Fabrication of quantum well wires and vertical quantum wells on submicron gratings by MOVPE

Abstract

The fabrication of quantum well wires (QWWs) by overgrowing submicron gratings is reviewed. The advantages of one-dimensional semiconductor structures have already been understood for some time and are expected to alter laser performances, such as extremely low threshold currents, very high modulation bandwidths, very low temperature dependence. The realization of the nanostructures, however, has set some major demands on crystal growth. The MOVPE growth on submicron gratings (etched in a GaAs substrate) has become one of the most successful techniques and is studied in this paper. Vertical ‘quantum wells’ (VQWS) (formed during growth of bulk Al x Ga 1- x As on gratings) are also studied and a new fabrication technique for QWW lasers is proposed. Finally the application of QWWs and VQWs is discussed for the realization of Fabry-Perot and distributed feedback laser diodes.