JPH10208989A - Substrate treating apparatus and gas concn. control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate treating apparatus and gas concn. control system for controlling the conc. of specified substance in an atmosphere gas, without increasing the installation area. SOLUTION: The gas concn. control system 3 is provided on a substrate treating part 1 and has a first measuring port 31 located at the downstream of a first filter 21, second measuring port 32 disposed in this part 1, three-way valve 33 for selectively communicating either first or second port 31, 32 with a concn. decision unit 34 which judges whether the ammonia concn. in an atmosphere gas fed from the first or second port 31, 32 over a specified reference value of not and alarms if the ammonia concn. exceeds the specified reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air concentration management system for managing the concentration of a predetermined substance in an atmospheric gas of a substrate processing apparatus, and a substrate processing apparatus having the same.

[0002]

2. Description of the Related Art A substrate processing apparatus is used to perform various processes on substrates such as a semiconductor wafer, a glass substrate for a liquid crystal display, a glass substrate for a photomask, and a glass substrate for an optical disk. In such a substrate processing apparatus, it is necessary to keep the concentrations (air concentrations) of various chemical substances such as alkali components and acidic components in the atmosphere as low as possible.

In particular, there is a case where a chemically amplified resist is used to increase the degree of integration of elements formed on a substrate.
Here, the chemically amplified resist refers to a resist capable of generating a specific acid upon exposure to light, acting as a catalyst, amplifying the reaction (decomposition or polymerization) of the exposed portion, and efficiently forming a pattern. .

[0004] When such a chemically amplified resist is used, if the atmosphere gas contains an alkali component (particularly ammonia), the acid will be neutralized and the quality of the resist will deteriorate. is there. Therefore,
It is necessary to suppress the concentration of ammonia in the atmosphere gas to a certain reference value or less. Therefore, an ammonia removing unit including a filter or the like is used in the substrate processing apparatus in order to remove ammonia in the atmospheric gas.

FIG. 4 is a schematic view of a conventional substrate processing apparatus provided with an ammonia removing unit. Substrate processing apparatus 100
a includes a substrate processing unit 60 that performs predetermined processing such as coating processing of a resist or the like on a substrate, development processing, heating processing, cooling processing, and the like. On the substrate processing unit 60, an ammonia removing unit 70 including a filter and a blower is provided.

Normally, air is supplied from above the substrate processing apparatus 100a as atmospheric gas. The air passes through the filter of the ammonia removing unit 70 and is supplied into the substrate processing unit 60. Thereby, the inside of the substrate processing unit 60 is maintained in an atmosphere of clean air from which ammonia has been removed.

When the capacity of the filter of the ammonia removing unit 70 decreases over time, the substrate processing unit 60
The concentration of ammonia inside increases. If the concentration of ammonia in the substrate processing unit 60 exceeds a certain reference value, the quality of the chemically amplified resist deteriorates, and it is necessary to replace the filter. In order to ascertain the filter replacement time, it is necessary to manage the ammonia concentration in the substrate processing unit 60.

Conventionally, an ammonia concentration measuring device 80 is used to manage the ammonia concentration in the substrate processing section 60. The ammonia concentration measuring device 80 is provided in the substrate processing section 6.
It is connected to the substrate processing apparatus 100 by a pipe 61 for guiding the atmospheric gas in the chamber 0 and a communication line 62. As the ammonia concentration measuring device 80, an ion chromatograph analysis system is generally used.

FIG. 5 is a block diagram showing an example of an ion chromatograph analysis system. The ion chromatograph analysis system of FIG. 5 includes a concentration analysis unit 81, a storage unit 82,
An arithmetic processing unit 83, an input unit 84, and an output unit 85 are provided.

[0010] The concentration analyzer 81 has a function of measuring the ammonia concentration in the atmospheric gas introduced from the substrate processing unit 60 through the pipe 61. The input unit 84 includes, for example, a keyboard, and the output unit 85 includes a monitor such as a CRT or an output device such as a printer. The storage unit 82 includes an arithmetic processing unit 8
The control program and various data for 3 are stored.

In the ion chromatograph analysis system of FIG. 5, the concentration of ammonia in the atmospheric gas introduced from the substrate processing unit 60 through the pipe 61 is measured by the concentration analysis unit 81, and the measurement result is displayed on the monitor of the output unit 85. Or output to an output device.

