JP2004056070A - Spin treatment apparatus and method of spin treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spin treatment apparatus capable of quickly and surely carrying out the drying process of a substrate. <P>SOLUTION: The spin treatment apparatus comprises a treatment vessel 1, a cup member 2 installed in the treatment vessel and having an opening on its upper face, a rotary table 16 installed in the cup member and driven to rotate while holding a substrate, a fan-filter unit 32 installed on the upper portion of the treatment vessel and introducing clean air into the treatment vessel, an exhaust pipe 5 and an exhaust pump 6 that exhaust the clean air fed from the fan-filter unit to the treatment vessel through the inner space of the cup member, and a lamp 51 arranged above the cup member at a position outer than at least the upper face of the substrate in the radial direction for irradiating the substrate with a light beam for heating. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin processing apparatus and a spin processing method for performing a drying process after processing a substrate with a processing liquid while rotating the substrate.
[0002]
[Prior art]
When manufacturing a semiconductor device or a liquid crystal display device, there is a lithography process for forming a circuit pattern on a substrate such as a semiconductor wafer or a glass substrate. In this lithography process, as is well known, a resist is applied to the substrate, and the resist is irradiated with light through a mask on which a circuit pattern is formed. The circuit pattern is formed on the substrate by repeating a series of steps such as removing the removed portion and etching the removed portion a plurality of times.
[0003]
In the above series of steps, if the substrate is contaminated, the circuit pattern cannot be precisely formed, which causes defective products. Therefore, when forming a circuit pattern in each step, the substrate is cleaned in a clean state in which fine particles such as resist and dust do not remain.
[0004]
A spin processing apparatus is known as an apparatus for cleaning the substrate. The spin processing apparatus has a processing tank, and a cup body is provided in the processing tank. A rotary table is provided in the cup body, and the substrate is detachably held on the rotary table.
[0005]
When the substrate is held on the rotary table and the processing liquid is supplied to the substrate while the rotary table is being rotated and the substrate is processed, the substrate is dried by rotating the rotary table at a higher speed than when processing with the processing liquid. To process.
[0006]
A fan / filter unit such as ULPA or HEPA is provided at the upper part of the processing tank so that clean air is supplied into the processing tank when processing a substrate. A discharge pipe is connected to the bottom of the cup body. An exhaust pump is connected to this exhaust pipe.
[0007]
As a result, the clean air supplied into the processing tank from the fan / filter unit passes through the inside of the cup and becomes a laminar flow discharged from the discharge pipe, so that the processing liquid scattered from the substrate becomes mist and is processed. Floating in the tank is prevented. As a result, the mist does not adhere to the substrate during the drying process, and thus the drying process can be performed without contaminating the substrate.
[0008]
As described above, when the substrate is treated with the treatment liquid and then dried, it is required to shorten the treatment time and improve the treatment efficiency. As a means for shortening the processing time, the drying time is shortened by not only rotating the substrate at high speed but also heating it during the drying process of the substrate.
[0009]
As such a conventional technique, a substrate processing apparatus disclosed in Japanese Patent Application Laid-Open No. 9-275088 has been proposed. The processing apparatus disclosed in this publication is configured to heat a structure above a substrate processing position. Specifically, a heater is provided on a lid or a side surface located above the spin chuck in a chamber in which the spin chuck holding the substrate is housed, and the substrate is heated by the heat of the heater.
[0010]
[Problems to be solved by the invention]
If a heater is provided in the chamber and the substrate is heated during the drying process, the drying time of the substrate can be reduced. However, since the heat of the heater provided in the chamber is easily radiated to the outside through the wall of the chamber, the efficiency of heating the substrate by the heater may be low.
[0011]
In addition, since the heater is provided on the lid or side surface of the chamber, a downflow in which clean air is supplied toward the substrate from the top of the chamber and discharged from the bottom of the chamber cannot be created. Therefore, the mist generated in the chamber cannot be discharged smoothly and reliably, so that the mist may adhere to the substrate during the drying process and contaminate the substrate.
[0012]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a spin processing apparatus and a spin processing method that can efficiently heat and dry a substrate, and can discharge mist in a processing tank smoothly and reliably by downflow.
[0013]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a spin processing apparatus for rotating and processing a substrate.
