Ultrathin-Body High-Mobility InAsSb-on-Insulator Field-Effect Transistors

Ultrathin-body InAsSb-on-insulator n-type field-effect transistors (FETs) with ultrahigh electron mobilities are reported. The devices are obtained by the layer transfer of ultrathin InAs_0.7Sb_0.3 layers (thickness of 7-17 nm) onto Si/SiO₂ substrates. InAsSb-on-insulator FETs exhibit an effective mobility of ~ 3400 cm²/V·s for a body thickness of 7 nm, which represents ~ 2× enhancement over InAs devices of similar thickness. The top-gated FETs deliver an intrinsic transconductance of ~ 0.56 mS/μm (gate length of ~ 500 nm) at V_DS = 0.5 V with I_ON/I_OFF of 10²-10³. These results demonstrate the utility of the transfer process for obtaining high-mobility n-FETs on Si substrates by using mixed anion arsenide-antimonide as the active channel material.