KR0157676B1 - Liquid quality monitoring method for high specific resistance liquid, liquid quality monitor thereof and liquid quality monitoring system - Google Patents

Abstract

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid quality monitoring method of a high resistivity liquid, a liquid quality monitoring apparatus and a liquid quality monitoring system thereof, which can be measured at the point of use of a high resistivity liquid.

In the liquid-resistance monitoring method of the high resistivity liquid of the present invention, in the piping portion used for flowing the high resistivity liquid, a portion of the piping portion in contact with the high resistivity liquid is less, and the conductive member is electrically insulated from the piping portion. It is characterized by detecting the charge amount of the sensor portion consisting of the conductive member. In addition, the sensor portion is provided near the point of use or the end of the point of use for taking out the high resistivity liquid. In addition, the charge amount is detected by measuring the amount of charge movement between the sensor portion and the ground point. The liquid quality monitoring value of the high resistivity liquid of the present invention is characterized by having the above-described liquid quality monitoring method of the high resistivity liquid. The liquid quality monitoring system of the high resistivity liquid of the present invention is characterized by having a warning means for issuing a warning.

Description

Liquid quality monitoring method of high resistivity liquid, liquid quality monitoring device, and liquid quality monitoring system

1 is a schematic view showing an example of a secondary pure water production line of the present invention.

FIG. 2 is an enlarged view of the vicinity of the sensor portion (point a) made of the conductive member of FIG.

3 is a graph showing the relationship between the discharge frequency of ultrapure water and the voltage value according to the second embodiment.

4 is a schematic view showing a structure of an end point of use point for taking out a high resistivity liquid according to Example 3. FIG.

5 is a schematic view showing the arrangement of each measuring apparatus according to Example 6. FIG.

6 is a graph showing the relationship between the ejection frequency of ultrapure water and the amount of charge according to Example 6. FIG.

7 is a schematic view showing the arrangement of each measuring apparatus according to Example 7

8 is a graph showing the relationship between the ejection frequency and charge amount of ultrapure water according to Example 7. FIG.

* Explanation of symbols for main parts of the drawings

101: primary water storage container 102: pump

103: heat exchanger 104: low pressure UV oxidizer

105: Anion Deminer 106: Deminer

107: UF 108: branch point

109: developer 110: piping

111,401,501,701: sensor 112: resistance

402: piping unit for introducing ultrapure water 502,702: conductive electrode

403: piping unit for introducing nitrogen gas 704: substrate

503,703: Faraday gauge 705: substrate support

The present invention relates to a liquid quality monitoring method of a high resistivity liquid, a liquid quality monitoring apparatus, and a liquid quality monitoring system. More specifically, the present invention relates to a liquid quality monitoring method of a high resistivity liquid capable of managing purity of a high resistivity liquid at a point of use and through a substance to be cleaned in the piping section, a liquid quality monitoring apparatus, and a liquid quality monitoring system.

In the high-tech industries such as semiconductors, various electronic components, or nuclear power, managing the resistivity of ultrapure water to be used leads to the realization of high yield or the high reliability. In particular, in the semiconductor field, the resistivity control of pure water used in the cleaning process is one of key technologies for manufacturing devices with higher integration density.

Background Art Conventionally, as a liquid quality monitoring apparatus for a high resistivity liquid, a complex sensor in which an element for measuring the conductivity of pure water and an element for measuring the temperature of pure water are integrated. For example, an element provided with a bipolar electrode made of Ti via an insulator for conductivity measurement may be a thermistor for temperature measurement. Here, the conductivity is an index that knows the total amount of electrolyte contained in pure water and is an inverse of the resistivity used as an index that knows the purity of pure water. This complex sensor has the advantage of being able to measure the conductivity with high accuracy while always being installed in the piping system where pure water flows.

However, the prior art has the following problems.

(1) This type is used by inserting the detection part into pure water. Pure water in the pipe may be used as storage water, or it may not be used near the point of use where the outside air contacts the pipe.

(2) Measurements can be made only at the location where the sensor is installed in the piping system, and the free measuring point cannot be selected in the piping system.

(3) Due to the high price of sensors, it is expensive to install multiple sensors in the piping system and to establish a pure liquid quality monitoring system for multi-point measurement.

According to the present invention, it is possible to measure the point of use of a high resistivity liquid, and to select a free measurement point in the piping system, and because the sensor is inexpensive, the quality monitoring of the high resistivity liquid is easy because the water quality monitoring system of the high resistivity liquid is easy to construct. It is an object to provide a method, a liquid quality monitoring device, and a liquid quality monitoring system thereof.

