JP5191254B2 - Substrate processing apparatus and substrate processing method - Google Patents

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method for performing predetermined processing while a substrate is held substantially horizontally. Here, the substrate to be processed includes a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for optical disk, and a magnetic substrate. A disk substrate and a magneto-optical disk substrate are included. The processing applied to the substrate includes development processing, etching processing, cleaning processing, rinsing processing, and drying processing.

  In a substrate processing apparatus and a substrate processing method for performing processing with the substrate held substantially horizontally, in order to prevent dust and mist from dropping and adhering to the upper surface of the substrate or exposing the substrate surface to air, In some cases, a blocking member that is approximately the same size as or slightly larger than the substrate is disposed at a position close to the top of the substrate to cover the substrate. For example, in the technique described in Patent Document 1, a blocking plate disposed to face the substrate is provided immediately above the substrate held horizontally by the spin chuck. This blocking plate is rotationally driven at the same rotational direction and rotational speed as the spin chuck. By doing so, the conventional technique obtains a blocking effect of blocking the substrate from dust, mist, outside air and the like.

JP 2002-273360 A

  In this type of substrate processing apparatus and substrate processing method, further improvement in processing throughput, that is, the number of processed substrates per unit time is required. As one of methods for enabling this, it is conceivable to install a larger number of processing units for processing a substrate in the same installation volume and process a large number of substrates in parallel. For this purpose, further downsizing of each processing unit is required. However, the prior art has a limit in reducing the size of the apparatus. The reason is that a space for temporarily retracting the shielding plate for loading / unloading of the substrate is required, and a drive mechanism for rotating and retracting the shielding plate needs to be provided. Etc.

  The present invention has been made in view of the above problems, and in a substrate processing apparatus and a substrate processing method for performing a predetermined process while a substrate is held substantially horizontally, the same blocking effect as a processing technique using a blocking plate is obtained. However, it aims at providing the technique more suitable for size reduction of an apparatus.

The substrate processing apparatus according to the present invention, for achieving the above object, a substrate holding means for substantially horizontally holding the board, and the processing solution supplying means for performing wet processing by supplying a processing liquid to the substrate, the substrate Gas discharge means for discharging gas disposed above the central portion of the substrate held by the holding means, and the gas discharge means includes a first discharge port that opens toward the central portion of the substrate; is provided and a second discharge port opening to surround the first discharge port, the along the substrate surface after the wet processing and discharging the first gas from the first discharge port while forming the first gas layer according to the first gas, the upper layer of the layer of the first gas by ejecting a small second gas specific gravity than the first gas from the second outlet port It is characterized by forming the second gas layer of the second gas

  In the invention configured as described above, the first gas having a large specific gravity discharged from the first discharge port toward the central portion of the substrate spreads along the substrate surface toward the periphery thereof, and the first gas is formed in the vicinity of the substrate surface. A gas layer is formed by the gas. And since the 2nd gas discharged from the 2nd discharge port provided so that the 1st discharge port may be surrounded has a specific gravity smaller than the 1st gas, it is the 2nd gas above the 1st gas layer. Form a layer. Thus, the first gas layer covering the substrate surface controls the atmosphere in the vicinity of the substrate surface, while the second gas layer formed on the upper portion of the first gas layer is mist, dust or the like on the first gas layer. Prevent contamination. In this way, in the present invention, necessary processing can be performed while blocking the substrate from dust, mist, outside air, and the like. In addition to being able to configure the gas discharge means to be smaller than the outer dimensions of the substrate, it is not necessary to rotate the gas discharge means, so that the apparatus can be greatly reduced in size.

  For example, a gas having an average molecular weight smaller than that of the first gas can be used as the second gas. Among different gases, the specific gravity is larger as the average molecular weight is larger unless a temperature difference is provided. Therefore, a gas having a large average molecular weight can be suitably used as the first gas, and a gas having a small average molecular weight can be suitably used as the second gas.

  For example, as the second gas, a gas having the same composition as the first gas and a temperature higher than that of the first gas can be used. If the gas has the same composition, the specific gravity is larger as the temperature is lower. Therefore, among the two gases having the same composition and different temperatures, a low-temperature gas can be suitably used as the first gas, and a high-temperature gas can be used as the second gas.

  The first gas is preferably an inert gas. Since the first gas may directly touch the substrate surface, the substrate surface can be prevented from being altered by using this gas as an inert gas.

  The second gas is preferably a gas from which moisture has been removed. By doing so, the ambient atmosphere around the substrate surface can be kept in a low humidity environment, and the occurrence of defects such as spots and watermarks due to the adhesion of moisture to the substrate surface can be prevented.

  In addition, it is preferable that the gas discharge unit discharges the first gas from the first discharge port at a flow rate higher than the flow rate of the second gas discharged from the second discharge port. Thus, by creating a flow of the second gas having a low flow velocity around the first discharge port, vortices generated in the vicinity of the first discharge port due to the discharge of the first gas are reduced, and the first gas It is possible to effectively prevent entrainment of mist and the like.

