Interface properties of MBE-grown MOS structures with InGaAs/InAlAs buried channel and in-situ high-k oxide

Abstract With the goal to demonstrate feasibility of high-mobility buried channel, we used in-situ high-k deposition approach and show for the first time operational MOSFET with buried HfO 2 /In 0.52 Al 0.48 As/In 0.53 Ga 0.47 As/InP channel with mobility 1800 cm 2 /V-s at 3×10 12  cm −2 and e-mode operation. Interface properties are compared with a similar gate stack with 2 monolayer thick InGaAs “passivation” layer between InAlAs and the oxide. The latter gate stack has shown significantly improved gate control and ON/OFF ratio due to reduction of the interface state density.