JP4912020B2 - Liquid processing equipment - Google Patents

Description

  The present invention relates to a liquid processing apparatus that performs predetermined liquid processing on a substrate such as a semiconductor wafer.

  In a semiconductor device manufacturing process and a flat panel display (FPD) manufacturing process, a process of supplying a processing liquid to a semiconductor wafer or a glass substrate, which is a substrate to be processed, and performing liquid processing is frequently used. As such a process, for example, a cleaning process for removing particles or contamination attached to the substrate, a coating process of a photoresist solution or a developing solution in a photolithography process, and the like can be given.

  As such a liquid processing apparatus, a substrate such as a semiconductor wafer is held on a spin chuck, a processing liquid is supplied to the front surface or front and back surfaces of the wafer while the substrate is rotated, and a liquid film is applied to the front or back surface of the wafer. A device that forms a film and performs processing is known.

  In this type of apparatus, the processing liquid is usually supplied to the center of the wafer, and by rotating the substrate, the processing liquid is spread outward to form a liquid film, and the processing liquid is generally released. ing. A member such as a cup surrounding the outside of the wafer is provided so as to guide the processing liquid shaken off the substrate downward, so that the processing liquid shaken off from the wafer is quickly discharged. However, when a cup or the like is provided in this way, the processing liquid may scatter as mist and reach the substrate to cause defects such as watermarks and particles.

As a technique capable of preventing such a problem, Patent Document 1 discloses a processing liquid that receives a processing liquid scattered in the outer peripheral direction from a substrate so as to rotate integrally with a rotation support unit that rotates the substrate while being horizontally supported. There is disclosed a technique in which a receiving member is provided to receive a processing liquid and guide the processing liquid to the outside for recovery. In this Patent Document 1, the processing liquid receiving member includes, in order from the substrate side, a horizontal eaves part, an inclined guide part that guides the processing liquid outward and downward, a horizontal guide part that guides the processing liquid horizontally outward, and a vertical standing part. It has a wall to be installed, and the process liquid is forced into a narrow area and discharged to the horizontal outside through the drain port provided at the corner of the process receiving member while preventing the mist from reattaching to the substrate. Furthermore, the liquid is drained through a groove extending outwardly inside the spacer disposed outside the processing liquid receiving member.
JP-A-8-1064

  However, in Patent Document 1, the processing liquid receiving member rotates together with the substrate to generate a swirling flow, and the outer portion of the processing liquid receiving member is in a high pressure state. Therefore, when the high pressure state is released after the rotation is completed, an air flow returning from the outer portion of the processing liquid receiving member to the substrate side is generated, and there is a possibility that the mist is attached to the substrate accompanied with the mist. In order to prevent this, it is conceivable to perform airflow control, but this is not sufficient, and mist reattaches to the substrate, causing watermarks and particles.

  The present invention has been made in view of such circumstances, and is a liquid processing apparatus that supplies a processing liquid to a substrate while rotating the substrate to perform liquid processing on the substrate, and suppresses re-adhesion of the mist of the processing liquid to the substrate. An object of the present invention is to provide a liquid processing apparatus that can perform the above process.

In order to solve the above problems, the present invention provides a substrate holding unit that holds a substrate horizontally and can rotate with the substrate, and a liquid supply mechanism that supplies a processing liquid to at least the surface of the substrate held by the substrate holding unit. A rotating cup that surrounds the substrate held by the substrate holding unit and is rotatable together with the substrate and discharges the processing liquid shaken off from the substrate to the outside as drainage, and the rotating cup and the substrate holding unit A rotating mechanism that rotates the rotating cup integrally, and an exhaust / draining cup that receives the drained liquid discharged from the rotating cup and exhausts the inside and the surroundings of the rotating cup. Provided is a liquid processing apparatus having a gas reservoir part capable of trapping an airflow flowing from the outside to the inside on the outside of a substrate held by a substrate holding part.

