FABRICATION OF BURIED GAALAS NM-STRUCTURES BY DEEP UV HOLOGRAPHIC LITHOGRAPHY AND MBE GROWTH ON FINELY CHANNELED SUBSTRATES

This paper describes a fabrication procedure for buried GaAlAs structures with lateral feature sizes in the nm range and with a high package density (periodicity LAMBDA = 135nm). GaAs substrates are finely structured by means of deep UV (lambda = 257nm) holographic lithography. We greatly improved this method by the application of a negative image reversal Novolak resist and an antireflective coating. Buried GaAs filaments are fabricated by growing GaAlAs/GaAs/GaAlAs quantum well (QW) structures on nonplanar substrates by molecular beam epitaxy (MBE). A crescent profile of the GaAs wires is obtained for [011] orientation of the grating lines. This is very attractive for the growth of quantum filaments (QF). Low temperature photoluminescence measurements reveal a high quality of QF grown by MBE over finely grooved substrates. The photoluminescence yielded by QF is comparable to that of QW grown on planar substrates.