  The second discharge port may open toward the periphery of the substrate. It is desirable that the first gas is blown toward the center of the substrate and flows from the center toward the outside along the substrate surface. On the other hand, the second gas does not need to be directly blown against the substrate surface, but rather flows outward along the upper portion of the first gas layer formed in the vicinity of the substrate surface. By doing so, it is possible to suppress the second gas from entering the first gas layer, and to prevent the mist or the like that has entered the second gas layer from approaching the substrate surface. it can.

Further, in the substrate processing apparatus includes a rotating means for rotating a substantially vertical axis of rotation about said substrate said substrate holding means driven to rotate, with respect to the substrate after pre-Symbol wet treatment by the gas discharge means In a state where the first gas layer and the second gas layer are formed by discharging the first and second gases, the substrate is rotated by the rotating means to remove the processing liquid from the substrate surface. And a control means for performing a drying process for drying the substrate. According to such a configuration, since the drying process is performed in a state where the substrate surface after the wet process is covered with the first and second gas layers, the substrate can be satisfactorily dried without causing defects. it can.

In order to achieve the above object, the substrate processing method according to the present invention includes a substrate holding step of holding the substrate substantially horizontally, a wet processing step of supplying a processing liquid to the substrate and performing a wet processing, and the substrate. A gas discharge means for discharging gas is disposed above the central portion of the first gas, and a first gas is discharged from the gas discharge means toward the central portion of the substrate to cover the substrate surface with the first gas. And a second gas layer that covers the first gas layer with the second gas by discharging a second gas having a specific gravity lower than that of the first gas from the gas discharge means. And a gas layer forming step for forming the substrate, and performing a predetermined process on the substrate after the wet process in a state where the first and second gas layers are formed.

  In the invention configured as described above, the atmosphere on the substrate surface is controlled by the first gas having a large specific gravity, while the second gas layer is formed above the first gas layer, as in the above-described substrate processing apparatus. By forming the mist, it is possible to prevent mist, dust and the like from being mixed into the first gas layer. Therefore, the same blocking effect can be obtained without providing a blocking plate, and the substrate can be processed with a simple and small apparatus configuration.

  Here, as the predetermined process, for example, a dry process may be performed in which the substrate after the wet process with the process liquid is rotated to remove the process liquid from the substrate surface and dry the substrate. By carrying out like this, a dry process can be performed in the state in which the substrate surface after wet processing was covered with the 1st and 2nd gas layers, and a substrate can be dried favorably, without producing a defect.

  According to the present invention, the first gas layer having a large specific gravity discharged toward the center of the substrate is formed near the substrate surface to control the atmosphere on the substrate surface, while the second gas layer having a smaller specific gravity is controlled. Is formed on the upper part of the first gas layer, so that mist from the surroundings can be effectively suppressed from entering the first gas layer. In addition, the device for gas discharge (gas discharge device) can be made smaller compared to the shielding plate that covers the entire substrate, and there is no need to rotate it, so the device is made smaller It becomes possible to do.

  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 substrate processing units as single-wafer type substrate processing apparatuses for performing processing with a processing liquid, processing gas, or the like on a 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 is a cassette C for storing substrates W (FOUP (Front Opening Unified Pod), SMIF (Standard Mechanical Interface) pod, OC (Open Cassette), etc.) for storing a plurality of substrates W in a sealed state). A plurality of cassette holders 21 that can hold a plurality of cassettes and the cassette C held in the cassette holder 21 are accessed to take out an unprocessed substrate W from the cassette C and store processed substrates in the cassette C. The indexer robot 22 is provided.

  In each cassette C, a plurality of substrates W are accommodated in one unit called “lot”. The plurality of substrates W are transferred between various substrate processing systems in units of lots, and the same type of processing is performed on each substrate W constituting the lot in each substrate processing system. 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 1, 2, 3, and 4 are mounted on the frame 30 so as to surround the substrate transfer robot 13. ing. In this embodiment, as the processing units 1 to 4, 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. In FIG. 1 (b), the processing unit 3B provided in the lower stage of the processing unit 3 and the processing unit 4B provided in the lower stage of the processing unit 4 are illustrated, but the lower stage of the processing units 1 and 2 is similarly illustrated. Another processing unit 1B and 2B are provided, and in this substrate processing system, a total of eight processing units are stacked in two stages of four and mounted on the frame 30.

  As the processing unit, for example, a chemical solution processing unit that performs chemical treatment with a chemical solution and rinse treatment with a rinse solution such as pure water on the substrate W can be employed. Hereinafter, the chemical solution and the rinse solution are collectively referred to as “treatment solution”. Each of the processing units 1, 2, 3 and 4 has processing chambers 1a, 2a, 3a and 4a in which processing spaces for processing the substrate W are formed. Then, the processing liquid is supplied to the substrate W in each of the processing chambers 1a to 4a, and wet processing is performed on the substrate W. The same applies to the processing units provided in the lower stage. As described above, in this embodiment, all of the plurality of processing units perform the same type of processing.