The present invention also provides a substrate holder that holds the substrate horizontally and can rotate together with the substrate, a surface liquid supply mechanism that supplies the processing liquid to the surface of the substrate, and a back surface liquid supply that supplies the processing liquid to the back surface of the substrate. A rotary cup that surrounds the substrate held by the substrate holding unit and is rotatable together with the substrate and discharges the processing liquid shaken off from the substrate to the outside as a drainage; and the rotary cup and the substrate A rotating mechanism that rotates the holding unit integrally; and an exhaust / drain cup that receives the drained liquid discharged from the rotating cup and exhausts the inside and the periphery of the rotating cup. The liquid processing apparatus is characterized in that it has a gas reservoir part capable of trapping an airflow flowing from the outside to the inside on the outside of the substrate held by the substrate holding part.

In the present invention, the rotating cup may further include a guide member that is provided outside the substrate on the substrate holding unit and guides the processing liquid shaken off from the substrate to the outside of the substrate.

  The gas reservoir may be configured to form a concentric ring with the substrate outside the substrate held by the substrate holder. The rotating cup covers the outside of the substrate held by the substrate holding unit, has a wall portion having a processing liquid discharge hole, and a ring provided in an annular shape inward from the upper end of the wall portion. And the gas reservoir may be formed on the flange member. In this case, it is preferable that the gas reservoir is formed in a tapered shape that extends inward and upward from the lower surface of the flange member.

According to the present invention, since the rotating cup that rotates together with the rotation of the substrate is provided, centrifugal force acts on the rotating cup, and the rebound of the mist of the processing liquid as in the case where the fixed cup is provided can be prevented. In this case, when the rotating cup is stopped, an air flow returning from the outer portion of the rotating cup, which was at a high pressure when the rotating cup rotates, to the substrate side is generated, and even if mist is accompanied by this air flow, Since the gas reservoir that can trap the airflow flowing from the outside to the inside is provided on the outside of the substrate, the airflow accompanied with mist is temporarily trapped in the gas reservoir when the rotary cup is stopped and is retained therein. In addition, the air flow accompanying the mist can be discharged by the air flow control of the exhaust / drain cup without reaching the substrate. For this reason, it is possible to effectively prevent mist from reattaching to the substrate.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, a case where the present invention is applied to a liquid processing apparatus that performs front and back surface cleaning of a semiconductor wafer (hereinafter simply referred to as a wafer) will be described.

  FIG. 1 is a sectional view showing a schematic configuration of a liquid processing apparatus according to a first embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is an enlarged sectional view showing an exhaust / drainage portion. The liquid processing apparatus 100 includes a wafer holding unit 1 that rotatably holds a wafer W that is a substrate to be processed, a rotation motor 2 that rotates the wafer holding unit 1, and a wafer W held on the wafer holding unit 1. A rotating cup 3 that is provided so as to rotate together with the wafer holder 1, a surface treatment liquid supply nozzle 4 that supplies a treatment liquid to the surface of the wafer W, and a back surface treatment liquid that supplies the treatment liquid to the back surface of the wafer W It has a supply nozzle 5 and an exhaust / drainage part 6 provided at the peripheral edge of the rotary cup 3. A casing 8 is provided so as to cover the periphery of the exhaust / drainage unit 6 and the upper portion of the wafer W. A fan filter unit (FFU) 9 is provided on the upper portion of the casing 8 so that a downflow of clean air is supplied to the wafer W held by the wafer holder 1.

  The wafer holding unit 1 includes a horizontally-rotating rotating plate 11 having a disk shape, and a cylindrical rotating shaft 12 connected to the center of the back surface and extending vertically downward. A circular hole 11 a that communicates with the hole 12 a in the rotating shaft 12 is formed at the center of the rotating plate 11. And the back surface treatment liquid supply nozzle 5 can be moved up and down in the holes 12a and 11a. As shown in FIG. 2, the rotary plate 11 is provided with three holding members 13 that hold the outer edge of the wafer W at equal intervals. The holding member 13 is configured to hold the wafer W horizontally with the wafer W slightly floating from the rotating plate 11. The holding member 13 is movable between a holding position that holds the wafer W and a release position that rotates backward to release the holding. In the vicinity of the end portion of the rotating plate 11, an inclined portion 11 b is formed by circling so that the outer portion is lower than the central portion. Therefore, the end portion of the rotating plate 11 is formed thinner than the other portions.

