JP2004247509A - Device and method for wet processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To monitor a chemical-supply flow in a pipe arrangement in a chemical-supply system to always supply and clean a chemical of a sustained flow, in a device and method for processing a wafer 30 provided by a spraying nozzle 13 for spraying chemicals to the respective surface of the wafer 30 contained in a hermetic container 2 where a plurality of wafers 30 are supported and contained. <P>SOLUTION: A flow of chemicals measured by a chemical-supply flow mater 6 is monitored by an abnormal detector 21 with respect to each spraying of the chemical to the surface of a wafer 30 by a spraying nozzle 13. When the detector 21 detects the flow of the chemical not more than the rated value, a pump 5 is stopped, and a supply opening/closing valve 9 and a circulation opening/closing valve 11 are closed to stop the processing of the wafer 30, resulting in preventing an occurrence of the wafer processing. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wet processing apparatus and a wet processing method in which a plurality of substrates such as a semiconductor wafer and a liquid crystal substrate are housed in a processing chamber, and a chemical solution is sprayed onto a surface of the substrate housed in the processing chamber to process the substrate.
[0002]
[Prior art]
Usually, in a manufacturing process of a semiconductor device, a wet processing method in which a chemical solution or a rinsing liquid is sprayed onto a substrate such as a semiconductor wafer to perform cleaning, processing, and the like has been performed. As one of such cleaning treatment methods, a chemical solution is sprayed from a chemical solution supply nozzle onto each semiconductor wafer while holding a plurality of semiconductor wafers in a processing tank, for example, in a state of being housed in a wafer boat. Particles and metal ions adhering to the substrate are removed, and the processing bath is filled with a cleaning liquid to clean the semiconductor wafer. There is also a method of cleaning the wafer by spraying a single chemical, for example, isopropyl alcohol on the surface of the substrate.
[0003]
However, in the former method, since the chemical solution remains in the processing tank, it takes time until the chemical solution is replaced with cleaning water (for example, pure water), and there is a problem that a large amount of pure water which is a large amount of cleaning water is consumed. there were.
[0004]
A cleaning apparatus has been proposed which solves this problem, reduces the amount of cleaning liquid used, and improves cleaning efficiency. FIG. 3 is a schematic cross-sectional view showing an example of a conventional cleaning apparatus in which the amount of a cleaning liquid used is reduced. As shown in FIG. 3, the cleaning apparatus includes a processing tank 41 for accommodating a wafer board 40 for supporting a plurality of semiconductor wafers W, and is connected to an opening at the upper end of the processing tank 41 and is connected to the processing tank 41 from the processing tank 41. An outer tank 42 for receiving the overflowed chemical solution and cleaning water, a pure water tank 43 for storing pure water 100 rapidly supplied into the processing tank 41, and a shower nozzle for spraying the pure water 100 onto the wafer W. 45, a supply nozzle 46 for supplying the pure water 100 in the pure water tank 43 to the wafer W and the processing tank, and a jet provided at the bottom of the processing tank 41 for supplying the chemical solution 101 or the pure water 100 to the wafer W. A nozzle 47 is provided.
[0005]
Then, a chemical is supplied from the chemical supply source 50 to the processing tank 41, the chemical is overflowed from the processing tank 41, and the chemical is overflowed by driving the pump 52 of the circulation pipe 51. 101 is ejected from the jet nozzle 47 to remove the deposits on the wafer W. After performing the chemical treatment for a predetermined time, the chemical in the treatment tank 41 is discharged from the drain pipe 55 and the chemical in the circulation pipe line 51 is discharged from the drain pipes 53 and 56.
[0006]
Next, the pump 52 is stopped, the switching valve 58 is opened, pure water is supplied from a pure water supply source 59, and the supplied pure water 100 is jetted from the jet nozzle 47 onto the wafer W to clean the wafer W. The switching valve 48 is opened, and the pure water 100 supplied from the pure water line of the factory is jetted from the shower nozzle 45 to the wafer W to remove the residual chemical liquid attached to the wafer W. Whether or not the cleaning of the wafer W has been completed is determined by measuring the specific resistance of the pure water 100 in the processing tank 41 by the specific resistance measuring device 49.