  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 point the substrate holding hand to any one of the indexer robot 22 and the processing units 1 to 4 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 described below 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 To house. 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, two embodiments of the processing unit mounted on the substrate processing system described above 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 diagram showing a first embodiment of a processing unit as a substrate processing apparatus according to the present invention. This processing unit 100 is a single wafer processing unit used for a cleaning process for removing unnecessary substances attached to the surface Wf of the substrate W such as a semiconductor wafer. More specifically, the substrate surface Wf was wetted with a rinsing solution after being subjected to a chemical treatment with a chemical solution such as hydrofluoric acid and a rinsing treatment with pure water or DIW (deionized water). An apparatus for drying the substrate surface Wf. In this embodiment, the substrate surface Wf means a pattern formation surface on which a device pattern made of poly-Si or the like is formed.

  The processing unit 100 of the first embodiment includes a spin chuck 101 that rotates while holding the substrate W in a substantially horizontal posture with the substrate surface Wf facing upward. The spin chuck 101 has a rotation support shaft 111 connected to a rotation shaft of a chuck rotation mechanism 154 including a motor, and can rotate about a rotation axis J (vertical axis) by driving the chuck rotation mechanism 154. A disc-shaped spin base 115 is integrally connected to an upper end portion of the rotation spindle 111 by a fastening component such as a screw. Therefore, the spin base 115 rotates around the rotation axis J by the chuck rotation mechanism 154 operating according to an operation command from the control unit 151 that controls the entire apparatus. Further, the control unit 151 controls the chuck rotation mechanism 154 to adjust the rotation speed.

  Near the peripheral edge of the spin base 115, a plurality of chuck pins 117 for holding the peripheral edge of the substrate W are provided upright. Three or more chuck pins 117 may be provided to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 115. Each of the chuck pins 117 includes a substrate support unit that supports the peripheral edge of the substrate W from below, and a substrate holding unit that holds the substrate W by pressing the outer peripheral end surface of the substrate W supported by the substrate support unit. Yes. Each chuck pin 117 is configured to be switchable between a pressing state in which the substrate holding portion presses the outer peripheral end surface of the substrate W and a released state in which the substrate holding portion is separated from the outer peripheral end surface of the substrate W.

  When the substrate W is delivered to the spin base 115, the plurality of chuck pins 117 are released, and when the substrate W is cleaned, the plurality of chuck pins 117 are pressed. To do. By setting the pressed state, the plurality of chuck pins 117 can hold the peripheral edge of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 115. As a result, the substrate W is supported with its front surface (pattern forming surface) Wf facing upward and the back surface Wb facing downward. The means for holding the substrate is not limited to using a chuck pin, and a vacuum chuck that supports the substrate W by sucking the back surface Wb of the substrate may be used.

  The spin chuck 101 holding the substrate W is rotated by the chuck rotating mechanism 154 to rotate the substrate W at a predetermined rotation speed, and supply the processing liquid to the substrate surface Wf from the following processing liquid supply nozzle. Then, predetermined wet processing (chemical solution processing and rinsing processing) is performed.

  A processing liquid supply means 120 is provided on the side of the spin chuck 101. The processing liquid supply unit 120 includes a supply nozzle 121 and a moving mechanism (not shown) that horizontally moves the supply nozzle 121 between a position facing the center of the substrate W and a standby position on the side of the spin chuck 101. The supply nozzle 121 is connected to a processing liquid supply source (not shown) by piping so that the rinsing liquid and the chemical liquid can be switched and supplied as the processing liquid.

  Further, a gas discharge head 200 is provided above a substantially central portion of the substrate W. Gas inlets 281 and 291 for taking in argon gas and nitrogen gas fed from an external argon (Ar) gas supply source GS1 and nitrogen (N2) gas supply source GS2, respectively, are provided above the gas discharge head 200. Is provided. More specifically, a pipe 172 connected to an external argon gas supply source GS1 and inserted through an open / close valve 171 is connected to the gas inlet 281. Further, a pipe 174 connected to the nitrogen gas supply source GS <b> 2 and inserted with an opening / closing valve 173 is connected to the gas introduction port 291. The on-off valves 171 and 173 are controlled to open and close by a valve control mechanism 152 controlled by the control unit 151, and supply of argon gas and nitrogen gas supplied from the argon gas supply source GS1 by opening the valves as necessary. Nitrogen gas supplied from the source GS <b> 2 is sent into the gas discharge head 200.

