THE ROLE OF ATOMIC-HYDROGEN FOR FORMATION OF QUANTUM DOTS BY SELF-ORGANIZING PROCESS IN MBE

We have investigated the effect of atomic hydrogen (H) irradiation on formation of In(Ga)As quantum dots (QDs) by self-organizing process. F or InGaAs QDs, the size of dots decreased from 40 to 20 nm by atomic H irradiation. The high density InGaAs QDs are formed uniformly by atom ic H irradiation, while they are distributed mainly along the step edg es without H irradiation. Atomic H also has beneficial effects on opti cal properties of QDs such as photoluminescence (PL) intensities and l ine widths. The waiting time dependence before GaAs cap layer depositi on on the optical properties of QDs is also investigated. PL character istics are improved in shorter waiting time.