[0007]
As described above, after performing the chemical solution treatment and draining the chemical solution, the process of supplying the pure water 100 in the pure water tank 43 into the processing tank 41 for storing the wafer W and immersing and cleaning the wafer W is repeated. By performing this, the recovery time of the pure water to a predetermined specific resistance value is reduced (Patent Document 1).
[0008]
[Patent Document 1]
JP-A-10-064872 (page 4-8, FIG. 1)
[0009]
[Problems to be solved by the invention]
However, in the above-described cleaning method, it is expected that the flow resistance of the chemical supply pipe to the jet nozzle for injecting the chemical is not always constant but changes. Therefore, it is difficult to uniformly remove contaminants adhering to the wafer surface to be cleaned with the chemical solution. During the repetition of the cleaning, the scale accumulates in the pipes of the chemical supply system, especially in the nozzles for injecting the chemical, and the flow rate of the chemical for cleaning the wafer is insufficient. There is a problem of causing poor cleaning.
[0010]
Accordingly, it is an object of the present invention to provide a wet processing apparatus and a wet processing method capable of monitoring a chemical solution supply flow rate in a pipe of a chemical solution supply system and constantly supplying and cleaning a chemical solution having a uniform flow rate.
[0011]
[Means for Solving the Problems]
A first feature of the present invention is a supporting member for holding a plurality of semiconductor wafers arranged in one direction, a sealed container for accommodating the semiconductor wafer and the supporting member, and a chemical solution on each surface of the semiconductor wafer. A plurality of chemical injection nozzles for injecting, a chemical tank for storing the used chemical discharged from the hermetic container via a discharge pipe, and a suction pipe for sucking the chemical in the chemical tank to supply the hermetically sealed container with a supply pipe. A supply pump that supplies the chemical solution, a chemical filter provided in the supply pipe at a stage subsequent to the supply pump, a circulation pipe branched from the supply pipe connected to the chemical filter, and connected to the discharge pipe, A first on-off valve for supplying and shutting off a chemical solution to the injection nozzle in a closed container, and the medicine supplied between the circulation pipe and the discharge pipe. A second on-off valve for supplying and shutting off, a chemical supply flow meter between the supply pump and the chemical filter for measuring the flow rate of the chemical, and an abnormality detection for detecting an abnormal flow of the chemical supply flow meter And a control unit for controlling the stop of the pump and the opening and closing of the first and second on-off valves based on a signal from the abnormality detector.
[0012]
In addition, it is desirable to have a rotation mechanism for rotating the support member. Further, it is preferable that a circulating chemical liquid flow meter for measuring a flow rate of the chemical liquid flowing through the circulation pipe is provided. On the other hand, preferably, the circulating chemical liquid flow meter and the chemical liquid supply flow meter have the same structure and the same performance.
[0013]
A second feature of the present invention is that a supporting member for holding a plurality of semiconductor wafers arranged in one direction, a sealed container for accommodating the semiconductor wafer and the supporting member, and a chemical solution on each surface of the semiconductor wafer. A plurality of chemical injection nozzles for injecting, a chemical tank for storing the used chemical discharged from the hermetic container via a discharge pipe, and a suction pipe for sucking the chemical in the chemical tank to supply the hermetically sealed container with a supply pipe. A supply pump that supplies the chemical solution, a chemical filter provided in the supply pipe at a stage subsequent to the supply pump, a circulation pipe branched from the supply pipe connected to the chemical filter, and connected to the discharge pipe, A first on-off valve for supplying and shutting off a chemical solution to the injection nozzle in a closed container, and the medicine supplied between the circulation pipe and the discharge pipe. A second on-off valve that shuts off, a chemical liquid supply flow meter between the supply pump and the chemical liquid filter that measures the flow rate of the chemical liquid, and an abnormality detector that detects a flow abnormality of the chemical liquid supply flow meter, A control unit for controlling the opening and closing of the first on-off valve and the second on-off valve in accordance with a signal from the abnormality detector, wherein the first on-off valve is opened and stored in the closed container. Each time a chemical solution is sprayed on the surface of the semiconductor wafer by the chemical solution spray nozzle and processed, the flow rate of the chemical solution measured by the chemical supply flow meter is monitored, and the flow rate of the chemical solution is equal to or less than a specified value. Is a wet processing method in which the supply pump is stopped and the first on-off valve and the second on-off valve are closed when the abnormality detector detects the abnormality.
