipe 160. The processing space 162 described above is a space in contact with the substrate surface in a space formed by surrounding the periphery of the substrate W held by the spin chuck 106 with the splash guard 150. In the processing space 162, the chemical solution A process, a rinse process, a replacement process, and a drying process are performed.

  A first gas supply nozzle 170 is disposed in the vicinity of the upper portion of the processing space 162. As shown in FIG. 2, the first gas supply nozzle 170 has a ring shape having a larger outer diameter than the upper end opening 150a of the splash guard 150, and the inner diameter of the ring is substantially the same as the upper end opening 150a. It has become. When dry nitrogen gas is pumped from the dry gas supply unit 142 through the supply tube 172 to the first gas supply nozzle 170, the dry nitrogen gas is discharged from the inner peripheral surface of the ring toward the center of the ring, and the substrate W Is supplied to the outer periphery of the surface.

  FIG. 4 is a partial cross-sectional view of the first gas supply nozzle, showing a cross section taken along line AA of FIG. FIG. 5 is a view showing main constituent members of the first gas supply nozzle, FIG. 5 (a) is a bottom view of the cover member, and FIG. 5 (b) is a plan view of the base member. The first gas supply nozzle 170 has a base member 174 and a cover member 176. In this base member 174, a ring portion 174a having a ring shape and three support portions 174b that support the ring portion 174a are integrally formed, and the support portion 174b is fixed to the apparatus main body (not shown). The base member 174 is disposed near the upper part of the processing space 162 as shown in FIG. An upper surface 174c of the ring portion 174a is a ring-shaped plane, and a plurality of ring-shaped grooves 174d are formed on the ring-shaped upper surface 174c. Further, on the ring-shaped plane, a plurality of screw holes 174e are arranged in a ring shape on the outer peripheral side of the ring-shaped groove 174d, and a plurality of screw holes 174f are arranged in a ring shape on the inner peripheral side. .

  On the other hand, the cover member 176 has a ring-shaped flat surface 176c facing the upper surface (ring-shaped upper surface 174c) of the ring portion 174a and having the same shape as the upper surface. Similarly to the upper surface of the ring portion 174a, the ring-shaped flat surface 176c is also provided with a ring-shaped groove 176d that is the same as the groove 174d. Further, four communication portions 176a are connected to the ring-shaped groove portion 176d. These communication portions 176a are provided on the ring-shaped flat surface 176c at equal angular intervals (90 ° intervals in this embodiment). In each communicating portion 176a, one end is connected to a ring-shaped groove 176d as shown in FIG. 4, while the other end is opened on the outer peripheral side surface of the ring-shaped flat surface 176c, and is connected to the other end of the communicating portion 176a. A supply tube 172 is inserted.

  The cover member 176 is provided with a screw insertion hole 176e at a position corresponding to the screw hole 174e. That is, as shown in FIG. 5A, on the ring-shaped flat surface 176c, a plurality of screw insertion holes 176e are arranged in a ring shape on the outer peripheral side of the ring-shaped groove 176d. A screw insertion hole 176f is provided at a position corresponding to the screw hole 174f. That is, as shown in FIG. 5A, on the ring-shaped flat surface 176c, a plurality of screw insertion holes 176f are arranged in a ring shape on the inner peripheral side of the ring-shaped groove 176d. Further, a plurality of recesses 176g are provided in the ring-shaped surface region located on the inner peripheral side with respect to the ring-shaped groove 176d in the ring-shaped flat surface 176c. Each recess 176g has one end connected to the groove 176d as shown in FIG. 5A and the other end extending in the radial direction of the cover member 176 (the direction toward the rotation axis of the spin chuck). Yes.

  Then, with the screw holes 174e and 174f and the screw insertion holes 176e and 176f corresponding to each other, the ring-shaped upper surface 174c and the ring-shaped flat surface 176c are brought into close contact with each other, and the screws 178 are inserted into the screw insertion holes 176e and 176f. The first gas supply nozzle 170 is configured by screwing the tip of the screw 178 into the screw holes 174e and 174f to integrate the base member 174 and the cover member 176. In the first gas supply nozzle 170 formed in this way, as shown in FIG. 4, the ring-shaped groove 174d and the groove 176d on the cover member 176 side are connected to face each other to form a ring-shaped buffer space 180. The Therefore, when dry nitrogen gas is pumped from the dry gas supply unit 142 to the first gas supply nozzle 170 via the supply tube 172, the dry nitrogen gas is temporarily stored in the ring-shaped buffer space 180 and then recessed. It is discharged from the inner peripheral surface of the ring toward the center of the ring through a slit space sandwiched between 176g and the ring-shaped upper surface 174c on the base member 174 side. Therefore, the dry nitrogen gas is uniformly supplied to the outer peripheral portion of the surface of the substrate W over the entire outer periphery of the substrate W.

  In the substrate processing apparatus according to this embodiment, a humidity sensor 182 for detecting the humidity inside the apparatus and the processing space 162 is provided. The humidity sensor 182 detects the humidity inside the apparatus while retreating to a retreat position away from the processing space 162 during a chemical solution process or a rinse process (wet process) described below. After the processing is completed, the humidity in the processing space 162 is detected until the processing space 162 or the vicinity thereof is moved to immediately before the drying processing. Then, it is retracted again to the retracted position before performing the drying process. As described above, in this embodiment, the humidity sensor 182 has the functions of the “first humidity detection unit” and the “second humidity detection unit” of the present invention. It goes without saying that a humidity sensor for detecting the humidity of the processing space 162 may be provided individually.

