JP6407829B2 - Substrate liquid processing apparatus and substrate liquid processing method - Google Patents

Description

  The present invention relates to a technique for preventing a droplet of a processing liquid from splashing out of a liquid receiving portion when performing a pre-dispensing process in a substrate liquid processing apparatus.

  Conventionally, a substrate processing system for processing a substrate by supplying a processing liquid to a substrate such as a semiconductor wafer or a glass substrate is known. In such a substrate processing system, a nozzle for discharging a processing liquid inside the processing chamber is provided so as to be movable between a processing position for processing the substrate and a retracted position outside the substrate. In addition, a liquid receiving portion is provided to receive the processing liquid discharged from the nozzle at the retracted position, and a pre-dispensing process for discharging a predetermined amount of chemical liquid is performed before the processing liquid is supplied to the substrate. The processing liquid collected by the liquid receiving unit is discharged through a drain pipe and is collected and reused or discarded outside the substrate processing system (for example, see Patent Document 1).

  A droplet of the processing liquid generated during the pre-dispensing process may be scattered outside the liquid receiving unit. There is a possibility that the substrate is contaminated by particles caused by the droplets.

JP 2007-258462 A

  An object of the present invention is to provide a technique for preventing droplets of a processing liquid generated when performing a pre-dispensing process at a retreat position from being scattered outside a liquid receiving unit.

According to an embodiment of the present invention holding a substrate holding mechanism for holding the substrate liquid processing is carried out, a nozzle for supplying a treatment liquid to the substrate held by the substrate holding mechanism, a nozzle, by the substrate holding mechanism A nozzle moving mechanism that moves between a processing position located above the substrate and a retreat position that is located outside the substrate held by the substrate holding mechanism , and is ejected from the nozzle. There is provided a substrate liquid processing apparatus that includes a liquid receiving portion made of a resin that receives the processing liquid, and has zero or plus charge on a path through which the processing liquid discharged from the nozzle falls to the liquid receiving portion.

  According to another embodiment of the present invention, the step of moving the nozzle for supplying the processing liquid to the substrate from the processing position located above the substrate to the retracted position located outside the substrate, and at the retracted position And a step of discharging the processing liquid toward the liquid receiving section in a state where the charge of the path in which the processing liquid discharged from the nozzle falls to the liquid receiving section is made zero or positive. A method is provided.

  According to the embodiment of the present invention, it is possible to prevent the liquid droplets of the processing liquid generated when the pre-dispensing process is performed at the retreat position from being scattered outside the liquid receiving unit.

1 is a plan view showing a schematic configuration of a substrate processing system according to an embodiment of a substrate liquid processing apparatus of the present invention. It is a sectional side view which shows schematic structure of a processing unit. It is a sectional side view which shows the effect | action of a processing unit. It is a schematic sectional drawing explaining the effect | action of liquid scattering. It is a schematic side view explaining the effect | action of liquid scattering prevention. It is a schematic plan view which shows other embodiment of liquid scattering prevention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined, and the positive direction of the Z axis is the vertically upward direction.

  As shown in FIG. 1, the substrate processing system 1 includes a carry-in / out station 2 and a processing station 3. The carry-in / out station 2 and the processing station 3 are provided adjacent to each other.

  The carry-in / out station 2 includes a carrier placement unit 11 and a transport unit 12. A plurality of carriers C that accommodate a plurality of wafers W in a horizontal state are placed on the carrier placement unit 11.

  The transport unit 12 is provided adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 inside. The substrate transfer device 13 includes a substrate holding mechanism that holds the wafer W. Further, the substrate transfer device 13 can move in the horizontal direction and the vertical direction and turn around the vertical axis, and transfers the wafer W between the carrier C and the delivery unit 14 using the substrate holding mechanism. Do.

  The processing station 3 is provided adjacent to the transfer unit 12. The processing station 3 includes a transport unit 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on the transport unit 15.

  The transport unit 15 includes a substrate transport device 17 inside. The substrate transfer device 17 includes a substrate holding mechanism that holds the wafer W. Further, the substrate transfer device 17 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the delivery unit 14 and the processing unit 16 using the substrate holding mechanism. I do.

  The processing unit 16 performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17.