[0014]
A third feature of the present invention is that a supporting member for holding a plurality of semiconductor wafers arranged in one direction, a sealed container for accommodating the semiconductor wafer and the supporting member, and a chemical solution on each surface of the semiconductor wafer. A plurality of chemical liquid injection nozzles for injecting, a chemical liquid tank for storing the used chemical liquid discharged from the hermetic container via a discharge pipe, and a suction pipe for the chemical liquid in the chemical liquid tank, and a supply pipe to the hermetic container via a supply pipe. A supply pump for supplying the chemical liquid, a chemical filter provided in the supply pipe at a stage subsequent to the supply pump, a circulation pipe branched from the supply pipe connected to the chemical filter and connected to the discharge pipe, A first on-off valve for supplying and shutting off the chemical supplied to the container, and supplying and shutting off the chemical supplied between the circulation pipe and the discharge pipe; A second on-off valve, a chemical supply flow meter between the supply pump and the chemical filter for measuring the flow rate of the chemical solution, and a flow rate meter for measuring the flow rate of the chemical solution flowing through the circulation pipe. A circulating chemical liquid flow meter having the same structure and the same performance as described above, an abnormality detector for detecting an abnormality in a difference between the flow rate of the chemical liquid supply flow meter and the flow rate of the circulating chemical liquid flow meter, and a signal from the abnormality detector. And a control unit for controlling the opening and closing of the first on-off valve and the second on-off valve, wherein the first on-off valve is opened and the surface of the semiconductor wafer stored in the closed container is opened. When the abnormality detector detects that the difference between the measured flow rate of the chemical supply flow meter and the measured flow rate of the circulating chemical flow meter is equal to or greater than a specified difference every time the chemical liquid is sprayed by the chemical liquid injection nozzle, Stopping the serial feed pump, which is the first on-off valve and the second on-off valve closes the wet processing method.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a schematic diagram showing a wet processing apparatus according to an embodiment of the present invention. In this wet processing apparatus, a support member 1 for holding a plurality of wafers 30 arranged in one direction, a sealed container 2 for accommodating the wafers 30 and the support member 1, and a chemical solution is sprayed on each surface of the wafer 30. A plurality of injection nozzles 13, a chemical solution tank 3 for storing a chemical solution 4 discharged from the sealed container 2 via a discharge pipe 14, and a pipe of a supply line 8 for sucking the chemical solution 4 from the chemical solution tank 3 to the sealed container 2 A supply pump 5 for supplying the chemical solution 4 via a pump, a filter 7 for the chemical solution provided in a supply line 8 at the subsequent stage of the pump 5, and a supply line 8 connected to the filter 7. A circulation line 10 connected to a pipe 14 for discharging the chemical solution 4, a supply opening / closing valve 9 for supplying and shutting off the chemical solution 4 to be supplied to the closed container 2, a circulation line 10 and a pipe 14 for discharging the chemical solution, A circulation on-off valve 11 for supplying and shutting off a chemical solution supplied from the pump 5, a chemical solution supply flowmeter 6 between the pump 5 and the filter 7 for measuring the flow rate of the chemical solution, and a chemical solution supply flowmeter 6 is provided with an abnormality detector 21 for detecting a flow rate abnormality, and a device control unit 12 for controlling the opening and closing of the supply opening / closing valve 9 and the circulation opening / closing valve 11 based on a signal 22 from the abnormality detector 21.