[0012]

The use of the above-mentioned ammonia concentration measuring device 80 makes it possible to accurately measure the ammonia concentration in the substrate processing section 60. However, since the ammonia concentration measuring device 80 is relatively large,
Substrate processing apparatus 100 by ammonia concentration measuring device 80
There is a problem that the footprint (installation area) of “a” increases. Further, since the ammonia concentration measuring device 80 is expensive, the cost for processing the substrate increases.

It is an object of the present invention to provide a substrate processing apparatus and an air concentration management system capable of inexpensively managing the concentration of a predetermined substance in an atmospheric gas without increasing the installation area.

[0014]

According to a first aspect of the present invention, there is provided a substrate processing apparatus for performing a predetermined process on a substrate, and an atmosphere gas supply for supplying a clean atmosphere gas to the substrate processing section. Means for determining whether or not the concentration of a predetermined substance in the atmosphere gas passing through the atmosphere gas supply means or in the atmosphere gas in the substrate processing unit is equal to or higher than a predetermined reference value. is there.

In the substrate processing apparatus according to the present invention, the determination means determines whether the concentration of the predetermined substance in the atmosphere gas passing through the atmosphere gas supply means or in the atmosphere gas in the substrate processing section is equal to or higher than a predetermined reference value. It is determined whether or not. Thereby, the maintenance or replacement time of the atmospheric gas supply means can be grasped.

In this case, since the determination means determines only whether or not the concentration of the predetermined substance in the atmospheric gas is equal to or higher than the reference value, the configuration is simple, the manufacturing is inexpensive, and the size is small. Is possible. Therefore, the installation area of the substrate processing apparatus does not increase.

The substrate processing apparatus according to a second aspect of the present invention, in the configuration of the substrate processing apparatus according to the first aspect, generates an alarm when the determination means determines that the concentration of the predetermined substance is equal to or higher than the reference value. Further, there is provided an alarm generating means. Thereby, the operator can easily grasp the maintenance or replacement time of the atmospheric gas supply means.

According to a third aspect of the present invention, there is provided the substrate processing apparatus according to the first or second aspect of the invention, wherein the determination means determines that the concentration of the predetermined substance is equal to or higher than the reference value. The apparatus further includes control means for stopping the processing by the substrate processing unit. As a result, it is possible to prevent a decrease in the quality of the substrate processing due to an increase in the concentration of the predetermined substance in the atmospheric gas.

According to a fourth aspect of the present invention, there is provided a substrate processing apparatus comprising:
In the configuration of the substrate processing apparatus according to the second or third invention, the determining means includes an atmosphere gas introducing means for guiding an atmosphere gas passing through the atmosphere gas supply means or an atmosphere gas in the substrate processing unit to the pH indicator; And a density determining means for determining whether or not the concentration of the predetermined substance is equal to or higher than a reference value based on the color change detected by the detecting means.

In this case, the atmosphere gas passing through the atmosphere gas supply means or the atmosphere gas in the substrate processing section is guided to the pH indicator, and a change in the color of the pH indicator is detected. p
Since the color of the H indicator changes according to the concentration of the substance in the atmosphere gas, the concentration of the predetermined substance in the atmosphere gas can be determined based on the change in the color of the pH indicator.

The determination means of the substrate processing apparatus according to the present invention determines only whether or not the concentration of a predetermined substance in the atmospheric gas is equal to or higher than a reference value.
In addition, it can be manufactured at low cost and can be downsized.

According to a fifth aspect of the present invention, there is provided a substrate processing apparatus comprising:
In the configuration of the substrate processing apparatus according to the second or third invention, the atmosphere gas supply means removes a predetermined substance in the atmosphere gas, and sends the atmosphere gas passing through the removal means to the substrate processing section. A first measuring port for sampling an atmosphere gas downstream of the removing means, a second measuring port for sampling an atmosphere gas in the substrate processing unit, and a first or second gas sampling means. Concentration determination means for determining whether the concentration of a predetermined substance in the atmospheric gas collected by the measurement port is equal to or higher than a reference value; and concentration determination means for selectively selecting one of the first and second measurement ports. And switching means for conducting the current.