A processing tank,
A cup body having an opening on an upper surface provided in the processing tank;
A rotary table provided in the cup body and rotatably driven while holding the substrate,
A fan / filter unit provided above the processing tank and introducing clean air into the processing tank;
Discharging means for discharging the clean air supplied into the processing tank from the fan / filter unit through the internal space of the cup body;
Light irradiation means for irradiating a heating light beam to the substrate, which is arranged radially outward from at least the upper surface of the substrate above the cup body,
A spin processing apparatus characterized by comprising:
[0014]
A second aspect of the present invention is the spin processing apparatus according to the first aspect, wherein the light irradiating means is disposed radially outward of an opening in the upper surface of the cup body.
[0015]
According to a third aspect of the present invention, in the spin processing apparatus according to the first aspect, the light irradiating means is a lamp, and the lamp is arranged so that an optical axis center is shifted from a rotation center of the substrate. is there.
[0016]
According to a fourth aspect of the present invention, there is provided the spin processing apparatus according to the first aspect, wherein the light irradiation means is a laser device for outputting a laser beam.
[0017]
According to a fifth aspect of the present invention, there is provided the spin processing apparatus according to the fourth aspect, wherein the laser light is oscillated between a center of rotation of the substrate and a radially outer end.
[0018]
The invention according to claim 6 is the spin processing apparatus according to claim 4, wherein the laser beam has a wavelength that is absorbed by the substrate.
[0019]
According to a seventh aspect of the present invention, there is provided a spin processing method in which a substrate is processed with a processing solution while rotating, and then a drying process is performed.
A processing step of supplying a processing liquid to the rotating substrate,
A drying step in which the substrate processed by the processing liquid is rotated at a higher speed than during the processing step to perform a drying process,
A light irradiation step of irradiating a light beam for heating the substrate before the processing step is completed,
A spin processing method characterized by comprising:
[0020]
According to the present invention, since the substrate is heated by irradiating a light beam, it is possible to efficiently heat the substrate, and further, since the light irradiation means for heating the substrate is arranged radially outward from the upper surface of the substrate, This light irradiating means does not obstruct the downflow in the processing tank.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0022]
FIG. 1 shows a schematic configuration of a spin processing apparatus according to an embodiment of the present invention. The spin processing apparatus has a box-shaped 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).
[0023]
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 discharge pipe 5 is provided with a butterfly valve 5a, and the opening of the butterfly valve 5a can be set by the controller 7.
[0024]
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 driving means is fitted and fixed in the mounting hole 9.
[0025]
The stator 12 has a cylindrical shape, and a cylindrical rotor 13 is rotatably fitted therein. 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 the rotation of the rotor 13. I have.
[0026]
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 periphery of the turntable 16, six (only two are shown) columnar holding members 17 are rotatably provided at predetermined intervals in the circumferential direction, at 60 ° intervals in this embodiment, by a drive mechanism (not shown). ing.
[0027]
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, so that the semiconductor wafer W supplied to the turntable 16 is held by the support pins 18.
[0028]
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.
[0029]
The upper surface of the upper cup 4 is open, and an annular wall 25 is provided on the inner peripheral surface of the opening 4a. The annular wall 25 has a lower half in the height direction located in the upper cup 4 and an upper half protruding upward from the upper surface of the upper cup 4. The upper half of the annular wall 25 prevents the turbulence from flowing into the cup 2 when turbulence occurs outside the cup 2.
[0030]
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.
[0031]
An opening 31 having a diameter larger than the planar shape of the rotary table 16 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 the air into the processing tank 1. The fan / filter unit 32 has a drive unit 33, and a fan (not shown) is rotationally driven by the drive unit 33 to introduce clean air into the processing tank 1.
[0032]
The clean air introduced into the processing tank 1 by the fan / filter unit 32 becomes a down flow flowing toward the cup body 2, and this down flow flows into the inside from the opening 4 a on the upper surface of the cup body 2. , Are discharged through a discharge pipe 5. That is, the clean air supplied from the fan / filter unit 32 into the processing tank 1 is smoothly discharged in a laminar flow state without being turbulent in the processing tank 1.
[0033]
The start and stop of the drive unit 33 are controlled by the control device 7.
[0034]
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.
