V-grooved InGaAs quantum-wire FET fabricated under an As/sub 2/ flux in molecular beam epitaxy

Selective growth on non-planar substrates has recently become accepted as a promising means for the fabrication of semiconductor quantum wires (QWRs) with improved electrical and optical characteristics. The most common selective growth method for QWRs, in which the V-grooves are prepared by chemical etching, has not been applied to InGaAs/InAlAs QWRs by the conventional MBE method using an As/sub 4/ flux. Because a strong migration of In atoms destroys the V-groove shape during formation of the InAlAs barrier layer, InGaAs QWRs cannot be fabricated on a V-grooved substrate. We have previously overcome this problem by utilizing an As/sub 2/ flux (Sugaya (1998)). The V-shape was preserved during InAlAs barrier layer growth due to the suppressed migration of In atoms under the As/sub 2/ flux. In this report, the V-grooved QWR-FETs are realized by the selective growth using As/sub 2/ flux and their transport characteristics are studied. An analysis of the depopulation of one-dimensional subbands in these structures reveals little evidence for sidewall depletion.