JP4680149B2 - Coating processing method, program, computer-readable recording medium, and coating processing apparatus - Google Patents

Description

  The present invention relates to a coating processing method, a program, a computer-readable recording medium storing the program, and a coating processing apparatus.

  For example, in a photolithography process in a semiconductor device manufacturing process, a coating process is performed in which a resist solution is applied to the surface of a wafer to form a resist film.

  The above-described coating process is usually performed in a resist coating apparatus, and is performed by supplying a predetermined amount of resist solution to the center of the rotated wafer surface and diffusing the resist solution over the entire surface of the wafer by centrifugal force. ing.

  By the way, the resist solution used for the coating process is very expensive, and it is desired to save the resist solution. Therefore, conventionally, a pre-wet process for supplying a solvent to the wafer surface immediately before applying the resist solution has been performed (see Patent Document 1). This pre-wetting treatment improves the wettability between the wafer surface and the resist solution, and even a small amount of resist solution diffuses over the entire surface of the wafer, so that the amount of resist solution used can be reduced.

JP-A-11-260717

  However, as the diameter of the wafer increases, a relatively large amount of resist solution is required even when the conventional pre-wet processing is performed. For this reason, the technique which further reduces the usage-amount of the resist liquid in a coating process is desired.

  The present invention has been made in view of the above points, and an object of the present invention is to save liquid in a coating solution in a coating process in which a coating solution such as a resist solution is applied to the surface of a substrate such as a wafer.

The present invention for achieving the above object is a coating processing method for applying a coating solution to the surface of a substrate, the first step of holding the substrate, and cooling the substrate to a dew point temperature of the surrounding atmosphere or lower, a second step of condensation on the surface of the substrate, rotating the substrate which is cooled below the dew point temperature, possess a third step of applying the coating solution on the surface of the substrate, a second step The substrate is rotated, and the substrate is cooled by supplying cooling liquid nitrogen to the substrate from the cooling nozzle. When the liquid nitrogen is supplied, the liquid is applied to the substrate surface by the cooling nozzle. The supply position of nitrogen is moved from the outer peripheral portion of the substrate toward the central portion, and liquid nitrogen is supplied to the entire surface of the substrate .

  According to the present invention, before the coating liquid is applied to the surface of the substrate, the substrate can be cooled below the dew point temperature of the surrounding atmosphere to cause condensation on the surface of the substrate. The interfacial energy decreases, and the wettability of the substrate surface with respect to the coating solution is dramatically improved. As a result, the coating liquid easily diffuses on the surface of the substrate, and even a smaller amount of the coating liquid can be applied to the entire surface of the substrate. In addition, since the substrate is cooled, the coating solution supplied to the substrate is also maintained at a low temperature, and the viscosity of the coating solution is maintained at a low level. This also makes it easier for the coating liquid to diffuse on the surface of the substrate, further reducing the amount of coating liquid used.

  According to another aspect of the present invention, there is provided a program for causing a computer to realize the above-described coating processing method.

  According to another aspect of the present invention, there is provided a computer-readable recording medium that records a program for causing a computer to realize the above-described coating treatment method.

According to another aspect of the present invention, there is provided a coating processing apparatus for applying a coating liquid to a surface of a substrate, the rotating mechanism for holding and rotating the substrate, and supplying the liquid nitrogen for cooling to the surface of the substrate to fix the substrate. A cooling nozzle that cools below the dew point temperature of the surrounding atmosphere, a coating liquid supply nozzle that supplies the coating liquid to the surface of the substrate, and the cooling nozzle that discharges the liquid nitrogen are arranged on the outer periphery of the substrate surface A moving mechanism for moving the substrate from above to the central portion; while rotating the substrate, supplying liquid nitrogen from the cooling nozzle to dew the surface of the substrate; then stopping the supply of liquid nitrogen and applying the coating A controller that controls the rotation mechanism, the moving mechanism, the liquid nitrogen supply pipe valve, and the coating liquid supply pipe valve so as to supply the coating liquid from the liquid supply nozzle to the substrate surface; Features having To.

  The coating processing apparatus further includes a substrate accommodating portion that accommodates the substrate held by the rotating mechanism and surrounds the periphery of the substrate, and the substrate accommodating portion exhausts an atmosphere of the surface of the substrate. May be formed.

  The exhaust port may be formed at a position outside the substrate surface in the substrate housing portion.

  The rotation mechanism may include a holding member that holds an outer peripheral portion of the substrate and a rotation driving unit that rotates the holding member.