  A belt 14 is wound around the lower end of the rotary shaft 12, and the belt 14 is also wound around a pulley 15. The pulley 15 can be rotated by the motor 2, and the rotation shaft 12 is rotated via the pulley 15 and the belt 14 by the rotation of the motor 2.

  The surface treatment liquid supply nozzle 4 is held at the tip of the nozzle arm 16 so that the treatment liquid is supplied from a liquid supply tube (not shown), and the treatment liquid is discharged through a nozzle hole provided therein. It has become. Examples of the processing liquid to be discharged include cleaning chemicals, rinsing liquids such as pure water, and dry solvents such as IPA. One type or two or more types of processing liquids can be discharged. As shown in FIG. 2, the nozzle arm 16 is provided so as to be rotatable about a shaft 17, and is driven between a discharge position on the center of the wafer W and a retreat position outside the wafer W by a drive mechanism (not shown). It is possible to move with. The nozzle arm 16 is provided so as to be movable up and down. When the nozzle arm 16 is rotated, the nozzle arm 16 is raised. When the treatment liquid is discharged from the surface treatment liquid supply nozzle 4, the nozzle arm 16 is lowered.

  The backside treatment liquid supply nozzle 5 has a nozzle hole 5a extending along the longitudinal direction thereof. A predetermined processing liquid is supplied from the lower end of the nozzle hole 5a through a processing liquid tube (not shown), and the processing liquid is discharged to the back surface of the wafer W through the nozzle hole 5a. Examples of the treatment liquid to be discharged include cleaning chemicals, rinsing liquids such as pure water, and dry solvents such as IPA, as with the surface treatment liquid supply nozzle 4. The liquid can be discharged. The back surface treatment liquid supply nozzle 5 also has a function as a wafer lifting member, and has a wafer support 18 for supporting the wafer W at the upper end thereof. On the upper surface of the wafer support 18, there are three wafer support pins 19 (only two are shown) for supporting the wafer W. A cylinder mechanism 21 is connected to the lower end of the back surface processing liquid supply nozzle 5 via a connecting member 20. The back surface processing liquid supply nozzle 5 is moved up and down by the cylinder mechanism 21 to move the wafer W up and down. W loading and unloading are performed.

  As shown in FIG. 3, the rotary cup 3 includes a cylindrical vertical wall member 31 provided around the substrate so as to extend upward from the end of the rotary plate 11 to form a vertical wall, and a vertical wall member 31. And an annular flange member 32 extending inwardly from the upper end of the ring. The rotating plate 11 forms the bottom of the rotating cup 3 and functions as a constituent member of the rotating cup 3.

  The vertical wall member 31 is formed with a plurality of discharge holes 33 and 34 that penetrate from the inside to the outside and discharge the processing liquid vertically and along the circumferential direction. Further, the rotary cup 3 is an annular and plate-shaped guide whose inner end reaches the vicinity of the periphery of the wafer W at a position substantially the same height as the wafer W between the discharge holes 33 and 34 of the vertical wall member 31. A member 35 is provided. The discharge hole 33 is provided such that the lower surface thereof is in contact with the surface of the guide member 35, and the discharge hole 34 is provided so that the lower surface thereof is in contact with the surface of the rotating plate 11.

  The flange member 32 is formed with a gas reservoir 32 a capable of trapping an airflow flowing from the outside to the inside on the outside of the wafer W held by the wafer holder 1. The gas reservoir 32a is provided outside the wafer W held by the wafer holder 1 so as to form a concentric ring with the wafer W, and is formed in a tapered shape from the lower surface of the flange member 32 toward the upper inside. ing.