[0035]
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 selectively jetting a processing liquid and a cleaning liquid toward the lower surface of the semiconductor wafer W held on the rotary table 16.
[0036]
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.
[0037]
An upper nozzle body 46 is disposed above the turntable 16 at a position radially outward from the upper surface of the substrate W. The upper nozzle body 46 sprays the processing liquid toward the semiconductor wafer W held on the turntable 16.
[0038]
In the upper part of the processing tank 1, radially outward from the upper surface of the substrate W held on the rotary table 16, preferably radially outward from the opening 4a of the upper cup 4 of the cup body 2. Is provided with a lamp 51 as a light irradiating means. In this embodiment, the lamp 51 is installed radially outward of the opening 4a of the upper cup 4. As the lamp 51, for example, an infrared lamp, a halogen lamp, or the like is used, and lighting of the lamp 51 is controlled by the control device 7.
[0039]
The lamp 51 emits a light beam for heating the substrate W toward the substrate W. As shown in FIG. 2, the lamp 51 has its optical axis L shifted radially outward from the center of rotation O of the substrate W held on the rotary table 16 by a distance indicated by X in FIG. Note that the irradiation range R of the substrate W by the lamp 51 extends over substantially the entire radius of the substrate W.
[0040]
By displacing the optical axis L of the lamp 51 radially outward from the rotation center O of the substrate W by a distance X, the plate surface of the substrate W can be heated substantially uniformly over the entire surface. FIG. 3A shows the result of measuring the temperature distribution along the radial direction of the substrate W when the optical axis L of the lamp 51 is shifted from the rotation center O of the substrate W as shown in FIG. () Shows the result of measuring the temperature distribution along the radial direction of the substrate W when the optical axis L is coincident with the rotation center O of the substrate W.
[0041]
As can be seen from these measurement results, it has been confirmed that the substrate W can be heated substantially uniformly in the radial direction by shifting the optical axis L of the lamp 51 from the rotation center O of the substrate W.
[0042]
This is considered for the following reasons. In other words, the intensity distribution of the light beam emitted from the lamp 51 in the irradiation range R is almost normal at the center of the optical axis, and is substantially normal. Since the peripheral speed is higher, the peripheral part has a lower temperature than the central part.
[0043]
Therefore, when the center of the optical axis at which the temperature of the lamp 51 becomes the highest becomes coincident with the rotation center O of the substrate W, not only the center portion of the substrate W is heated to a higher temperature than the peripheral portion, but also the peripheral portion is rotated with the rotation. Since the temperature drop is larger than that of the central portion, the temperature of the central portion is higher than that of the peripheral portion as shown in FIG.
[0044]
On the other hand, when the optical axis L of the lamp 51 is shifted from the rotation center O of the substrate W as shown in FIG. 2, the substrate W is heated to a higher temperature in the peripheral portion than in the central portion. In this case, the temperature drop is greater in the peripheral portion than in the central portion, and as a result, the temperature distribution along the radial direction of the substrate W becomes substantially uniform as shown in FIG.
[0045]
Next, a case where the substrate W is processed by the spin processing apparatus having the above configuration will be described.
[0046]
By operating the fan / filter unit 32 to supply the clean air into the processing tank 1 and setting the butterfly valve 5a to a predetermined opening, the air was supplied from the fan / filter unit 32 into the processing tank 1. The clean air flows down, passes through the inside of the cup body 2, and is discharged through the discharge pipe 5 on which the suction force of the exhaust pump 6 acts. That is, the clean air supplied from the fan / filter unit 32 into the processing tank 1 forms a laminar flow, passes through the cup body 2, and is discharged from the discharge pipe 5.
[0047]
When the clean air is flowed into the processing tank 1, the rotating table 16 holding the substrate W is rotated, and a processing liquid such as pure water is supplied from the nozzle body 46 to the upper surface of the substrate W. Thus, the upper surface of the substrate W is cleaned by the processing liquid. Before the processing step of the substrate W with the processing liquid is finished, the lamp 51 is turned on, and the substrate W is irradiated and heated with a light beam.
[0048]
When the processing of the substrate W with the processing liquid is completed, the substrate W is dried. In the drying process, the substrate W is rotated at a higher speed than in the process. As a result, the processing liquid adhering and remaining on the substrate W is removed by centrifugal force, so that the substrate W is dried.
