Selective formation of InAs single and multiple quantum dots on GaAs wire structures for application of single electron memory

We describe formation of self-assembling InAs quantum dots (QDs) combined with selective area metalorganic vapor phase epitaxy (SA-MOVPE) on masked [001] GaAs substrates. It was found that formation of QDs in SA-MOVPE depended on the direction and top width of the GaAs mesa and wire structures. In particular, surface steps, which are mainly formed at the edge of the [001] top surface, affect the formation of QDs. Such step-induced islanding is utilized to form a position controlled single InAs QD at the bend of the wires in two directions. We also discuss a possible application of QDs for single electron memories where position-controlled QDs are used in combination with ridge quantum wires realized by the SA-MOVPE technology.