VACUUM EQUIPMENT FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A vacuum equipment is provided to prevent defects on a wafer and an inner contamination of a chamber from being produced by preventing an inflow into the chamber of an alien substance inside a pump line. CONSTITUTION: A vacuum pump(32) is connected to a pump line, and makes a high vacuum state in a chamber(31). An isolation valve(34) closes and opens the pump line to maintain an inner vacuum state of the chamber(31). A ballast gas supplying part(35) supplies the vacuum pump with a ballast gas, and has a ballast valve(38) so as to prevent the vacuum pump from being damaged. A ballast valve driving part(39) supplies the ballast valve(38) with a driving gas to operate the ballast valve(38). A delay timer(44) delays an operating time of the ballast valve so as to prevent the ballast gas from being flown in the chamber.