When the switching means is set so that the first measurement port is electrically connected to the concentration judging means, the atmospheric gas downstream of the removing means of the atmospheric gas supplying means is sampled, and the concentration in the atmospheric gas is measured. It is determined whether the value is equal to or greater than the reference value. When the concentration in the atmosphere gas downstream of the removing unit is lower than the reference value, the concentration in the atmosphere gas in the substrate processing unit is also lower than the reference value.

When the concentration in the atmosphere gas on the downstream side of the removing means becomes higher than the reference value, the concentration in the atmosphere gas in the substrate processing section eventually becomes more than the reference value. The switching means is set to conduct.
Thereby, the atmospheric gas in the substrate processing unit is sampled, and it is determined whether or not the concentration in the atmospheric gas is equal to or higher than the reference value. Therefore, the removing means of the atmospheric gas supply means can be replaced before the concentration in the atmospheric gas in the substrate processing section becomes equal to or higher than the reference value.

An air concentration management system according to a sixth aspect of the present invention is an air concentration management system for managing the concentration of a predetermined substance in an atmosphere gas in a substrate processing apparatus. Sampling means for sampling, atmosphere gas introducing means for guiding the atmospheric gas collected by the sampling means to the pH indicator, detecting means for detecting a change in the color of the pH indicator, and based on the color change detected by the detecting means. Concentration determining means for determining whether the concentration of the predetermined substance is equal to or higher than a reference value.

In the air concentration management system according to the present invention, the atmospheric gas in the substrate processing apparatus is collected and guided to the pH indicator. Since the color of the pH indicator changes according to the concentration of the predetermined substance in the atmospheric gas, the concentration of the predetermined substance can be determined based on the change in the color of the pH indicator.

In this aerial concentration management system, since it is determined only whether the concentration of a predetermined substance is equal to or higher than a reference value based on a change in the color of the pH indicator, the configuration is simple and inexpensive. And can be miniaturized.
Therefore, even if the air concentration management system is provided in the substrate processing apparatus, the installation area of the substrate processing apparatus does not increase.

The air concentration management system according to a seventh aspect of the present invention is the air concentration management system according to the sixth aspect, wherein the detecting means comprises: light irradiating means for irradiating the pH indicator with light; Light receiving means for receiving the reflected light of the emitted light, and the concentration determining means determines whether or not the concentration of the predetermined substance is equal to or higher than a reference value based on the amount of light received by the light receiving means.

Since the concentration of the color of the pH indicator changes in accordance with the concentration of a predetermined substance in the atmosphere gas, the concentration of the substance in the atmosphere gas can be determined based on the amount of reflected light from the pH indicator. . In the air concentration management system according to the present invention, since it is determined only whether the concentration of the substance in the atmospheric gas is equal to or higher than the reference value based on the amount of light received by the light receiving means, the configuration is simple, and It can be manufactured at low cost and can be miniaturized.

An air concentration management system according to an eighth aspect of the present invention is the air concentration management system according to the sixth aspect, wherein the pH indicator is filled in the transparent pipe, and the atmosphere gas introducing means is provided by the sampling means. The collected atmospheric gas is led to one end of the pH indicator in the transparent pipe, and the detecting means is arranged along the transparent pipe and the p in the transparent pipe.
A plurality of detecting means for irradiating the H indicator with light and detecting a change in color based on the reflected light; It is to determine whether the value is equal to or more than the reference value.

When an atmosphere gas containing a predetermined substance is supplied to one end of the pH indicator filled in the transparent pipe, the color of the pH indicator changes in order from one end to the other end.
In this case, the rate of change of the color of the pH indicator corresponds to the concentration in the atmospheric gas. Therefore, the concentration of the substance in the atmospheric gas can be determined based on the time difference between the detection timings of the plurality of detection means arranged along the transparent pipe. In the air concentration management system according to the present invention, since it is determined only whether or not the concentration of the substance in the atmospheric gas is equal to or higher than the reference value based on the time difference between the detection timings of the plurality of detection means, the configuration is simple. , And can be manufactured at low cost, and can be miniaturized.

[0032]

FIG. 1 is a schematic diagram showing the structure of a substrate processing apparatus according to one embodiment of the present invention.

The substrate processing apparatus 100 shown in FIG. 1 includes a substrate processing section 1, an atmosphere adjusting section 2, and an air concentration management system 3. The substrate processing unit 1 includes a rotary coating unit (spin coater) that applies a resist or the like to the substrate, a rotary developing unit (spin developer) that performs a developing process on the substrate, and a rotary cleaning unit (spin scrubber) that performs a cleaning process on the substrate. ,
The apparatus includes one or a plurality of substrate processing units such as a heating unit (hot plate) for performing a heating process on a substrate and a cooling unit (cooling plate) for performing a cooling process on the substrate.