  Next, the operation of the processing unit (substrate processing apparatus) 100 configured as described above will be described in detail with reference to FIGS. In this embodiment, the unit control unit 118 controls each part of the apparatus according to a program stored in a memory (not shown), and performs chemical liquid processing, rinsing processing, replacement processing, and drying processing on the substrate W. Among these, the chemical treatment and the rinse treatment correspond to the “wet treatment” of the present invention. In the chemical treatment, a chemical solution such as hydrofluoric acid is used as the “treatment solution” of the present invention, and in the rinse treatment, a rinse solution such as DIW is used. It is used as the “treatment liquid” in the present invention.

  The unit controller 118 controls the guard lifting mechanism 152 to lower the splash guard 150 so that the spin chuck 106 protrudes from the opening 150 a of the splash guard 150. At this time, the supply of dry nitrogen gas from the first gas supply nozzle 170 is stopped. In addition, all the nozzles 126, 128, 130, 132 are retracted outside the splash guard 150. In this state, an unprocessed substrate W is carried into the processing chamber 102 by the substrate transport robot 13. More specifically, the substrate W is carried into the apparatus with the substrate surface facing upward and held by the spin chuck 106. Following this, the splash guard 150 is raised by one step and the chemical liquid processing is started on the substrate W (FIG. 6A).

  In the chemical processing, the nozzle arm moving mechanism 138 moves the nozzle arm 122 so that the chemical supply nozzle 126 is positioned above the center of the substrate surface, and the substrate W held on the spin chuck 106 by driving the chuck rotating mechanism 110. Is rotated at a rotation speed (for example, 800 rpm) determined within a range of 200 to 1200 rpm. Further, the chemical liquid supply unit 134 feeds hydrofluoric acid as a chemical liquid toward the chemical liquid supply nozzle 126 and supplies the liquid to the substrate surface from the nozzle 126. The hydrofluoric acid supplied to the central portion of the substrate surface in this way is expanded in the radial direction by centrifugal force, and etching processing (chemical solution processing) of the substrate surface with hydrofluoric acid is performed.

  When the chemical liquid processing is completed, the nozzle arm moving mechanism 138 moves the nozzle arm 122 so that the rinsing liquid supply nozzle 128 is replaced with the chemical liquid supply nozzle 126 and positioned above the center of the substrate surface. Then, the rinse liquid is discharged from the rinse liquid supply nozzle 128. Further, a rinsing liquid is discharged toward the back surface of the substrate from a nozzle hole (not shown) formed in the upper end portion of the rotation spindle 108. The rinse liquid discharged to the front and back surfaces of the substrate in this way spreads over the entire front and back surfaces of the substrate W due to the centrifugal force of the rotation of the substrate W, and rinse treatment with the rinse liquid is performed. In this embodiment, the rotation speed of the substrate W is reduced to 300 rpm at the final point of the rinsing process.

  When the rinsing process is completed, the paddle forming process is executed next. That is, after the rinsing process ends, the unit control unit 118 reduces the rotation speed of the substrate W to a rotation speed (5 rpm in this embodiment) that is slower than the rotation speed during the rinsing process. As a result, the rinsing liquid discharged from the rinsing liquid supply nozzle 128 is accumulated on the substrate surface, and a rinsing liquid film is formed in a paddle shape (paddle formation process). The rotational speed during the paddle formation process is not limited to 5 rpm, but the condition that the centrifugal force acting on the rinse liquid is smaller than the surface tension acting between the rinse liquid and the substrate surface is satisfied. It is necessary to set the rotation speed within the range. This is because the above conditions must be satisfied in order to form a rinse liquid film in a paddle shape.

  When the paddle formation is completed in this manner, the nozzle arm moving mechanism 138 moves the nozzle arm 122 away from the substrate W to retreat both nozzles 126 and 128 to the outside of the splash guard 150, and then controls an on-off valve (not shown). Then, dry nitrogen gas is pumped from the dry gas supply unit 142 to the first gas supply nozzle 170, and the dry nitrogen gas is supplied from the first gas supply nozzle 170 to the outer peripheral portion of the surface of the substrate W (FIG. 3C). . At the same time as or before and after the supply of dry nitrogen gas, the unit control unit 118 controls the exhaust adjustment mechanism 164 to suppress exhaust from the processing space 162 (−20 Pa in this embodiment). Thus, the humidity in the processing space 162 can be effectively reduced. In this embodiment, since the nitrogen gas having a relative humidity of 10% or less is used as the dry nitrogen gas, the humidity of the processing space 162 can be reduced to the same level as the relative humidity of the dry nitrogen gas.

  Subsequently, while the dry nitrogen gas is supplied from the outer peripheral side of the substrate W, the replacement process, the humidity lowering process, and the drying process are continuously performed. That is, the nozzle arm moving mechanism 144 moves the nozzle arm 124 so that the second gas supply nozzle 132 is positioned above the center of the substrate surface. As a result, the IPA liquid supply nozzle 130 is also positioned above the central portion of the substrate surface along with the second gas supply nozzle 132. In this embodiment, the second gas supply nozzle 132 is positioned on the rotating shaft in order to surely dry the central portion of the substrate surface by a drying process described later.

