Highly purified ammonia for use in semiconductor manufacturing is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous ...http://www.google.fr/patents/US6001223?utm_source=gb-gplus-shareBrevet US6001223 - On-site ammonia purification for semiconductor manufacture
On-site ammonia purification for semiconductor manufacture