  According to the present invention, it is possible to save the coating liquid applied to the surface of the substrate, and therefore, for example, the running cost of the coating processing apparatus can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a plan view showing an outline of the configuration of a coating and developing treatment system 1 in which the coating treatment apparatus according to the present embodiment is mounted, and FIG. 2 is a front view of the coating and developing treatment system 1. FIG. 2 is a rear view of the coating and developing treatment system 1.

  As shown in FIG. 1, the coating and developing treatment system 1 includes, for example, a cassette for loading / unloading a plurality of wafers W from / to the coating / developing processing system 1 in cassette units and loading / unloading wafers W to / from the cassette C A station 2, a processing station 3 in which a plurality of various processing apparatuses for performing predetermined processing in a single wafer type in a photolithography process are arranged in multiple stages, and an exposure apparatus provided adjacent to the processing station 3 It has a configuration in which an interface station 4 that transfers the wafer W to and from (not shown) is integrally connected.

  In the cassette station 2, a cassette mounting table 5 is provided, and the cassette mounting table 5 is capable of mounting a plurality of cassettes C in a row in the X direction (vertical direction in FIG. 1). The cassette station 2 is provided with a wafer transfer body 7 that can move on the transfer path 6 along the X direction. The wafer carrier 7 is also movable in the wafer arrangement direction (Z direction; vertical direction) of the wafers W accommodated in the cassette C, and can selectively access a plurality of wafers W in the cassette C. Further, the wafer transfer body 7 is rotatable around a vertical axis (θ direction) and can access each processing apparatus of a third processing apparatus group G3 described later on the processing station 3 side described later.

  The processing station 3 includes, for example, five processing device groups G1 to G5 in which a plurality of processing devices are arranged in multiple stages. A first processing device group G1 and a second processing device group G2 are arranged in this order from the cassette station 2 side on the X direction negative direction (downward direction in FIG. 1) side of the processing station 3. A third processing device group G3, a fourth processing device group G4, and a fifth processing device group G5 are sequentially arranged from the cassette station 2 side on the X direction positive direction (upward direction in FIG. 1) side of the processing station 3. Has been placed. A first transfer device 10 is provided between the third processing device group G3 and the fourth processing device group G4. The first transfer device 10 can selectively access each device in the first processing device group G1, the third processing device group G3, and the fourth processing device group G4 to transfer the wafer W. A second transfer device 11 is provided between the fourth processing device group G4 and the fifth processing device group G5. The second transfer device 11 can selectively access each device in the second processing device group G2, the fourth processing device group G4, and the fifth processing device group G5 to transfer the wafer W.

  As shown in FIG. 2, in the first processing unit group G1, a liquid processing apparatus that performs processing by supplying a predetermined liquid to the wafer W, for example, a resist coating apparatus 20 as a coating processing apparatus according to the present embodiment, 21 and 22 and bottom coating devices 23 and 24 for forming an antireflection film for preventing reflection of light during the exposure process are stacked in five stages in order from the bottom. In the second processing unit group G2, liquid processing units, for example, development processing units 30 to 34 for supplying a developing solution to the wafer W and performing development processing are stacked in five stages in order from the bottom. In addition, chemical chambers 40 and 41 for supplying various processing liquids to the liquid processing apparatuses in the processing apparatus groups G1 and G2 are provided at the bottom of the first processing apparatus group G1 and the second processing apparatus group G2. Are provided.

  For example, as shown in FIG. 3, the third processing unit group G3 includes a temperature control device 60, a transition device 61 for delivering the wafer W, and a high-precision temperature control that adjusts the wafer temperature under high-precision temperature control. The heat treatment apparatuses 65 to 68 for heat-treating the apparatuses 62 to 64 and the wafer W at a high temperature are sequentially stacked in nine stages from the bottom.

  In the fourth processing unit group G4, for example, a high-precision temperature control device 70, pre-baking devices 71 to 74 that heat-treat the resist-coated wafer W, and post-baking devices 75 to 79 that heat-process the developed wafer W. Are stacked in 10 steps from the bottom.

  In the fifth processing apparatus group G5, a plurality of heat treatment apparatuses for heat-treating the wafer W, for example, high-precision temperature control apparatuses 80 to 83 and post-exposure bake (post-exposure bake) apparatuses 84 to 89 are stacked in 10 stages in order from the bottom. ing.

  As shown in FIG. 1, a plurality of processing devices are arranged on the positive side in the X direction of the first transfer device 10. For example, as shown in FIG. 3, an adhesion device 90 for hydrophobizing the wafer W. , 91 are stacked in two steps in order from the bottom. As shown in FIG. 1, a peripheral exposure device 92 that selectively exposes only the edge portion of the wafer W, for example, is disposed on the positive side in the X direction of the second transfer device 11.

