JPH11108708A - Flow rate measuring device and substrate treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow rate detection device with few defective products. SOLUTION: Treating liquid is supplied through a tube 11 and pressure of the treatment liquid is adjusted by a pressure adjusting mechanism 13. The treating liquid flows through a flow meter 16 to a filter F. After its impurities are removed by the filter F, the treating liquid is discharged from a nozzle 15 via a valve 14. A float 17 is placed within the flow meter 16, and the float 17 is raised by the liquid flowing within the flow meter 16 and the float 17 is lowered when the flow stops. By detecting time required for rising or falling of the float 17 by two pairs of sensors 18a, 18b, 19a, 19b, changes with lapse of time in supply pressure of the treating liquid at the time of discharge and in viscosity of the treating liquid can be measured and a tendency to occurrence of discharge failure and the like can be known previously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is supplied when a predetermined process such as a developing process or a cleaning process is performed on a thin plate-like substrate (hereinafter, simply referred to as a "substrate") such as a semiconductor wafer or a liquid crystal panel. The present invention relates to a flow rate detection device that detects a flow rate of a processing liquid and a substrate processing apparatus to which the flow rate detection device is applied.

[0002]

2. Description of the Related Art Conventionally, various kinds of processing liquids corresponding to processing contents are supplied to a substrate in a substrate manufacturing process.
The amount of the processing liquid supplied to the substrate to be processed is measured by a flow meter.

However, a conventional flowmeter provided in a substrate processing apparatus floats a float in a pipe and detects whether the float has passed a predetermined detection position. Therefore, in the conventional flow meter, it was only possible to detect whether or not the processing liquid was discharged at a flow rate higher than the set condition.

[0004]

With the conventional flow meter as described above, it is not possible to measure the excessive discharge of the processing liquid or the change over time in the discharge state. Therefore, when the conventional flow meter detects a discharge failure, the substrate has already become defective.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a flow rate detection device that hardly produces defective products and a substrate processing apparatus to which the flow rate detection device is applied.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, when a processing liquid necessary for performing a predetermined processing on a substrate is supplied, the processing liquid is supplied. An apparatus for measuring the flow rate of (a) a float provided in the pipe, (b) a sensor for detecting the moving speed or moving time of the float, and (c) means for storing a detection value of the sensor It has.

According to a second aspect of the present invention, the apparatus according to the first aspect further comprises (d) analysis means for statistically analyzing a detection value of the sensor, wherein the analysis means performs processing based on the analysis result. It is characterized in that the flow rate when supplying the liquid is controlled.

According to a third aspect of the present invention, there is provided an apparatus for performing a predetermined process on a substrate, comprising the flow rate measuring apparatus according to the first or second aspect.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an overall configuration of a substrate processing apparatus will be described. FIG. 1 is a perspective view of a substrate processing apparatus 1 to which a flow detection device according to an embodiment of the present invention is applied. The substrate processing apparatus 1 includes an indexer unit 5 for carrying in / out a substrate from outside the apparatus, and a processing unit 3 for performing various processes on the substrate W.

In the indexer section 5, the substrates W are loaded and unloaded from a carrier 9 that accommodates a plurality of substrates W in a horizontal posture, and a plurality of carriers 9 are arranged. In addition, the indexer section 5 includes a substrate in / out robot TR.
The substrate loading / unloading robot TR1 takes in and out the substrates W from the carrier 9 one by one.

The processing unit 3 includes a spin coater 61 for applying a resist solution, spin developers 63 and 65 for performing a developing process, a plurality of hot plates HP for performing a heating process, and a plurality of cool plates CP for performing a cooling process.
And a transfer robot TR2 that transfers the substrate W while moving in the transfer path. In such a processing unit 3, a resist liquid is supplied to the substrate as a processing liquid by the spin coater 61, and a developing liquid or a rinsing liquid is supplied by the spin developers 63 and 65.

Next, the configuration of the spin coater 61 and the spin developers 63 and 65 of the substrate processing apparatus 1 will be described. FIG. 2 is a schematic diagram showing a mechanism for supplying a processing liquid to a substrate according to the embodiment of the present invention. As shown in FIG. 2, the substrate W held by the chuck unit 22 is configured to rotate when driven by a motor M. Further, a cup 21 is provided to prevent a processing liquid such as a resist liquid or a developing liquid supplied to the substrate W from scattering due to the rotation of the substrate W.

The processing liquid is supplied through a pipe 11 from a processing liquid supply unit (not shown). Then, the pressure of the processing liquid is adjusted by the pressure adjusting mechanism 13. Then, the processing liquid flows to the filter F through the flow meter 16. The processing liquid from which impurities have been removed by the filter F is supplied to the valve 14.
Is configured to be discharged from the nozzle 15 through the nozzle.

