JP2004228205A - Spin treatment method of substrate and treating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spin treatment method capable of preventing particles from adhering to equipment when treating a semiconductor wafer by a treatment liquid before drying and treatment. <P>SOLUTION: The spin treatment method for treating the semiconductor wafer by the treatment liquid before drying and treatment includes a process for supplying the treatment liquid for treatment while the semiconductor is being rotated; a process for stopping the supply of the treatment liquid and rotating the semiconductor wafer for specific time without increasing the speed of the semiconductor wafer after the semiconductor wafer is completely treated by the treatment liquid; and a process for stopping the supply of the treatment liquid for rotating the semiconductor wafer for the specific time, before the rotational speed of the semiconductor wafer is set faster than that in the treatment by the treatment liquid for drying and treating. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a spin processing method and a spin processing apparatus in which a substrate is processed with a processing liquid while rotating, and then dried.
[0002]
[Prior art]
For example, in a manufacturing process of a liquid crystal display device or a semiconductor device, there are a film forming process and a photo process for forming a circuit pattern on a substrate such as a rectangular glass substrate or a semiconductor wafer. In these processes, after a substrate is treated with a chemical solution as a treatment liquid using a spin treatment apparatus, a cleaning treatment with a cleaning liquid as a treatment liquid is performed, and a drying treatment for removing the cleaning liquid is repeatedly performed.
[0003]
As is well known, the spin processing apparatus has a processing tank, and a cup body is provided in the processing tank. A rotary table that is driven to rotate by a drive source is provided in the cup body. The turntable is adapted to hold the substrate detachably.
[0004]
The substrate is processed by rotating the substrate at a low speed of several tens to several hundred rotations per minute while supplying a processing liquid to the plate surface. After the processing with the processing liquid has been performed for a predetermined time, the substrate is rotated at a high speed of several thousand rotations per minute. As a result, the processing liquid adhering to the substrate is removed by the centrifugal force and the airflow generated by the high-speed rotation, so that the substrate is dried.
[0005]
Conventionally, the substrate has been rotated at a high speed immediately after the processing with the processing liquid at a low speed has been completed to perform a drying process.
[0006]
[Problems to be solved by the invention]
When the processing with the processing liquid is completed, a large amount of the processing liquid remains on the plate surface of the substrate. When the substrate is rotated at a high speed to dry it in this state, a large amount of the processing liquid scatters vigorously around the substrate at a high speed according to the rotation speed of the substrate and collides with the inner peripheral surface of the cup body I do. For this reason, a large amount of mist is generated in the cup body, and the mist may adhere to the substrate during the drying process and cause contamination.
[0007]
A substrate having a large amount of the processing liquid remaining on the upper surface increases in weight in proportion to the amount of the processing liquid, and thus has a large inertia. Therefore, when the rotation speed is changed from the low-speed rotation to the high-speed rotation for drying the substrate, a slip is likely to occur between the substrate and the holding mechanism that holds the substrate on the rotary table. When the slip occurs, the substrate may be damaged or particles may be generated.
[0008]
In order to prevent a slip from occurring between the rotary table and the substrate during the drying process, it is necessary to increase the holding force (chuck force) of the holding mechanism. The holding force applied to the substrate by the holding mechanism is a force directed radially inward from the outer peripheral surface of the substrate.
[0009]
Therefore, when the holding force is increased, the substrate is likely to be distorted. In the state where the distortion is generated, the processing with the processing liquid may not be performed uniformly on the substrate, or the subsequent drying processing may not be performed uniformly. Therefore, it is not preferable to increase the holding force of the substrate in order to prevent the occurrence of slip.
[0010]
An object of the present invention is to provide a spin processing method and a spin processing apparatus that can suppress generation of mist due to scattering of a processing liquid and generation of slip due to high-speed rotation when a substrate is dried.
[0011]
[Means for Solving the Problems]
The present invention relates to a spin processing method in which a substrate is treated with a treatment liquid and then dried,
A step of supplying a processing liquid while rotating the substrate to perform processing;
When the processing of the substrate with the processing liquid is completed, stopping the supply of the processing liquid and rotating the substrate for a predetermined time without increasing the rotation speed of the substrate,
After the supply of the processing liquid is stopped, rotating the substrate for a predetermined time, and then performing a drying process at a higher rotation speed of the substrate than during the processing with the processing liquid. Processing method.
