Reduction of etching damage in the fabrication of quantum wires

Abstract

Quantum wire structures were fabricated by patterning quantum well samples with electron beam lithography and various wet chemical etching procedures. Wire structures with 800 Å wire width were achieved by wet etching in NH 4OHH 2O 2H 2O (20:7:973). These samples were characterized by scanning electron microscopy, photoluminescence (PL), and polarization-dependent photoluminescence excitation (PLE) measurements. The PL spectra show significantly stronger peaks than that taken from an unetched quantum well sample. A wire width of 400 Å was estimated from the blue shift of PL peaks. A 22% anisotropy was observed from polarization-dependent PLE spectra, further indicating the existence of two-dimensional quantum confinement.