VACUUM PRESSURE CONTROL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a vacuum pressure control system capable of preventing particles from flying up within a vacuum vessel and of controlling freely the vacuum pressure changing speed in the vessel when the vessel is to be filled with gas. SOLUTION: Vacuum pressure values changed relative to the vacuum pressure in a reaction chamber measured by a vacuum pressure sensor at a target vacuum pressure changing speed acquired at S24 are generated step by step as internal commands (S26). Feedback control is executed as followup control (S27) by changing the target value for feedback control one after another (S26) while the internal commands generated one by one are used as the target values for feedback control. Thereby the vacuum pressure in the reaction chamber can be changed uniformly at the target vacuum pressure changing speed.