[0049]
Since the lamp 51 is lit and heats the substrate W from the processing step before the processing of the substrate W becomes the drying step, the substrate W is heated to a predetermined temperature when the processing step is completed. I have. Therefore, in the drying step following the processing step, the drying step is started, and at the same time, the heating and drying is performed by the lamp 51 in combination with the drying by the centrifugal force. It becomes possible.
[0050]
The lamp 51 shifts the optical axis L radially outward by a distance X from the rotation center O of the substrate W. Therefore, the substrate W is heated to a higher temperature in the outer portion than in the center portion in the radial direction by the lamp 51. However, when the substrate W is rotated at a high speed, the peripheral portion is different from the central portion due to a difference in peripheral speed. Temperature drop becomes large. As a result, the substrate W is heated to a substantially uniform temperature in the entire radial direction. That is, since the substrate W can be heated almost uniformly over the entire length in the radial direction by the lamp 51, the drying by heating can be performed almost uniformly.
[0051]
In the above-described embodiment, the optical axis L of the lamp 51 is shifted to the lamp 51 side, that is, the near side with respect to the rotation center O of the substrate W. It may be shifted to the opposite side of the direction.
[0052]
Since the substrate W is heated by being irradiated with the light beam emitted from the lamp 51, the heat from the lamp 51 can be efficiently absorbed by the substrate W. That is, since the substrate W is heated by the radiant heat from the lamp 51, the heating efficiency can be greatly improved as compared with the case of heating by the conductive heat.
[0053]
In addition, since the substrate W is heated by the radiant heat of the lamp 51, the fan / filter unit 32 can be provided above the processing tank 1 so that a downflow occurs in the processing tank 1.
[0054]
The lamp 51 is disposed radially outward of the upper surface of the substrate W, in this embodiment, radially outward of the opening 4a of the upper cup 4. Therefore, the lamp 51 does not disturb the flow of the downflow flowing from the fan / filter unit 32 into the cup body 2, and the mist generated in the cup body 2 in the processing step and the drying step is removed from the inside of the cup body 2. Can be discharged smoothly and reliably through the discharge pipe 5. In other words, since the mist can be prevented from floating in the cup body 2 during the processing step and the drying step, the drying process can be performed without contaminating the substrate W with the mist.
[0055]
In the above-described embodiment, the lamp is arranged radially outward of the opening of the cup body above the inside of the processing tank, but the lamp is disposed radially inward of the opening of the cup body. Even so, if it is arranged radially outward of the substrate, it is possible to suppress the down flow flowing into the cup from becoming turbulent due to the lamp. Further, in this case, if the blow-out range from the fan / filter unit is limited to the range of the upper surface of the substrate, which is radially inward from the lamp, the occurrence of turbulence is further effectively prevented. it can.
[0056]
Even if the lamp is located radially outward from the top surface of the substrate, if the lamp is installed in the flow path of clean air blown out from the fan / filter unit, the external shape of the lamp is low in air resistance, such as a streamline type. The shape can prevent the down flow from being disturbed by the ramp.
[0057]
4 and 5 show another embodiment of the present invention. In this embodiment, a laser device 61 is used as light irradiation means instead of the lamp 51 of the above-described embodiment. This laser device 61 is disposed above the cup body 2 and radially outward of the opening 4 a of the upper cup 4, similarly to the lamp 51.
[0058]
The laser device 61 is supported on a rotating shaft 63 of a drive source 62. The rotating shaft 63 is driven to rotate at an angle within a set range. In this embodiment, the rotation angle of the rotation shaft 63 is set such that the laser beam 64 output from the laser device 61 is from the center of rotation of the upper surface of the substrate W shown by a solid line in FIG. Set to scan a range. Accordingly, if the laser device 61 is swung by rotating the substrate W, the laser light 64 irradiates the entire upper surface of the substrate W.
[0059]
When the substrate W is a silicon wafer, a laser device 61 such as an Nd-YAG laser that outputs a laser beam 64 having a wavelength of about 1 μm, which is absorbed by the silicon wafer, is used as the laser device 61. The wavelength of the laser light 64 output from the laser device 61 has a narrow band distribution centered at about 1 μm as shown in FIG. Therefore, most of the laser light 64 is absorbed by the substrate W made of a silicon wafer.