  The gas inlet 281 communicates with a gas outlet 283 that opens toward the approximate center of the substrate W on the lower surface (the surface facing the substrate surface Wf) of the gas discharge head 200 by a gas supply path 282. In addition, the gas introduction port 291 is communicated with a gas supply port 292 that is open toward the approximate center of the substrate W on the lower surface of the gas discharge head 200. A more detailed structure of the gas discharge head 200 will be described later.

  The gas discharge head 200 is held above the spin base 115 by an arm (not shown), and the arm is connected to a head lifting mechanism 153 controlled by a control unit 151 so as to be lifted and lowered. With this configuration, the gas discharge head 200 is positioned to face the surface Wf of the substrate W held on the spin chuck 101 at a predetermined interval (for example, about 2 to 10 mm). Further, the gas ejection head 200, the spin chuck 101, the head lifting mechanism 153, and the chuck rotating mechanism 154 are accommodated in the processing chamber 100a.

  FIG. 3 is a diagram showing a more detailed structure of the gas discharge head. More specifically, FIG. 3A is a view of the gas discharge head 200 as viewed obliquely from below, and FIG. 3B is a view of the gas discharge head 200 as viewed from below. As shown in FIGS. 3A and 3B, the gas discharge head 200 has a double tube structure in which two hollow tubes having different diameters are provided coaxially with the spin chuck rotating shaft J. The gas discharge port 283 for discharging argon gas is provided so as to open downward toward the center of the substrate W on the rotation axis J. On the other hand, the gas discharge port 293 that discharges nitrogen gas is opened downward so as to surround the periphery of the gas discharge port 283 for argon gas.

  FIG. 4 is a diagram showing the operating principle of the gas discharge head. More specifically, FIG. 4A is a diagram for explaining the operation of the gas discharge head 200 in the present embodiment. FIG. 4B is a diagram showing a conventional technique for discharging only one kind of gas toward the substrate as a comparative example.

  The gas discharge head 200 is positioned above the center of the substrate between the rinse process and the drying process, which will be described later, and the argon gas introduced from the gas inlet 281 is discharged from the gas outlet 283 through the gas supply path 282. On the other hand, the nitrogen gas introduced from the gas introduction port 291 is discharged from the gas discharge port 293 through the gas supply path 292. As shown in FIG. 4 (a), the argon gas and the nitrogen gas discharged substantially downwardly spread radially outward along the substrate surface Wf.

  Here, while the molecular weight of nitrogen gas is about 28, the molecular weight of argon gas is about 40, and the specific gravity of argon gas is larger unless there is a large difference between the two temperatures. Due to the difference in specific gravity, two types of gas layers are formed on the substrate W. That is, the argon gas discharged from the gas discharge port 283 toward the center of the substrate W has a large specific gravity, and therefore forms a gas layer L1 that flows in the vicinity of the substrate surface Wf from the center toward the periphery. On the other hand, the nitrogen gas discharged from the gas discharge port 293 that opens so as to surround the gas discharge port 283 has a specific gravity smaller than that of the argon gas, and thus forms a gas layer L2 that flows above the argon gas layer L1.

  By doing in this way, the following effects are obtained. First, since an air flow is formed along the substrate surface Wf from the center toward the periphery, the dust D floating in the processing chamber 100a and the mist M of the processing liquid are captured by the air flow and moved to the outside of the substrate. It is swept away and adhered to the substrate surface Wf. Even if dust D, mist M, or the like enters the nitrogen gas layer L2, since the nitrogen gas layer L2 flows in an upper layer away from the substrate surface Wf, the dust D, mist M, etc. approach the substrate surface Wf. This is further effectively suppressed.

  Further, as shown in the comparative example of FIG. 4B, when only one kind of gas (for example, nitrogen gas) is discharged from the nozzle Nz and sprayed onto the surface Wf of the substrate W, the gas flow and the ambient atmosphere The vortex of the gas flow is generated in the vicinity of the nozzle, particularly in the vicinity of the discharge port of the nozzle Nz. There is a fear. On the other hand, in the present embodiment shown in FIG. 4A, the gas discharge port 283 that discharges the argon gas blown to the substrate W is surrounded by another gas discharge port 293, and the gas discharge port 293 Since nitrogen gas is discharged, there are few vortices generated in the vicinity of the gas discharge port 283, and the possibility of entraining mist M or the like is reduced. Further, even if a vortex due to nitrogen gas is formed in the vicinity of the gas discharge port 293, the nitrogen gas layer L2 flows above the argon gas layer L1 as described above, so that the taken mist or the like is immediately removed from the substrate surface. Proximity to Wf and adhesion is prevented.

  Here, the flow rates of argon gas and nitrogen gas will be examined. FIG. 5 is a diagram showing the gas flow rate. As shown in FIG. 5A, here, the average flow rate of argon gas discharged from the gas discharge port 283 is represented by reference symbol V1, and the average flow rate of nitrogen gas discharged from the gas discharge port 293 is represented by reference symbol V2. Here, the term “average flow velocity” is used in consideration of the difference in speed depending on the position at the gas discharge port.

