JP2004134461A - Spin treating device and method for drying treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spin treating device that can detect whether a semiconductor wafer is dried or not and can terminate drying treatment simultaneously with the detection. <P>SOLUTION: This spin treating device dries the semiconductor wafer W after the wafer W is treated with a treating liquid by rotating the wafer W. This device is provided with a turntable 16 which is rotationally driven in a state where the wafer W is held on the turntable 16, a temperature sensor 47 which detects the dried state of the wafer W dried by rotating the turntable 16, and a controller 7 which terminates the drying treatment performed on the wafer W based on the detected results of the sensor 47. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a spin processing apparatus and a drying processing method for performing a cleaning processing with a processing liquid while rotating a substrate and then performing a drying processing.
[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, a substrate is treated with a chemical solution using a spin treatment device, then a cleaning process is performed with a cleaning solution as a processing solution, and then a drying process of removing the cleaning solution is repeatedly performed.
[0003]
As is well known, the spin processing apparatus has a processing tank, and a cup is provided in the processing tank, and the cup is provided with a rotary table that is driven to rotate by a driving source. The substrate is detachably held on the turntable.
[0004]
The substrate is cleaned by being rotated at a speed of several hundred revolutions per minute while the cleaning liquid is supplied to the plate surface. After performing the cleaning process for a predetermined time, the substrate is rotated at a high speed of 1000 rotations or more per minute. As a result, the cleaning liquid adhering to the substrate is removed by centrifugal force, and the substrate is dried.
[0005]
Conventionally, as the drying time of the substrate, a time at which the substrate will dry is set in advance, and the drying process is performed according to the set time.
[0006]
[Problems to be solved by the invention]
However, if the drying processing time of the substrate is set in advance, the drying processing time (set time) may become longer or shorter than necessary. If the drying time is set to be long, the time required to dry one substrate becomes long, which causes a decrease in productivity. If the processing time is set to be short, the substrate is dried. Is insufficiently dried, particles are likely to adhere, and a water mark is formed by remaining droplets, thereby causing contamination.
[0007]
An object of the present invention is to provide a spin processing apparatus and a drying processing method for detecting whether or not a substrate has been subjected to a drying process, and terminating the drying process based on the detection.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a spin processing apparatus for rotating and drying a substrate processed by a processing liquid,
A rotary table that holds and rotates the substrate,
Detecting means for detecting a dry state of the substrate to be dried by being rotated by the rotating table;
Control means for ending the drying process of the substrate based on the detection of the detection means,
A spin processing apparatus characterized by comprising:
[0009]
The invention according to claim 2 is the spin processing apparatus according to claim 1, wherein the detecting means is a temperature sensor for detecting a temperature of the substrate.
[0010]
The invention according to claim 3 is the spin processing apparatus according to claim 1, wherein the detection means is an imaging device that detects the presence or absence of a droplet on the upper surface of the substrate.
[0011]
A fourth aspect of the present invention is the spin processing apparatus according to the first aspect, wherein the detecting means is a scattered object detection sensor that detects whether or not droplets scatter from the rotating substrate.
[0012]
According to a fifth aspect of the present invention, the rotary table is housed in a cup body, and the detecting means is a flow rate detection sensor for detecting the presence or absence of the processing liquid discharged from the cup body. Of the spin processing device.
[0013]
According to a sixth aspect of the present invention, there is provided a spin processing method for rotating and drying a substrate processed by a processing liquid,
Rotating the substrate processed by the processing liquid;
A step of detecting a dry state of the substrate to be dried by being rotated,
Terminating the drying process of the substrate based on the detection of the dry state,
A spin processing method characterized by comprising:
[0014]
According to the present invention, the drying state of the substrate to be dried by being rotated is detected, and the drying processing is terminated based on the detection result, so that the time required for the drying processing of the substrate can be made short and short. .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
1 to 3 show a first embodiment of the present invention. 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 driving means is fitted and fixed in the mounting hole 9. The start and stop and rotation speed of the control motor 11 are controlled by the control device 7.
