OPTICAL-PROPERTIES OF MODULATION-DOPED QUANTUM WIRES FABRICATED BY ELECTRON-CYCLOTRON-RESONANCE REACTIVE ION ETCHING

Modulation-doped GaAs/AlGaAs quantum wires have been fabricated using electron-beam lithography followed by electron-cyclotron resonance rea ctive ion etching to selectively deplete the electron gas. This techni que has the advantages of low damage to the quantum well, strongly ani sotropic etching, and reproducible control over the etch depth. The qu antum wires exhibit high photoluminescence efficiencies when etched as close as 200 angstrom to the electron gas. The fundamental gaps show the large optical red shifts associated with strongly spatially indire ct transitions. The spacings between one-dimensional subbands determin ed from inelastic light scattering measurements are larger than 2 meV.