  The flow rate V1 of argon gas discharged from the gas discharge port 283 toward the center of the substrate is required to be low enough not to blow off the processing liquid from the substrate surface Wf during the wet processing, for example, while the drying processing is performed. In the method, the processing liquid may be blown away at a higher speed, so that it should be determined according to the content of processing on the substrate. On the other hand, the flow rate V2 of nitrogen gas discharged from the gas discharge port 293 can be considered as follows.

  First, it is conceivable to make the average flow rates V1 and V2 of the two types of gases equal. This is preferable in that the vortex in the vicinity of the gas discharge port 283 hardly occurs and the flow of the argon gas discharged toward the substrate surface Wf is not disturbed. However, a relatively large vortex is generated in the vicinity of the gas discharge port 293, and there is a possibility that the amount of mist or the like involved in the nitrogen gas layer L2 increases. This can be a problem especially when the flow rate is high. Further, when the flow rate V2 of the nitrogen gas is made larger than the flow rate V1 of the argon gas, a vortex is generated in the vicinity of the gas discharge port 283 so that the nitrogen gas is involved in the argon gas flow. This means that mist or the like taken into the nitrogen gas layer L2 may be mixed into the argon gas layer L1 flowing near the substrate surface Wf.

  On the other hand, when the flow rate V2 of nitrogen gas is smaller than the flow rate V1 of argon gas, the position Xj corresponding to the central axis J on the coordinate axis X orthogonal to the central axis J is shown in FIG. The flow velocity distribution becomes a maximum while the flow velocity gradually decreases with increasing distance from the flow velocity. For this reason, the generation of vortices in the vicinity of the gas discharge port 283 is suppressed, and the generation of vortices in the vicinity of the gas discharge port 293 can be reduced, so that mist and the like in the ambient atmosphere approach the substrate surface Wf. Is most preferable in that it can be most effectively suppressed. From the above, it is preferable that the flow rate V2 of nitrogen gas is set to be approximately the same as or smaller than the flow rate V1 of argon gas.

  As described above, in this embodiment, the gas flow discharged from the periphery of the gas discharge head 200 falls toward the substrate surface Wf in the same manner as the blocking member provided to face the substrate in the above-described conventional substrate processing apparatus. It has the function of blocking incoming dust, mist, etc. and the external atmosphere from the substrate surface. However, in this embodiment, since the blocking function is realized by discharging gas from the gas discharge head 200 provided substantially above the center of the substrate W, it is necessary to mechanically cover the entire substrate surface like a blocking member. The gas discharge head 200 can be formed smaller than the dimension of the substrate W. That is, the diameter of the gas discharge head 200 can be made smaller than the diameter of the substrate W. For example, if the flow rate and flow velocity of the gas flow are appropriately set, a sufficient blocking function can be obtained even if the diameter of the gas discharge head 200 is set to half or less of the diameter of the substrate W.

  For this reason, it is not necessary to largely retract the gas discharge head 200 when the substrate W is carried in and out of the spin chuck 101 or when the processing liquid is supplied to the substrate surface Wf. Further, it is not necessary to rotate the gas discharge head 200 together when rotating the substrate. Thus, in addition to being able to reduce the size of the gas discharge head 200, a space for retracting the gas discharge head 200 and a mechanism for rotating the gas discharge head 200 are not required. It can be made small, and its height can be particularly suppressed. In addition, since movable parts can be reduced, generation of dust in the processing chamber 100a can be suppressed.

  As a result, as shown in FIG. 1B, the processing units can be stacked and installed in the height direction, and more processing units are installed in the same installation area to perform processing in parallel. be able to. Thus, in the substrate processing system including the processing unit of this embodiment, a high substrate processing throughput can be obtained. In addition, the footprint of the apparatus per processing unit can be reduced.

  FIG. 6 is a flowchart showing the flow of substrate processing in the first embodiment. Before the start of processing, both the open / close valves 171 and 173 are closed, and the spin chuck 101 is stationary. First, a single substrate W is carried into the processing unit 100 by the substrate transfer robot 13, placed on the spin chuck 101, and held by the chuck pins 117 (step S101; substrate holding step). At this time, if the head lifting mechanism 153 is operated as necessary to move the gas discharge head 200 to the separation position from the spin chuck 101, the substrate can be carried in more smoothly. If a sufficient distance is secured between the two, the movement of the gas discharge head 200 is unnecessary. The same applies to the substrate unloading described later. At this time, the supply nozzle 121 is also moved to the standby position.