[0017]
Further, it is desirable to provide a rotation mechanism 23 that rotates the support member 1 that supports the wafer 30 so that the chemical liquid ejected from the ejection nozzle 13 uniformly contacts the surface of the wafer 30. The rotating shaft of the rotating mechanism 23 has one end attached to the support member 1 and the other end connected to the output shaft of a rotating motor. The shaft portion of the rotating shaft has a structure that can be airtightly rotated on the lid of the sealed container 2 via a seal.
[0018]
Further, the chemical supply flow meter 21 for measuring the flow rate of the chemical supplied from the pump 5 is preferably a turbine flow meter. The chemical supply flow meter 21 is provided in the middle of the pipe between the pump 5 and the filter 7. The chemical solution flowing through the pipe rotates the blades in the chemical solution supply flow meter 21, detects the movement of the magnetic material blades by detecting a change in magnetic resistance with a detector outside the tube, and changes the pulse frequency according to the rotation speed to a flow rate. Has been detected as Here, the measured flow rate is sent to the apparatus control unit 12 as a pulse frequency, and the abnormality detector 21 determines whether the flow rate is normal. For example, the abnormality detector 21 generates a stop signal when the flow rate of the supplied chemical decreases by, for example, 10% from the reference value (initial value).
[0019]
Next, the operation of the wet processing apparatus will be described. First, a chemical is supplied from a chemical supply source (not shown) to the chemical tank 3 and a predetermined amount of the chemical 4 is stored in the chemical tank 3. Next, the chemical 4 is sucked from the chemical tank 3 by the pump 5, and the chemical is supplied to the supply line 8 through the chemical supply flow meter 21 and the filter 7.
[0020]
Next, the apparatus control unit 12 opens the supply opening / closing valve 9, injects the chemical from the injection nozzle 13, and brings the chemical into contact with the wafer 30. At this time, the chemical liquid supply flowmeter 21 measures the flow rate of the chemical liquid and causes the device control unit 12 to store the measured value as an initial value (reference value). Then, the support member 1 is rotated by the rotation mechanism 23 to make the contact between the chemical solution and the wafer 30 uniform. The chemical after contact with the wafer 30 is stored in the chemical tank 3 via the pipe 14. After the elapse of the predetermined processing time, the supply on / off valve 9 is closed to stop the supply of the chemical solution to the injection nozzle 13.
When the supply of the chemical to the closed container 2 is interrupted, the device control unit 12 opens the circulation on-off valve 11, sucks the chemical by the pump 5, and stores the chemical in the chemical tank 3 via the circulation line 10. This means that the used chemical is regenerated by the filter 7 and stored in the chemical tank 3. Then, the wafer 30 is taken out of the closed container 2 during the regeneration of the chemical solution, and is replaced with an unprocessed wafer 30. Next, in the same manner as described above, the chemical liquid 4 is sucked from the chemical liquid tank 3 by the pump 5, and the chemical liquid is supplied to the supply line 8 through the chemical liquid supply flow meter 21 and the filter 7. The chemical liquid is sprayed by the spray nozzle 13 on the surface of the stored wafer 30 to process the wafer 30. At this time, the flow rate of the chemical solution measured by the chemical solution supply flow meter 21 is stored in the device control unit 12. Then, the abnormality detector 21 determines whether there is a decrease in the flow rate as compared with the previous initial value.
[0021]
Then, as long as the abnormality detector 21 does not detect a decrease in the flow rate, the processing of the wafer 30 is repeatedly performed. If the flow resistance of the chemical solution in the supply line 8 including the injection nozzle 13 and the filter 7 increases and the flow rate of the chemical solution decreases, it is determined that any increase in the flow resistance has occurred and the abnormality detector 21 is abnormal. Then, a signal is sent to the device controller 12 to stop the pump 5, and the supply opening / closing valve 9 and the circulation opening / closing valve 11 are closed. That is, the cleaning process of the wafer 30 is stopped. At this time, it is also desirable that the device control unit 12 generates an alarm. Then, the pipe of the supply line 8, the filter 7, and the injection nozzle 13 are removed, and the apparatus is recovered by cleaning or replacing.
