Terahertz imaging of silicon wafers

Silicon samples with and without implanted layers have been imaged with a standard time-domain terahertz (THz) imaging system. The carrier concentration and mobility of the substrate have been extracted from the frequency dependence of the THz transmittance using a simple model based on the Drude approximation. The carrier concentration of implanted layers could be determined simply from the relative amplitude of the main THz pluse with a spatial resolution of approximate to1 mm. Both substrates and thin layers of a semiconductor were characterized with the same THz system. (C) 2002 American Institute of Physics.