[0019]
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 rotation of the rotor 13. .
[0020]
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.
[0021]
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.
[0022]
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.
[0023]
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.
[0024]
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.
[0025]
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.
[0026]
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.
[0027]
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 so that the processing liquid ejected from the nozzle can reach the lower surface of the semiconductor wafer W through the opening 45. Has become.
[0028]
Above the semiconductor wafer W held on the rotary table 16, there are an upper nozzle body 46 that supplies a processing liquid to the upper surface of the semiconductor wafer W during the cleaning process and a detection unit that detects the surface temperature of the semiconductor wafer W during the drying process. A temperature sensor 47 is provided. As the temperature sensor 47, a radiation thermometer or the like is used.
[0029]
A detection signal from the temperature sensor 47 that detects the surface temperature of the semiconductor wafer W during the drying process is input to the control device 7. The controller 7 determines whether or not the drying process of the semiconductor wafer W has been completed as described later based on a change in the surface temperature of the semiconductor wafer W detected by the temperature sensor 47. The rotation stops immediately.
[0030]
Next, a procedure for cleaning and drying the semiconductor wafer W by the spin processing apparatus having the above configuration will be described with reference to FIGS.
[0031]
FIG. 2 is a flowchart of a process of cleaning a semiconductor wafer W and then performing a drying process. After the cleaning process is started after supplying an uncleaned semiconductor wafer W to the turntable 16, the turntable 16 is turned on at several hundred minutes in S 1. The cleaning liquid is supplied to the semiconductor wafer W from the upper nozzle body 46 at S2.
[0032]
By supplying the cleaning liquid to the rotating semiconductor wafer W, the upper surface of the substrate W is cleaned. In S3, it is determined whether or not the cleaning processing time with the cleaning liquid has reached a preset time. When the cleaning processing time reaches a preset time, in S4, the supply of the cleaning liquid is stopped, and the cleaning processing ends.
[0033]
Next, in S5, the rotary table 16 is driven to rotate at a higher speed than during the cleaning process. The turntable 16 is rotated at a high speed of, for example, 1000 rotations or more per minute. At the same time, the temperature of the upper surface of the semiconductor wafer W is detected by the temperature sensor 47 in S6. The detection signal from the temperature sensor 47 is input to the control device 7. The control device 7 determines whether or not the upper surface of the semiconductor wafer W has dried based on the detection signal of the temperature sensor 47 according to the temperature change characteristic of the semiconductor wafer W shown in FIG.
[0034]
FIG. 3 shows the rotation speed of the turntable 16 and the temperature change characteristics of the upper surface of the semiconductor wafer W when the semiconductor wafer W is cleaned and then dried. In the figure, a curve X indicates a change in the rotation speed of the turntable 16, and a curve Y indicates a temperature change characteristic of the surface temperature of the semiconductor wafer W.
[0035]
When the rotation speed of the turntable 16 is increased during the drying process, the cleaning liquid having a relatively large particle diameter is scattered from the upper surface of the semiconductor wafer W, and then, droplets or mist having a small particle diameter remaining on the upper surface of the semiconductor wafer W The cleaning liquid is evaporated by an air current generated by the rotation of the semiconductor wafer W, and the temperature of the semiconductor wafer W is lowered by the heat of vaporization caused by the evaporation. Therefore, the temperature of the semiconductor wafer W decreases due to heat of vaporization until a predetermined time has elapsed since the start of the drying process, that is, until the cleaning liquid adhering and remaining on the semiconductor wafer W is completely vaporized.
[0036]
As the evaporation of the cleaning liquid adhering to the upper surface of the semiconductor wafer W progresses, the temperature of the semiconductor wafer W starts to rise and approaches room temperature (room temperature), and the temperature of the semiconductor wafer W does not change after T time when the evaporation is completed. That is, the point in time at which the temperature change of the semiconductor wafer W has ceased can be regarded as the end of the drying processing of the semiconductor wafer W.