The atmosphere adjusting unit 2 includes a primary filter 21 composed of a chemical adsorption filter, a blower 22, a secondary filter 23 composed of a chemical adsorption filter, and an ULPA (Ultra Lo
w Penetration Air) Including the filter 24, the substrate processing unit 1
Mounted on top.

The blower 22 converts the atmospheric gas supplied from above into the primary filter 21, the secondary filter 23 and the UL filter.
The light passes through the PA filter 24 and is guided into the substrate processing unit 1.
The primary filter 21 and the secondary filter 23 include particles for neutralizing a predetermined substance, and remove the predetermined substance in the atmospheric gas supplied from above. ULPA filter 24
Removes particles (dust) in the atmospheric gas.
Thus, a clean atmosphere gas from which predetermined substances and particles have been removed is supplied into the substrate processing unit 1.

The atmosphere gas is, for example, air. The predetermined substance in the atmospheric gas is a predetermined alkali component or a predetermined acid component, and in this embodiment, is ammonia.

The air concentration management system 3 includes a substrate processing unit 1
A first measurement port 31, a second measurement port 32, a three-way valve 33, and a concentration determiner 34 are provided. First
Measurement port 31 is a primary filter 21 and a secondary filter 2
3, that is, downstream of the primary filter 21. The second measurement port 32 is arranged in the substrate processing section 1. The first measurement port 31 and the second measurement port 32 are composed of nozzles for sucking atmospheric gas, and are connected to the three-way valve 33 by pipes 35 and 36, respectively.

The three-way valve 33 selectively selects one of the atmosphere gas supplied from the first measurement port 31 and the atmosphere gas supplied from the second measurement port 32 in the concentration determination unit 34.
It can be switched manually or automatically so as to guide the user.

The concentration determiner 34 is provided on the substrate processing section 1 so as to be detachable. This density determination 34 is based on the first
It is determined whether the ammonia concentration in the atmospheric gas supplied from the measurement port 31 or the second measurement port 32 is equal to or higher than a predetermined reference value, and an alarm is generated when the ammonia concentration is equal to or higher than the reference value. It has a function to do.

The air concentration management system 3 includes the substrate processing apparatus 1
It can function alone even when detached from 00.

Normally, the three-way valve 33 is set so as to conduct between the first measurement port 31 and the concentration determiner 34. In this case, it is determined whether or not the ammonia concentration in the atmosphere gas downstream of the primary filter 21 is equal to or higher than the reference value, and an alarm is issued when the ammonia concentration in the atmosphere gas becomes equal to or higher than the reference value. This allows the operator to determine that the primary filter 21 has reached the end of its life.

In this case, the three-way valve 33 is switched so that the connection between the second measurement port 31 and the concentration judging device 34 is established. Thereby, it is possible to monitor whether the ammonia concentration in the atmospheric gas in the substrate processing section 1 is equal to or higher than the reference value. At this time, ammonia in the atmospheric gas supplied to the substrate processing unit 1 is removed only by the secondary filter 23. In the meantime, the primary filter 21 is replaced, and the three-way valve 33 is switched so that the first measurement port 31 and the concentration determiner 34 are electrically connected. Since the substrate processing section 1 is operating continuously, the secondary filter 24 is periodically replaced.

In this embodiment, the atmosphere adjuster 2 corresponds to an atmosphere gas supply unit, and the air concentration management system 3 corresponds to a determination unit. The primary filter 21 corresponds to a removing unit, and the blower 22 corresponds to an air sending unit. Furthermore, the first
The measurement port 31 and the second measurement port 32 correspond to sampling means, the three-way valve 33 corresponds to switching means, the concentration determiner 34 corresponds to concentration determination means, and the pipes 35 and 36 correspond to atmosphere gas introduction means. Equivalent to.

According to the air concentration management system 3 in the substrate processing apparatus 100 of this embodiment, it is possible to easily determine whether or not the ammonia concentration in the atmospheric gas in the substrate processing apparatus 100 is higher than a predetermined reference. Can be. Thereby,
The operator can easily grasp the time to replace the primary filter 21 of the atmosphere adjusting unit 2. In this case, real-time monitoring of the ammonia concentration in the substrate processing apparatus 100 is unnecessary.

