BEEM STUDIES ON GAAS AL2GA1-XAS QUANTUM-WIRE STRUCTURES/

Ballistic electron emission microscopy (BEEM) was used to study latera lly patterned GaAs/AlxGa1-xAs heterostructures. The measurements were carried out at room temperature in air as well as in liquid helium. We t chemically etched quantum wires were identified both in topographic and BEEM current imaging. We find that the BEEM current is enhanced if ballistic electrons are injected directly into the quantum wire. The subsurface AlxGa1-xAs barrier influences the collector current by dete rmining the BEEM current threshold and by influencing the Fermi level pinning position. (C) 1996 Academic Press Limited