  Then, the IPA liquid is pumped from the IPA liquid supply unit 140, and the IPA liquid is supplied from the IPA liquid supply nozzle 130 toward the center of the surface of the substrate W (FIG. 7A). In this embodiment, the rotation speed of the substrate W is changed as the replacement process proceeds. That is, in the initial stage of supplying the IPA liquid, the central portion of the rinse liquid film is replaced with the IPA liquid at the central portion of the surface of the substrate W, and a replacement region is formed in the liquid film. The rotation speed at this time is set to the same level as the paddle formation process (in this embodiment, 10 rpm). When a predetermined time, for example, 2.5 seconds elapses after the IPA liquid supply, the rotation speed of the substrate W is accelerated from 10 rpm to 100 rpm while the IPA liquid supply is continued. Thus, the acceleration of the rotation speed increases the centrifugal force acting on the liquid film (rinsing liquid region + IPA liquid region (replacement region)) on the substrate surface, so that the rinse liquid is shaken off and the replacement region expands in the radial direction. . At this time, the thickness of the liquid film on the substrate surface is reduced to a thickness corresponding to the rotation speed, and the rinsing liquid present on the outer peripheral portion of the surface of the substrate W after a predetermined time (1 second in this embodiment) has elapsed. Are all shaken off from the substrate W, the replacement region is uniformly spread over the entire surface of the substrate, and the substrate surface is entirely covered with the IPA liquid film. Further, the unit controller 118 accelerates the rotation speed of the substrate W from 100 rpm to 300 rpm over 0.5 seconds. This is performed in order to replace the rinsing liquid remaining in the gap of the fine pattern (not shown) formed on the substrate surface with the IPA liquid. In other words, the IPA liquid largely flows on the substrate surface due to the acceleration of the rotation speed, whereby the residual rinse liquid is replaced with the IPA liquid in the gaps of the fine pattern. This ensures that the rinse liquid adhering to the substrate surface is replaced with the IPA liquid.

  Thus, when the replacement process is completed, the unit control unit 118 stops supplying the IPA liquid, and then rotates the substrate W at the final rotation speed in the replacement process and keeps the exhaust at (−20 Pa). Is controlled to control the on / off valve so that dry nitrogen gas is pumped from the dry gas supply unit 142 to the second gas supply nozzle 132. As a result, the dry nitrogen gas is supplied from the second gas supply nozzle 132 to the center of the surface of the substrate W while the second gas supply nozzle 132 is opposed to the center of the surface of the substrate W ((b) in the figure). Thus, the dry nitrogen gas is supplied not only to the outer peripheral portion of the surface of the substrate W but also to the central portion of the surface, so that the humidity of the processing space 162 is effectively reduced (humidity reduction processing). Thereby, the humidity of the processing space 162 can be reduced to the relative humidity of the dry nitrogen gas. After this humidity reduction process, the substrate W is rotated at a high speed of 300 to 2500 rpm, and the drying process of the substrate W is executed ((c) in the figure).

  When the drying process of the substrate W is completed, the unit controller 118 controls the chuck rotating mechanism 110 to stop the rotation of the substrate W. Then, the supply of the dry nitrogen gas is stopped, and the nozzle arm moving mechanism 144 moves the nozzle arm 124 away from the substrate W to retract both nozzles 130 and 132 to the outside of the splash guard 150, and then the splash guard 150 is moved. The spin chuck 106 is lowered and protruded from above the splash guard 150. Thereafter, the substrate transfer robot 13 carries out the processed substrate W from the processing unit 100, and a series of substrate processing for one substrate W is completed. Then, the same processing as described above is performed for the next substrate W.

  As described above, according to this embodiment, the supply of dry nitrogen gas to the processing space 162 is two systems, that is, (1) a system for supplying dry nitrogen gas from the outer peripheral portion of the surface of the substrate W, and (2) a substrate. The humidity of the processing space 162 can be uniformly reduced by simultaneously performing dry nitrogen gas from the center of the surface of W. Further, since the exhaust of the processing space 162 is suppressed together with the supply of the dry nitrogen gas to the processing space 162 as compared with the exhaust during the wet processing, the humidity of the processing space 162 can be rapidly reduced. Since the drying process is performed in a state where the humidity of the processing space 162 is reduced in this way, the substrate can be dried while suppressing the generation of a watermark or the like on the surface of the substrate.

  The effect of supplying the dry nitrogen gas to the processing space 162 in two systems (peripheral portion supply + center portion supply) as described above is also apparent from the following experimental results. Hereinafter, the details of the experiment and the results of the experiment will be described in detail with reference to FIG.

Here, a series of substrate processing was performed on the silicon wafer (substrate) W using the substrate processing apparatus configured as described above. That is, while the substrate W is rotated at 800 rpm, a chemical solution treatment is performed by supplying hydrofluoric acid as a chemical solution to the substrate surface. When this chemical solution processing is completed, DIW is supplied to the substrate surface as a rinsing solution while continuing the substrate rotation at the same rotation speed, and the rinsing processing is executed. After the rinsing process, the rotational speed of the substrate W is reduced to 5 rpm, and the replacement process using the IPA liquid is performed after the paddle-shaped DIW liquid film becomes almost uniform over the entire surface of the substrate W. In this replacement process, as described above, the rotational speed of the substrate W is gradually accelerated from 10 → 100 rpm → 300 rpm to replace DIW adhering to the substrate surface with the IPA liquid. Thereafter, the humidity lowering process was performed in three different supply modes (1) to (3), and spin drying was performed. In the humidity reduction process, exhaust gas is set to −20 Pa along with the supply of dry nitrogen gas.
(1) Peripheral part supply + center part supply (upper part of FIG. 8)
Gas supply flow rate from nozzle 170 = 225 (liters / minute)
Gas supply flow rate from nozzle 132 = 60 (liter / min)
Rotational speed of substrate during spin drying = 800 rpm
(2) Only outer periphery supply (middle of Fig. 8)
Gas supply flow rate from nozzle 170 = 240 (liter / min)
Gas supply flow rate from nozzle 132 = 0 (liter / min)
Rotational speed of substrate during spin drying = 800 rpm
(3) Central supply only (bottom of Fig. 8)
Gas supply flow rate from nozzle 170 = 0 (liter / min)
Gas supply flow rate from nozzle 132 = 60 (liter / min)
Rotational speed of substrate during spin drying = 800 rpm

  For each substrate W, the surface of the substrate before and after treatment was monitored using a particle evaluation apparatus SP1-TBI manufactured by KLA-Tencor, and the particle distribution shown in the photograph in FIG. 8 was observed. In the figure, white circle lines indicate peripheral edges of the substrate W, and white dots indicate particles adhering to the substrate surface. From these experimental results, in order to satisfactorily reduce the humidity of the processing space 162 and dry the substrate before drying, supply dry nitrogen gas to both the outer peripheral portion and the central portion of the substrate surface. Is important.

