VACUUM CHUCK APPARATUS OF SEMICONDUCTOR FABRICATION EQUIPMENT

摘要

PURPOSE: A vacuum adsorption unit in a semiconductor manufacturing equipment is provided to sense correctly an adsorbing state of an object by using a digital vacuum sensor for sensing a state of adsorption of a wafer or a reticle. CONSTITUTION: A digital vacuum sensor(34) is installed at a vacuum line(32) for providing a vacuum state. The digital vacuum sensor(34) senses an adsorbing state of an object by utilizing an internal pressure of the vacuum line(32). A reference voltage stabilizing circuit(38) outputs a reference voltage of a predetermined level. A comparison portion(36) compares the reference voltage with a sensing signal of the digital vacuum sensor(34) and outputs a comparing signal about the adsorbing state.