Experimental investigation of silicon-on-insulator metal-oxide- semiconductor field-effect transistors at high magnetic field and low temperature

Abstract

Shubnikov–de-Haas (SDH) oscillations as well as low-temperature measurements have been systematically performed in order to characterize thin-film silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFETs). The two-dimensional properties of the SOI MOS inversion layers highly depend on the quality of the front and buried Si-SiO2 interfaces. The influence of interface coupling on the quantized SDH oscillations is assessed. Even in 70 nm thin films, the carriers remain essentially confined to the lowest subband at an interface. Parasitic effects such as series resistance influence have been carefully examined in the case of short-channel devices. It is also shown that for submicronic devices, the attenuation of the oscillations as a function of the lateral electric field strongly increases with channel length. Eventually, it is demonstrated that unlike conventional bulk silicon MOSFETs, a fully depleted SOI MOSFET allows studying charge localization in MOS inversion layers, without needing any temperature variation to estimate the density of localized electrons.