ON-SITE MANUFACTURE OF ULTRA-HIGH-PURITY NITRIC ACID FOR SEMICONDUCTOR PROCESSING

摘要

A system and method for semiconductor manufacture using on-site distillation to obtain ultra pure nitric acid from technical grade starting material. The source material for distillation (T-3) is provided at a concentration higher than that of the high boiling point azeotrope, so that dilution does not occur during condensation (C-1). A reflux condenser (CD-1) is used, with a purge of at least 5 % to prevent impurities from accumulating. This is performed on site, at a semiconductor manufacturing facility and the ultrapure chemical thus generated is routed directly, through ultraclean piping, to the point of use in a semiconductor front end (T-5).