  In the above embodiment, the gas supply to the outer peripheral portion of the surface of the substrate W is started, and the gas supply to the center portion of the surface of the substrate W is started after the replacement process is completed. By setting the supply start order of the dry nitrogen gas to the processing space 162 as described above, the following operational effects can be obtained.

  When dry nitrogen gas is supplied from the second gas supply nozzle 132 to the center of the surface of the substrate W, the humidity reduction range in the processing space 162 can be expanded as the nozzle 132 is brought closer to the substrate surface. On the other hand, if the nozzle 132 is brought close to the substrate surface, the drying nitrogen gas discharged from the nozzle 132 starts drying from the central portion of the substrate surface, and the humidity is sufficiently reduced at the outer peripheral portion of the substrate surface. There is a possibility that the drying process proceeds without being performed and a drying defect occurs at the outer peripheral portion of the surface. On the other hand, before starting the gas supply to the surface center portion of the substrate W, the gas supply to the surface outer periphery portion of the substrate W is started to reduce the humidity in the vicinity of the surface outer periphery portion, thereby reducing the center of the substrate surface. The humidity in the vicinity of the outer periphery of the surface has already been sufficiently reduced at the stage where the drying at the part has started. As a result, the substrate can be satisfactorily dried over the entire substrate surface.

  Moreover, in the said embodiment, although the substitution process using an IPA liquid is performed in order to improve a drying performance, dry nitrogen gas is supplied to the surface outer peripheral part and the surface center part before a drying process, and the humidity of the process space 162 Therefore, the phenomenon shown in FIG. 9 can be effectively suppressed and the substrate can be dried satisfactorily.

  FIG. 9 is a diagram schematically showing the mechanism of occurrence of poor drying due to evaporation of the IPA liquid. Thus, when a relatively highly volatile solvent such as the IPA liquid evaporates, the IPA liquid film moves along with the centrifugal force of the substrate rotation and the IPA evaporation. In addition, although the substrate surface is dried and exposed at the end of the IPA liquid film due to IPA evaporation, heat of vaporization is generated simultaneously with the IPA evaporation, and the ambient temperature in the exposed region is locally and rapidly decreased (see FIG. a)). At this time, if a large amount of water vapor component is present around the exposed area, it may aggregate in the exposed area and adhere as water droplets due to the temperature drop ((b) in the figure). Since such a phenomenon occurs sequentially as the IPA liquid film is dried and moved, a belt-like drying defect occurs. Since such a dry defect greatly depends on the ambient humidity around the substrate surface, the dry defect is effectively reduced by greatly reducing the humidity of the processing space 162 prior to the dry process as in this embodiment. In addition, it can be surely prevented. Therefore, it can be said that it is a very useful technique in the substrate processing apparatus and the substrate processing method that perform the replacement process using a low surface tension solvent such as an IPA liquid.

Second Embodiment
In the first embodiment, the chemical liquid supply nozzle 126 and the rinse liquid supply nozzle 128 are attached to the tip of the nozzle arm 122, while the IPA liquid supply nozzle 130 and the second gas supply nozzle 132 are attached to the tip of the nozzle arm 124. However, the arrangement and configuration of the nozzles are not limited to this and are arbitrary. For example, all the nozzles may be attached to one nozzle arm. In addition, an IPA liquid supply unit 140 is connected to one nozzle via an IPA liquid on-off valve and a dry gas supply unit 142 is connected via a gas on-off valve to control opening and closing of both on-off valves. You may comprise so that an IPA liquid and dry nitrogen gas may be selectively discharged from one nozzle.

<Third Embodiment>
FIG. 10 is a view showing a third embodiment of the substrate processing apparatus according to the present invention, and shows a partial cross section of the first gas supply nozzle. FIG. 11 is a view showing main constituent members of the first gas supply nozzle in the third embodiment, wherein FIG. 11 (a) is a bottom view of the cover member, and FIG. 11 (b) is a plan view of the base member. It is. The third embodiment is greatly different from the first embodiment in the configuration of the first gas supply nozzle 170, and the other configurations are the same. Therefore, the following description will focus on the above differences.

  In the third embodiment, the base member 174 is provided with a flange portion, and the flange portion serves as a ring portion 174a. On the upper surface (ring-shaped upper surface 174c) of the ring portion 174a, FIG. As shown in b), two types of ring-shaped grooves 174d and 174h are formed. Among these, the ring-shaped groove portion 174d forms a buffer space for temporarily storing dry nitrogen gas fed by pressure through the supply tube 172 as in the first embodiment. On the other hand, the ring-shaped groove portion 174h functions as an O-ring press-fitting groove, and is finished to a size capable of press-fitting a resin O-ring 184. Further, a plurality of screw holes 174e are arranged in a ring shape on the outer peripheral side of the ring-shaped groove portion 174h.

  On the other hand, the cover member 176 is provided with a plurality of through holes 176h in a ring shape so as to face the groove 174d. And the lower end part (front-end | tip part) of the supply tube 172 is inserted from the upper side with respect to each through-hole 176h, and is attached to the cover member 176 (In addition, illustration of the supply tube 172 to Fig.11 (a) is shown. Omitted). A plurality of screw insertion holes 176e are provided at positions corresponding to the screw holes 174e on the outer peripheral side of the through holes 176h.

