JP2573554B2 - Hazardous gas detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agent for detecting harmful gas, and more particularly to an agent for detecting harmful gas components handled in semiconductor manufacturing factories.

[0002]

2. Description of the Related Art In recent years, in semiconductor manufacturing plants and the like, volatile inorganic hydrides, volatile inorganic halides, volatile amine compounds, organometallic compounds, and the like have various odors, explosion hazards, or toxicity to human bodies. Dealing with various gases.
Therefore, measures such as prevention of leakage of these harmful gases and elimination of exhaust gas containing these harmful gases have been taken.

[0003] In the above-mentioned harmful gas leakage prevention and abatement measures, various detecting agents have conventionally been used to detect even when these harmful gases are present in minute amounts. As one means for easily detecting leakage, a method using a detection tube filled with a detection agent is known. In addition, after the exhaust gas containing the harmful gas is subjected to detoxification treatment by a detoxifying cylinder or the like filled with the detoxifying agent, the detection tube filled with the detecting agent is also used to confirm that the exhaust gas is appropriately detoxified. The exhaust gas after the treatment is circulated.

Hitherto, research and development have been actively conducted on detection agents mainly for detecting volatile inorganic hydrides such as silane, arsine, and phosphine. For example, the main component of the reaction is a mixture of a copper salt, a nickel salt or a zinc salt with a gold salt (JP-A-2-32254, JP-A-5-60126, and JP-A-5-226008); The one with copper as the main reaction component
JP-79576-A), a compound containing a copper salt of an organic acid as a main reaction component (Japanese Patent Publication No. 4-79577), and a mixture containing a mixture of a cupric salt and a palladium salt as a main reaction component (JP-B-4-79577). No. 79578), those containing copper nitrate as the main reaction component (JP-A-4-97752), those containing an acidic / basic indicator as the main reaction component (JP-A-62-19765), and many others. Sensing agents are known.

However, as the organometallic compound detecting agent, a mixture containing a mixture of a cupric salt and a gold salt as a main component is disclosed in JP-A-2-110369 and JP-A-2-110370.
However, the fact is that development is delayed.

[0006]

The above-mentioned various conventional detection agents have their advantages and disadvantages, and need to be properly used depending on the environment, the gas to be detected, and the like. Does not have an appropriate detection agent.

For example, those using a gold salt as a main component of the reaction
There is a problem that it is unstable to light or heat, easily discolored, and erroneous in determination. In particular, there is a disadvantage that it is reduced by hydrogen gas and blackened. Further, those containing a copper salt as a main component of the reaction have a low discoloration sensitivity. In particular, basic copper carbonate is highly toxic and requires careful handling.

Further, when the exhaust gas contains an organometallic compound, there is a problem that labor and cost are required, such as the necessity of means for analyzing the exhaust gas.

Accordingly, the present invention is widely applied to harmful gas components generally used in semiconductor manufacturing factories, such as volatile inorganic hydrides, volatile inorganic halides, volatile amine compounds, and organometallic compounds. It is an object of the present invention to provide a detection agent that can perform the detection.

[0010]

Means for Solving the Problems To achieve the above object, the harmful gas detecting agent of the present invention comprises bismuth chloride (B
It is characterized by using iCl ₃ ) as a color-changing component, and further comprising a mixture of bismuth chloride and an acidic or basic indicator as a main component.

The above-mentioned bismuth chloride is a colorless to white substance, and when it comes into contact with volatile inorganic hydrides such as arsine and phosphine, the color quickly changes to black. Also,
Bismuth chloride is a chemically stable compound, has no toxicity, is easy to handle, and does not discolor even on contact with hydrogen gas.

In addition, bismuth chloride is not limited to volatile inorganic hydrides, but also volatile inorganic halides such as phosphorus chloride and arsenic chloride; volatile amine compounds such as trimethylamine;
Furthermore, it has the ability to detect organometallic compounds such as metal alkyl compounds and metal alkoxides.

This bismuth chloride can be used as a powder or supported on an appropriate carrier. Usually, this is used by filling at least a part thereof in a transparent cylinder (column).

On the other hand, when bismuth chloride is used alone, discoloration is somewhat slow with respect to silicon compounds such as silane, which is a kind of volatile inorganic hydride, but bismuth chloride is mixed with an acidic or basic indicator. By doing so, the sensitivity to the silicon compound can be improved. Therefore, the mixing of an acidic or basic indicator may be selected according to the possibility that the silane compound is contained in the exhaust gas.

As the acidic or basic indicator, those which have been widely used can be used.
For example, methanil yellow, thymol blue, tropeolin OO, 2,2-dinitrophenol, methyl yellow,
Bromophenol blue, methyl orange, Congo red, alizarin S, bromocresol green, 2,
5-dinitrophenol, methyl red, lacmoid,
p-nitrophenol, chlorophenol red, bromocresol purple, bromothymol blue, phenol red, rosolic acid, neutral red, cresol red, phenolphthalein, o-cresolphthalein, thymolphthalein, alizarin yellow G
G, tropeolin O, nitramine, 1,3,5-trinitrobenzene, xylene cyanol FF, methylene blue, litmus and the like can be used.

