Room temperature observation of lateral quantization effects in modulated barrier InGaAs/InP wires

We have fabricated buried InGaAs/InP quantum wires with widths down to 15 nm by high resolution electron beam lithography and selective wet chemical etching. In our approach, only the InP cap layer of an InGaAs/InP quantum well is locally removed. In the etched parts of the sample, InGaAs surface quantum wells are formed, where the conduction and valence band discontinuity between InGaAs and InP (600 meV) is replaced by the high vacuum barrier (/spl sim/5 eV). Therefore the quantization energies are enlarged in the InGaAs surface quantum wells. This creates a lateral potential, that confines the carriers to the InP covered regions, which act as wires. The different thermal stability of both regions is used to enhance the lateral potential significantly in a subsequent rapid thermal annealing step. The wires show clear lateral quantization effects with energy shifts up to 13 meV and high luminescence intensities up to room temperature.