[0037]
Therefore, in S6, the controller 7 determines whether the temperature of the upper surface of the semiconductor wafer W detected by the temperature sensor 47 has changed, and when the temperature has changed, the cleaning liquid is vaporized from the upper surface of the semiconductor wafer W. It is determined that the drying process has not been completed, the drying process is continued, and if there is no change, the vaporization of the processing liquid from the upper surface of the semiconductor wafer W ends, and it is determined that the drying process has ended.
[0038]
In S7, when the control device 7 determines that the drying process of the semiconductor wafer W has been completed, the rotation of the turntable 16 is immediately stopped. Thereby, the drying process of the semiconductor wafer W ends.
[0039]
As described above, the temperature change of the surface of the semiconductor wafer W is measured, and it is determined whether or not the semiconductor wafer W has been subjected to the drying process based on the temperature change, and the drying process is immediately terminated based on the determination. The drying process of the semiconductor wafer W can be performed with sufficient time.
[0040]
Therefore, as in the related art in which the drying processing time of the semiconductor wafer W is set to a predetermined time in advance, the drying processing time becomes too long to cause a decrease in productivity, or the drying processing time is too short to make the drying processing uncertain. It can be performed without becoming fuzzy.
[0041]
In the first embodiment, a radiation thermometer has been described as the temperature sensor 47. However, as the temperature sensor 47, a thermocouple is embedded in the support pins 18 supporting the semiconductor wafer W, and Alternatively, the temperature of the semiconductor wafer W may be detected.
[0042]
FIG. 4 shows a second embodiment of the present invention. In this embodiment, the dry state of the semiconductor wafer W is detected by the imaging device 51. That is, the imaging device 51 includes a camera 52 installed above the semiconductor wafer W held on the rotary table 16 and an image processing device 53 to which an imaging signal of the semiconductor wafer W captured by the camera 52 is input. . The image processing device 53 processes the imaging signal and detects whether or not the droplet remains on the upper surface of the semiconductor wafer W.
[0043]
The detection signal from the image processing device 53 is input to the control device 7. When the image processing device 53 detects that the liquid droplets remain on the upper surface of the semiconductor wafer W, the control device 7 performs the drying process without stopping the rotation of the turntable 16 based on the detection signal. To continue.
[0044]
When the image processing device 53 detects that no droplet remains on the upper surface of the semiconductor wafer W, the control device 7 immediately stops the rotation of the turntable 16 based on the detection signal. That is, the drying process ends.
[0045]
Therefore, also in this case, the drying process of the semiconductor wafer W can be completed without time shortage.
[0046]
FIG. 5 shows a third embodiment of the present invention. In this embodiment, the dry state of the semiconductor wafer W is detected by the scattered object detection sensor 55. That is, the scattered object detection sensor 55 such as a reflection type laser sensor is disposed above the semiconductor wafer W and at a position deviated from the outer peripheral surface of the semiconductor wafer W. The scattered object detection sensor 55 detects whether a droplet is scattered from the semiconductor wafer W rotating at a high speed, and inputs a detection signal to the control device 7. As a result, the control device 7 determines whether or not the semiconductor wafer W has been dried, and controls the rotation of the turntable 16 based on the determination.
[0047]
That is, if the semiconductor wafer W is in an undried state, droplets are scattered from the semiconductor wafer W rotating at a high speed. Therefore, the semiconductor wafer W is in an undried state while the scattered object detection sensor 55 is detecting the liquid droplets, so that the rotating table 16 is continuously rotated to continue the drying process.
[0048]
When the droplets no longer scatter from the rotating semiconductor wafer W and the scattered object detection sensor 55 no longer detects the droplets, the semiconductor wafer W has been dried. Therefore, in that case, the control device 7 immediately stops the rotation of the turntable 16, and the drying process ends. That is, even in the case where the scattered object detection sensor 55 is used, the drying process of the semiconductor wafer W can be completed without time shortage.