[0012]
It is preferable that the rotation speed when the substrate is rotated for a predetermined time after the supply of the processing liquid is stopped is set to be the same as when the substrate is processed with the processing liquid.
[0013]
It is preferable that the rotation speed when the substrate is rotated for a predetermined time after the supply of the processing liquid is stopped is lower than when the substrate is processed with the processing liquid.
[0014]
The present invention provides a spin processing apparatus for processing a substrate with a processing liquid and then drying the substrate.
A rotary table that holds and rotates the substrate,
A drive source for rotating the rotary table,
Supply means for supplying a processing liquid to the substrate rotating with the rotary table,
The rotation speed of the rotary table is set to a first rotation speed at which the substrate is processed by the processing liquid, and the rotation speed of the rotary table is not increased while the supply of the processing liquid is stopped after the processing by the processing liquid is completed. And a control means for controlling the rotation speed of the turntable after the second rotation speed for a predetermined time and a third rotation speed for increasing the rotation speed of the turntable higher than the first rotation speed after the second rotation speed. The spin processing apparatus for a substrate is characterized in that:
[0015]
According to the present invention, before the substrate processed by the processing liquid is rotated at a high speed to perform the drying process, the substrate is rotated without increasing the rotation speed while the supply of the processing liquid is stopped. Therefore, the substrate is rotated at a high speed after the processing liquid remaining on the upper surface is discharged at a gentle speed, so that not only the generation of mist but also the occurrence of slip due to the weight of the processing liquid is prevented. You.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a spin processing device, and the spin processing device includes a processing tank 1. A cup 2 is arranged in the processing tank 1. The cup body 2 includes a lower cup 3 provided on a bottom plate of the processing tank 1 and an upper cup 4 provided to be vertically movable with respect to the lower cup 3 by a vertical drive mechanism (not shown).
[0017]
A plurality of discharge pipes 5 are connected to the bottom wall of the lower cup 3 at predetermined intervals in the circumferential direction. These discharge pipes 5 communicate with an exhaust pump 6. The start and stop and rotation speed of the exhaust pump 6 are controlled by a control device 7.
[0018]
A base plate 8 is arranged on the lower surface side of the cup body 7. The base plate 8 has a mounting hole 9 at a position corresponding to the lower cup 3. The upper end of the stator 12 of the control motor 11 constituting the drive source is fitted and fixed in the mounting hole 9.
[0019]
The stator 12 has a cylindrical shape, and a cylindrical rotor 13 is rotatably fitted therein. The control motor 11 is controlled by the control device 7 so that the start and stop and the rotation speed are described later.
[0020]
A cylindrical connecting body 14 is integrally fixed to the upper end face of the rotor 13 with the lower end face in contact therewith. A flange 15 having a diameter larger than the inner diameter of the stator 12 is formed at the lower end of the connecting body 14. The flange 15 is slidably in contact with the upper end surface of the stator 12, thereby preventing the rotor 13 from falling off the stator 12 without preventing rotation of the rotor 13. .
[0021]
The lower cup 3 has a through hole 3a formed at a portion corresponding to the rotor 13, and the connecting body 14 protrudes into the cup body 2 from the through hole 3a. A turntable 16 is attached to the upper end of the connector 14. At the peripheral portion of the turntable 16, six (only two are shown) columnar holding members 17 are provided at predetermined intervals in the circumferential direction, at 60 ° intervals in this embodiment, so as to be rotatable by a drive mechanism (not shown). Have been.
[0022]
A support pin 18 having a tapered surface is provided on the upper end surface of the holding member 17 at a position eccentric from the rotation center of the holding member 17. A semiconductor wafer W as a substrate is supplied to the turntable 16 such that the lower surface of the peripheral portion abuts on the tapered surface of the support pin 18. If the holding member 17 is rotated in this state, the support pins 18 are eccentrically rotated. Therefore, the semiconductor wafer W supplied to the turntable 16 is held by the chucking force of the support pins 18.
The chucking force of the support pins 18 on the semiconductor wafer W can be set by the eccentric rotation angle of the holding member 17 by the driving mechanism. When the driving mechanism is configured to rotate the holding member 17 eccentrically by the spring force, the chucking force can be adjusted by the strength of the spring.
