Methods for nondestructive measurement of thickness of underlying layer

摘要

A method of nondestructive measurement of the underlying film thickness is provided. The method comprises irradiating a pump laser pulse to a sample comprising a substrate, a lower film on the substrate, and an upper film on the lower film, irradiating a probe laser pulse to the sample, and reflectance of the sample to the probe laser pulse. And measuring a change as a function of time to obtain a first graph recording a change in reflectance as a function of time, and obtaining the thickness of the sub-film from the first graph.