  After the resin O-ring 184 is press-fitted into the ring-shaped groove 174h, the ring-shaped upper surface 174c and the ring-shaped flat surface 176c are brought close to each other with the screw hole 174e and the screw insertion hole 176e corresponding to each other. Is closely attached to the upper end of the O-ring 184, the screw 178 is inserted into the screw insertion hole 176e, and the tip of the screw 178 is screwed into the screw hole 174e to integrate the base member 174 and the cover member 176. Thus, the first gas supply nozzle 170 is configured. In the first gas supply nozzle 170 configured as described above, as shown in FIG. 10, a gap is formed between the ring-shaped upper surface 174c and the ring-shaped flat surface 176c to form a ring-shaped discharge port 170a. When dry nitrogen gas is pumped from the dry gas supply unit 142 through the supply tube 172 to the first gas supply nozzle 170, the dry nitrogen gas is temporarily stored in the ring-shaped buffer space, that is, the groove 174d. Thus, the ink is discharged from the inner peripheral surface of the ring toward the center of the ring through the discharge port 170a. Therefore, the dry nitrogen gas is uniformly supplied to the outer peripheral portion of the surface of the substrate W over the entire outer periphery of the substrate W.

<Fourth embodiment>
In the above embodiment, the ring-shaped nozzle 170 constituted by the base member 174 having a ring shape and the cover member 176 is used as the “first gas supply means” of the present invention, but the plurality of nozzles are used to form the substrate W. You may supply dry nitrogen gas to a surface outer peripheral part. Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.

  FIG. 12 is a view showing a fourth embodiment of the substrate processing apparatus according to the present invention. The fourth embodiment is greatly different from the first embodiment in the configuration of the first gas supply nozzle 170, and the other configurations are the same. Below, it demonstrates centering on the said difference.

  In the fourth embodiment, four first gas supply nozzles 186 are arranged at positions just above the splash guard 150 and at equal angular intervals (here, 90 ° intervals). Each nozzle 186 is connected to the dry gas supply unit 142. The tip of each nozzle 186 is disposed in the vicinity of the opening 150 a of the splash guard 150. In the substrate processing apparatus configured as described above, when dry nitrogen gas is pumped from the dry gas supply unit 142, the dry nitrogen gas is discharged from the four nozzles 186 toward the outer peripheral portion of the surface of the rotating substrate W. Is done. Therefore, the dry nitrogen gas is uniformly supplied to the outer peripheral portion of the surface of the substrate W over the entire outer periphery of the substrate W. Thus, in the fourth embodiment, the four first gas supply nozzles 186 function as the “first gas supply means” of the present invention, but the number and arrangement of the nozzles 186 are not limited thereto. Instead, a plurality of nozzles 186 may be disposed along the opening 150 a of the splash guard 150.

<Fifth Embodiment>
In the above-described embodiment, the exhaust adjustment mechanism 164 is provided to adjust the exhaust amount from the processing space 162. However, as the exhaust adjustment mechanism 164, as long as the exhaust amount can be controlled, the configuration and The operation and the like are not particularly limited and are arbitrary. For example, an exhaust adjustment mechanism 164 shown in FIG. 13 can be employed. Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG.

  FIG. 13 is a view showing an exhaust adjustment mechanism that can be employed in the substrate processing apparatus according to the present invention. The exhaust adjustment mechanism 164 has a narrower diameter than the exhaust pipe 160 and a branch pipe 164a branched from the exhaust pipe 160 and communicated with the exhaust pipe 160 again, and a branch position P1 where the bypass pipe 164a branches from the exhaust pipe 160. And an on-off valve 164b inserted between the bypass pipe 164a and a communication position P2 communicating with the exhaust pipe 160. At the time of wet processing (chemical solution and rinsing processing), the on-off valve 164b is opened in accordance with a command from the unit control unit 118, and the processing space 162 can be exhausted with a relatively large capacity. On the other hand, the opening / closing valve 164b is closed in accordance with a command from the unit control unit 118 during the humidity lowering process, and the exhaust amount of the processing space 162 is suppressed more than that during the wet process.

<Sixth Embodiment>
As a result of various experiments and verifications, when the humidity inside the apparatus at the time of starting the chemical treatment is relatively high, even if dry nitrogen gas is supplied to the processing space 162, the humidity of the processing space 162 remains high. The inventor of the present application has found a phenomenon that the desired drying performance cannot be obtained without sufficiently decreasing. Thus, performing a series of processes while the humidity inside the apparatus is relatively high causes a large loss in terms of production efficiency, leading to an increase in product cost. Further, the relationship between the humidity and the drying performance is not limited before the start of the chemical treatment, and the same is true immediately before the start of the drying treatment. That is, when the humidity of the processing space 162 is not sufficiently reduced even by the supply of the dry nitrogen gas to the processing space 162 (for example, when the relative humidity is not 30% or less), it is desirable to regulate the drying process. . Therefore, in the sixth embodiment of the present invention, the unit controller 118 controls the start of the chemical treatment and the drying treatment based on the humidity inside the apparatus. That is, the unit control unit 118 controls each part of the apparatus as shown in FIG. 14 according to a program stored in advance in a memory (not shown) to control the start of the chemical processing and the drying processing.

