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