  In the interface station 4, for example, as shown in FIG. 1, a wafer transfer body 101 that moves on a transfer path 100 extending in the X direction and a buffer cassette 102 are provided. The wafer carrier 101 is movable in the Z direction and rotatable in the θ direction, and accesses an exposure apparatus (not shown) adjacent to the interface station 4, the buffer cassette 102, and the fifth processing apparatus group G5. The wafer W can be transferred.

  An air supply device 110 is installed on the ceiling of the coating and developing treatment system 1 as shown in FIG. 2, and clean air adjusted to a predetermined temperature and humidity is supplied into the coating and developing treatment system 1. A downflow can be formed in the stations 2, 3, 4.

  Next, the structure of the resist coating apparatuses 20 to 22 will be described in detail. 4 is an explanatory diagram of a vertical section showing an outline of the configuration of the resist coating apparatus 20, and FIG. 5 is an explanatory diagram of a horizontal section showing an outline of the configuration of the resist coating apparatus 20. As shown in FIG.

  As shown in FIG. 4, the resist coating apparatus 20 has a casing 20a, and a spin chuck 120 as a rotating mechanism for holding and rotating the wafer W is provided in the casing 20a. The spin chuck 120 is formed of, for example, a material having lower thermal conductivity than the wafer W, such as PEEK (polyether ether ketone) or carbon-added conductive PEEK. The spin chuck 120 has a horizontal upper surface, and a suction port (not shown) for sucking the wafer W, for example, is provided on the upper surface. The wafer W can be sucked onto the spin chuck 120 by suction from the suction port. The spin chuck 120 can rotate the wafer W at a predetermined speed by a rotation drive unit 121 such as a motor built in the spin chuck 120, for example.

  For example, a cup 130 as a substrate housing portion is provided around the spin chuck 120. The cup 130 is made of, for example, a material having low thermal conductivity, for example, a fluorine resin. The cup 130 includes an outer cup 131 and an inner cup 132. Each of the outer cup 131 and the inner cup 132 is formed in a substantially cylindrical shape, and is arranged concentrically in a double manner on the outer side and the inner side. The outer cup 131 includes a vertical wall 131 a formed from the height of the bottom surface of the cup 130 to the height above the wafer W on the spin chuck 120. The inner cup 132 includes a vertical wall 132 a at a position below the outer peripheral portion of the wafer W on the spin chuck 120. A cylindrical partition plate 133 is formed in the vicinity of the central portion between the outer cup 131 and the inner cup 132. The partition plate 133 forms a liquid recovery part 134 on the outer cup 131 side and a gas recovery part 135 on the inner cup 132 side at the bottom of the cup 130. The partition plate 133 is formed at a predetermined height upward from the bottom surface of the cup 130, and the liquid recovery unit 134 and the gas recovery unit 135 communicate with each other above the partition plate 133.

  Connected to the upper end of the vertical wall 132a of the inner cup 132 is a guide wall 132b that is inclined obliquely outward from the vicinity of the back surface of the outer periphery of the wafer W and whose tip communicates with the liquid recovery part 134. A drainage pipe 136 is connected to the lower surface of the liquid recovery unit 134, and an exhaust pipe 137 is connected to the lower surface of the gas recovery unit 135. With this configuration, the liquid splashed from the wafer W passes between the guide wall 132 b and the vertical wall 131 a of the outer cup 131 and is collected by the liquid collecting unit 134 and discharged from the drain pipe 136. The ambient atmosphere around the wafer W is sent to the liquid recovery unit 134 by the guide wall 132 b, then flows over the partition plate 133 into the gas recovery unit 135 and is exhausted from the exhaust pipe 137.

  As shown in FIG. 5, for example, a rail 140 extending along the Y direction (left and right direction in FIG. 5) is formed on the negative X direction (downward direction in FIG. 5) side of the cup 130. The rail 140 is formed, for example, from the outside of the cup 130 on the Y direction positive direction (right direction in FIG. 5) to the vicinity of the end of the cup 130 on the Y direction negative direction (left direction in FIG. 5) side. The rail 140 is provided with an arm 141, and a resist solution supply nozzle 142 is supported on the arm 141. The arm 141 is movable on the rail 140 by a driving unit 143 such as a motor, and the resist solution supply nozzle 142 is transferred from the standby unit 144 installed outside the cup 130 onto the wafer W in the cup 130. can do. Further, the arm 141 is movable up and down by, for example, the drive unit 143 and can move the resist solution supply nozzle 142 up and down.

