L _g=150nm recessed quantum-well In _0.7Ga _0.3As MOS-HEMTs with Al ₂O ₃/In _0.52Al _0.48As composite insulator

A report is prsented on recessed QW In _0.7Ga _0.3As MOS-HEMTs with excellent subthreshold characteristics that combine an ALD-grown 3nm Al ₂O ₃ and an MBE-grown 10nm In _0.52Al _0.48As barrier as a composite gate insulator. In particular, an L _g=150nm In _0.7Ga _0.3As MOS-HEMT exhibits V _T=-0.3V, g _m-max=0.68S/mm, DIBL=35mV/V and S=70mV/decade at V _DS=0.5V. To the knowledge of the authors, the subthreshold characteristics demonstrated are the best ever reported for any planar III-V MOSFET with similar values of L _g.