[0022]
FIG. 2 is a schematic diagram showing a wet processing apparatus according to another embodiment of the present invention. As shown in FIG. 2, the wet processing apparatus includes a circulating chemical flow meter 20 for measuring the flow rate of the chemical flowing in the circulation line 10 in addition to the chemical supply flow meter 6 for measuring the flow rate of the chemical flowing in the supply line 8. That is the provision. Other than that, the chemical liquid tank 3, the sealed container 2, the device control unit 12, and the filter 7 are provided in the same manner as in the wet processing apparatus of the above-described embodiment.
[0023]
It is desirable that the circulating chemical solution flow meter 20 has the same structure and the same performance as the chemical solution supply flow meter 6. That is, the same measurement resolution is used for a turbine flowmeter having the same diameter. The comparison between the chemical supply flow meter 6 and the circulating chemical flow meter 20 is made in a state where the chemical is circulating, that is, in a state where the supply opening / closing valve 9 is closed and the circulation opening / closing valve 11 is open. Therefore, the flow rate (circulation flow rate) of the chemical liquid flowing through the chemical liquid supply flow meter 6 and the circulating chemical liquid flow meter 20 should be the same. Can be compared.
[0024]
Therefore, the wet processing apparatus of this embodiment monitors the difference between the flow rate of the chemical solution in the circulation line and the flow rate of the chemical solution in the chemical supply line with the abnormality detector 21, and when there is a change in the difference in the flow rate, the abnormality detector A signal is transferred from the control unit 21 to the device control unit 12 to stop the pump 5 and close the chemical liquid supply on-off valve 9 and the circulation on-off valve 11.
[0025]
In addition, the flow rate difference between these flowmeters can detect a failure of the flowmeter itself in addition to the clogging of the injection nozzle 13 and the filter 7. In this case, the flow rate difference due to the flow resistance of the injection nozzle 13 and the filter 7 gradually increases over a long period of time, but the failure of the flow meter occurs in a relatively short time.
[0026]
【The invention's effect】
As described above, the present invention makes it possible to make the amount of the chemical liquid ejected from the injection nozzle uniform by providing a means for constantly monitoring the flow rate of the chemical liquid supplied to the injection nozzle that injects the chemical liquid onto the wafer surface, There is an effect that processing defects of the wafer can be reduced.
[0027]
A similar effect can be obtained by providing a means for constantly monitoring the flow rate in the circulation line branched from the chemical supply line as necessary, and monitoring the flow difference between the chemical supply line and the circulation line.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a wet processing apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a wet processing apparatus according to another embodiment of the present invention.
FIG. 3 is a schematic sectional view showing an example of a conventional cleaning apparatus in which the amount of a cleaning liquid used is reduced.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Support member 2 Closed container 3 Chemical liquid tank 4 Chemical liquid 5 Pump 6 Chemical liquid supply flow meter 7 Filter 8 Supply line 9 Supply on-off valve 10 Circulation line 11 Circulation on-off valve 12 Device control unit 13 Injection nozzle 14 Pipe 20 Circulating chemical liquid flow meter 21 Abnormality Detector

Claims (6)

A support member for holding a plurality of semiconductor wafers arranged in one direction, a sealed container for accommodating the semiconductor wafer and the support member, and a plurality of chemical injection nozzles for injecting a chemical onto each surface of the semiconductor wafer; A chemical liquid tank for storing the used chemical liquid discharged from the sealed container via a discharge pipe, and a supply pump for sucking the chemical liquid in the chemical liquid tank and supplying the chemical liquid to the sealed container through a supply pipe; A chemical liquid filter provided in the supply pipe at the subsequent stage of the supply pump, a circulation pipe branched from the supply pipe connected to the chemical liquid filter and connected to the discharge pipe, and a discharge pipe to the injection nozzle in the closed vessel. A first opening / closing valve for supplying and shutting off a chemical solution, and a second opening / closing for shutting off the chemical solution sent between the circulation pipe and the discharge pipe. And, between the supply pump and the chemical liquid filter, a chemical liquid supply flow meter that measures the flow rate of the chemical liquid, an abnormality detector that detects a flow abnormality of the chemical liquid supply