Device and method for detecting nitrogen trifluoride

Abstract

The invention relates to a device and method for detecting nitrogen trifluoride. The device for detecting nitrogen trifluoride comprises a high-temperature cracking furnace, a conversion pipe, a nitrogen dioxide sensor air chamber and an air extracting pump, wherein the high-temperature cracking furnace, a selective filter, the conversion pipe, a nitrogen dioxide sensor and the air extracting pump are sequentially connected through a pipe; a conversion agent is contained in the conversion pipe; and the nitrogen dioxide sensor is arranged in the nitrogen dioxide sensor air chamber. The method for detecting nitrogen trifluoride comprises the steps of (1) introducing air mixed with nitrogen trifluoride into the high-temperature cracking furnace, implementing cracking reaction, and cooling generated gas in a pipeline; (2) converting nitric oxide into nitrogen dioxide through the conversion agent in the conversion pipe; (3) detecting by the nitrogen dioxide sensor and outputting an electric signal; and (4) calculating concentration of the nitrogen trifluoride according to the detected electric signal and air inflow of the high-temperature cracking furnace in the step (1). The device is little in interference gas, does not use catalysts and is low in cost.

Description

technical field [0001] The invention belongs to the field of nitrogen trifluoride detection, in particular to a device and method for detecting nitrogen trifluoride. Background technique [0002] Nitrogen trifluoride is an industrial special gas, mainly used as propellant (rocket), fluorinating agent, electron gas, plasma etching and for doping, laser, optical fiber, etc. Especially as an excellent plasma etching gas, it is widely used in today's rapidly developing microelectronics field. At the same time, nitrogen trifluoride is a toxic substance with strong oxidizing properties, and can react strongly with reducing agents, causing combustion and explosion. Therefore, the leak analysis and detection of nitrogen trifluoride is not only the need of production safety, but also the need of environmental protection. At present, catalytic thermal cracking + electrochemical method is a good method for analyzing nitrogen trifluoride. This method uses catalytic and high temperatur...

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Problems solved by technology

However, at present, the foreign nitrogen trifluoride analysis instruments developed using this principle (there is no such instrument in China), all use catalysts in thermal cracking without exception. Although this method realizes nitrogen trifluoride at a lower temperature However, due to the use of catalysts, the decomposition products are very complex, and the target detection gas required by the sensor behind - the nitrogen dioxide content is small, but there are many interfering gases, which ultimately makes the overall performance of the instrument not good enough. The result is not ideal

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