건식저진공펌프의 진공계통 부식 및 개선연구

Abstract

Vacuum system of Primary dry pump is composed of cast iron mainly even each vacuum pump maker has different type of complex structure with various pressure and temperature. Increased mass usage of Cl-based etchant and F-based etchant which used for main source of etching and chamber cleaning process induced serious problem through corrosion on vacuum system of Primary dry pump. Corrosion on vacuum system makes insufficient pumping ability and clogging failure by touching between rotor and stator because of very narrow space between rotor and stator on vacuum system. Cl-based etchant which used for etching process for a long time caused volatilization as FeCl2 after surface corrosion on vacuum system but F-based etchant which used for chemical etching process and chamber cleaning induced weight and diameter increase of rotor and shaft creating absorbed chemical combination following surface corrosion on vacuum system. SEM, EDS and XRD analysis showed that this chemical combination had Fluorine at a high rate and the composition was FeFx as bright color.