Title:
PROCESS FOR PURIFYING NITROGEN TRIFLUORIDE GAS
Document Type and Number:
WIPO Patent Application WO/1991/004942
Kind Code:
A1
Abstract:
A process for purifying a nitrogen trifluoride gas according to the invention comprises heating a NF3 gas containing N2F2 as an impurity to a specific temperature in a vessel lined with a tough passivated nickel fluoride coating. This process enables the removal of N2F2 gas at a high rate with a small loss of NF3. Thus, a high-purity NF3 gas favorable as a starting material for a dry etching agent for semiconductors can be obtained with ease and safety by again purifying the NF3 gas, which has been purified by this process, using a known adsorbent.
Inventors:
HARADA ISAO (JP)
HOKONOHARA HISASHI (JP)
YAMAGUCHI TOSHIAKI (JP)
HOKONOHARA HISASHI (JP)
YAMAGUCHI TOSHIAKI (JP)
Application Number:
PCT/JP1989/001038
Publication Date:
April 18, 1991
Filing Date:
October 09, 1989
Export Citation:
Assignee:
MITSUI TOATSU CHEMICALS (JP)
International Classes:
C01B9/08; C01B21/083; H01L21/3065; (IPC1-7): C01B21/083
Foreign References:
| JPS5915081B2 | 1984-04-07 | |||
| JPH01261206A | 1989-10-18 | |||
| JPH01261208A | 1989-10-18 |
Other References:
See also references of EP 0543009A1
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