  As shown in the enlarged view of FIG. 3, the exhaust / drainage unit 6 receives the drainage discharged from the discharge holes 33 and 34 of the vertical wall member 31 in the rotary cup 3, and also in and around the rotary cup 3. The exhaust / drain cup 41 has an annular shape for exhausting the air. An exhaust / drainage port 43 is provided at the bottom of the exhaust / drainage cup 41, and an exhaust / drainage pipe 44 is connected to the drainage port 43. A suction mechanism (not shown) is provided on the downstream side of the exhaust / drainage pipe 44, and exhaust / drainage is performed from the exhaust / drainage cup 41 by this suction mechanism. The exhaust / drain pipe 44 is provided with a gas-liquid separation mechanism (not shown). The exhaust / drain port 43 may be formed at one place or at a plurality of places.

  The exhaust / drainage cup 41 also surrounds the rotating cup 3, and its upper wall 41 a is located above the flange member 32. The exhaust / drain cup 41 is configured to suck and exhaust gas from the opening 41b between the upper wall 41a and the flange member 32. The exhaust / drain cup 41 is provided with a plurality of air intakes 47 along the circumferential direction on the upper wall thereof, and a plurality of air intakes 48 along the circumferential direction on the inner wall thereof. . The air intake 47 sucks the atmosphere in the upper region of the exhaust / drain cup 41, and the air intake 48 sucks the atmosphere of the mechanism part existing below the rotating plate 11, and the gas of the staying processing liquid It is possible to remove chemical components.

  The guide member 35 is provided such that the front and back surfaces thereof are substantially continuous with the front and back surfaces of the wafer W. The processing liquid shaken off from the surface of the wafer W is guided to the surface of the guide member 35 provided substantially continuously, reaches the vertical wall member 31, passes through the discharge hole 33 by centrifugal force, and is outside the rotary cup 3. To be discharged. Similarly, when the wafer holding member 1 and the rotating cup 3 are rotated together with the wafer W and the processing liquid is supplied from the back surface processing liquid supply nozzle 5 to the center of the back surface of the wafer W, the processing liquid is subjected to centrifugal force by the wafer W. Is spread from the periphery of the wafer W. The processing liquid shaken off from the back surface of the wafer W is discharged to the outside of the rotary cup 3 through the discharge hole 34 by centrifugal force. By providing the guide member 35, the processing liquid detached from the peripheral edge of the wafer W is not easily turbulent, and the processing liquid can be guided out of the rotating cup without being misted. The height of the front and back surfaces of the portion adjacent to the wafer W of the guide member 35 is preferably the same as the height of the front and back surfaces of the wafer W. As shown in FIG. 2, the guide member 35 is provided with a notch 36 at a position corresponding to the wafer holding member 13 so as to avoid the wafer holding member 13.

  Next, the operation of the liquid processing apparatus 100 configured as described above will be described with reference to FIG. First, as shown in FIG. 4A, the wafer W is delivered onto the support pins of the wafer support 18 from a transfer arm (not shown) with the back surface treatment liquid supply nozzle 5 raised. Next, as shown in FIG. 4B, the back surface treatment liquid supply nozzle 5 is lowered to a position where the wafer W can be held by the holding member 13, and the wafer W is chucked by the holding member 13. Then, as shown in FIG. 4C, the surface treatment liquid supply nozzle 4 is moved from the retracted position to the discharge position on the center of the wafer W.

  In this state, as shown in FIG. 4 (d), the motor 2 rotates the holding member 1 together with the rotary cup 3 and the wafer W while performing predetermined processing from the surface treatment liquid supply nozzle 4 and the back surface treatment liquid supply nozzle 5. The liquid is supplied to perform the cleaning process.

