Heteroepitaxial Growth of InAs on Si: the New Type of Quantum Dots

Under certain growth conditions InAs/Si heteroepitaxial growth proceeds via Stranski-Krastanow or Volmer-Weber growth modes depending on the growth parameters. The critical thickness at which three dimensional InAs islands start to appear at the Si (100) surface is within the range of 0.7−4.0 monolayers (substrate temperature range is 350 °C — 430 °C). Their size depends critically on the growth conditions and is between 5 nm and 80 nm (uncapped islands). Critical lateral size of the coherent (Si capped) dislocation-free island is equal to 2−5 nm depending on the island height. Islands having larger size are dislocated. Optical properties of InAs nanoscale islands capped with Si reveal a luminescence band in the 1.3 µm region.