Method of Characterizing Layer Thickness

Abstract

A method of characterizing thickness of at least one layer of a material includes irradiating the material with a THz pulse such that at least a portion of the THz pulse is reflected from the material as a reflected THz signal; acquiring a time-domain waveform of the reflected THz signal; fitting the time-domain waveform to a superposition of waveforms to determine pluralities of amplitudes and time shifts where each waveform in the superposition of waveforms is a reference waveform scaled by an amplitude in the plurality of amplitudes and time shifted by a time shift in the plurality of time shifts; and determining a proportional thickness of at least one layer of the material from a corresponding difference between two time shifts in the plurality of time shifts.

Dependencies are inferred from the claim text.