An investigation of surface state capture cross-sections for metal-oxide-semiconductor field-effect transistors using HfO_2 gate dielectrics

摘要

MOSFETs and MOSCs incorporating HfO_2 gate dielectrics were fabricated. The I_(DS)-V_(DS), I_(DS)-V_(GS), gated-diode and C-V characteristics were investigated. The subthreshold swing and the interface trap density were obtained. The surface recombination velocity and the minority carrier lifetime in the field-induced depletion region measured from the gated diodes were about 2.73 × 10~3 cm/s and 1.63 × 10~(-6) s, respectively. The effective capture cross section of surface state was determined to be 1.6 × 10~(15) cm~2 using the gated-diode technique in comparison with the subthreshold swing measurement. A comparison with conventional MOSFETs using SiO_2 gate oxide was also made.