[0023]
The turntable 16 is covered with a turbulence prevention cover 21. The turbulence prevention cover 21 has an outer peripheral wall 22 that covers the outer peripheral surface of the rotary table 16 and an upper surface wall 23 that covers the upper surface. The outer peripheral wall is formed with a small-diameter portion 22a on the upper side and a large-diameter portion 22b on the lower side. Have been. When the turntable 16 is rotated, the turbulence prevention cover 21 prevents turbulence from occurring on the upper surface of the turntable 16. The upper surface of the upper cup 4 is open, and a ring-shaped member 25 is provided on the inner peripheral surface thereof.
[0024]
When supplying an unprocessed semiconductor wafer W to the rotary table 16 or removing a dried semiconductor wafer W, the upper cup 4 is lowered as described later.
[0025]
An opening 31 is formed in the upper wall of the processing tank 1. The opening 31 is provided with a fan / filter unit 32 such as ULPA or HEPA. The fan / filter unit 32 further purifies the air in the clean room and introduces it into the processing tank 1. The amount of the clean air introduced is controlled by the control unit 7 by the drive unit 33 of the fan / filter unit 32. And then do it. That is, by controlling the number of revolutions of the fan (not shown) of the fan / filter unit 32 by the drive unit 33, the supply amount of clean air into the processing tank 1 can be controlled.
[0026]
An opening 34 is formed on one side of the processing tank 1. The access port 34 is opened and closed by a shutter 35 provided on one side of the processing tank 1 so as to be slidable in the vertical direction. The shutter 35 is driven by a cylinder 36 operated by compressed air. That is, the cylinder 36 is provided with a control valve 37 for controlling the flow of the compressed air, and the switching of the control valve 37 by the control device 7 allows the shutter 35 to be moved up and down. ing.
[0027]
A cylindrical fixed shaft 41 is inserted into the rotor 13 of the control motor 11. At the upper end of the fixed shaft 41, a nozzle head 43 is provided which protrudes from a through hole 42 formed in the rotary table 16 to the upper surface side of the rotary table 16. The nozzle head 43 is provided with a pair of nozzles 44 for injecting a treatment liquid as a processing liquid and pure water toward the lower surface of the semiconductor wafer W held on the rotary table 16.
[0028]
An opening 45 is formed in the upper surface wall 23 of the turbulence prevention cover 21 so as to face the nozzle head 43, and the processing liquid ejected from the nozzle 44 can reach the lower surface of the semiconductor wafer W through the opening 45. It has become.
[0029]
Above the semiconductor wafer W held by the rotary table 16, an upper nozzle body 46 is provided as a supply unit that supplies a processing liquid such as a chemical solution or a cleaning liquid to the upper surface of the semiconductor wafer W during the cleaning processing.
[0030]
Next, a procedure of processing the semiconductor wafer W with the processing liquid by the spin processing apparatus having the above configuration and then performing the drying processing will be described with reference to FIGS.
[0031]
FIG. 2 is a flowchart showing a procedure for drying the semiconductor wafer W after processing it with the processing liquid, and FIG. 3 is a time chart showing the relationship between the rotation speed of the semiconductor wafer W and the processing. As shown in FIG. 2, an unprocessed semiconductor wafer W is supplied to the turntable 16 in S1. In S2, the rotary table 16 is rotationally driven at a low rotational speed V1 of several tens to several hundreds per minute by a drive signal from the control device 7. Next, in S3, the processing liquid is supplied to the semiconductor wafer W from the upper nozzle body 46.
[0032]
By supplying the processing liquid to the rotating semiconductor wafer W, the upper surface of the semiconductor wafer W is processed according to the type of the processing liquid. In S4, it is determined whether or not the processing time with the processing liquid has reached a predetermined time set in the control device 7 in advance. When the processing time with the processing liquid reaches the set time, in S5, the supply of the processing liquid is stopped, and the processing with the processing liquid ends. The processing time by the processing liquid is indicated by T1 in FIG.
[0033]
Next, in S6, while the supply of the processing liquid to the semiconductor wafer W is stopped, the rotating table 16, that is, the semiconductor wafer W is rotated for a predetermined time at the same low-speed rotation speed V1 as when the processing liquid is being processed. This rotation time is indicated by T2 in FIG. Thereby, the processing liquid remaining on the upper surface of the semiconductor wafer W flows out of the upper surface at a low speed according to the rotation speed of the semiconductor wafer W.