[0060]
If the wavelength of the laser beam 64 output from the laser device 61 is a wavelength that is absorbed by the substrate W, the substrate beam W can be efficiently and quickly heated by the laser beam 64, and the substrate W can be heated quickly. And heating of the rotary table 16 and the like located below the substrate W can be prevented.
[0061]
If the laser beam 64 passes through the substrate W and heats the rotary table 16, as described above, not only the heating efficiency of the substrate W by the laser beam 64 decreases, but also the heat of the The heating condition may not be constant.
[0062]
However, by setting the wavelength of the laser light 64 to the wavelength absorbed by the substrate W as described above, it is possible to prevent the laser light 64 from transmitting through the substrate W, so that the substrate W can be efficiently heated. it can. In addition, when the substrate W is heated, the laser beam 64 is swung between the central portion of the substrate W and the outer peripheral end in the radial direction, so that the entire surface of the rotating substrate W can be uniformly heated.
[0063]
In this embodiment, since the substrate W is a silicon wafer, the wavelength of the laser light 64 is set to about 1 μm. However, the wavelength of the laser light 64 depends on the type of the substrate W and the material of the film formed on the surface. Since the wavelength to be efficiently absorbed differs, the wavelength of the laser light may be most easily absorbed according to the type of the substrate to be heated.
[0064]
【The invention's effect】
As described above, according to the present invention, the drying process of the substrate is performed by rotating the substrate at a high speed and heating with a light beam, so that the drying process can be performed quickly and reliably.
[0065]
Since the light irradiating means for heating the substrate is arranged at least radially outward from the upper surface of the substrate above the inside of the processing tank, the light irradiating means is used for cleaning air supplied from above the substrate toward the substrate. Disturbing the down flow can be prevented.
[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 diagram for explaining a relationship between a rotation center of a substrate and an optical axis of a lamp that irradiates and heats the substrate.
3A is a diagram showing a temperature distribution along the radial direction from the center of the substrate to the outer peripheral edge when the optical axis of the lamp is shifted from the center of the substrate, and FIG. The figure which shows the temperature distribution along the radial direction from the center of a board | substrate to the outer peripheral edge when it is centered.
FIG. 4 is an explanatory view showing a laser device as light irradiation means according to another embodiment of the present invention.
FIG. 5 is a diagram showing the wavelength of laser light output from a laser device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Processing tank 2 ... Cup body 5 ... Discharge pipe (discharge means)
6. Exhaust pump (discharge means)
16 rotary table 32 fan / filter unit 51 lamp (light irradiation means)
61 laser device (light irradiation means)

Claims (7)

In a spin processing apparatus for processing by rotating a substrate,
A processing tank,
A cup body having an opening on the upper surface provided in the processing tank,
A rotary table provided in the cup body and rotatably driven while holding the substrate,
A fan / filter unit which is provided above the processing tank and introduces clean air into the processing tank;
Discharging means for discharging the clean air supplied from the fan / filter unit into the processing tank through the internal space of the cup body;
Light irradiation means for irradiating the substrate with a light beam for heating, which is arranged radially outward from the upper surface of the substrate at least above the cup body,
A spin processing device comprising: 2. The spin processing apparatus according to claim 1, wherein the light irradiating means is disposed radially outward of an opening on an upper surface of the cup body. 2. The spin processing apparatus according to claim 1, wherein the light irradiating means is a lamp, and the lamp is arranged so that an optical axis center is shifted from a rotation center of the substrate. 2. The spin processing apparatus according to claim 1, wherein said light irradiation means is a laser device for outputting a laser beam. 5. The spin processing apparatus according to claim 4, wherein said laser beam is swung between a rotation center portion of said substrate and a radially outer end. 5. The spin processing apparatus according to claim 4, wherein the laser beam has a wavelength absorbed by the substrate. In a spin processing method of performing a drying process after processing with a processing solution while rotating a substrate,
A processing step of supplying a processing liquid to the rotating substrate,
A drying step in which the substrate processed by the processing liquid is rotated at a higher speed than during the processing step to perform a drying process,
A light irradiation step of irradiating a light beam for heating the substrate before the processing step is completed,
A spin processing method comprising:

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