According to the present invention, in a pipe portion used for flowing a high resistivity liquid, a portion of the pipe portion in contact with the high resistivity liquid is composed of at least a conductive member electrically insulated from the pipe portion, and is made of the conductive member. SUMMARY OF THE INVENTION There is a gist in the liquid quality monitoring method of a high resistivity liquid, characterized by detecting the charge amount of the sensor portion.

In the invention according to claim 1, at least a portion of the pipe portion used for flowing the high resistivity liquid is composed of at least a conductive member electrically insulated from the pipe portion. Charge of charge occurs. As a result, the resistivity change of the high resistivity liquid can be measured by detecting the charge amount.

In addition, since the detection can be performed only by forming at least a portion of the pipe portion from the conductive member electrically insulated from the pipe portion, multi-point measurement can be realized at low cost.

In the invention according to claim 2, since a part of the sensor is provided near the point of use for taking out the high resistivity liquid, the liquid quality of the high resistivity liquid just before being discharged from the point of use can be detected. As a result, when the high resistivity liquid does not flow, it is possible to monitor the liquid quality of the high resistivity liquid with high precision in the vicinity of the point of use where the inside of the pipe becomes outside air.

In the invention according to claim 3, since a part of the sensor is provided at the end of the point of use for taking out the high resistivity liquid, the liquid quality of the high resistivity liquid immediately before use ejected from the point of use can be detected. The shape of the sensor portion can be arbitrarily selected, and the sensor portion can be detached at any time. As a result, it is possible to repair, inspect, or replace the sensor section without stopping the pipe section used for flowing the high resistivity liquid.

In the invention according to claim 4, since the amount of charge can be detected by measuring the amount of charge transfer between the sensor portion and the ground point, the liquid quality monitor of the high resistivity liquid in the inline can be easily realized without disturbing the liquid. have. As a result, it is possible to manage the liquid quality without affecting the high resistivity liquid.

In the invention according to claim 5, since the sensor portion has a ring shape through which the high resistivity liquid passes, the sensor portion can stably contact the high resistivity liquid without depending on the flow rate of the high resistivity liquid. Will be. As a result, the detection sensitivity can be stabilized.

In the invention according to claim 6, since the high resistivity liquid is pure water or heavy water, it can be applied to a wide range of applications from washing water solubility in the semiconductor field where trace amounts of impurities are problematic to cooling water applications in the nuclear field. .

In the invention according to claim 7, in order to measure the amount of electric charge applied to the high resistivity liquid by applying the high resistivity liquid ejected from the point of use directly to the conductive electrode connected to the Faraday gauge without interposing the surface of the object to be cleaned. The effect of contamination in the space between the point of use and the conductive electrode on the high resistivity liquid can be detected. As a result, cleanliness management in the space between the point of use and the conductive electrode becomes possible.

In the invention according to claim 8, the amount of charge applied to the high resistivity liquid can be measured by applying the high resistivity liquid ejected from the point of use to the conductive electrode connected to the Faraday gauge indirectly through the surface of the object to be cleaned. Therefore, the cleanliness of the surface of the object to be cleaned, that is, the degree of cleaning can be detected. As a result, even if the degree of contamination of the to-be-cleaned object is different, the optimal washing | cleaning conditions etc. can be determined sequentially for each to-be-cleaned object.

In the invention according to claim 9, the liquid quality monitoring device for a highly versatile and inexpensive high specific resistance liquid is obtained by having the liquid quality monitoring method for the high resistivity liquid according to any one of claims 1 to 8.

In the invention according to claim 10, since it has a warning means for warning when the value of the charge amount or the charge amount changes, it is possible to control the liquid quality monitoring of the high-resistance liquid.

As a result, a high quality liquid resistivity monitoring system is obtained.

EXAMPLE

Example 1

Hereinafter, an embodiment of the present invention will be described.

In this example, the pipe portion used for flowing the high resistivity liquid differs from the conventional one in that a part of the pipe portion in contact with the high resistivity liquid is composed of at least a conductive member electrically insulated from the pipe portion. Pure water was used as the high resistivity liquid, and electrical conductivity of pure water was detected by detecting the charging of the sensor portion made of the conductive member.

Hereinafter, this example will be described with reference to FIGS. 1 and 2. 1 is a schematic view showing an example of the secondary pure water production line of the present invention. FIG. 2 is an enlarged view of the vicinity of the sensor portion (point a) made of the conductive member of FIG. 1, and FIG. 2 (a) is a perspective view, FIG. 2 (b) is a sectional view of part A-A 'of FIG. 2 (a). to be.