[0034]
In S7, it is determined whether or not the time T2 for rotating the semiconductor wafer W at the low rotation speed V1 has elapsed. After the time T2 has elapsed, in S8, the turntable 16 is rotated at a high speed V2 of one thousand to several thousand rotations by a control signal from the control device 7. Thus, the processing liquid slightly adhering and remaining on the upper surface of the semiconductor wafer W is removed by the centrifugal force and the airflow generated by the high-speed rotation, and the semiconductor wafer W is dried.
[0035]
In S9, it is determined whether or not a drying time T3 has elapsed while rotating the semiconductor wafer W at the high rotation speed V2. If the drying time T3 has elapsed, the rotation table 16 is controlled by a control signal from the control device 7. Is stopped, and the process ends.
[0036]
As described above, after the semiconductor wafer W is rotated at the low rotation speed V1 and the processing liquid is supplied for the predetermined time T1 to perform the processing, the supply of the processing liquid to the semiconductor wafer W is stopped. After rotating at the same low-speed rotation speed V1 as in the processing and for the time indicated by T2 in FIG. 3, the rotation speed is converted to the high-speed rotation speed V2 for the drying process.
[0037]
That is, after processing the semiconductor wafer W with the processing liquid, the processing liquid remaining on the upper surface of the semiconductor wafer W can be removed by rotating the semiconductor wafer W at the low rotation speed V1 for the time T2. Therefore, the time T2 is a liquid draining time for removing the processing liquid remaining on the upper surface of the semiconductor wafer W.
[0038]
By providing the liquid draining time T2, the semiconductor wafer W is rotated at the high rotational speed V2 after the processing liquid remaining on the upper surface is slowly flowed out and removed according to the low rotational speed V1 of the semiconductor wafer W. The processing liquid on the upper surface of the semiconductor wafer W can be removed without colliding with the inner peripheral surface of the cup body 2 at a high speed. That is, it is possible to prevent a large amount of mist from being generated in the cup body 2 due to the processing liquid colliding with the inner peripheral surface of the cup body 2 at a high speed.
[0039]
Therefore, when the semiconductor wafer W is processed with the processing liquid and then rotated at the high rotation speed V2 to perform the drying process, a large amount of mist does not float in the cup body 2, so that the mist adheres to the semiconductor wafer W. To prevent contamination.
[0040]
As described above, after processing the semiconductor wafer W with the processing liquid, the processing liquid remaining on the upper surface of the semiconductor wafer W during the draining time T2 is removed, and then the semiconductor wafer W is rotated at the high rotation speed V2. Drying process.
[0041]
Therefore, the weight of the processing liquid is hardly added to the semiconductor wafer W during the drying process, so that when the rotation speed of the semiconductor wafer W is converted from the low rotation speed V1 to the high rotation speed V2, the inertia generated in the semiconductor wafer W is greatly reduced. To be reduced. This prevents the semiconductor wafer W from slipping with respect to the support pins 18 of the turntable 16.
[0042]
As a result, damage to the outer peripheral edge of the semiconductor wafer W and generation of particles can be prevented. Moreover, it is not necessary to increase the chucking force on the semiconductor wafer W in order to prevent the occurrence of slip. Therefore, since no distortion occurs in the semiconductor wafer W held on the turntable 16, the processing with the processing liquid and the drying processing can be performed uniformly over the entire surface.
[0043]
FIG. 4 is a graph showing the relationship between the time T2 during which the semiconductor wafer W is rotated at a low rotation speed V1 without supplying the processing liquid after the processing liquid is supplied, and the particles adhering to the semiconductor wafer W.
[0044]
Assuming that the time T2, that is, the liquid drainage time T2 is 0, and the amount of particles attached to the dried semiconductor wafer W in the conventional case is 1, the liquid drainage time T2 is about 1 second, The particle adhesion ratio decreased to 0.5, increased to about 0.7 when the time T2 was about 4 seconds, and gradually increased to about 0.75 thereafter.
[0045]
Therefore, it has been confirmed that the provision of the liquid draining time T2 reduces the amount of particles adhering to the semiconductor wafer W as compared with the conventional case where the liquid draining time T2 is zero. The drainage time T2 is preferably set to 1 second or more for control, but is preferably set within a range of 1 to 5 seconds in order to suppress an increase in tact time.