  The resist solution supply nozzle 142 communicates with the resist solution supply source 151 through a supply pipe 150, for example, as shown in FIG. The supply pipe 150 is provided with a valve 152, and the resist solution can be discharged from the resist solution supply nozzle 142 at a predetermined timing by opening and closing the valve 152.

  A cooling nozzle 160 is disposed above the wafer W held by the spin chuck 120. The cooling nozzle 160 is connected to a cooling liquid storage bottle 162 by a supply pipe 161. In the present embodiment, for example, liquid nitrogen at about −200 ° C. is stored in the storage bottle 162 as a cooling liquid. As the supply pipe 161, for example, a metal double pipe capable of evacuating the outer pipe is used. Thereby, the temperature of the liquid nitrogen until the liquid nitrogen is transferred to the cooling nozzle 160 can be maintained and volatilization of the liquid nitrogen can be prevented. For example, the supply pipe 161 extends in the horizontal direction from the tip end to which the cooling nozzle 160 is connected, reaches the upper part of the storage bottle 162, and then refracts at a right angle downward and enters the storage bottle 162. For example, a rotation driving unit 163 such as a motor is attached to the bending portion of the supply pipe 161, and the supply pipe 161 as shown in FIG. 161 can be rotated in the horizontal direction. Thereby, the cooling nozzle 160 can move in the radial direction of the wafer W on the surface of the wafer W. In this embodiment, for example, the supply pipe 161 and the rotation drive unit 163 constitute a moving mechanism for the cooling nozzle 160.

  As the supply pressure of liquid nitrogen from the storage bottle 162 to the cooling nozzle 160, the self-volatilization pressure of liquid nitrogen in the storage bottle 162 is used. As shown in FIG. 4, the supply pipe 162 is provided with a valve 164, and when the valve 164 is opened, liquid nitrogen in the storage bottle 162 is pumped to the cooling nozzle 160.

  The storage bottle 162 is provided with a barometer 165 that measures the pressure in the storage bottle 162 and a gas supply pipe 166 that supplies nitrogen gas into the storage bottle 162. The barometer 165 is provided with a degassing function, and when the pressure in the storage bottle 162 becomes larger than a specified value, the pressure in the storage bottle 162 can be extracted to lower the pressure. The gas supply pipe 166 communicates with a nitrogen gas supply source (not shown). When the pressure of the storage bottle 162 drops below a specified value, the storage bottle 162 is replenished with nitrogen gas to increase the pressure. Can be recovered. Thereby, the pressure (supply pressure of liquid nitrogen) in the storage bottle 162 can be kept constant.

  The control unit 170 controls the operation of the drive system such as the rotation driving operation of the spin chuck 120, the rotation operation of the cooling nozzle 160, and the opening / closing operation of the valves 152 and 164. The control unit 170 is configured by, for example, a general-purpose computer, and controls the operation of the spin chuck 120 and the like by executing the program P recorded in the memory, thereby realizing the coating process described later. In addition, the program P for realizing the coating process in the present embodiment may be installed in the control unit 170 by a computer-readable recording medium.

  Since the configuration of the resist coating apparatuses 21 and 22 is the same as that of the above-described resist coating processing 20, description thereof will be omitted.

  Next, a coating process performed by the resist coating apparatus 20 configured as described above will be described together with a wafer processing process performed by the entire coating and developing system 1.

  When the wafer processing is started, a downflow is formed in the coating and developing processing system 1, and the coating and developing processing system 1 has an air atmosphere at a predetermined temperature (for example, 23 ° C.) and humidity (for example, 45% Rh). Maintained. First, unprocessed wafers W are taken out one by one from the cassette C on the cassette mounting table 5 by the wafer transfer body 7 shown in FIG. 1 and sequentially transferred to the processing station 3. The wafer W is transferred to the temperature control device 60 belonging to the third processing device group G3 of the processing station 3, and the temperature is adjusted to a predetermined temperature. Thereafter, the wafer W is transferred to, for example, the bottom coating apparatus 23 by the first transfer apparatus 10 to form an antireflection film. Thereafter, the wafer W is sequentially transferred to the heat treatment apparatus 65 and the high-precision temperature control apparatus 70 by the first transfer apparatus 10 and subjected to predetermined processing in each processing apparatus. Thereafter, the wafer W is transferred to, for example, the resist coating apparatus 20 by the first transfer apparatus 10.