  First, wet processing is performed by supplying a predetermined processing liquid to the substrate surface Wf using the processing liquid supply means 120 while rotating the spin chuck 101 (steps S102 and S103). As the processing contents of the wet processing, known ones can be applied, and the description thereof is omitted here. As the wet process, a rinsing process is performed after the chemical process. In the rinsing process, pure water (or deionized water) is supplied to the rotating substrate surface Wf to wash away the chemical solution as the processing liquid. Thereafter, a drying process is performed to remove pure water remaining on the substrate surface Wf while discharging argon gas and nitrogen gas from the gas discharge head 200 (gas layer forming step). That is, the supply nozzle 121 is moved to the standby position, the open / close valves 171 and 173 are opened while the substrate W is rotated, and argon gas and nitrogen gas are respectively supplied from the gas discharge ports 283 and 293 provided in the gas discharge head 200. Discharge (step S104).

  With the two gas layers thus formed above the substrate W, the supply of the processing liquid (here, pure water or deionized water as a rinsing liquid) is stopped (step S105), and the rotation speed of the spin chuck 101 is reduced. Then, the substrate W is rotated at a high speed (step S106), and the substrate is dried by shaking off pure water on the substrate surface Wf. During the drying process, by continuously supplying the argon gas and the nitrogen gas from the gas discharge head 200, adhesion of mist and the like to the dried substrate surface Wf and oxidation of the substrate Wf are prevented. When the drying process is completed, the rotation of the spin chuck 101 is stopped (step S107), and the discharge of argon gas and nitrogen gas is stopped (step S108). Then, the substrate transfer robot 13 takes out the dried substrate W from the spin chuck and carries it out of the unit (step S109), whereby the processing for one substrate is completed. Further, by repeating the above processing, a plurality of substrates can be processed sequentially.

  As described above, in this embodiment, in the processing unit that performs processing while rotating the substrate held substantially horizontally, the gas discharge head 200 is provided substantially above the center of the substrate W, and the center is opened toward the substrate surface Wf. By discharging argon gas having a large specific gravity from the gas discharge port 283 toward the center of the substrate, the vicinity of the substrate surface Wf is maintained in an argon gas atmosphere. At the same time, nitrogen gas having a smaller specific gravity is discharged from a gas discharge port 293 that surrounds and opens the gas discharge port 283, thereby covering the argon gas layer formed in the vicinity of the substrate surface Wf with the nitrogen gas layer. In this embodiment, by performing processing in a state where two types of gas layers having different specific gravities are formed on the substrate in this way, in this embodiment, it is possible to prevent particles and mist from adhering to the substrate surface Wf. It is possible to process the substrate without causing any problems. Further, the gas discharge head 200 can be made smaller in diameter than the substrate W, and since it is not necessary to retract or rotate the gas discharge head 200, the processing unit can be made compact.

  Thus, in the said embodiment, argon gas and nitrogen gas were used as two types of gas. That is, in this embodiment, argon gas and nitrogen gas correspond to the “first gas” and “second gas” of the present invention. The gas discharge head 200 functions as the “gas discharge means” of the present invention, and the gas discharge ports 283 and 293 correspond to the “first discharge port” and the “second discharge port” of the present invention, respectively. ing. In the above embodiment, the spin chuck 101 and the chuck rotating mechanism 154 function as “substrate holding means” and “rotating means” of the present invention, while the control unit 151 functions as “control means” of the present invention. Yes. Furthermore, in this embodiment, the processing liquid supply unit 120 functions as the “processing liquid supply means” of the present invention.

  The combination of “first and second gases” is not limited to the above, and other gases having different specific gravities may be used. However, the gas forming the layer close to the substrate surface Wf, that is, the “first gas” is preferably an inert gas that does not cause a chemical reaction on the substrate surface Wf. For example, nitrogen gas or other inert gas having a relatively large molecular weight can be used.

  Further, in principle, the “second gas” does not necessarily need to be an inert gas because it does not directly contact the substrate surface Wf, and in order to keep the vicinity of the substrate W in a low-humidity atmosphere, It is desirable that the gas has a small specific gravity and does not contain water vapor and moisture or is removed as much as possible. As such a gas, in addition to the nitrogen gas as in the present embodiment, a gas having a relatively small molecular weight such as dry air (CDA) can be used. For example, CDA can be used instead of the nitrogen gas in the above embodiment.

  Further, the first and second gases are not limited to a single gas, and may be a mixture of a plurality of gas species. In this case, if there is no temperature difference in the gas, it is possible to distinguish the magnitude of the specific gravity based on the average molecular weight of the gas.

  Moreover, even if it is the gas of the same composition, you may make it produce | generate and use two types of gas from which specific gravity differs by providing a temperature difference like 2nd Embodiment demonstrated below.

Second Embodiment
Next, a second embodiment of the processing unit as the substrate processing apparatus according to the present invention will be described. This embodiment is the first implementation in that nitrogen gas is used as both the “first and second gases” of the present invention, and two gas layers are formed by a specific gravity difference caused by a temperature difference. Except for this point, the basic apparatus configuration is the same as that of the first embodiment. Therefore, in the following description, the same components as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted, and the characteristic parts of the present embodiment will be described mainly.