  FIG. 14 is a flowchart showing a fifth embodiment of the substrate processing apparatus according to the present invention. In this embodiment, before performing a series of processes on the substrate W, as described above, the humidity sensor 182 can be retracted to a retreat position away from the processing space 162 to detect the humidity inside the apparatus. Yes. Then, the unit control unit 118 obtains the humidity inside the apparatus based on the detection result by the humidity sensor 182 (step S1), and then determines whether or not the detection result is equal to or lower than a preset first specified humidity. (Step S2). This “first specified humidity” is the humidity inside the apparatus at the time of starting the chemical treatment, which is required to obtain good drying performance as described above, and is set to, for example, 40% relative humidity. Can do. That is, when the humidity inside the apparatus exceeds the first specified humidity (for example, relative humidity 40%), “NO” is determined in step S2, and the substrate processing is stopped (step S3). Further, the unit controller 118 issues an alarm (step S4). As a result, the humidity inside the apparatus is relatively high, and even if the substrate processing is performed as it is, good substrate processing cannot be performed, and the user is informed that the substrate processing is stopped. In response, the user manually operates or the unit control unit 118 automatically executes a program for reducing the humidity inside the apparatus, thereby eliminating the cause of the high humidity inside the apparatus (step S5). ), The unit controller 118 cancels the alarm (step S6), and returns to step S1.

  On the other hand, when it is confirmed in step S2 that the humidity inside the apparatus is equal to or lower than the first specified humidity, a series of substrate processing is started. In this embodiment, the processing space 162 is set before performing the drying processing. The humidity is detected and the process according to the detected humidity is executed in the same manner as described above. That is, the process from the chemical process to the humidity reduction process is executed in the same manner as in the first embodiment (steps S7 to S11). In this embodiment, as described above, the humidity sensor 182 retreats to the retreat position away from the processing space 162 during the chemical solution treatment and the rinse treatment (step S7), and the humidity inside the apparatus is reduced. Although detected, it has moved to the processing space 162 or the vicinity after the rinsing process is completed.

  After the humidity lowering process (step S11), that is, immediately before the drying process, the unit controller 118 detects the humidity of the processing space 162 based on the detection result by the humidity sensor 182 (step S12). Then, the unit controller 118 determines whether or not the detection result of the humidity sensor 182 is equal to or lower than a preset second specified humidity (step S13). The “second specified humidity” is the humidity of the processing space 162 at the time of starting the drying process, which is required to obtain good drying performance as described above. For example, the relative humidity is set to 30%. be able to. That is, when the humidity of the processing space 162 exceeds the second specified humidity (for example, relative humidity 30%), “NO” is determined in Step S13, and the substrate processing is stopped (Step S14). Further, the unit control unit 118 issues an alarm (step S15). As a result, the humidity in the processing space 162 is not sufficiently reduced even by the humidity reduction process (step S11), and even if the drying process is performed as it is, the substrate W cannot be dried satisfactorily. To be informed. In response, the user manually operates or the unit control unit 118 automatically executes a program for lowering the humidity of the processing space 162, thereby eliminating the cause of the high humidity of the processing space 162 ( In step S16), the unit controller 118 releases the alarm (step S17) and returns to step S12. On the other hand, when it is confirmed in step S13 that the humidity of the processing space 162 is equal to or lower than the second specified humidity, a drying process is executed (step S18).

  As described above, in the fifth embodiment, since substrate processing is started after confirming that the humidity inside the apparatus is equal to or lower than the first specified humidity, it is possible to prevent unnecessary substrate processing from being performed. be able to. In addition, since the drying process is started after confirming that the humidity of the processing space 162 is sufficiently lowered, it is possible to reliably prevent the drying process from being ended defectively.

<Sixth Embodiment>
In the fifth embodiment, when the internal humidity of the apparatus is relatively high and it is determined that good substrate processing cannot be performed even if the substrate processing is performed as it is, the substrate processing is stopped. By configuring as follows, the humidity inside the apparatus can be maintained below the first specified humidity. The sixth embodiment of the present invention will be described below with reference to FIG.

  FIG. 15 is a view showing a sixth embodiment of the substrate processing apparatus according to the present invention. The sixth embodiment is greatly different from the first embodiment in that the silica gel layer 104d is provided on the fan filter unit (FFU) 104 to reduce the humidity of clean air. This keeps the inside of the apparatus at a low humidity. The moisture removal layer 104d such as a silica gel layer has a reduced water absorption capability as moisture in the clean air is removed. Therefore, in the present embodiment, the heating layer 104c is disposed in the vicinity of the humidity removal layer 104d, and it is determined that the humidity inside the apparatus is relatively high while the substrate processing is not performed, and the substrate processing is stopped. In the meantime (step S3 in the fifth embodiment), the heating layer 104c operates. As a result, the water absorption capability of the humidity removing layer 104d is restored, which greatly contributes to a decrease in humidity inside the apparatus.

  As described above, according to the sixth embodiment, since the moisture in the clean air is removed by the humidity removing layer 104d such as the silica gel layer and the clean air is supplied to the inside of the device, the humidity inside the device is increased. Can be surely prevented. Further, based on the detection result of the humidity sensor 182, the humidity inside the apparatus before the start of the wet process, that is, the “initial humidity” of the present invention is higher than the first specified humidity (in the above embodiment, the relative humidity is set to 40%). If the initial humidity is determined to be high and relatively high, the heating layer 104c restores the water absorption capacity of the humidity removal layer 104d to reduce the humidity of the clean air. Substrate drying can be performed satisfactorily. Thus, in the present embodiment, the heating layer 104c and the humidity removal layer 104d function as the “humidity adjusting mechanism” of the present invention.

