Impact of interfacial InAs layers on Al_2O_3/GaSb metal-oxide-semiconductor interface properties

摘要

We have systematically studied the impact of interfacial InAs layers on Al_2O_3/GaSb metal-oxide-semiconductor (MOS) interface properties. The interfacial InAs layers improved the capacitance versus voltage (C-V) curves of the Al_2O_3/GaSb MOS capacitors (MOSCAPs) fabricated by an ex-situ process. The minimum interface-trap density (D_(it)) value of an Al_2O_3/1.5-nm-thick InAs/p-GaSb MOSCAP is ～6.6 × 10~(12) cm~(-2)eV~(-1), which is reduced by ～50% from that of ～1.4 × 10~(13)cm~(-2)eV~(-1) in an Al_2O_3/p-GaSb MOSCAP. Also, the interfacial InAs layers significantly improved the C-V curves of the Al_2O_3-GaSb MOSCAPs. The InAs layer can improve the Al_2O_3/GaSb MOS interface properties both in valence band side and in conduction band side.