Formation of quantum dot structures by atomic hydrogen assisted selective area molecular beam epitaxy

We have fabricated InGaAs/GaAs quantum dot structures by atomic hydrogen assisted selective area molecular beam epitaxy (H-MBE). First, GaAs pyramidal structures with fourfold symmetric {011} facet sidewalls have been formed in (001) GaAs by using SiO2 as a mask with square openings. The shape and width of pyramidal structures observed by using a scanning electron microscope (SEM) and atomic force microscope (AFM) have been determined to be uniform. Using these pyramids, InGaAs quantum dots have been overgrown on top of the pyramids under different growth conditions. Photoluminescence (PL) spectra have been measured in order to study PL peaks arising from quantum dots. Furthermore, we have fabricated GaAs quantum dot array structures coupled to quantum wire networks by our H-MBE selective area growth technique.