flow meter, and a signal from the abnormality detector A wet processing apparatus comprising: a control unit that controls opening and closing of the first on-off valve and the second on-off valve. The wet processing apparatus according to claim 1, further comprising a rotation mechanism configured to rotate the support member. The wet processing apparatus according to claim 1, further comprising a circulating chemical solution flow meter configured to measure a flow rate of the chemical solution flowing through the circulation pipe. The wet processing apparatus according to claim 3, wherein the circulating chemical solution flow meter and the chemical solution supply flow meter have the same structure and the same performance. A support member for holding a plurality of semiconductor wafers arranged in one direction, a sealed container for accommodating the semiconductor wafer and the support member, and a plurality of chemical injection nozzles for injecting a chemical onto each surface of the semiconductor wafer; A chemical liquid tank for storing the used chemical liquid discharged from the sealed container via a discharge pipe, and a supply pump for sucking the chemical liquid in the chemical liquid tank and supplying the chemical liquid to the sealed container through a supply pipe; A chemical liquid filter provided in the supply pipe at the subsequent stage of the supply pump, a circulation pipe branched from the supply pipe connected to the chemical liquid filter and connected to the discharge pipe, and a discharge pipe to the injection nozzle in the closed vessel. A first on-off valve for supplying and shutting off a chemical solution, and supplying and shutting off the chemical solution sent between the circulation pipe and the discharge pipe. A second on-off valve, a chemical liquid supply flowmeter between the supply pump and the chemical liquid filter for measuring the flow rate of the chemical liquid, an abnormality detector for detecting an abnormal flow rate of the chemical liquid supply flowmeter, A control unit that controls the opening and closing of the first on-off valve and the second on-off valve in accordance with a signal from a vessel, wherein the first on-off valve is opened and the semiconductor housed in the closed container is opened. Each time a chemical solution is sprayed on the surface of a wafer by the chemical solution spray nozzle and processed, the flow rate of the chemical solution measured by the chemical solution supply flow meter is monitored, and it is determined that the flow rate of the chemical solution is equal to or less than a specified value. A wet processing method comprising: stopping a supply pump; and closing the first on-off valve and the second on-off valve when a detector detects the condition. A support member for holding a plurality of semiconductor wafers arranged in one direction, a sealed container for accommodating the semiconductor wafer and the support member, and a plurality of chemical injection nozzles for injecting a chemical onto each surface of the semiconductor wafer; A chemical liquid tank that stores the used chemical liquid discharged from the sealed container via a discharge pipe, and a supply pump that sucks the chemical liquid in the chemical liquid tank and supplies the chemical liquid to the sealed container through a supply pipe, A chemical liquid filter provided in the supply pipe at the subsequent stage of the supply pump, a circulation pipe branched from the supply pipe connected to the chemical liquid filter and connected to the discharge pipe, and a supply and supply of the chemical liquid to be supplied to the closed container; A first on-off valve for shutting off, a second on-off valve for supplying and shutting off the chemical solution supplied between the circulation pipe and the discharge pipe, A chemical supply flow meter that is located between a supply pump and the chemical filter and measures the flow rate of the chemical, and has the same structure and the same performance as the chemical supply flow meter while measuring the flow rate of the chemical flowing through the circulation pipe. A circulating chemical solution flow meter, an abnormality detector for detecting an abnormality in a difference between the flow rate of the chemical solution supply flow meter and the flow rate of the circulating chemical solution flow meter, and the first on-off valve and the A control unit for controlling the opening and closing of a second on-off valve, wherein the first on-off valve is opened and a chemical is sprayed on the surface of the semiconductor wafer stored in the closed container by the chemical injection nozzle. Each time, when the abnormality detector detects that the difference between the measured flow rate of the chemical supply flow meter and the flow rate of the circulating chemical flow meter is equal to or greater than a specified difference, stopping the supply pump, Wet processing method, characterized in that said closing the serial first on-off valve and the second on-off valve.

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