  FIG. 6 is a flowchart showing an example of a coating process in the resist coating apparatus 20. The inside of the resist coating apparatus 20 is maintained in the above-described downflow air atmosphere. When the wafer W is loaded into the resist coating apparatus 20, the wafer W is sucked and held by the spin chuck 120 (step S1 in FIG. 6). Next, rotation of the wafer W is started by the spin chuck 120 (step S2 in FIG. 6). At this time, the cooling nozzle 160 moves above the outer peripheral portion of the wafer W. After the rotation of the wafer W is started, liquid nitrogen at about −200 ° C. is discharged from the cooling nozzle 160 onto the surface of the wafer W.

  As shown in FIG. 7, the cooling nozzle 160 moves from the outer peripheral portion to the central portion on the surface of the wafer W while discharging low-temperature liquid nitrogen. Thus, liquid nitrogen is supplied to the entire surface of the wafer W (step S3 in FIG. 6). With this supply of liquid nitrogen, the wafer W reaches a dew point of ambient air, for example, 10 ° C. (when the temperature in the resist coating apparatus 10 is 23 ° C. and the humidity is 45% Rh) or less, for example, about 10 ° C. to −20 ° C. To be cooled. Note that the temperature of the wafer W at this time is maintained at a temperature at which the resist solution and the solvent contained therein do not solidify (a temperature higher than the melting point of the resist solution and the solvent). By this cooling of the wafer W, moisture B contained in the air around the wafer is condensed on the surface of the wafer W as shown in FIG.

  After the cooling nozzle 160 has moved to the center of the surface of the wafer W, the supply of liquid nitrogen is stopped. Then, the supply pipe 161 is rotated by the rotation driving unit 163 so that the cooling nozzle 160 is retracted to the outside of the cup 130.

  In a state where the wafer W is maintained at a low temperature, the resist solution supply nozzle 142 moves above the center portion of the wafer W, and a predetermined amount of the resist solution supply nozzle 142 is moved from the resist solution supply nozzle 142 to the center portion of the surface of the rotating wafer W. A resist solution is supplied (step S4 in FIG. 6). The resist solution is diffused over the entire surface of the wafer W by the rotation of the wafer W, and a resist film is formed on the surface of the wafer W.

  Thereafter, the wafer W is rotated at high speed to adjust the thickness of the resist film and dry, and then the rotation of the wafer W is stopped (step S5 in FIG. 6). When the rotation of the wafer W is stopped, the wafer W is transferred to the external first transfer device 10 and unloaded from the resist coating device 20 by the first transfer device 10 to complete a series of coating processes. To do. In this series of coating processes, for example, the control unit 170 executes the program P to control the rotation driving operation of the spin chuck 120, the rotation operation of the cooling nozzle 160, the opening / closing operation of the valves 152 and 164, and the like. It is realized by.

  The wafer W on which the resist film is formed is transferred to the pre-baking device 71 by the first transfer device 10 and subjected to a pre-baking process. Subsequently, the wafer W is sequentially transferred to the peripheral exposure apparatus 91 and the high-precision temperature control apparatus 83 by the second transfer apparatus 11 and subjected to predetermined processing in each apparatus. Thereafter, the wafer W is transferred to an exposure apparatus (not shown) by the wafer transfer body 101 of the interface station 4 and exposed. The wafer W after the exposure processing is transferred to the post-exposure baking device 84 by the wafer transfer body 101, for example, and subjected to post-exposure baking, and then transferred to the high-precision temperature control device 81 by the second transfer device 11 to adjust the temperature. Is done. Thereafter, the wafer W is transferred to the development processing apparatus 30 and the resist film on the wafer W is developed. The developed wafer W is transferred to the post-baking device 75 by the second transfer device 11 and subjected to a post-baking process. Thereafter, the wafer W is transferred to the high-precision temperature controller 63 and the temperature is adjusted. Then, the wafer W is transferred to the transition device 61 by the first transfer device 10 and returned to the cassette C by the wafer transfer body 7 to complete a series of wafer processing.

  According to the above embodiment, the wafer W is cooled below the dew point temperature of the surrounding air before the resist solution is applied to the surface of the wafer W to cause condensation on the surface of the wafer W. And the wettability of the wafer W with respect to the resist solution can be dramatically improved. As a result, the resist solution can be applied to the entire surface of the wafer W using a small amount of resist solution. Further, since the wafer W is cooled, the resist solution supplied to the wafer W also becomes a low temperature, and the viscosity of the resist solution is kept low. As a result, the resist solution on the surface of the wafer W is more easily diffused, and even a smaller amount of resist solution is applied to the entire surface of the wafer W, so that the resist solution can be saved.

