Charge instability of atomic-layer deposited TaSiOx insulators on Si, InP, and In0.53Ga0.47As.

Low barriers for electrons are found to be the reason for significant charge instability at interfaces of (100)InP and (100)In0.53Ga0.47As with atomic-layer deposited TaSiOx insulators. The formation of these reduced barriers is associated with the growth of a narrow-bandgap interlayer between the semiconductor and TaSiOx, which enables electron tunneling at low electric fields and subsequent trapping in the insulator. A wide-gap passivation layer may be required to improve the performance of TaSiOx as gate insulator. [ABSTRACT FROM AUTHOR]