<Seventh embodiment>
By the way, in the said embodiment, although the substitution process using an IPA liquid is performed in order to improve drying performance, heat of vaporization generate | occur | produces simultaneously with IPA evaporation, and the surrounding temperature of an exposed area falls locally and rapidly. Is greatly related to the generation mechanism of poor drying due to evaporation of the IPA liquid. This has already been described in detail with reference to FIG. 9, but it is beneficial to heat the substrate W from the back side of the substrate W in order to suppress the influence of this temperature drop. That is, by increasing the temperature of the substrate W in anticipation of a temperature decrease due to evaporation of the IPA liquid, it is possible to prevent water droplet adhesion accompanying the temperature decrease and prevent defective drying. However, if the temperature of the substrate W is excessively increased, the IPA liquid is evaporated in a short time when supplied to the substrate W, and the IPA liquid supplied to the surface of the substrate W evaporates before reaching the entire surface. As a result, the replacement process cannot be performed satisfactorily, which may cause poor drying. Therefore, in consideration of these points, the temperature of the substrate W after being heated by the heat treatment, that is, the target temperature Tr is higher than the temperature Tst immediately before the discharge of the IPA liquid, and more than the boiling point (about 83 ° C.) of the IPA liquid. Need to set low. More preferably, the target temperature Tr can be set to a value (= Tst + ΔT) obtained by adding a temperature decrease ΔT due to evaporation of the IPA liquid to the temperature Tst immediately before discharge. The seventh embodiment of the present invention will be described below with reference to FIG.

  FIG. 16 is a view showing a seventh embodiment of the substrate processing apparatus according to the present invention. The seventh embodiment is greatly different from the first embodiment in that a high-temperature gas supply mechanism 190 that supplies a high-temperature gas to the back side of the substrate W is added. Other configurations are the same as those of the first embodiment.

  In the seventh embodiment, a high-temperature gas supply mechanism 190 is connected to a flow path formed between the rotation support shaft 108 and the hollow tube 109 surrounding the rotation support shaft 108. The upper end of this space faces the center of the back surface of the substrate W, and a heating gas such as high-temperature nitrogen gas or air is supplied from the high-temperature gas supply mechanism 190 to the back surface of the substrate from the start of the chemical treatment. The substrate W is heated by the supply of the high temperature gas. In this type of substrate processing apparatus, the temperature at the time of supplying the IPA liquid to the substrate surface is normal temperature (for example, 25 ° C.), and therefore the temperature of the substrate W is heated to a higher value, for example, 35 to 40 ° C. It is desirable to perform this, and moisture condensation accompanying a decrease in substrate temperature due to evaporation of the IPA liquid can be suppressed by this substrate heating.

  In this embodiment, nitrogen gas at 80 to 100 ° C. is supplied to the back surface of the substrate W at a flow rate of 100 (liters / minute) from the start of the chemical processing, and heating of the back surface of the substrate is started to start replacement processing. The substrate temperature is heated to 35-40 ° C. The heating start timing is not limited to this. Heating of the substrate W is started at any timing before the start of the replacement process, and the temperature of the substrate W is heated to the target temperature at the start of the replacement process. do it. However, the following points should be considered. In a so-called single-wafer type substrate processing apparatus, the time from chemical solution processing to replacement processing is short, and in order to improve process stability, it is necessary to avoid suddenly increasing the substrate temperature or conversely decreasing the temperature. Considering this point, it is desirable to set the supply time of the heating gas longer. In addition, if the substrate temperature changes during the chemical processing, if the processing characteristics (for example, etching characteristics) due to the chemical processing are adversely affected, the heating gas should be supplied to the backside of the substrate at times other than when the substrate heating is required. It is preferable to stop and supply the heating gas only when the substrate heating is necessary. More specifically, a switching mechanism (not shown) is provided between the flow path and the high-temperature gas supply mechanism 190 so that the flow destination of the heating gas can be switched between the substrate back surface and the exhaust path. Otherwise, the heating gas may be supplied to the back surface of the substrate through the switching mechanism only when the substrate is heated while the heating gas is turned to the exhaust path. In the seventh embodiment, nitrogen gas is used as the heating gas. However, the heating gas is not limited to this, and air or the like may be used. Moreover, as a back surface heating system, various heating systems, such as a hot plate system and a microwave system, can be employ | adopted instead of using the gas for a heating.

<Others>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. In the above-described embodiment, dry nitrogen gas is used as the “dry gas” of the present invention, but other dry gases such as dry air can be used.

  In the above embodiment, the humidity of the processing space 162 is rapidly reduced by supplying the dry nitrogen gas to the processing space 162 and suppressing the exhaust of the processing space 162 more than the exhaust during the wet processing. The air volume of clean air sent from the fan filter unit 104 into the apparatus may be adjusted. That is, the fan 104a of the fan filter unit 104 is driven and controlled by a fan adjustment mechanism 192 provided in the unit control unit 118. The rotational speed of the fan 104a is controlled by the fan adjustment mechanism 192, and the amount of clean air sent into the apparatus Can be adjusted. The unit control unit 118 controls the fan adjusting mechanism 192 so that the air volume of clean air can be suppressed after the wet process and before the dry process than the air volume during the wet process. Can be effectively reduced. In such an embodiment, the fan adjustment mechanism 192 functions as the “air volume adjustment unit” of the present invention.

  In the replacement process of the above-described embodiment, the replacement process is performed using the IPA liquid as a low surface tension liquid in order to prevent problems such as collapse of the pattern formed on the substrate surface and improve the drying performance. However, in addition to the IPA liquid, various organic solvents such as ethyl alcohol and methyl alcohol may be used as the low surface tension liquid. Also, various alcohol vapors may be dissolved in DIW as an organic solvent component to produce a low surface tension liquid. In addition, although the substitution process is performed before the drying process, this is not an essential process and may be omitted.

  In the above embodiment, the present invention is applied to an apparatus and a method for performing chemical processing, rinsing processing, replacement processing, and drying processing on a substrate W such as a semiconductor wafer. The present invention is not limited to this, and the present invention can be applied to a substrate processing apparatus and method for drying a substrate after supplying a processing liquid to the substrate and performing wet processing.

  The present invention is wet on all substrates including semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, FED substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, etc. The present invention can be applied to a substrate processing apparatus and method for performing processing and drying processing.