  Further, in the above embodiment, when cooling the wafer W, the cooling nozzle 160 is moved from the outer peripheral portion of the wafer W toward the central portion while discharging liquid nitrogen from the cooling nozzle 160. . In this case, as the cooling nozzle 160 moves, the wafer W is cooled from the outer periphery toward the center. Since the liquid nitrogen supplied onto the wafer W from the cooling nozzle 160 flows outward from the supply position due to the centrifugal force of the wafer W, the liquid nitrogen continues in the wafer area outside the position of the cooling nozzle 160. Supplied. Therefore, the wafer region where the cooling nozzle 160 passes above is maintained at a predetermined low temperature. As a result, when the cooling nozzle 160 finishes moving to the central portion, the temperature in the wafer surface is kept uniform, and condensation forms on the entire surface of the wafer W without any spots. As a result, the resist solution is uniformly applied on the entire wafer surface without unevenness. Further, since the wafer W is cooled from the outside and is thermally contracted from the outside, the stress applied to the wafer W can be released to the outside, and damage to the wafer W due to the thermal contraction can be prevented.

  In the above embodiment, when liquid nitrogen is supplied to the wafer W and the wafer W is cooled, the atmosphere on the surface of the wafer W may be exhausted. In such a case, for example, as shown in FIG. 9, an exhaust port 180 is formed inside the vertical wall 131 a of the outer cup 131. The exhaust port 180 is formed at a position slightly higher than the height of the wafer W on the spin chuck 120, for example. For example, the exhaust ports 180 are formed at equal intervals in a plurality of locations in the circumferential direction of the vertical wall 131a. Each exhaust port 180 is connected to a negative pressure generator 182 outside the cup 130 by, for example, an exhaust pipe 181 passing through the inside of the outer cup 131.

  For example, when liquid nitrogen is supplied to the wafer W from the cooling nozzle 160, the atmosphere near the surface of the wafer W is exhausted from the exhaust port 180. By doing so, for example, low-temperature nitrogen gas generated by volatilization of liquid nitrogen does not contact or adhere to the peripheral member, and temperature fluctuation and contamination of the peripheral member can be suppressed.

  In the above embodiment, liquid nitrogen is supplied to the front surface of the wafer W, but may be supplied to the rear surface of the wafer W. FIG. 10 shows such an example. The resist coating process 190 in this example includes a hollow spin chuck 191 having a substantially cylindrical shape, for example. The diameter of the upper part of the spin chuck 191 is larger than that of the lower part. For example, a plurality of holding members 192 that rotate inward are attached to the top of the spin chuck 191. A step portion 192 a on which the wafer W is placed is formed on the upper end portion of the holding member 192. When the wafer W is placed on the stepped portion 192a, each holding member 192 rotates inward by the weight of the wafer W, for example, and holds the outer periphery of the wafer W from the outside to fix the wafer W. it can.

  A counter plate 193 that faces the back surface of the wafer W is provided inside the spin chuck 191. The counter plate 193 is formed in a disk shape having a diameter that is slightly smaller than the wafer W and has the same diameter as the wafer W, for example. The counter plate 193 is arranged on the back side of the wafer W held by the spin chuck 191 so that a gap D is formed between the counter plate 193 and the wafer W. For example, a liquid nitrogen supply port 194 serving as a liquid supply unit for liquid nitrogen is formed at the center of the upper surface of the counter plate 193.

  A supply pipe 195 is connected to the liquid nitrogen supply port 194. The supply pipe 195 passes through the inside of the counter plate 193 in the vertical direction, passes through the rotation axis of the spin chuck 191, exits from the lower surface of the spin chuck 191, and is connected to the liquid nitrogen supply source 196. The supply pipe 195 is provided with a valve 197 and can supply liquid nitrogen at a predetermined timing. A belt 198 is hung, for example, in the horizontal direction below the spin chuck 191, and the spin chuck 191 can be rotated by rotating the belt 198 with a motor 199 as a rotation drive unit.

  The opening / closing operation of the valve 197 and the rotation operation of the spin chuck 191 are controlled by the control unit 170 as in the above embodiment. Since the other configuration of the resist coating apparatus 190 is the same as that of the resist coating apparatus 120, the same reference numerals are used and description thereof is omitted.

  During the coating process, when the wafer W is held on the spin chuck 191 by the holding member 192 as shown in FIG. 10, the wafer W is rotated by the spin chuck 191. Thereafter, liquid nitrogen is discharged from the liquid nitrogen supply port 194, and the liquid nitrogen N is filled in the gap D between the back surface of the wafer W and the counter plate 193 as shown in FIG. By doing so, the wafer W is rapidly cooled below the dew point temperature of the surrounding air. Thereafter, the resist solution is supplied from the resist solution supply nozzle 142 to the center of the surface of the wafer W, and a resist film is formed on the surface of the wafer W.

