Molecular beam deposition of high-density InAs quantum dots on SiOx films

InAs quantum dots (QDs) were grown on SiOx films by molecular beam deposition (MBD), and then an SiOx capping layer was deposited by rf magnetron sputtering. High arsenic pressure and As2 molecular beam flux enhanced InAs nucleation and the dot growth. Ultrahigh-density InAs QDs with 8.5 × 1011 cm−2 was obtained for As2 molecular beam of 3.0 × 10−5 Torr. The amount of InAs growth grown by As2 was about three times higher than that by As4. Photoluminescence (PL) properties depended on InAs QD structures. The vacuum transport process between InAs MBD and SiOx sputtering was effective to improve the quality of InAs QDs on a SiOx film. Furthermore, strong PL intensity was obtained from InAs QDs in a SiOx matrix, fabricated by the vacuum transport process.