Substrate temperature and monolayer coverage effects on epitaxial ordering of InAs and InGaAs islands on GaAs

Abstract

For InAs Stranski–Krastanov (SK) island growth on GaAs by molecular-beam epitaxy, we show that the in-plane island diameter varies exponentially with the growth temperature over the range of 390–540 °C. A transition region in SK growth between isolated island growth and island coalescing is investigated as functions of growth temperature and equivalent InAs layer-by-layer monolayer (ML) coverage in order to extend the isolated island regime for quantum confinement applications. InAs islands of 150 Å in diameter have been grown. Growth of In0.5Ga0.5As islands indicates an increased 2D epitaxial region before island nucleation and a decreased island concentration compared to growth of InAs islands.