Formation of self-assembled InGaAs quantum dot arrays aligned along quasiperiodic multiatomic steps on vicinal (111)B GaAs

摘要

Dense and highly ordered arrays of self-assembled InGaAs quantum dots are formed by molecular beam epitaxy along multiatomic steps on vicinal (111)B GaAs. This unique structure has been synthesized by depositing a nominally 3-nm-thick In_(0.3)Ga_(0.7)As layer onto a periodically corrugated surface prepared on a GaAs substrate tilted 8.5° from (111)B. Each dot is typically 30-50 nm in lateral size and about 4 nm in height. Accumulation and release processes of strains in InGaAs layers deposited on stepped surfaces are discussed to suggest a possible mechanism for the aligned dot formation.