  Also in this example, since the wafer W can be cooled below the dew point temperature of the surrounding air before the resist solution is applied to the surface of the wafer W to cause condensation on the surface of the wafer W, the wafer W is wetted with the resist solution. Thus, the resist solution can be applied to the entire surface of the wafer W using a small amount of resist solution. In addition, the resist solution supplied to the wafer W also becomes a low temperature and the viscosity of the resist solution is maintained in a low state, so that the resist solution can be properly applied to the entire surface of the wafer W even with a small amount of resist solution. .

  Moreover, since liquid nitrogen is supplied to the back surface of the wafer W to cool the wafer W, the wafer W can be cooled without directly touching the film structure already formed on the surface of the wafer W, for example.

  In the above-described embodiment, liquid nitrogen is supplied to the back surface of the wafer W to cool the wafer W. However, the wafer W may be cooled by bringing a low-temperature cooling plate into contact with the back surface of the wafer W. FIG. 12 shows such an example. For example, the resist coating apparatus 200 is provided with a cooling plate 201 in place of the above-described counter plate 193. The cooling plate 201 is made of a material having high thermal conductivity, such as aluminum. The cooling plate 201 has a disk shape having the same size as the wafer W.

  A rod 202 that passes through the inside of the spin chuck 191 in the axial direction is connected to the center of the lower surface of the cooling plate 201. The rod 202 can be moved up and down by an elevating drive unit 203 such as a cylinder and can move the cooling plate 201 up and down. Inside the cooling plate 201, a conduit 204 through which the refrigerant flows is formed. A circulation path 205 is connected to the pipe line 204 through the inside of the spin chuck 191 and from the lower surface of the spin chuck 191 to an external refrigerant supply source (not shown). By supplying the refrigerant to the pipe line 204 through the circulation path 205, the cooling plate 201 can be maintained at a predetermined low temperature. In addition, as a refrigerant | coolant, inert refrigerant | coolants, such as a fluorine-type inert liquid, are used, for example. Further, in the present embodiment, for example, the lifting mechanism is constituted by the rod 202 and the lifting drive unit 203. Further, since the other configuration of the resist coating apparatus 200 is the same as that of the above-described resist coating apparatus 190, the description thereof is omitted using the same reference numerals.

  During the coating process, when the wafer W is held on the spin chuck 191 by the holding member 192, the cooling plate 201 rises as shown in FIG. 13 and the cooling plate 201 comes into contact with the back surface of the wafer W. The cooling plate 201 is maintained at a low temperature of, for example, −20 ° C. to 10 ° C. or less in advance by the refrigerant E, and the wafer W in contact with the cooling plate 201 is cooled to the dew point temperature of the surrounding air. At this time, moisture in the surrounding air is condensed on the surface of the wafer W. When the wafer W is sufficiently cooled, the cooling plate 201 is lowered and separated from the back surface of the wafer W. After the wafer W is separated from the cooling plate 201, the wafer W is rotated by the spin chuck 191, the resist solution is supplied from the resist solution supply nozzle 142 to the center of the surface of the wafer W, and the resist film is applied to the surface of the wafer W. Is formed.

  Also in this example, since the wafer W can be cooled below the dew point temperature of the surrounding air before the resist solution is applied to the surface of the wafer W to cause condensation on the surface of the wafer W, the wafer W is wetted with the resist solution. Thus, the resist solution can be applied to the entire surface of the wafer W using a small amount of resist solution. Further, the resist solution supplied to the wafer W also becomes a low temperature, and the resist solution can be maintained in a low viscosity state, so that the resist solution can be properly applied to the entire surface of the wafer W even with a small amount of resist solution.

  Further, since the cooling plate 201 is brought into contact with the back surface of the wafer W to cool the wafer W, for example, the wafer W can be cooled without directly touching the film structure already formed on the front surface of the wafer W.

  Further, since the cooling plate 201 can be raised and lowered, the cooling plate 201 is not separated from the wafer W after cooling, and the rotation of the wafer W is not hindered.

  In the above embodiment, the wafer W is cooled and condensed on the surface of the wafer W. However, the humidity in the ambient atmosphere of the wafer W may be increased so that the condensation is likely to occur at that time. For example, when the wafer W is cooled, air having a higher humidity than air during other processes (the above-described downflow air) may be supplied.