Secondary pure water production line of the present invention was composed of each of the following devices 101-110.

101 is a primary storage container for storing ultrapure water (resistance is MΩcm order) treated in a primary pure water production line (not shown), 102 is a pump for circulating ultrapure water, and 103 is a constant temperature of ultrapure water It maintained at 24 degreeC as a heat exchanger for this. 104 is a low pressure UV oxidizer for decomposing organic matter, 105 is an ion exchanger (Anion Deminer) for removing anion (neon ion), and its main purpose is organic acid or carbonate ion generated from low pressure UV oxidizer of the previous stage. Is in the removal of. 106 is an ion exchanger (miner) for removing ions regardless of government, 107 is a final filter (UF) for removing particulates, 108 is a branch point for branching secondary pure water to a point of use, and 109 is a secondary pure water. Use point (developer).

As shown in FIG. 1, 101-108 are annular and 108 and 109 were connected by the piping part 110 in a linear form. As a material of the pipe part 110, PVDF (Poly vinylidene fluoride) which is an insulating member was used. At a point a of the pipe part 110, a part of the pipe part 110 was replaced with a sensor part 111 made of a conductive member. SUS304 was used as a material of the sensor part 111. As shown in FIG.

As shown in FIG. 2, the sensor part 111 was installed in the position which the ultrapure water which flows in the piping part 110 directly contacts. Charging occurs in the sensor unit 111 by the flow of ultrapure water. Between the sensor part 111 and the point, the resistance 112 of 100 MΩ was mounted, and the voltage value applied to both ends of the resistance 112 was measured. That is, the change in the charge amount due to the charging was observed as the change in the charging value.

In this example, when the relationship between the charge amount and the voltage value described above was examined, the voltage value was about -0.3 mV when a normal ultrapure water having a specific resistance of 18 MΩcm was flowed. On the other hand, when the purity of this ultrapure water was reduced, it was found that the voltage value tends to decrease in the absolute value in the 0 mV direction. Therefore, it was judged that purity management of ultrapure water can be performed by using the sensor part 111 of this invention.

In this example, although the sensor part 111 was arrange | positioned at the point a of the piping part 110, it does not matter even if it is the point b or c which is not the annular part of FIG.

In this example, a high resistivity liquid was used as ultrapure water, but the same effect was confirmed even when heavy water was used.

Example 2

This example differs from Example 1 in that the position where the sensor portion made of the conductive member is provided is near the point of use for taking out the high resistivity liquid. The vicinity of the point of use for taking out the high resistivity liquid indicates the point d in FIG.

The other point was carried out similarly to Example 1.

3 shows the voltage value when the ultrapure water is ejected for 60 seconds after sealing for 2 hours without flowing ultrapure water near the point of use. The flow rate of ultrapure water was 4300 cc / min. The abscissa is the ejection frequency of ultrapure water.

It can be seen from FIG. 3 that the voltage value is changed by the ejection frequency. As the number of ejections increased, the voltage level stabilized at -30 mV. From this, the vicinity of the point of use was contaminated by the bag of ultrapure water, and it was judged that ultrapure water can be used with a stable purity by starting the use of ultrapure water after ejecting the ultrapure water two or three times.

In addition, the use of the sensor unit of this example makes it possible to manage ultrapure water even in the vicinity of the point of use where the inside of the piping unit, which could not be measured conventionally, is in contact with the outside air.

Example 3

This example differs from Example 2 in that the position where the sensor portion made of the conductive member is provided is the end point of the use point for taking out the high resistivity liquid.

The structure shown in FIG. 4 was used as an end point of use point for taking out the high resistivity liquid. At the end point of FIG. 4, a nozzle made of SUS304 is a sensor portion 401, and a pipe portion 402 for introducing ultrapure water and a piping port 403 for introducing nitrogen gas are connected to the sensor portion 401. By supplying ultrapure water and nitrogen gas simultaneously, the ultrapure water in the form of a spray was ejected from the sensor unit 401.

Other points were the same as in Example 2.

In this example, the same effects as in Example 2 were obtained. Therefore, since the position where the sensor portion made of the conductive member is provided may be an end point of use point for taking out the high resistivity liquid, the shape of the sensor portion can be arbitrarily selected, and detachment can be performed at any time for each use point.

Example 4

In this example, as already shown in Example 1, a resistor is disposed between the sensor portion and the ground portion, and the charge generated by the liquid of the high-resistance liquid flowing through the sensor portion flows through the resistance to be applied to both ends of the resistance. Voltage value was measured.