Since the air concentration management system 3 does not have excessive additional equipment such as a monitor, the configuration is simple.
It is compact. Therefore, the air concentration management system 3 can be built in the substrate processing apparatus 100, and the footprint of the substrate processing apparatus 100 does not increase. Also,
Since the configuration of the air concentration management system 3 is simple, the initial cost and the operating cost are reduced.

FIG. 2 is a block diagram showing an example of the configuration of the density judgment unit 34. 2 includes transparent pipes 41 and 42, a pH test paper (pH indicator) 43, and a light source 4.
4, including a light receiving element 45, a comparing section 46, and an alarm generating section 47. The control unit 11 controls the processing of the substrate in the substrate processing unit 1 of FIG.

The pH test paper 43 is sandwiched between one end of the transparent pipe 41 and one end of the transparent pipe 42. A fixed amount of atmospheric gas collected by the first measurement port 31 or the second measurement port 32 of FIG.
Through the pH test paper 43 between the transparent pipes 41 and 42.

The distance p from the light source 44 to the transparent pipes 41 and 42
The H test paper 43 is irradiated with light, and the reflected light is
5 is received. The light receiving element 45 supplies an output signal corresponding to the amount of received light to the comparator 46. When the atmosphere gas containing ammonia is supplied to the pH test paper 43 between the transparent pipes 41 and 42, the color of the pH test paper 43 changes. Since the color density of the pH test paper 43 changes in accordance with the concentration of ammonia in the atmosphere gas, the ammonia concentration in the atmosphere gas can be determined based on the amount of reflected light from the pH test paper 43.

The comparing section 46 compares the level of the output signal supplied from the light receiving element 45 with a predetermined value, and
When the level of the output signal becomes equal to or higher than a predetermined value, an alarm signal is given to the alarm generator 47 and the controller 11. The alarm generation unit 47 generates an alarm sound in response to an alarm signal given from the comparison unit 46. The control unit 11 stops the processing of the substrate in the substrate processing unit 1 in response to the alarm signal given from the comparison unit 46 when the second measurement port 32 and the concentration determination unit 34 are set to the conductive state. Let it. FIG.
Has a simple configuration, and can be manufactured inexpensively and compactly.

FIG. 3 is a block diagram showing another example of the configuration of the density determination unit 34. 3 includes a transparent pipe 51, a flocculent pH test paper (pH indicator) 52, a plurality of reflection sensors 53 to 57, a data processing unit 58, and an alarm generation unit 59.

The cotton-like pH test paper 52 is filled in the transparent pipe 52. A fixed amount of atmospheric gas collected by the first measurement port 31 or the second measurement port 32 of FIG. 1 is led to one end of the transparent pipe 51 via the three-way valve 33.

The plurality of reflection sensors 53 to 57 are arranged outside the transparent pipe 51 from one end to the other end of the pH test paper 52. These reflection sensors 53-
Each of the lights 57 irradiates the pH test paper 52 in the transparent pipe 51 with light, receives the reflected light, and turns on when the amount of the reflected light exceeds a predetermined value. Reflection type sensors 53 to 57
Is supplied to the data processing unit 58.

When the atmosphere gas containing ammonia is supplied to the transparent pipe 51, the color of the pH test paper 52 changes sequentially from one end to the other end. When the ammonia concentration in the atmosphere gas is low, the color change speed of the pH test paper 52 is slow, and when the ammonia concentration in the atmosphere gas is high, the color change speed of the pH test paper 52 is fast.

The data processing unit 58 measures the time difference between the timings at which the plurality of reflection sensors 53 to 57 are turned on, and determines whether or not the ammonia concentration in the atmospheric gas is equal to or higher than a predetermined reference value based on the measured time difference. Is determined. The data processing unit 58 provides an alarm signal to the alarm generation unit 59 and the control unit 11 when the ammonia concentration in the atmospheric gas becomes equal to or higher than a predetermined reference value. The alarm generation section 59 generates an alarm sound in response to an alarm signal given from the data processing section 58. When the second measurement port 32 and the concentration determiner 34 are set to the conducting state, the control unit 11 performs the processing of the substrate in the substrate processing unit 1 in response to the alarm signal given from the data processing unit 58. Stop. The density determiner 34 in FIG. 3 has a simple configuration, and can be manufactured at low cost and small size.

