Fabrication and characterization of mesoscopic wires in GaAs

Abstract

W e report on an effort to make narrow, quasi lD, wires in thin epilayers of n*-GaAs, using reactive ion etching (RIE) at accelerating voltages as low as 10 V, We measure depletion widths of the order of 40 nm (while the natural width is about 20 nm). Magnetoresistance measurements on wires with electrical width of 100-300 nm show the phase coherence length of the electrons to be temperature independent below 6 K with a value close to 400 nm. At high magnetic fields (1-6 T) the magnetoresistance exhibits unusual quasi periodic oscillations, the origin of which is unclear.

Mesoscopic Phenomena in Microstructures of IV–VI Epilayers

“…In the case of semiconductors, however, the situation is less clear. In particular, the presence of a component periodic in the magnetic field has been detected in microstructures of n+ GaAs [4], Hg 1-x-yCdyMnTe bicrystals [5], GaAs/AlGaAs heterostructures [6]. Besides, recent studies of magnetic metallic [7] and Hg1xy Cdy Mnx Te microstructures [8] have contradicted those (551) theoretical suggestions [9] which concern the time dependence of the fluctuation pattern in the spin-glass phase.…”

Mesoscopic Phenomena in Microstructures of IV-VI Epilayers

“…In the case of semiconductors, however, the situation is less clear. In particular, the presence of a component periodic in the magnetic field has been detected in microstructures of n+ GaAs [4], Hg 1-x-yCdyMnTe bicrystals [5], GaAs/AlGaAs heterostructures [6]. Besides, recent studies of magnetic metallic [7] and Hg1-x -y Cdy Mnx Te microstructures [8] have contradicted those (551) theoretical suggestions [9] which concern the time dependence of the fluctuation pattern in the spin-glass phase.…”