  In the example in which liquid nitrogen is supplied to the surface side of the wafer W in the above-described embodiment, the wafer W may be rotated by holding the outer peripheral portion of the wafer W by the holding member 192 as in the above-described embodiment. .

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs. For example, in the above embodiment, the resist solution coating process has been described as an example. However, the present invention is not limited to the resist solution, but an antireflection film, an SOG (Spin On Glass) film, an SOD (SOD) film, and the like. The present invention can also be applied to a coating treatment of a coating solution such as a spin on dielectric (Film) film. In the above embodiment, liquid nitrogen is used as the cooling liquid. However, other liquids such as carbon dioxide may be used. In the above embodiment, the application process is performed on the wafer W. However, the present invention applies other substrates such as an FPD (flat panel display) and a mask reticle for a photomask other than the wafer. It can also be applied to processing.

  The present invention is useful for reducing the amount of coating liquid applied to a substrate.

It is a top view which shows the outline of a structure of the coating and developing treatment system in this Embodiment. It is a front view of a coating and developing treatment system. It is a rear view of a coating and developing treatment system. It is explanatory drawing of the vertical cross section which shows the outline of a structure of a resist coating device. It is a top view which shows the outline of a structure of a resist coating apparatus. It is a flowchart which shows the process of a resist coating process. It is explanatory drawing which shows a mode that the nozzle for cooling moves on a wafer. It is explanatory drawing which shows a mode that the dew condensation produced on the surface of the wafer. It is explanatory drawing of the vertical cross section which shows the structure of the resist coating apparatus provided with the exhaust port. It is explanatory drawing of the vertical cross section which shows the structure of the resist coating device provided with the opposing board facing the back surface of a wafer. It is explanatory drawing which shows the state with which liquid nitrogen was filled between the opposing board and the back surface of the wafer. It is explanatory drawing of the vertical cross section which shows the structure of the resist coating device provided with the cooling plate which contacts the back surface of a wafer. It is explanatory drawing which shows the state which made the cooling plate contact the back surface of a wafer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating / development processing system 20 Resist coating apparatus 120 Spin chuck 142 Resist liquid supply nozzle 160 Cooling nozzle W Wafer

Claims (7)

A coating treatment method for applying a coating solution to the surface of a substrate,
A first step of holding a substrate;
A second step of cooling the substrate below the dew point temperature of its surrounding atmosphere to cause condensation on the surface of the substrate;
Rotating the substrate which is cooled below the dew point temperature, possess a third step of applying the coating solution on the surface of the substrate, and
In the second step, by rotating the substrate and supplying liquid nitrogen for cooling from the cooling nozzle to the substrate, the substrate is cooled,
When supplying the liquid nitrogen, the supply position of the liquid nitrogen to the substrate surface by the cooling nozzle is moved from the outer peripheral portion to the central portion of the substrate to supply the liquid nitrogen to the entire surface of the substrate. A coating treatment method characterized by: The program for making a computer implement | achieve the application | coating processing method of Claim 1 . A computer-readable recording medium on which a program for causing a computer to realize the coating treatment method according to claim 1 is recorded. A coating processing apparatus for applying a coating liquid to the surface of a substrate,
A rotation mechanism for holding and rotating the substrate;
A cooling nozzle that supplies liquid nitrogen for cooling to the surface of the substrate to cool the substrate below the dew point temperature of the surrounding atmosphere;
A coating liquid supply nozzle for supplying the coating liquid to the surface of the substrate;
A moving mechanism for moving the cooling nozzle that discharges the liquid nitrogen from the outer peripheral portion of the surface of the substrate to the central portion;
While rotating the substrate, liquid nitrogen is supplied from the cooling nozzle to condense the substrate surface, and then the supply of liquid nitrogen is stopped and the coating liquid is supplied from the coating solution supply nozzle to the substrate surface. A controller for controlling the rotation mechanism, the moving mechanism, the valve of the liquid nitrogen supply pipe, and the valve of the coating liquid supply pipe;
A coating treatment apparatus comprising: A substrate storage unit that stores the substrate held by the rotating mechanism and surrounds the periphery of the substrate,
The coating processing apparatus according to claim 4, wherein an exhaust port for exhausting an atmosphere on a surface of the substrate is formed in the substrate housing portion. The coating processing apparatus according to claim 5, wherein the exhaust port is formed at a position outside the substrate surface in the substrate housing portion. The said rotation mechanism has a holding member holding the outer peripheral part of a board | substrate, and the rotation drive part which rotates the said holding member, The coating processing apparatus in any one of Claims 4-6 characterized by the above-mentioned.

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