Site-controlled growth and luminescence of InAs quantum dots using in situ Ga-assisted deoxidation of patterned substrates

Site-controlled growth of single and pairs of InAs quantum dots is demonstrated on ex situ electron-beam patterned (001) GaAs substrates using in situ Ga-assisted deoxidation prior to overgrowth. 6–8 ML of gallium deposited at a substrate temperature of $460°C$ in the absence of arsenic followed by a brief anneal under arsenic is used to remove the surface oxide without damaging a pattern consisting of $∼100nm$ wide, $∼20nm$ deep holes. Single dot luminescence is shown from a dilute array (⁠$10μm$ spacing) of such site-controlled dots, located only $8nm$ from the regrowth interface.