Capacitance-frequency Estimates of Border-trap Densities in Multi-fin MOS Capacitors

Abstract

This thesis focuses on radiation effects of multi-fin MOS capacitors with high-K dielectrics built in Ge and InGaAs FinFET technologies. Capacitance-frequency (C-f) measurements are applied to provide lower-bound estimates of border-trap densities in these devices before and after X-ray irradiation. The method is illustrated for SiO2-based planar MOS capacitors, and compared with high-frequency capacitance-voltage (C-V) measurements. Lower border-trap densities are found before and after irradiation for multi-fin capacitors built in a strained Ge pMOS FinFET technology than for similar devices built using an early-developmental stage InGaAs MOS technology. These results show the utility of C-f measurements in characterizing defect densities in MOS capacitors, particularly when large border-trap densities exist.