  FIG. 7 is a diagram showing a second embodiment of the processing unit according to the present invention. In this embodiment, the nitrogen gas supplied from the nitrogen gas supply source GS3 provided outside the apparatus and supplying nitrogen gas is introduced into the pipe 174 at room temperature, while the nitrogen gas supplied from the same nitrogen gas supply source GS3 is cooled. After being cooled to about −50 ° C. by the vessel 500, it is introduced into the pipe 172. Therefore, nitrogen gas having a high specific gravity is discharged from the gas discharge port 283 at a low temperature, while nitrogen gas having a higher temperature and a low specific gravity is discharged from the gas discharge port 293. As a result, as in the first embodiment, a two-layer gas flow is formed on the substrate surface Wf by gases having different specific gravities.

  In the second embodiment, similarly to the first embodiment described above, the atmosphere of the substrate surface Wf is controlled by the gas layer flowing along the substrate surface Wf, and the upper portion thereof is covered with a gas layer having a low specific gravity, Mixing of dust, mist, and the like into the atmosphere of the substrate surface Wf can be suppressed, and adhesion to these substrate surfaces can be prevented. Moreover, since only nitrogen is used as the gas species, the processing cost can be reduced as compared with the case where expensive argon gas is used. In particular, by using a gas from the same gas supply source with a temperature difference, the cost reduction effect is further increased.

  In this embodiment, nitrogen is used as the gas species. However, as in the first embodiment, argon or CDA may be used instead.

<Third Embodiment>
Next, a third embodiment of the processing unit according to the present invention will be described. In this third embodiment, the shape of the gas discharge unit is different from that of the first embodiment. Except for this point, the basic apparatus configuration and operation of the third embodiment are the same as those of the first embodiment. The same. Therefore, in the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted, and the structure of the gas discharge unit, which is a characteristic part of the present embodiment, will be described.

  FIG. 8 is a diagram showing a third embodiment of the processing unit according to the present invention. More specifically, FIG. 8A is a view of the gas discharge unit 300 in this embodiment as viewed obliquely from below, and FIG. 8B is a side view of the gas discharge unit 300. In the gas discharge unit 300 of this embodiment, the gas inlets 381 and 391 are connected to an argon gas supply source and a nitrogen gas supply source (not shown), respectively. And the periphery of the gas discharge port 383 which discharges argon gas is bent outward, and the collar part 384 is formed. Similarly, a flange portion 394 is provided on the outer wall of the casing of the gas discharge unit 300, and a gas discharge port 393 that opens outward in the horizontal direction is formed between the flange portions 384 and 394.

  Therefore, the argon gas is discharged from the gas discharge port 383 toward the substrate surface Wf as in the first embodiment, but the nitrogen gas from the gas discharge port 393 is substantially parallel to the substrate surface Wf in the peripheral direction of the substrate. It will be discharged toward. According to such a configuration, the argon gas discharged downward from the gas discharge port 383 hits the center of the substrate and spreads toward the periphery, whereas the nitrogen gas from the gas discharge port 393 is discharged from the beginning toward the substrate periphery. Is done. For this reason, it is suppressed that the nitrogen gas flow disturbs the layer of argon gas flowing from the center of the substrate toward the periphery, and two gas layers with less disturbance can be formed on the substrate W.

  Even with such a configuration, similarly to the first embodiment described above, it is possible to suppress the entry of dust, mist, and the like into the atmosphere of the substrate surface Wf and to prevent the adhesion to the substrate surface. Further, since it is not necessary to secure a flow path for the nitrogen gas flow that changes from downward to outward, the gas discharge head 300 can be disposed closer to the substrate surface Wf than in the first embodiment. For this reason, the atmosphere control in the vicinity of the substrate surface Wf can be performed more effectively.

<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. For example, as described above, the types of gas that can be used as the “first and second gases” of the present invention are not limited to those of the above embodiment.

  Further, the substrate processing unit of each of the above embodiments executes a process of rinsing and drying the chemical-treated substrate with pure water or deionized water as a rinsing liquid, but it adheres to the substrate surface after rinsing. The present invention can also be applied to a treatment unit in which a rinsing liquid (pure water or deionized water) is replaced with a solvent having a lower surface tension than water such as isopropyl alcohol (IPA) and then dried. is there. In this case, the chemical solution, the rinsing solution, and the solvent may be supplied from a single supply nozzle, or a plurality of supply nozzles that discharge different processing solutions may be provided around the substrate. Further, the nozzle for supplying these processing liquids may be configured integrally with the gas discharge head.

  Moreover, although the gas discharge heads 200 and 300 of the above embodiments can be formed of a metal such as stainless steel or aluminum, they may be formed of a resin. By doing so, it is possible to reduce the weight of the gas discharge head and improve the chemical resistance. Examples of resin materials suitable for such applications include polyether ether ketone (PEEK), polyvinyl chloride (PVC), and polychlorotrifluoroethylene (PCTFE).

