On the choice of precursors for the MOVPE-growth of high-quality Al(0.30)Gao(0.70)As/GaAs v-groove quantum wires with large subband spacing

MOVPE growth is used to prepare high-quality v-groove quantum wires in the AlGaAs/GaAs system. The particular aim of this work is to find suitable pre cursor combinations and growth conditions with which quantum wire structure s can be achieved, where only the lowest subband is occupied and on which t ruly one-dimensional transport can be studied. Different precursor combinat ions of triethylgallium (TEGa), trimethylgallium (TMGa), trimethylaluminium (TMAl) and dimethylethylaminenalane (DMEAAl) were employed for growth of t he Al0.30Ga0.70As barrier layer. Calculations of the 2D-Schrodinger-equatio n show, that suitable quantum wire geometries are obtained when using combi nations with TMGa. High-quality material is achieved at 575 degreesC for TM Ga/DMEAAl and 595 degreesC for TMGa/TMAl. In general, lower grow-th tempera tures lead to the preferential lower radii of curvature for a given precurs or combination. A comparison of the best two combinations shows that TMGa/T MAl is best suited for growth of the Al0.30Ga0.70As barrier layer with resp ect to the intended application. (C) 2000 Elsevier Science B.V. All rights reserved.