In this example, it is possible to measure cheaper and easier than conventional liquid quality monitoring apparatus.

In this example, the voltage generated at both ends of the resistor was measured by a voltmeter. Similar results were confirmed even when a microammeter was disposed between the sensor portion and the ground point.

Example 5

This embodiment differs from the first embodiment in that the shape of the sensor portion is formed into a ring shape through which the high resistivity liquid passes through the inside of the sensor.

Other points were the same as in Example 1.

In this example, almost the same effects as in Example 1 were obtained. However, in this example, the detection sensitivity is stabilized more than the shape of Example 1 because of the large contact area with the high resistivity liquid.

Moreover, in this example, the shape of the sensor part was made into a ring shape, but the same effect was also confirmed when a mesh was installed as a conductive material in the ring shape.

Example 6

In this example, the amount of charge applied to the high resistivity liquid was measured by directly applying the high resistivity liquid ejected from the point of use to the conductive electrode connected to the Faraday gauge without interposing the surface of the object to be cleaned.

5 is a schematic view showing the arrangement of each measuring apparatus in this example.

As the end point of the use point for taking out the high resistivity liquid, a nozzle made of SUS304 was used as the sensor portion 501 as in FIG. The conductive electrode 502 was provided at the position to which the ultrapure water ejected from the nozzle was irradiated. The conductive electrode 502 is connected to the Faraday gauge 503, and the charge applied to the ultrapure water discharged was measured by the Faraday gauge 503 via the conductive electrode 502.

FIG. 6 shows the amount of charge applied to the ultrapure water ejected when the ultrapure water was ejected for 60 seconds after sealing for 2 hours without flowing ultrapure water near the point of use. The flow rate of ultrapure water was 430 cd / min. The abscissa is the ejection frequency of ultrapure water.

It can be seen from FIG. 6 that the amount of charge applied to the ultrapure water jetted by the jet frequency changes. In particular, when the number of ejections was four or more, the charge amount was stabilized at about 120nC. It was also confirmed that this stable charge amount and the charge amount detected in Example 3 were different in polarity, and the absolute value was the same within a disturbance of ± 3%.

On the other hand, in the result (Example 2 or Example 3) of the sensor part installed in the vicinity of a use point or the end of a use point, the purity of ultrapure water was recovering more than 2 times.

From these two results, it was determined that the purity of ultrapure water did not recover unless the present example ejected more than a few times due to the effect of contamination in space between the point of use and the conductive electrode. As a result, the present invention enables the cleanliness management in the space between the point of use and the conductive electrode.

Example 7

In this example, the amount of charge applied to the high resistivity liquid was measured by indirectly applying the high resistivity liquid ejected from the point of use to the conductive electrode connected to the Faraday gauge via the surface of the object to be cleaned.

7 is a schematic view showing the arrangement of each measuring apparatus in this example.

As the end point of the point of use for taking out the high resistivity liquid, a nozzle made of SUS304 was used as the sensor portion 701 as in FIG. The board | substrate 704 which formed Al into a film as a to-be-cleaned object was provided in the position where the ultrapure water sprayed from the said nozzle is irradiated. The substrate 704 was mounted on a substrate support 705 having a vacuum chuck mechanism. When cleaning the substrate 704 with ultrapure water, the substrate support 705 was rotated. The electroconductive electrode 702 was provided in the position to which the ultrapure water scattered from the said board | substrate 704 is irradiated by this rotation. The conductive electrode 702 is connected to the Faraday gauge 703, and the charge applied to the ultrapure water that is scattered was measured by the Faraday gauge 703 via the conductive electrode 702.

FIG. 8 shows the amount of charge applied to the ultrapure water scattered from the substrate when the ultrapure water was ejected for 60 seconds after sealing for 2 hours without flowing ultrapure water near the point of use. The flow rate of ultrapure water was 530 cc / min. The abscissa is the ejection frequency of ultrapure water.

It can be seen from FIG. 8 that the amount of charge applied to the ultrapure water scattered from the substrate is changed by the ejection frequency. In particular, when the number of ejection cycles was 10 or more, the charge amount was stabilized at about 120 nC. This result also differs in the amount of charge detected in Example 3 and in the same polarity as in Example 6, and the absolute value is distorted within ± 3%.

On the other hand, when the amount of charge applied to the high resistivity liquid was measured by directly applying the high resistivity liquid ejected from the point of use to the conductive polarity connected to the Faraday gauge without interposing the surface of the object to be cleaned (Example 6), The recovery was more than four times to restore the purity of ultrapure water.