A float 17 is provided inside the flow meter 16. The float 17 rises due to the flow of the liquid inside the flow meter 16, and when the flow stops, the float 17 descends. The flow meter 16 has two sets of sensors 18 for detecting that the float 17 has passed.
a, 18b, 19a, and 19b are provided. Specifically, as shown in FIG. 3, the sensors 18a and 18b constitute one set, and the sensors 19a and 19b constitute one set. For example, when the sensors 18a, 18b, 19a, and 19b are photoelectric transmission sensors, the sensors 18a and 19a are on the light emitting side, and the sensors 18b and 19b are on the light receiving side. In addition, these sensors are not limited to photoelectric sensors, but may be sensors such as magnetism and ultrasonic waves. Further, as long as the float 17 can be detected, a reflection sensor may be used instead of the transmission sensor.

Next, a description will be given of the detection principle of a flow rate detection device to which this flow meter is applied. FIG. 4 is a diagram illustrating the detection principle of the flow rate detection device. As shown in FIG. 4A, when the flow of the processing liquid in the flow meter 16 is stopped, the float 17 is located at the bottom in the flow meter 16. Then, when the valve 14 shown in FIG. 2 is opened to supply the processing liquid to the substrate, the processing liquid in the flow meter 16 starts to flow upward. Along with this, the float 17 also rises,
First, as shown in FIG. 4B, the flow meter 16 reaches a position LO near the bottom. At this time, light from the sensor 18a is blocked by the float 17. Then, when the float 17 further rises, as shown in FIG.
6 reaches a position between the lower position LO and the upper position HI. Then, when the float 17 further rises, as shown in FIG. 4D, the float 17 reaches the position HI above the flow meter 16, and the light from the sensor 19a is blocked by the float 17,
It does not reach the sensor 19b. Then, when the float 17 further rises, as shown in FIG.
6 reaches a position above the upper position HI. In addition,
When the discharge of the processing liquid is stopped, the float 17 descends in the reverse order.

As described above, when the processing liquid flows through the flow meter 16, the float 17 rises.
a, 18b after passing through the position LO.
The time required to pass the position HI of 9b, that is, the speed at which the float 17 rises is related to the flow rate and the viscosity of the processing liquid. On the other hand, the speed at which the float 17 descends when the discharge is stopped is related to the viscosity of the processing liquid. Therefore, the position LO
By measuring the transit time from passing through the position HI to passing through the position HI, it is possible to measure the change over time in the supply pressure and the viscosity of the treatment liquid when the treatment liquid is discharged, and the float 17 is lowered. By measuring the time, the time-dependent change in the viscosity of the processing solution can be measured. In addition, by reducing the speed at which the float rises, it is possible to know that the supply pressure has decreased, the viscosity of the processing liquid has decreased, or that the filter F has deteriorated. It can be known that the viscosity of the treatment liquid has decreased due to the increase in the speed of the treatment liquid.

In order to make such a determination, this embodiment has a configuration as shown in FIG.
That is, as shown in FIG. 5, the sensors 18a, 18b,
Output of 19a, 19b, valve 14, pressure adjustment mechanism 1
3, all of the memory 32 and the alarm generator 33 are connected to the CPU 31 via the data bus. Here, the alarm generator 33 is for notifying the operator that the supply pressure has decreased, the viscosity of the processing liquid has decreased, or that components in the piping system such as a filter have deteriorated. Device. The CPU 31 includes the sensors 18a, 18
The moving speed at the time of raising or lowering the float 17 is derived from the outputs of b, 19a and 19b and stored in the memory 32. The information stored in the memory 32 is the float 17
Any quantity representing the moving speed of the moving object may be used. Therefore, the passing time obtained by the sensors 18a, 18b, 19a, and 19b may be stored in the memory 32 because the passing time between two points and the moving speed have a fixed relationship.

Further, the CPU 31 stores in the memory 32 an amount representing the speed at which the float 17 moves each time the processing liquid is discharged onto the substrate W. Therefore, the memory 32 stores history information about the moving speed of the float 17 and the like according to the number of times the processing liquid is discharged.
By statistically analyzing the history information, the CPU 31 can know that the supply pressure has changed or that the viscosity of the processing liquid has changed. And CP
U <b> 31 causes the alarm generator 33 to generate an alarm based on the result of the statistical analysis, and outputs a control signal to the pressure adjustment mechanism 13.

For example, FIG. 6 is a diagram showing an example of the history information of the moving speed when the float 17 rises. In FIG. 6, H1 and L1 indicate upper and lower limits when an alarm is generated by the alarm generator 33, and H2 and L2 indicate movement corresponding to the flow rate of the processing liquid that may cause the substrate W to be defective. Shows the upper and lower speed limits. Then, as shown in FIG. 6, since the processing liquid discharge shows a stable moving speed until the vicinity of the N1th discharge, it can be seen that the supply pressure and the viscosity of the processing liquid do not decrease. Thus, if the embodiment is operating in a stable state, the float passes between any two points within a certain range of variation. Then, the number of discharges of the processing liquid is N1
Later, the moving speed of the float 17 starts to gradually decrease. Therefore, the CPU 31 can know that the supply pressure of the processing liquid is gradually decreasing, that the viscosity of the processing liquid is gradually decreasing, that the filter F is deteriorated, and the like. In this case, if the moving speed of the float 17 at the time of descending does not show a tendency to decrease, it can be said that the effect is not due to the decrease in the viscosity of the processing liquid. Therefore,
In this case, it is considered that the influence is caused by a gradual decrease in the supply pressure of the processing liquid or a gradual deterioration of components in the piping system such as the filter F.

