In situ STM observation of site‐ controlled InAs nano‐dot growth on GaAs(001) during In and As 4 irradiations

We have successfully fabricated site‐controlled InAs nano dots during In and As 4 irradiations, observing by a STMBE: in situ scanning tunneling microscopy (STM) during molecular beam epitaxy (MBE) growth. After 1.5 monolayers (ML) of InAs wetting layer (WL) growth by ordinal Stranski‐Krastanov (S‐K) dot fabrication procedures, we applied voltage at a particular site on InAs WL during As 4 irradiation at 300 °C, creating the site where In atoms, which were migrating on the WL, favored to congregate. Then, we started supplying In atoms again. After supplying 1.52 ML (1.5 + 0.02 ML) of InAs, spontaneously, In atoms congregated this site, forming a dot structure without breaking a normal MBE growth. After further continually supplying 1.66 ML (1.5 + 0.16 ML) of InAs, we also confirmed that ordinal S‐K dots were appeared. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)