From these two results, it is judged that the purity of ultrapure water does not recover unless the present example ejects more times than it is due to the cleanliness of the substrate 704 to be cleaned, that is, the degree of cleaning. As a result, according to the present invention, even if the degree of contamination of the object to be cleaned differs, optimum cleaning conditions and the like can be sequentially determined for each object to be cleaned.

As described above, the liquid-resistance monitoring method of the high resistivity liquid shown in Examples 1 to 7 can be easily assembled to the already-installed secondary pure water production line. In addition, since the structure of the sensor unit is simple and a general purpose product can be used, it is possible to provide a liquid quality monitoring device of a high resistivity liquid at a lower cost than in the prior art.

Further, by providing a warning means for warning when the charge amount or the value of the charge amount changes, the provision of a high-resistance liquid quality monitoring system capable of feedback control of the monitoring of the high-resistance liquid It became possible.

As described above, according to the invention according to claim 1, a liquid quality monitoring method of a high resistivity liquid which can realize multi-point measurement at low cost and can be easily realized.

According to the invention according to claim 2, a liquid quality monitoring method of a high resistivity liquid detectable near the point of use for extracting the high resistivity liquid is obtained.

According to the invention according to claim 3, the shape of the sensor portion can be arbitrarily selected, and the liquid quality monitoring method of the high resistivity liquid can be obtained at any time.

According to the invention according to claim 4, a liquid-resistance monitoring method of a high resistivity fluid, which does not affect the high resistivity liquid, is obtained.

According to the invention according to claim 5, a liquid quality monitoring method of a high resistivity liquid with stable detection sensitivity is obtained.

According to the invention according to claim 6, there is obtained a liquid quality monitoring method of a high resistivity liquid that can be applied to a wide range of applications.

According to the invention according to claim 7, a liquid quality monitoring method of a high resistivity liquid capable of managing cleanliness in a space between a point of use and a conductive electrode is obtained.

According to the invention according to claim 8, there is obtained a liquid quality monitoring method of a high resistivity liquid capable of sequentially determining optimum cleaning conditions and the like for each object to be cleaned.

According to the invention according to claim 9, a liquid quality monitoring method for a high versatility and inexpensive high resistivity liquid is obtained.

According to the invention according to claim 10, a liquid quality monitoring system of a high resistivity liquid with high reliability is obtained.

Claims (10)

In a pipe section used for flowing a high resistivity liquid, a part of the pipe section where the high resistivity liquid is in contact is composed of at least a conductive member electrically insulated from the piping section, and the sensor section comprising the conductive member. A liquid quality monitoring method for a high resistivity liquid, characterized by detecting the charge amount. The method for monitoring the quality of liquid of a high resistivity liquid according to claim 1, wherein the sensor part is provided near a point of use for extracting the high resistivity liquid. The method of monitoring liquid quality of a high resistivity liquid according to claim 1, wherein the sensor part is provided at an end point of a use point for extracting the high resistivity liquid. 4. The method of monitoring liquid quality of a high resistivity liquid according to any one of claims 1 to 3, wherein a charge amount is detected by measuring an amount of charge transfer between the sensor portion and the ground point. The method of monitoring liquid quality of a high resistivity liquid according to any one of claims 1 to 3, wherein the sensor part has a ring shape through which a high resistivity liquid passes. The method of monitoring liquid quality of a high resistivity liquid according to any one of claims 1 to 3, wherein the high resistivity liquid is pure water or heavy water. The high resistivity liquid of any one of claims 1 to 3, wherein the high resistivity liquid ejected from the point of use is directly caught by a conductive electrode connected to a Faraday gauge without interposing the surface of the object to be cleaned. A liquid quality monitoring method for a high resistivity liquid, characterized by measuring the amount of charged charge. 4. The high resistivity liquid according to any one of claims 1 to 3, wherein the high resistivity liquid ejected from the point of use is indirectly caught by the conductive electrode connected to the Faraday gauge via the surface of the object to be cleaned. A liquid quality monitoring method for a high resistivity liquid, characterized in that the amount of charge is measured. A liquid quality monitoring apparatus for a high resistivity liquid, comprising: a liquid quality monitoring method for a high resistivity liquid according to any one of claims 1 to 8. A liquid-resistance monitoring system for a high resistivity liquid according to any one of claims 1 to 9, comprising a warning means for issuing a warning when the charge amount or the value of the charge amount changes.