POSITION SENSOR OF WAFER FOR HEATER STAGE

摘要

PURPOSE: A position sensor of a wafer for a heater stage is provided to prevent a defect of the wafer and a breakdown of the heater stage by detecting a position error of the wafer placed on the heater stage before a fabricating process is performed. CONSTITUTION: The position sensor of the wafer(12) for the heater stage(14) detects the position state of the wafer placed on the heater stage installed in a chamber(10). A plurality of gas holes(16) are formed along the outer end portion so as to be connected to the inside of the chamber when a position error occurs in the wafer. A gas supply member(18) including a pressure gauge(20) is connected to each gas hole.