When the moving speed of the rise of the float 17 tends to decrease, the CPU 31 sends a signal to the pressure adjusting mechanism to increase the pressure, and can eliminate this decreasing tendency. Then, the state shifts to the stable state again. However, in spite of such control by the CPU 31, when the discharge reaches the lower limit L1 in the N2th discharge, the CPU 31 sends a signal to the alarm generator 33 to notify the operator of the abnormality. At this time, the lower limit L
Since 1 is set to a value larger than the lower limit value L2 at which the board becomes defective, the failure of the substrate does not occur immediately even if an alarm is issued. Then, the operator sets the filter F
It is possible to return to a normal stable state again by performing an appropriate process such as replacement of the device.

FIG. 7 is a diagram showing another example of the history information of the moving speed when the float 17 rises. As shown in FIG. 7, the moving speed of the float 17 decreases stepwise before and after the number of times the processing liquid is discharged is about M times. Such a rapid decrease in the moving speed of the float 17 within a small number of discharges may be caused by a sudden failure such as pipe disconnection or pipe breakage, or may be caused by the supply from the utility side. This is due to a sudden drop in supply pressure on the utility side of the processing liquid or the like that is being used. Therefore, when the history information on the moving speed of the float 17 and the like is statistically analyzed to recognize that the moving speed has sharply changed as shown in FIG. Can be detected. If an alarm is issued by the alarm generator 33 when such a sudden change in the moving speed is detected, early measures can be taken.

As described above, the flow rate measuring apparatus of this embodiment statistically analyzes the history information of the moving speed when the float 17 rises, and thereby the fact that the supply pressure has decreased and the processing liquid That the viscosity has decreased,
It is possible to detect deterioration of components in a piping system such as a filter, a sudden failure such as a pipe disconnection or a pipe breakage, and a sudden drop in supply pressure on the utility side.

Further, by statistically analyzing the history information of the moving speed when the float 17 descends, it is possible to detect a change in the viscosity of the processing liquid, which is used for predicting the replacement / addition time of the processing liquid. be able to.

[0024]

As described above, according to the first aspect of the present invention, since the detection value obtained from the sensor for detecting the moving speed or the moving time of the float provided in the pipe is stored, the processing is performed. Since the change over time in the liquid discharge state can be measured, it is possible to realize a flow rate detection device that is less likely to produce defective substrates due to defective discharge or the like.

According to the second aspect of the present invention, there is further provided an analyzing means for statistically analyzing the detection value of the sensor, and the flow rate when supplying the processing liquid is controlled based on the analysis result. Such a flow can be prevented in advance, and a flow rate detection device with less defective products can be realized.

According to the third aspect of the present invention, since the substrate processing apparatus for performing a predetermined processing on the substrate is provided with the flow rate measuring apparatus, the substrate processing apparatus which does not produce defective products due to ejection failure or the like is small. Can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view of a substrate processing apparatus to which a flow rate detection device according to an embodiment of the present invention is applied.

FIG. 2 is a schematic diagram showing a mechanism for supplying a processing liquid to a substrate according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a flow meter according to the embodiment of the present invention.

FIG. 4 is a diagram illustrating a detection principle of the flow rate detection device according to the embodiment of the present invention.

FIG. 5 is a schematic block diagram illustrating a configuration of a flow rate detection device according to the embodiment of the present invention.

FIG. 6 is a diagram showing an example of history information of a moving speed of a float according to the embodiment of the present invention.

FIG. 7 is a diagram showing another example of the history information of the moving speed of the float according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 11 Tube 13 Pressure adjustment mechanism 14 Valve 16 Flowmeter 17 Float 18a, 18b, 19a, 19b Sensor 31 CPU 32 Memory 33 Alarm generator F Filter W Substrate

Claims (3)

[Claims] 1. An apparatus for measuring a flow rate of a processing liquid when supplying a processing liquid necessary for performing a predetermined processing on a substrate, comprising: (a) a float provided in a pipe; (B) a sensor for detecting a moving speed or a moving time of the float; and (c) means for storing a detection value of the sensor. 2. The apparatus according to claim 1, wherein: (d) analysis means for statistically analyzing a detection value of the sensor;
The flow rate measuring device, further comprising: controlling the flow rate when supplying the processing liquid based on the analysis result. 3. An apparatus for performing a predetermined process on a substrate, comprising the flow rate measuring apparatus according to claim 1 or 2.