Method for purifying gas of nitrogen trifluoride

Abstract

A process for purifying NF3 gas containing N2F2, which is generated by electrolysis method, includes such steps as loading one or more of Fe, stainless steel, Cu, Ni and Monel alloy in cracking tower, heating to 100-400 deg.C, filling the gas mixture of NF3 and N2F2, and removing N2F2 by its high-temp decomposing.

Description

(1) Technical field [0001] The invention relates to a purification method of nitrogen trifluoride gas, which is suitable for NF prepared by electrolysis. 3 Gas purification. (2) Background technology [0002] NF 3 As a source of fluorine, gas is widely used in the fields of high-energy lasers and semiconductor industries, and has good application prospects. As the cleaning gas in the plasma CVD (‘chemical vapor deposition’ chemical vapor deposition) chamber and the etching gas in the plasma CDE (‘chemical deposition etch’ chemical deposition etching) process, NF 3 The gas is called "electronic gas". High purity NF 3 Gas is vital to the production of semiconductor components, and VLSI is critical to NF 3 The gas purity is required to be above 99.99%. [0003] NF prepared by electrolysis 3 N in the gas 2 F 2 Impurities are easily decomposed into N during the purification process 2 And F 2 If N 2 F 2 Impurities are enriched in the purification equipment to a certain extent, N 2 F 2 ...

AI Technical Summary

Problems solved by technology

Thermal cracking to release N 2 f 2 Impurity gas refers to the gas that will contain N 2 f 2 NF of impurities 3 The gas is passed through a high temperature vessel to make N 2 f 2 decomposition, but this method is prone to NF 3 decomposition