Nondestructive rapid measurement of GaAs, GaN, SiC, and Si semiconductors using one tunable terahertz source

The carrier density was determined from the reflectance measurement using one or two waves in the reflective spectra of semiconductors. The mapping of Si was carried out at the rate of 2 s per point. The tunable terahertz (THz) source was able to generate the THz-wave in the range from 2.5 to 30 THz.