  Further, the substrate processing system 1 includes a control device 4. The control device 4 is a computer, for example, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores a program for controlling various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage unit 19.

  Such a program may be recorded on a computer-readable storage medium, and may be installed in the storage unit 19 of the control device 4 from the storage medium. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

  In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 of the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement unit 11 and receives the taken-out wafer W. Place on the transfer section 14. The wafer W placed on the delivery unit 14 is taken out from the delivery unit 14 by the substrate transfer device 17 of the processing station 3 and carried into the processing unit 16.

  The wafer W loaded into the processing unit 16 is processed by the processing unit 16, then unloaded from the processing unit 16 by the substrate transfer device 17, and placed on the delivery unit 14. Then, the processed wafer W placed on the delivery unit 14 is returned to the carrier C of the carrier platform 11 by the substrate transfer device 13.

  Next, a schematic configuration of the processing unit 16 will be described with reference to FIGS.

  As shown in FIG. 2, the processing unit 16 includes a chamber 20, a substrate holding mechanism 30, a processing fluid supply unit 40, and a recovery cup 50.

  The chamber 20 accommodates the substrate holding mechanism 30, the processing fluid supply unit 40, and the recovery cup 50. An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20. The FFU 21 forms a down flow in the chamber 20.

  The substrate holding mechanism 30 includes a holding unit 31, a support unit 32, and a driving unit 33. The holding unit 31 holds the wafer W horizontally. The support | pillar part 32 is a member extended in a perpendicular direction, a base end part is rotatably supported by the drive part 33, and supports the holding | maintenance part 31 horizontally in a front-end | tip part. The drive unit 33 rotates the column unit 32 around the vertical axis. The substrate holding mechanism 30 rotates the support unit 32 by rotating the support unit 32 using the drive unit 33, thereby rotating the wafer W held by the support unit 31. .

  The processing fluid supply unit 40 supplies a processing fluid to the wafer W. The processing fluid supply unit 40 is connected to a processing fluid supply source 70.

  The collection cup 50 is disposed so as to surround the holding unit 31, and collects the processing liquid scattered from the wafer W by the rotation of the holding unit 31. A drain port 51 is formed at the bottom of the recovery cup 50, and the processing liquid collected by the recovery cup 50 is discharged from the drain port 51 to the outside of the processing unit 16. Further, an exhaust port 52 for discharging the gas supplied from the FFU 21 to the outside of the processing unit 16 is formed at the bottom of the recovery cup 50.

  The processing fluid supply unit 40 has a nozzle 41 that discharges the processing liquid onto the wafer W. The nozzle 41 (at least the tip of the nozzle 41 that is the liquid removal target) does not generate metal ions and does not generate particles, specifically, for example, a fluororesin (specifically, for example, PTFE (polyethylene)). Tetrafluoroethylene), PFA (perfluoroalkoxyethylene, etc.).

  The nozzle 41 is held at the tip of the arm 42. The base end of the arm 42 is attached to the upper end of the support column 43. The lower end of the support column 43 is attached to the arm drive unit 44. The arm drive unit 44 can rotate the support column 43 around the vertical axis, and can move the support column 43 up and down. Therefore, by operating the arm drive unit 44, the nozzle 41 is moved to the processing position (the position shown in FIG. 2) where the nozzle 41 is located above the wafer W (more specifically, directly above the center of the wafer W). And the nozzle 41 can be moved between a retracted position outside the wafer W (more specifically, outside the recovery cup 50 in a plan view). In addition, the arm 42 is not limited to what makes a turning motion around the vertical axis as described above, and may be another motion, for example, a motion that translates horizontally.

  The processing fluid supply source 70 includes a chemical solution supply mechanism and a pure water supply mechanism (both not shown). A chemical solution (for example, a cleaning solution such as SC1 or DHF) and pure water as a rinse solution are provided in one nozzle 41. And can be selectively supplied. Two or more nozzles may be provided, and each nozzle may be supplied with only one type of processing solution (chemical solution, rinse solution).