The alarm generator 47, shown in FIGS.
Reference numeral 59 denotes an alarm sound as an alarm.
7, 59 may turn on or blink a display such as a lamp as an alarm.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of a configuration of a density determiner.

FIG. 3 is a block diagram showing another example of the configuration of the density determiner.

FIG. 4 is a schematic view of a conventional substrate processing apparatus.

FIG. 5 is a block diagram illustrating an example of an ion chromatograph analysis system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate processing part 2 Atmosphere adjustment part 3 Air concentration management system 11 Control part 21 Primary filter 22 Blower 23 Secondary filter 31 First measurement port 32 Second measurement port 33 Three-way valve 34 Concentration determination device 35, 36 Piping 41, 42, 51 Transparent pipe 43, 52 pH test paper 44 Light source 45 Light receiving element 46 Comparison unit 47, 59 Alarm generation unit 53-57 Reflection type sensor 58 Data processing unit

Claims (8)

[Claims] A substrate processing unit for performing a predetermined process on the substrate; an atmosphere gas supply unit for supplying a clean atmosphere gas to the substrate processing unit; and an atmosphere gas passing through the atmosphere gas supply unit or the substrate. A substrate processing apparatus comprising: a determination unit configured to determine whether a concentration of a predetermined substance in an atmospheric gas in the processing unit is equal to or higher than a predetermined reference value. 2. The substrate according to claim 1, further comprising an alarm generating unit that generates an alarm when the determination unit determines that the concentration of the predetermined substance is equal to or higher than the reference value. Processing equipment. 3. The apparatus according to claim 2, further comprising control means for stopping processing by said substrate processing unit when said determination means determines that the concentration of said predetermined substance is equal to or higher than said reference value. 3. The substrate processing apparatus according to 1 or 2. 4. An atmosphere gas introducing means for guiding an atmosphere gas passing through the atmosphere gas supply means or an atmosphere gas in the substrate processing unit to a pH indicator, and detecting a change in color of the pH indicator. 2. A method according to claim 1, further comprising: detecting means; and density determining means for determining whether or not the concentration of the predetermined substance is equal to or higher than the reference value based on a change in color detected by the detecting means. ,
4. The substrate processing apparatus according to 2 or 3. 5. The atmosphere gas supply unit includes: a removal unit that removes a predetermined substance in the atmosphere gas; and an air supply unit that sends the atmosphere gas that has passed through the removal unit to the substrate processing unit. The means includes: a first measurement port for sampling an atmosphere gas on the downstream side of the removal means; a second measurement port for sampling an atmosphere gas in the substrate processing unit; and a sampling by the first or second measurement port. Concentration determining means for determining whether or not the concentration of the predetermined substance in the measured atmosphere gas is equal to or higher than the reference value; and selectively selecting one of the first and second measurement ports. 4. The substrate processing apparatus according to claim 1, further comprising: a switching unit that conducts the current to the substrate. 6. An air concentration management system for managing a concentration of a predetermined substance in an atmosphere gas in a substrate processing apparatus, wherein: a sampling unit for sampling an atmosphere gas in the substrate processing apparatus; Atmosphere gas introducing means for guiding the collected atmosphere gas to a pH indicator; detecting means for detecting a change in color of the pH indicator; and a concentration of the predetermined substance based on the change detected by the detecting means. A concentration determining means for determining whether or not the concentration is equal to or more than a reference value. 7. The detecting means includes: a light irradiating means for irradiating the pH indicator with light; and a light receiving means for receiving a reflected light of the light applied to the pH indicator. 7. The air concentration management system according to claim 6, wherein whether or not the concentration of the predetermined substance is equal to or higher than the reference value is determined based on an amount of light received by a light receiving unit. 8. The transparent pipe is filled with the pH indicator, the atmosphere gas introducing means guides the atmospheric gas collected by the collecting means to one end of the pH indicator in the transparent pipe, and the detecting means A plurality of detection means arranged along the transparent pipe and irradiating a pH indicator in the transparent pipe with light to detect a change in color based on the reflected light; 7. The air concentration management system according to claim 6, wherein whether or not the concentration of the predetermined substance is equal to or higher than the reference value is determined based on a time difference between detection timings of the detection means.