JPH0617900B2 - Selective detection agent - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydrogen selenide detection agent, and more specifically, it selectively detects hydrogen selenide, the amount of which has recently been increasing in the semiconductor manufacturing industry. It relates to a possible detection agent.

Hydrogen selenide is being used in increasing amounts as a source gas in the production of compound semiconductors such as ZnSe or as a Se source as a dopant in GaAs devices. Thus hydrogen selenide is a useful compound,
On the other hand, since it is extremely toxic (allowable concentration 0.05 ppm) and flammable, it must be handled with caution.

To maintain the safety of the work environment, it is necessary to constantly measure the work environment, and in the unlikely event that these gases leak, it is necessary to take appropriate measures so that the worker can be informed.

In addition, the gas discharged from the semiconductor manufacturing process contains these gases, and it is necessary to process them using a detoxification device.

[Conventional technology]

As a method for detecting hydrogen selenide, a detection tube in which a glass tube is filled with a detection agent has been conventionally known, and the fact that the detection agent is discolored by the reaction between the detection agent and hydrogen selenide is used. As the detection agent, a detection tube for hydrogen selenide is used in which gold chloride is supported on silica gel particles. This detector, which is originally pale yellow, turns blackish brown when it comes into contact with a gas containing hydrogen selenide. However, this detector shows a similar discoloration when it comes into contact with phosphine, arsine or diborane, and it is inconvenient to use it as a detector for hydrogen selenide when these gases may coexist. .

Furthermore, since an expensive gold compound is used as a raw material, it is not economically advantageous.

[Problems to be solved by the invention]

An object of the present invention is to obtain a detection agent capable of selectively detecting only hydrogen selenide even in the coexistence of a hydrogen compound-based gas such as arsine, phosphine and diborane.

[Means for solving problems]

The present inventors have conducted intensive studies to solve the problems of the prior art, and as a result, have found that a cobalt (II) salt is excellent as a discoloring component and arrived at the present invention.

That is, the present invention relates to the inorganic acid or organic acid cobalt (I
I) A selective detection agent for hydrogen selenide, which comprises a salt as a color-changing component and the color-changing component supported on a carrier.

The detection agent of the present invention is nitrogen gas, hydrogen gas, argon gas,
It can be used to detect hydrogen selenide in a gas containing hydrogen selenide in helium gas and air, or in a gas containing these gases further containing a hydride-based gas such as arsine, phosphine and diborane.

When the sensing agent of the present invention is brought into contact with these gases, it is sensitively discolored depending on the hydrogen selenide in the gas, but even if it is brought into contact with phosphine, arsine or diborane which is a hydride gas like hydrogen selenide. Does not discolor, or is very sensitive to discoloration.

In the present invention, a cobalt (II) salt of an inorganic acid or an organic acid is used as the discoloring component. Cobalt sulfate,
Cobalt nitrate, cobalt chloride, cobalt acetate, and cobalt naphthenate are preferable, and among these, water-soluble inorganic acid salts and cobalt acetate are particularly preferable.

In the present invention, the cobalt (II) salt, which is a color change component, is supported on a carrier to serve as a detection agent. The type of carrier can be selected from a wide range, and examples thereof include white to colorless silica gel, ordinary catalyst carriers such as silica alumina and α-alumina, and paper. Among these, silica gel, silica alumina and α-
Catalyst support is preferred, such as alumina, typically have a specific surface area of 800 m ² / g or less, preferably of less than 2m ² / g is used.

The carrier may be prepared, for example, by dissolving the color-changing component in water or an organic solvent and immersing the carrier in these solutions, or by spraying these solutions on the surface of the carrier to carry them. A commercially available desiccant or the like carrying a cobalt (II) salt may be usually used as it is. The supported amount is not particularly limited, but the cobalt compound is 0.01 to 10 parts by weight, preferably 0.01 to 100 parts by weight of the carrier.
~ 3 parts by weight.

The detection agent carrying the color-changing component changes from blue to black when brought into contact with hydrogen selenide. The black color is maintained for about a week even if left in air or nitrogen gas, and then gradually turns red.

The detection limit concentration of hydrogen selenide as a detection agent has a lower limit of 1 ppm and can be detected even if the upper limit is 100%.

The flow velocity of the gas to be brought into contact with the detection agent is usually 0.0 in linear velocity.
It is 1 to 100 cm / sec. The concentration and pressure of the gas at the time of contact are usually -20 to 100 ° C and 0.001 to 20.
It is kg / cm ² abs.

The detection agent of the present invention is a solid and is usually used by putting it in a transparent container (usually a tube), and the presence of hydrogen selenide in the system can be selectively known by the color change of the detection agent. The detection agent of the present invention can be used even if it is put in a detection tube, but it can also be used in a simpler form. For example, the presence of hydrogen selenide in the gas can be easily detected by putting it in a transparent container such as glass or plastic and passing the gas through the container. In this case, the detecting agent is put in the removing cylinder of the hydride gas containing hydrogen selenide after the removing agent layer or between a plurality of layers, or is put in the detecting cylinder and the detecting cylinder is connected after the removing cylinder. Used as is.

[Action, effect]

The detection agent of the present invention is sensitive to discoloration by contact with hydrogen selenide contained in the gas, while almost all discoloration is caused by hydride-based gas which is frequently contained at the same time such as arsine, phosphine and diborane. Therefore, the presence of hydrogen selenide in the gas in the semiconductor industry can be selectively and accurately known.

Example 1 1 g of blue silica gel small particles for drying (Kanto Chemical first grade) impregnated with commercially available cobalt chloride as a detection agent, an inner diameter of 13 mm,
The container was filled with a transparent vinyl chloride resin container having an outer diameter of 18 mm and a length of 50 mm. 200% nitrogen gas containing 1% hydrogen selenide
The discoloration was observed by passing through the container at a speed of mmin. Immediately after the start of distribution, the blue silica gel layer began to turn black from the gas inlet side, and after about 2 minutes, the entire silica gel layer turned black.

Comparative Examples 1, 2, 3 As in Example 1, phosphine was used only for circulation.
Arsine or diborane, each having a concentration of 1%, contained in nitrogen and contacted in the same manner as in Example 1,
The state of discoloration was observed. In the case of any of the gases, even if the gas was allowed to flow for 15 minutes, the detection agent remained blue and no discoloration occurred.

Example 2 α-alumina (5218, 3/16 inch, manufactured by Norton Co.) was impregnated with a 5% aqueous solution of cobalt acetate and dried to obtain α-.
A blue detector having 1 wt% cobalt acetate supported on alumina was prepared. Under the same conditions as in Example 1, the hydrogen selenide concentration was set to 10 ppm and the state of discoloration was observed.

Black discoloration started about 2 minutes after the start of distribution, and the whole discolored black after 10 minutes.

Claims (1)

[Claims] 1. A selective detection agent for hydrogen selenide, which comprises a cobalt (II) salt of an inorganic acid or an organic acid as a color-changing component, and the color-changing component is supported on a carrier.