  In this cleaning process, a processing liquid is supplied to the center of the front and back surfaces of the wafer W, and the cleaning liquid spreads outside the wafer W by centrifugal force and is shaken off from the periphery of the wafer W. In this case, since the cup provided so as to surround the outside of the wafer W is the rotating cup 3 that rotates together with the wafer W, as shown in FIG. Even if it hits 31, the centrifugal force acts on the processing liquid and forms a liquid film 37 around the discharge holes 33, 34 of the vertical wall member 31, so that scattering (misting) unlike the case of the fixed cup hardly occurs. Then, the processing liquid that has reached the vertical wall member 31 is discharged to the outside of the rotary cup 3 from the discharge holes 33 and 34 by centrifugal force. Therefore, it is possible to prevent the processing liquid that has been mist from hitting the cup as in the case of providing the fixed cup from returning to the wafer W. When the supply of the processing liquid is stopped, the processing liquid accumulated around the discharge holes 33 and 34 of the vertical wall member 31 as the liquid film 37 is also discharged from the discharge holes 33 and 34, and the processing liquid is put into the rotary cup 3. It is assumed that it does not exist.

  Further, the processing liquid is discharged outward from the discharge holes 33 and 34 by centrifugal force, but due to the presence of the liquid film 37, the mist of the processing liquid that has bounced off the wall of the exhaust / drainage cup 41 is even though the discharge hole 33. , 34, the mist is prevented from entering the rotary cup 3.

  By the way, since the rotary cup 3 is rotated during the cleaning process as described above, as shown in FIG. 6 (a), in the vicinity of the side wall of the exhaust / drain cup 41 on the outside. The region A is in a high pressure state due to the swirling flow at that time. However, when the cleaning process is completed and the rotation of the rotary cup 3 is stopped, the high pressure state of the portion of the region A is released, and an air flow is generated from the outer region A toward the inner side in the horizontal direction. At this time, the rotating cup 3 is stopped, the liquid film 37 is not present on the inner surface of the vertical wall member 31, and the airflow enters the rotating cup 3 through the discharge holes 33 and 34. In the case where mist present in the exhaust / drain cup 41 accompanies this air flow, when this mist reaches the wafer W by riding on the air flow, there is a risk that the mist will reattach and water marks and particles may be generated. .

  However, in the present embodiment, since the annular gas reservoir portion 32a is provided on the outer side of the wafer W of the flange member 32 of the rotary cup 3, as shown in FIG. It is possible to temporarily trap the air flow accompanying the mist entering the rotary cup 3 and accompanying the inward mist at the gas reservoir 32a and stay in the trap. In this case, since the gas reservoir portion 32a is formed in a tapered shape inwardly upward from the lower surface of the flange member 32, even if trapped gas flows out of the gas reservoir portion 32a, it flows out to the wafer W side. It is hard to do. And while trapping the airflow in this way, the trapped gas can be discharged by the airflow control by the suction mechanism of the exhaust / drainage section 6. For this reason, the air flow accompanied with mist hardly reaches the surface of the wafer W, and re-adhesion of the mist on the surface of the wafer W due to the returning air flow can be sufficiently suppressed. However, in the case of this embodiment, the airflow that has entered the rotary cup 3 from the discharge hole 34 reaches the wafer W to some extent although it is attenuated. However, since the airflow that has entered through the discharge holes 34 reaches the back side of the wafer W, there is no significant influence. From the viewpoint of sufficiently suppressing mist reattachment to the back side of the wafer W, for example, as shown in FIG. 7, a guide member 35 'having a thick base end portion is provided instead of the guide member 35. It is preferable to provide a gas reservoir 35a on the outer portion of the wafer W held by the wafer holder 1 of 35 '.

  The present invention can be variously modified without being limited to the above embodiment. For example, the guide member is provided to prevent the generation of mist due to turbulent flow, but it is not always necessary. Moreover, in the said embodiment, although the gas reservoir part 32a was provided in cyclic | annular form, it is not necessarily restricted to cyclic | annular form, What is necessary is just to be able to trap the airflow which goes to the inner side from the outer side of the rotation cup 3. FIG. Further, the liquid process is not limited to the cleaning process, and other liquid processes such as a resist liquid coating process and a subsequent development process may be used. Furthermore, in the above-described embodiment, the case where a semiconductor wafer is used as the substrate to be processed has been described. Needless to say, this is applicable.