  As shown in FIG. 3, a liquid receiver 60 is provided at a position corresponding to the retracted position of the nozzle 41. The liquid receiving unit 60 can be used to receive a processing liquid discharged from the nozzle 41 during dummy dispensing. That is, in the present embodiment, the liquid receiving unit 60 is shared as a liquid receiver for dummy dispensing and a liquid receiver for the liquid falling from the nozzle 41 when the outer surface of the nozzle 41 is cleaned. A drainage pipe (not shown) for discarding the liquid received by the liquid receiver 60 to the factory drain system is connected to the bottom of the liquid receiver 60.

The liquid receiving portion 60 includes a cylindrical cylindrical portion 61 and a mortar-shaped bottom portion 62 that is connected to the lower portion of the cylindrical portion 61 and gradually decreases in diameter as it goes downward. A discharge port 63 is provided at the lower end of the bottom 62, and a drainage conduit is connected to the discharge port 63. In addition, the liquid receiving portion 60 is made of a conductive resin, and is specifically formed of PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxyethylene) containing carbon, for example. The liquid receiving unit 60 is grounded by a ground wire 64.

  Next, a series of procedures executed in the processing unit 16 will be described. The following series of procedures can be automatically performed under the control of the control device 4.

  The wafer W is loaded into the processing unit 16 by the substrate transfer device 17 and held by the holding unit 31. As the wafer W starts to rotate, the nozzle 41 is positioned directly above the center of the wafer W. In this state, a chemical solution is supplied from the nozzle 41 to the wafer W to perform a chemical solution processing step, and then pure water as a rinse solution is supplied to the wafer W to perform a rinse step. Thereafter, the discharge of the processing liquid (pure water) from the nozzle 41 is stopped, and the wafer W is continuously rotated (preferably by increasing the rotation speed), whereby the wafer W shake-off drying process is performed. The You may implement the process of replacing pure water with the organic solvent for drying assistance, such as IPA (isopropyl alcohol), between the rinse process and the shake-off drying process. The nozzle 41 is moved to the retracted position at an appropriate timing before the end of the drying process. When the drying process is completed, the wafer W is unloaded from the processing unit 16 by the substrate transfer device 17. As described above, a series of processes for one wafer W is completed.

  Next, the operation of the pre-dispensing process will be described with reference to FIG.

  In the pre-dispensing process, for example, in order to prevent the processing liquid from being deteriorated, the processing liquid is appropriately discharged from the nozzle 41 during standby without discharging the processing liquid to the wafer W or before supplying the processing liquid to the wafer W. That's it.

  The pre-dispensing process is executed when a preset condition (for example, an elapsed time from the previous pre-dispensing process) is satisfied.

  As shown in FIG. 3, when performing the pre-dispensing process of the nozzle 41, the control device 4 controls the swivel raising / lowering mechanism (not shown) to move the arm 42 so that the nozzle 41 is moved to the liquid receiving unit 60. Place above.

  Then, the control device 4 opens a valve (not shown) for a predetermined time, and discharges the processing liquid from the nozzle 41 for a predetermined time. The processing liquid discharged from the nozzle 41 is discharged from the discharge port 63 of the liquid receiving unit 60 to the outside.

  As shown in FIGS. 4A to 4B, droplets are generated when the pre-dispensing process is performed. Specifically, when the supply of the processing liquid is stopped, the liquid flow of the processing liquid discharged from the nozzle 41 gradually narrows, and finally the behavior of the liquid flow returning to the nozzle 41 is exhibited. At that time, a part of the processing liquid that could not be returned is torn into droplets. The torn droplets have a negative charge due to peeling charging (FIG. 4A). Further, since the resin generally has a negative charge, an electrostatic repulsive force acts between the liquid receiving portion 60, particularly the cylindrical portion 61, on the droplet. For this reason, the liquid droplet may not be collected by the liquid receiving unit 60 and may be scattered outside the liquid receiving unit 60 (FIG. 4B). In this case, the wafer W may be contaminated by particles caused by the droplets.

