Thin film process monitoring techniques using acoustic waves

摘要

A system and method is disclosed for measuring thickness of at least one film on a substrate by propagating an acoustic wave through the film on a substrate such that echo waves are generated and received by a transducer. An output signal is generated and processed to give a thickness value. The thickness valve is obtained from the time lapse between the propagated wave and receipt of the echo wave; by the frequency domain of the echo wave; or the phase of the echo wave.