Corrosive and Toxic Gas Abatement in Vacuum Systems
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19
A vacuum system design that minimizes exposure of pump fluids to corrosive, toxic, and reactive species is described. It incorporates a gate valve and spool section between the diffusion pump and the liquid nitrogen (LN2) trap, two parallel foreline traps, and a filter system. The system provides for extended life operation of the mechanical pump, using cheaper but superior (in terms of lubricity) mineral oils. In a ferrite reactive-ion-etching process, a manganese-zinc ceramic is etched to predefined dimensions in a planar diode system using a carbon tetrachloride (CCL4)-argon gas mixture (Fig. 1). During a run that lasts a couple of hours, the etch gas mixture (CCL4-Ar) is introduced into the system at a finite rate. Mechanical and diffusion pumps both utilize perfluoroether-type fluids.