Investigation of Surface Channel InGaAs MOSFETs with Al2O3 and ZrO2 ALD Gate Dielectric

Abstract

This paper studies In0.53Ga0.47As and In0.7Ga0.3As surface channel metal-oxide-semiconductor field-effect-transistors (MOSFETs) with atomic layer deposition (ALD) of Al2O3 and ZrO2. This work systematically compared performance of InGaAs channel device with different Indium percentage. This includes drain current, transconductance, subthreshold swing, interface trap density and reliability. For both oxide systems, In0.53Ga0.47As channel MOSFETs show better subthreshold swing (125mV/dec versus 160mV/dec for Al2O3 EOT=4.4nm) and higher transconductance than In0.7Ga0.3As channel MOSFETs. Interface trap density measured by conductance method (1.08×1012 eV-1cm-2 versus 3.24×1012 eV-1cm-2 for Al2O3) also suggests that interface between In0.53Ga0.47As substrate and Al2O3 (or ZrO2) high-k dielectric is better than that of In0.7Ga0.3As.