  In each of the above embodiments, the head elevating mechanism 153 is provided, and the gas discharge head 200 or 300 is moved up and down to enhance the convenience of loading and unloading of the substrate. The mechanism is not an essential component. For example, if there is no interference between the substrate transfer robot 13 and the gas discharge head when the substrate is carried in and out, the head discharge mechanism may be omitted and the gas discharge head may be fixed. If this can be done, the processing unit can be further reduced in size.

  The present invention is not limited to the above-described embodiment, and can be applied to a substrate processing apparatus and a substrate processing method in general that perform a predetermined process while the substrate is held substantially horizontally. Here, the substrate to be processed includes a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for optical disk, and a magnetic substrate. A disk substrate and a magneto-optical disk substrate are included. The processing applied to the substrate includes development processing, etching processing, cleaning processing, rinsing processing, and drying processing. In addition, the present invention is preferably applied not only to a substrate processing system having a plurality of processing units as in the above embodiment, but also to a substrate processing apparatus having only one set of substrate holding means and gas discharge means. Can do.

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 concerning this invention. It is a figure which shows the more detailed structure of a gas discharge head. It is a figure which shows the principle of operation of a gas discharge head. It is a figure which shows the flow rate of gas. It is a flowchart which shows the flow of the board | substrate process in 1st Embodiment. It is a figure which shows 2nd Embodiment of the processing unit concerning this invention. It is a figure which shows 3rd Embodiment of the processing unit concerning this invention.

Explanation of symbols

1, 2, 3, 4, 1B, 2B, 3B, 4B, 100 ... processing unit 1a, 2a, 3a, 4a, 100a ... processing chamber 101 ... spin chuck (substrate holding means)
120 ... Processing liquid supply unit (processing liquid supply means)
151... Control unit (control means)
154 ... Chuck rotating mechanism (rotating means)
200, 300 ... Gas discharge head (gas discharge means)
283, 383 ... Gas outlet (first outlet)
293 ... Gas outlet (second outlet)

Claims (10)

A substrate holding means for substantially horizontally holding the board,
A processing liquid supply means for supplying a processing liquid to the substrate and performing wet processing;
A gas discharge means for discharging gas disposed above a central portion of the substrate held by the substrate holding means;
The gas discharge means is provided with a first discharge port that opens toward the center of the substrate, and a second discharge port that opens so as to surround the first discharge port. the one that forms the first gas layer according to the first gas along the substrate surface, from the second outlet port of the first from the discharge port to discharge the first gas after said wet processing the substrate processing apparatus characterized by a small second gas specific gravity than gas is discharged to form a second gas layer according to the second gas in the upper layer of the first gas. Rotating means for rotating the substrate holding means to rotate the substrate about a substantially vertical rotation axis;
In the state where the first gas layer and the second gas layer are formed by discharging the first gas and the second gas to the substrate after the wet processing by the gas discharging unit. Control means for performing a drying process of rotating the substrate to remove the processing liquid from the substrate surface and drying the substrate;
The substrate processing apparatus according to claim 1 comprising a. It said gas outlet means, a substrate processing apparatus according to claim 1 or 2 for discharging a small gas average molecular weight than the first gas as said second gas. It said gas outlet means, a substrate processing apparatus according to any one of claims 1 to 3 for discharging the hot gas than said first gas having the same composition as the first gas as said second gas. It said gas outlet means, a substrate processing apparatus according to any one of claims 1 to 4 for discharging the inert gas as the first gas. It said gas outlet means, a substrate processing apparatus according to any one of claims 1 to 5 for discharging the water gas which is removed as the second gas. It said gas outlet means, at a higher flow rate than the flow rate of said second gas to be discharged from the second outlet port, either from the first outlet of the claims 1 to 6 for discharging said first gas A substrate processing apparatus according to claim 1. Said second discharge opening, a substrate processing apparatus according to any one of claims 1 and opens towards the periphery of the substrate 7. A substrate holding step for holding the substrate substantially horizontally;
A wet processing step of supplying a processing liquid to the substrate and performing wet processing;
A gas discharge means for discharging gas is disposed above the center of the substrate, a first gas is discharged from the gas discharge means toward the center of the substrate, and the substrate surface is covered with the first gas. A second gas layer forming a first gas layer and discharging a second gas having a specific gravity lower than that of the first gas from the gas discharge means to cover the first gas layer with the second gas; A gas layer forming step of forming a gas layer,
A substrate processing method , comprising: performing a predetermined process on the substrate after the wet process in a state where the first and second gas layers are formed.   The substrate processing method according to claim 9, wherein as the predetermined processing, a drying process is performed in which a substrate after wet processing with a processing liquid is rotated to remove the processing liquid from the substrate surface and dry the substrate.

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