[0016]

EXAMPLES Examples and comparative examples of the present invention will be described below. Example 1 After dissolving bismuth chloride in ethanol, it was impregnated with silica gel (Carrierct 10, manufactured by Fuji Silysia Ltd .; the same applies hereinafter) and dried in vacuum at 40 ° C. for 5 hours to obtain a detection agent having bismuth chloride supported on silica gel. . At this time, the content of bismuth chloride was 1% by weight. This detection agent is packed in a column with an inner diameter of 30 mm, and phosphine is added at 10 ppm.
When a hydrogen gas containing the gas was passed, the color changed from white to black in about 1 minute.

Example 2 Methyl orange was dissolved in hot water and impregnated in silica gel, dried under vacuum at 40 ° C. for 5 hours, further impregnated with an ethanol solution of bismuth chloride, and dried under vacuum at 40 ° C. for 5 hours. The detection agent was a mixture of bismuth and an indicator.

This detecting agent was used in the same manner as in Example 1,
When a hydrogen gas containing 10 ppm of phosphine was charged into a column having a diameter of 10 mm, the color changed from yellow to red-black in about 1 minute. When a hydrogen gas containing 10 ppm of silane was supplied, the color changed from yellow to red in about 2 minutes.

Example 3 Bismuth chloride and phenolphthalein were dissolved in ethanol and impregnated in silica gel, followed by vacuum drying at 40 ° C. for 5 hours to obtain a detector comprising a mixture of bismuth chloride and an indicator. This detecting agent was used in an inner diameter of 3 as in Example 1.
When the column was packed into a 0 mm column and a hydrogen gas containing 10 ppm of phosphine was flowed, the color changed from white to black in about 1 minute.

Comparative Example 1 Chloroauric acid and copper sulfate were dissolved in water, impregnated with silica gel, and dried at 40 ° C. for 5 hours under vacuum to obtain a detecting agent.
At this time, the contents of chloroauric acid and copper sulfate are each 0.1.
1% by weight and 1% by weight. In addition, since a large amount of chloroauric acid will cause blackening immediately, the amount of chloroauric acid is reduced.

This detecting agent was used in the same manner as in Example 1,
The column was packed with hydrogen gas containing 10 ppm of phosphine.
It took 0 minutes. In the case of hydrogen gas containing silane at 10 ppm, it took about 60 minutes to change from white to black.

Comparative Example 2 Basic copper carbonate was sprinkled on silica gel and vacuum dried at 40 ° C. for 5 hours to obtain a detecting agent. At this time, the content of the basic copper carbonate was 1% by weight. This detection agent was packed in a column having an inner diameter of 30 mm in the same manner as in Example 1, and phosphine was added to the column.
Although hydrogen gas containing 0 ppm was supplied, it took about 10 minutes to change from light green to black.

Comparative Example 3 Copper nitrate was dissolved in water and impregnated with silica gel.
It was vacuum-dried at 5 ° C. for 5 hours to obtain a detecting agent. At this time, the content of copper nitrate was 1% by weight. This detection agent was packed in a column having an inner diameter of 30 mm in the same manner as in Example 1, and a hydrogen gas containing 10 ppm of phosphine was supplied. It took about 60 minutes to change from blue to black. In addition, 1 silane
In the case of hydrogen gas containing 0 ppm, it took about 60 minutes to change from blue to black.

Example 4 As harmful gas components, arsine in volatile inorganic hydrides, dichlorosilane and boron trichloride in volatile inorganic halides, tertiary butylarsine and trimethylaluminum in organometallic compounds were used. , Each one
Using a hydrogen gas containing 0 ppm, the discoloration state of the detection agent of Example 1 (detection agent 1) and the detection agent of Example 2 (detection agent 2) were observed. The results are shown below.

Hazardous gas component Detecting agent 1 Detecting agent 2 Arsine white → black (1 minute) Yellow → black (1 minute) Dichlorosilane white → black (5 minutes) Yellow → red black (3 minutes) Boron trichloride white → black ( 5 minutes) yellow → red black (3 minutes) tertiary butyl arsine white → black (2 minutes) yellow → black (2 minutes) trimethyl aluminum white → black (2 minutes) yellow → black (2 minutes)

Example 5 As a harmful gas containing a volatile amine compound, hydrogen gas containing 10 ppm each of ammonia and trimethylamine was used, and the discoloration state of the detecting agent of Example 3 was observed. As a result, in both cases of ammonia and trimethylamine, the color changed from white to pink in about 2 minutes.

[0027]

As described above, the harmful gas detecting agent of the present invention containing bismuth chloride as a color-changing component can be used by mixing it with an acidic or basic indicator if necessary.
Various harmful gas components such as volatile inorganic hydrides, volatile inorganic halides, volatile amine compounds and organometallic compounds can be detected with certainty. In addition, they are chemically stable compounds and have no toxicity. Is also easy.

Claims (2)

(57) [Claims] 1. A detecting agent for harmful gases, comprising bismuth chloride as a discoloring component. 2. An agent for detecting harmful gases, comprising as a main component a mixture of bismuth chloride and an acidic or basic indicator.