[0046]
FIG. 5 is a time chart showing the relationship between the rotation speed of a semiconductor wafer W and processing according to another embodiment of the present invention. In this embodiment, after the time T1 during which the processing is performed with the processing liquid while the semiconductor wafer W is being rotated at the low rotation speed V1 and the supply of the processing liquid is stopped, the rotation speed of the semiconductor wafer W is reduced to the low rotation speed V1. The rotation speed is further reduced to a lower rotation speed V3, and the low rotation speed V3 is maintained for a predetermined time indicated by T2a in FIG. Thereafter, the rotation speed of the semiconductor wafer W is accelerated to the high rotation speed V2, and the drying process is performed only for the time indicated by T3 in FIG.
[0047]
As described above, after the processing with the processing liquid is completed, the semiconductor wafer W is rotated without supplying the processing liquid, and the rotation speed during the liquid removal time T2a is lower than the low-speed rotation speed V1 when processing with the processing liquid. Speed V3.
[0048]
Therefore, the speed at which the processing liquid flows out from the upper surface of the semiconductor wafer W at the time of draining can be further reduced as compared with the embodiment described above. The amount of mist generated by colliding with the peripheral surface can be further reduced. As a result, the drying process of the semiconductor wafer W can be performed even more cleanly.
[0049]
In this embodiment, the liquid removal time T2a for rotating the semiconductor wafer W at the low rotation speed V3 is such that the amount of mist adhering to the semiconductor wafer W is minimized, similarly to the time T2 shown in the above-described embodiment. Is set.
[0050]
In each of the above embodiments, a semiconductor wafer is given as a substrate to be processed. However, the substrate is not limited to a semiconductor wafer, and the present invention is applied to a rectangular glass substrate used for a liquid crystal display panel. be able to.
[0051]
【The invention's effect】
As described above, according to the present invention, before the substrate processed by the processing liquid is rotated at a high speed and dried, the substrate is rotated without increasing the rotation speed in a state where the supply of the processing liquid is stopped. I did it.
[0052]
As a result, the substrate is dried after the processing liquid remaining on the upper surface is removed at a gentle speed, so that not only mist generation can be prevented, but also slip due to the weight of the processing liquid can be prevented. it can.
[Brief description of the drawings]
FIG. 1 is a sectional view of a schematic configuration of a spin processing apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing processing steps of a semiconductor wafer.
FIG. 3 is a time chart showing the relationship between the rotation speed of a semiconductor wafer and processing.
FIG. 4 is a graph showing a relationship between a liquid removal time for removing a processing liquid remaining on an upper surface of a semiconductor wafer and particles adhering to the upper surface of the semiconductor wafer.
FIG. 5 is a time chart showing a relationship between a rotation speed of a semiconductor wafer and processing according to another embodiment of the present invention.
[Explanation of symbols]
7: control device (control means), 11: control motor (drive source), 16: rotary table, 46: upper nozzle body (supply means).

Claims (4)

In a spin processing method of drying a substrate after processing the substrate with a processing liquid,
A step of supplying a processing liquid while rotating the substrate to perform processing;
When the processing of the substrate with the processing liquid is completed, stopping the supply of the processing liquid and rotating the substrate for a predetermined time without increasing the rotation speed of the substrate,
After the supply of the processing liquid is stopped, rotating the substrate for a predetermined time, and then performing a drying process at a higher rotation speed of the substrate than during the processing with the processing liquid. Processing method. 2. The substrate spin processing according to claim 1, wherein a rotation speed when the substrate is rotated for a predetermined time after the supply of the processing liquid is stopped is set to be the same as when the substrate is processed by the processing liquid. Method. 2. The substrate spin processing method according to claim 1, wherein a rotation speed when the substrate is rotated for a predetermined time after the supply of the processing liquid is stopped is lower than when the substrate is processed with the processing liquid. . In a spin processing apparatus for processing a substrate with a processing liquid and then performing a drying process,
A rotary table that holds and rotates the substrate,
A drive source for rotating the rotary table,
Supply means for supplying a processing liquid to the substrate rotating with the rotary table,
The rotation speed of the rotary table is set to a first rotation speed at which the substrate is processed by the processing liquid, and the rotation speed of the rotary table is not increased while the supply of the processing liquid is stopped after the processing by the processing liquid is completed. And a control means for controlling the rotation speed of the turntable after the second rotation speed for a predetermined time and a third rotation speed for increasing the rotation speed of the turntable higher than the first rotation speed after the second rotation speed. A spin processing apparatus for a substrate, comprising:

Images