  Here, in the present embodiment, the charge of the path through which the processing liquid discharged from the nozzle 41 falls to the liquid receiving unit 60 is set to be zero. Specifically, the liquid receiver 60 is formed of a conductive resin and is further grounded. As shown in FIG. 5, since the electric charge of the liquid receiving part 60 does not have a negative charge and becomes zero, an electrostatic repulsive force does not act between the liquid droplet and the liquid receiving part 60, and the liquid droplet is received by the liquid receiving part. Drop to 60. Accordingly, it is possible to prevent the droplets from splashing out of the liquid receiving unit 60. The liquid receiving part 60 is not limited to the case where the whole is made of conductive resin and grounded so that the electric charge becomes zero as a whole. For example, the metal plating applied to the inner peripheral surface is grounded. The charge may be partially reduced to zero. Here, the path is a region around the locus in the locus of the treatment liquid until the treatment liquid discharged from the nozzle 41 reaches the liquid receiving unit 60. In addition, the charge other than the droplet can affect the charge of the droplet. In the present invention, the charge of the path is set to zero or plus, and is not limited to the case where the total charge of the path is set to zero or plus, but includes the case where the charge of a part of the path is set to zero or plus. . Note that when the charge is zero, no repulsive force is generated between the liquid droplets having a negative charge, and thus the liquid droplets discharged from the nozzle 41 can be naturally dropped onto the liquid receiving unit 60. In addition, when the charge is positive, a suction force is generated between the liquid droplets having a negative charge, so that the liquid droplets discharged from the nozzle 41 are forced to the liquid receiving unit 60. Can be aspirated. As described above, in the present invention, the region where the droplet does not receive an electric repulsive force in the path between the nozzle 41 and the liquid receiving unit 60 (or the region where the droplet receives an electric suction force) is provided. Thus, the liquid droplets discharged from the nozzle 41 are prevented from falling outside the liquid receiving unit 60 without falling into the liquid receiving unit 60.

  Further, when pre-dispensing is performed, friction may occur between the processing liquid and the nozzle 41, and the processing liquid in the nozzle 41 may be charged. Further, when the liquid receiving part 60 is not a conductive resin, the surface of the liquid receiving part 60 is easily charged. When the processing liquid is discharged toward the charged liquid receiving unit 60, the charge of the liquid receiving unit 60 may move through the processing liquid, and the processing liquid in the nozzle 41 may be charged. When the charged processing liquid is supplied to the central portion of the wafer W, arcing occurs at the moment when the processing liquid comes into contact with the wafer W, causing a problem that the pattern is destroyed.

  Here, in the present embodiment, the processing liquid discharged from the nozzle 41 collides with the liquid receiving unit 60. When performing the pre-dispensing, the processing liquid in the nozzle 41 is grounded at the moment when the processing liquid comes into contact with the bottom 62 of the liquid receiving portion 60, so that the charge can be removed even if the processing liquid is charged. Therefore, it is possible to suppress the treatment liquid in the nozzle 41 from being charged after pre-dispensing. For this reason, even if the processing liquid is supplied to the wafer W after pre-dispensing, the wafer W can be processed without causing arcing. In FIG. 5, the bottom portion 62 is formed in a bowl shape with the lower end decentered from the center, and the nozzle 41 is positioned above the center portion of the bottom portion 62 (liquid receiving portion 60). The bottom portion 62 is formed in a mortar shape with the lower end positioned at the center in the same manner as described above, and the nozzle 41 is positioned at a position shifted from above the center portion of the bottom portion 62 (liquid receiving portion 60), and the processing liquid discharged from the nozzle 41 May collide with the bottom 62 without being discharged directly from the discharge port 63.

<Modification>
Next, a modified example will be described with reference to FIGS. The liquid receiving part 600 has a cylindrical cylindrical part 601 in order from the top, and a bowl-shaped bottom part 602 that is connected to the cylindrical part and gradually reduces in diameter as it goes downward. A discharge port 603 is provided at the lower end of the bottom 602. On the inner surface of the cylindrical portion 601 of the liquid receiving portion 600, a droplet adsorption portion 700 is provided. The droplet adsorption unit 700 is configured by a member having a positive charge on the surface thereof. Since the charge on the path of dropping to the liquid receiving unit 600 is positive, a droplet having a negative charge is attracted to the droplet adsorption unit 700 by electrostatic attraction force. Accordingly, it is possible to prevent the liquid receiver 600 from being scattered outside. In order to have a positive charge on the surface of the member constituting the droplet adsorption unit 700, the surface of the member constituting the droplet adsorption unit 700 is forcibly charged with an ionizer having only a positive electrode. Can have a positive charge. In addition, the droplet adsorption unit 700 can suppress power consumption by energizing only during pre-dispensing when the processing liquid is discharged from the nozzle 41 to the liquid receiving unit 60.