  The present invention is effective for a cleaning apparatus for removing particles and contamination adhering to a semiconductor wafer.

1 is a cross-sectional view illustrating a schematic configuration of a liquid processing apparatus according to an embodiment of the present invention. 1 is a schematic plan view showing a liquid processing apparatus according to an embodiment of the present invention with a part cut away. Sectional drawing which expands and shows the exhaust_gas | exhaustion part of the liquid processing apparatus of FIG. The figure for demonstrating the processing operation of the liquid processing apparatus which concerns on one Embodiment of this invention. The schematic diagram for demonstrating the state of the process liquid shaken off from the wafer. In the liquid processing apparatus of this invention, the schematic diagram which compares and shows the state of an airflow in the state which the rotation cup is rotating, and the state which the rotation cup has stopped. The figure which shows the state which provided the gas reservoir part also in the rotation plate which is one component of a rotation cup.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Wafer holding part 2; Rotary motor 3; Rotary cup 4; Surface treatment liquid supply nozzle 5; Back surface treatment liquid supply nozzle 6; Exhaust / drainage part 8; Casing 9;
11; rotating plate 12; rotating shaft 13; holding member 31; vertical wall member 32; eaves member 32a, 35a; gas reservoir 33, 34; discharge hole 35; guide member 37; liquid film 41; ; Liquid processing equipment W; Wafer

Claims (6)

A substrate holding unit that holds the substrate horizontally and can rotate with the substrate;
A liquid supply mechanism for supplying a treatment liquid to at least the surface of the substrate held by the substrate holding unit;
A rotating cup that surrounds the substrate held by the substrate holding unit and is rotatable together with the substrate and discharges the processing liquid shaken off from the substrate to the outside as a drainage;
A rotation mechanism for integrally rotating the rotary cup and the substrate holding part;
While receiving the drainage discharged from the rotating cup , it comprises an exhaust / drainage cup that exhausts in and around the rotating cup ,
The liquid processing apparatus according to claim 1, wherein the rotary cup has a gas reservoir that can trap an airflow flowing from the outside to the inside outside the substrate held by the substrate holding unit. A substrate holding unit that holds the substrate horizontally and can rotate with the substrate;
A surface liquid supply mechanism for supplying a treatment liquid to the surface of the substrate;
A back surface liquid supply mechanism for supplying a processing liquid to the back surface of the substrate;
A rotating cup that surrounds the substrate held by the substrate holding unit and is rotatable together with the substrate and discharges the processing liquid shaken off from the substrate to the outside as a drainage;
A rotation mechanism for integrally rotating the rotary cup and the substrate holding part;
While receiving the drainage discharged from the rotating cup , it comprises an exhaust / drainage cup that exhausts in and around the rotating cup ,
The liquid processing apparatus according to claim 1, wherein the rotary cup has a gas reservoir that can trap an airflow flowing from the outside to the inside outside the substrate held by the substrate holding unit. The said rotary cup is further provided with the guide member provided in the outer side of the board | substrate on the said board | substrate holding part which guides the process liquid shaken off from the board | substrate to the outward of a board | substrate. 2. The liquid processing apparatus according to 2.   The said gas reservoir part is provided in the outer side of the board | substrate hold | maintained at the said board | substrate holding | maintenance part so that the concentric ring may be made with a board | substrate, The any one of Claims 1-3 characterized by the above-mentioned. The liquid processing apparatus as described.   The rotating cup covers the outside of the substrate held by the substrate holding portion, has a wall portion having a processing liquid discharge hole, and a flange member provided annularly from the upper end of the wall portion toward the inside. The liquid processing apparatus according to claim 1, wherein the gas reservoir is formed on the flange member.   The liquid processing apparatus according to claim 5, wherein the gas reservoir is formed in a tapered shape that extends inward and upward from the lower surface of the flange member.

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