[0049]
FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, the dry state of the semiconductor wafer W is detected by the flow rate detection sensor 58. That is, one of the plurality of discharge pipes 5 connected to the lower cup 3 of the cup body 2 is provided with the flow rate detection sensor 58 for detecting the cleaning liquid flowing through the discharge pipe 5. The detection signal of the flow rate detection sensor 58 is input to the control device 7. The control device 7 determines whether or not the drying process of the semiconductor wafer W has been completed based on the detection signal of the flow rate detection sensor 58, and controls the rotation of the turntable 16 based on the determination.
[0050]
That is, when the semiconductor wafer W is in an undried state, droplets scatter from the semiconductor wafer W rotating at high speed together with the rotary table 16, and the droplets flow through the discharge pipe 5. Therefore, while the semiconductor wafer W is in an undried state while the flow rate detection sensor 58 is detecting the cleaning liquid, the drying process is continued.
[0051]
If the cleaning liquid does not flow through the discharge pipe 5 and the flow detection sensor 58 does not detect the cleaning liquid, the semiconductor wafer W has been dried. Therefore, in that case, the control device 7 immediately stops the rotation of the turntable 16 and ends the drying process. Therefore, even when the flow rate detection sensor 58 is used, the drying process of the semiconductor wafer W can be completed without time shortage.
[0052]
In the second to fourth embodiments shown in FIGS. 4 to 6, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0053]
【The invention's effect】
As described above, according to the present invention, the drying state of the substrate to be dried by rotation is detected, and the drying processing is terminated based on the detection result.
[0054]
Therefore, when the substrate is dried, the drying process can be terminated at that point, and the drying process of the substrate can be performed with sufficient time.
[Brief description of the drawings]
FIG. 1 is a sectional view of a schematic configuration of a spin processing device according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing processing steps of a semiconductor wafer.
FIG. 3 is a graph showing a temperature change characteristic of a semiconductor wafer during a drying process.
FIG. 4 is a sectional view of a schematic configuration of a spin processing device according to a second embodiment of the present invention.
FIG. 5 is a sectional view of a schematic configuration of a spin processing device according to a third embodiment of the present invention.
FIG. 6 is a sectional view of a schematic configuration of a spin processing device according to a fourth embodiment of the present invention.
[Explanation of symbols]
7. Control device (control means)
16 rotary table 47 temperature sensor (detection means)
51 ... Imaging device (detection means)
55: Flying object detection sensor (detection means)
58 ... Flow rate detection sensor (detection means)

Claims (6)

In a spin processing apparatus for rotating and drying a substrate processed by the processing liquid,
A rotary table that holds and rotates the substrate,
Detecting means for detecting a dry state of the substrate to be dried by being rotated by the rotating table;
Control means for ending the drying process of the substrate based on the detection of the detection means,
A spin processing device comprising: 2. The spin processing apparatus according to claim 1, wherein said detecting means is a temperature sensor for detecting a temperature of said substrate. 2. The spin processing apparatus according to claim 1, wherein the detection unit is an imaging device that detects the presence or absence of a droplet on the upper surface of the substrate. 2. The spin processing apparatus according to claim 1, wherein said detection means is a scattered object detection sensor for detecting whether or not droplets scatter from a rotating substrate. 2. The spin processing apparatus according to claim 1, wherein the rotary table is housed in a cup body, and the detection means is a flow rate detection sensor for detecting the presence or absence of a processing liquid discharged from the cup body. In a spin processing method of rotating and drying a substrate processed by the processing liquid,
Rotating the substrate processed by the processing liquid;
A step of detecting a dry state of the substrate to be dried by being rotated,
Terminating the drying process of the substrate based on the detection of the dry state,
A spin processing method comprising:

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