  Further, a static elimination unit 701 that is grounded may be provided at a position where the processing liquid discharged from the nozzle 41 collides with the bottom 602. When performing the pre-dispensing, since the processing liquid in the nozzle 41 is grounded, the processing liquid can be neutralized even if the processing liquid is charged. Accordingly, since the processing liquid in the nozzle 41 can be prevented from being charged after pre-dispensing, the wafer W can be processed without causing arcing.

  Furthermore, the liquid receiving unit 600 may be provided with a cleaning liquid supply unit 702 that supplies a cleaning liquid toward the droplet adsorption unit 700. By opening an on-off valve (not shown), the cleaning liquid is supplied from the cleaning liquid supply unit 702 toward the droplet adsorption unit 700. Since the droplets adhering to the droplet adsorption unit 700 can be washed, the risk that the wafer W is contaminated with particles caused by the droplets can be reduced.

  The droplet adsorbing unit may be in a path where the processing liquid falls to the liquid receiving unit, and may not be the inner surface of the cylindrical unit 601. Specifically, as shown in FIG. 6C, a liquid receiving portion 600 ′ that receives the processing liquid discharged from the nozzle 41, and the processing liquid is above the liquid receiving portion 600 ′ and the liquid receiving portion 600 ′. A droplet adsorbing part 700 ′ is provided in the path of falling. Even in this case, since the charge of the path falling to the liquid receiving portion 600 ′ becomes positive, a droplet having a negative charge is attracted to the droplet adsorption portion 700 ′ by electrostatic attraction force. Accordingly, it is possible to prevent the liquid receiving portion 600 'from being scattered outside.

  In the above embodiment, the substrate processed by the processing unit 16 is not limited to the semiconductor wafer W, but may be any substrate used in the technical field of semiconductor device manufacture, such as a glass substrate for LCD and a ceramic substrate. .

30 Substrate holding mechanism 41 Nozzle 44 Arm drive unit (nozzle moving mechanism)
60, 600 Liquid receiver

Claims (7)

A substrate holding mechanism for holding a substrate on which liquid processing is performed;
A nozzle for supplying a processing liquid to the substrate held by the substrate holding mechanism;
The nozzle, a processing position located above the substrate held by the substrate holding mechanism, a nozzle moving mechanism for moving between a retracted position located outside of the substrate held by the substrate holding mechanism,
A liquid receiving portion that is provided at the retracted position and is made of a resin that receives the processing liquid discharged from the nozzle;
With
A substrate liquid processing apparatus characterized in that the charge of a path through which the processing liquid discharged from the nozzle falls to the liquid receiving portion is given to zero or plus. The liquid receiver is
The substrate liquid processing apparatus according to claim 1, wherein the substrate liquid processing apparatus is made of a resin having conductivity and is grounded. The liquid receiver is
It has a cylindrical tube part at the top of the liquid receiving part and a mortar-shaped bottom part at the bottom of the cylinder part,
The bottom is
The substrate liquid processing apparatus according to claim 2, wherein the substrate liquid processing apparatus is provided at a position where the processing liquid discharged from the nozzle collides. The liquid receiver is
It has a cylindrical tube part at the top of the liquid receiving part and a mortar-shaped bottom part at the bottom of the cylinder part,
The substrate liquid processing apparatus according to claim 1, further comprising: a droplet adsorbing portion having a positive charge on an inner surface of the cylindrical portion. The liquid receiver is
5. The substrate liquid processing apparatus according to claim 4, further comprising a grounded static eliminating unit at a position where the processing liquid discharged from the nozzle collides. Moving a nozzle for supplying a processing liquid to the substrate from a processing position located above the substrate to a retracted position located outside the substrate;
Discharging the processing liquid toward the liquid receiving unit in the state where the electric charge of the path where the processing liquid discharged from the nozzle falls to the liquid receiving unit is set to zero or plus at the retracted position;
A substrate liquid processing method comprising: The substrate liquid processing method according to claim 6, further comprising: supplying a processing liquid from the nozzle toward the substrate at the processing position after performing the process of discharging the processing liquid toward the liquid receiving unit.

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