It is a figure which shows the substrate processing system which can apply this invention suitably. It is a figure which shows 1st Embodiment of the processing unit as a substrate processing apparatus concerning this invention. It is a block diagram which shows the electric constitution which controls the processing unit of FIG. It is a fragmentary sectional view of the 1st gas supply nozzle. It is a figure which shows the main structural members of a 1st gas supply nozzle. It is a figure which shows operation | movement of the processing unit of FIG. It is a figure which shows operation | movement of the processing unit of FIG. It is a figure which shows the comparison result of an Example and a comparative example. It is a figure which shows typically the generation | occurrence | production mechanism of the dry defect resulting from evaporation of an IPA liquid. It is a figure which shows 3rd Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows the main structural members of the 1st gas supply nozzle in 3rd Embodiment. It is a figure which shows 4th Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows the exhaust_gas | exhaustion adjustment mechanism employable with the substrate processing apparatus concerning this invention. It is a flowchart which shows 5th Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows 6th Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows 7th Embodiment of the substrate processing apparatus concerning this invention.

Explanation of symbols

1A to 4A, 1B to 4B, 100... Processing unit (substrate processing apparatus)
104 ... Fan filter unit 104c ... Heating layer (humidity control mechanism)
104d ... Silica gel layer (humidity control mechanism)
106: Spin chuck (substrate holding means)
120... Chuck pin (substrate holding means)
130 ... IPA liquid supply nozzle (solvent supply means)
132 ... second gas supply nozzle 160 ... exhaust pipe (exhaust means)
162 ... Processing space 164 ... Exhaust adjustment mechanism 164a ... Bypass piping (exhaust adjustment mechanism)
164b ... On-off valve (exhaust adjustment mechanism)
170, 186: first gas supply nozzle 182: humidity sensor (first humidity detection means, second humidity detection means)
192: Fan adjustment mechanism (air flow adjustment means)
P1 ... Branch position P2 ... Communication position W ... Board

Claims (10)

In the substrate processing apparatus for supplying a processing liquid to the surface of the substrate and subjecting the substrate surface to a predetermined wet process, and then drying the substrate,
Substrate holding means for holding the substrate in a substantially horizontal posture;
First gas supply means for supplying a dry gas to the outer peripheral portion of the surface of the substrate held by the substrate holding means;
Second gas supply means for supplying a dry gas to the center of the surface of the substrate held by the substrate holding means;
Exhaust means for exhausting a processing space in contact with the substrate surface;
An exhaust adjusting means for adjusting the exhaust of the processing space;
While supplying dry gas from the first gas supply means to the outer peripheral portion of the surface of the substrate and supplying dry gas from the second gas supply means to the center of the surface of the substrate, the exhaust adjustment means exhausts the processing space. The substrate processing apparatus is characterized in that the substrate is dried in a state in which the humidity of the processing space is reduced by suppressing the wet processing. A solvent supply means for supplying a low surface tension solvent having a surface tension lower than that of the processing liquid to the surface of the substrate and replacing the processing liquid on the substrate surface with the low surface tension solvent;
The substrate processing apparatus according to claim 1, wherein after the replacement with the low surface tension solvent, the low surface tension solvent is removed from the substrate surface to dry the substrate surface.   The first gas supply means starts supplying the dry gas after the wet process and before the replacement with the low surface tension solvent, while the second gas supply means is started after the replacement is completed and before the dry process. The substrate processing apparatus according to claim 2, wherein supply of the dry gas is started. The exhaust means has an exhaust pipe, and the processing space is exhausted through the exhaust pipe,
The exhaust adjusting means has a narrower diameter than the exhaust pipe and is branched from the exhaust pipe and communicated with the exhaust pipe again; a branch position where the bypass pipe branches from the exhaust pipe; and the bypass pipe Is provided with an on-off valve inserted into the exhaust pipe between a communication position communicating with the exhaust pipe, and the on-off valve is opened during the wet processing, and the on-off valve is closed during the humidity reduction processing. The substrate processing apparatus according to claim 1, wherein an exhaust amount of the processing space is suppressed to be less than an exhaust amount during the wet processing. A first humidity detecting means for detecting the humidity inside the apparatus;
5. The start of the wet processing is regulated when the initial humidity detected by the first humidity detection means before the start of the wet processing exceeds a first specified humidity. The substrate processing apparatus according to item. A second humidity detecting means for detecting the humidity of the processing space;
6. The start of the drying process is regulated when the humidity of the processing space before the start of the drying process detected by the second humidity detecting unit exceeds a second specified humidity. The substrate processing apparatus as described in any one of Claims. While performing clean air from the fan filter unit toward the substrate held by the substrate holding means, the wet processing to the drying processing are performed,
The substrate processing apparatus according to claim 1, wherein the dry gas has a lower humidity than the clean air. An air volume adjusting means for adjusting the air volume of clean air sent from the fan filter unit;
The substrate processing apparatus according to claim 7, wherein the air volume adjusting unit suppresses the air volume of the clean air after the wet process and before the drying process to reduce the humidity of the processing space by suppressing the air volume during the wet process. A humidity control mechanism for adjusting the humidity of the clean air sent out from the fan filter unit;
First humidity detecting means for detecting the humidity inside the device,
When the initial humidity detected by the first humidity detection means before the start of the wet processing exceeds the first specified humidity, the humidity of the clean air is lowered by the humidity control mechanism, and the initial humidity The substrate processing apparatus according to claim 7, wherein is suppressed to the first specified humidity or less. A wet process of supplying a treatment liquid to the surface of the substrate and applying a predetermined wet process to the substrate surface;
A humidity lowering step of supplying dry gas to each of the outer peripheral portion and the central portion of the surface of the substrate after the wet process and lowering the humidity in the process space by suppressing exhaust of the process space as compared with the wet process. When,
A substrate processing method comprising: a drying step of drying the substrate after the humidity reduction step.