Field-Effect Mobility of InAs Surface Channel nMOSFET With Low Scaled Gate-Stack

Frequency (100 MHz) and temperature ( ) characteristics of low interface state density high- gate-stacks on n-InAs have been investigated. Capacitance–voltage ( – ) curves exhibit typical accumulation/depletion/inversion behavior with midgap of and cm eV at −50 °C and 20 °C, respectively. Asymmetry of low-frequency s – curves and – dependence for negative voltage showing a sharp transition of dB/decade between low- and high-frequency behavior indicate surface inversion. An inversion carrier activation energy and an InAs hole lifetime of 0.32 eV and 2 ns have been extracted, respectively. Surface - hannel nMOSFETs with gate length 1 , channel thickness = 10 nm, and equivalent oxide thickness (EOT) nm have been fabricated. For nm, a subthreshold swing mV/decade, transconductance mS/ , and ON-current 426 at an OFF-current nA/ (supply voltage 0.5 V) have been measured. Peak electron field-effect mobilities of 6000–7000 cm /Vs at sheet electron densities of 2– cm were obtained for EOT as small as 1 nm.