Charge pumping and DCIV currents in SOI FinFETs

FinFETs on silicon on insulator (SOI) substrates are promising candidates for ultimately scaled CMOS devices at and beyond the 22 nm technology node [1]-[3]. Charge pumping (CP) and DCIV measurements are routinely used to determine MOS gate oxide interface trap densities on bulk devices [4], and have also been applied to SOI devices with body contacts or gated diode structures with modified contacts and/or doping [5]. Charge pumping measurements are usually not performed on conventional FinFET devices with a floating body [5], because there is no substrate contact. We have investigated charge pumping (ACIV) and DCIV currents in floating body n-channel FinFETs. These flow into or out of (depending on bias) the monitored drain and source contacts. The currents depend on frequency, gate voltage, and geometry. The change in ACIV current with frequency before and after electrical stress allows estimates of stress-induced interface trap densities in SOI FinFETs.