Carrier-density-wave transport and local internal electric field measurements in biased metal-oxide-semiconductor n-Si devices using contactless laser photo-carrier radiometry

Abstract

Laser infrared photo-carrier radiometry was used with an n-type Si metal-oxide-semiconductor (MOS) diode and with a Si–SiO2 structure with a transparent electrode and under external bias. Application of three-dimensional PCR theory yielded values of the minority carrier (hole) transport properties in the presence of the thus created local internal electric field at fixed frequencies. Furthermore, the internal electric field at fixed applied voltage was calculated. Under the combination of increased temperature and voltage, the sub-interface position of the carrier-density-wave centroid was found to depend on a trade-off between increased recombination lifetime and decreased ambipolar (conductivity) mobility. The ability of PCR to measure local internal electric fields by combining applied bias sweeps and frequency scans appears to pave the way towards the contactless reconstruction of depth profiles of these fields in active devices.