Precise control of size and density of self-assembled Ge dot on Si(1 0 0) by carbon-induced strain-engineering

In order to produce dome-shaped Ge dots with small size and high density, C submonolayers (C-SMLs) were incorporated at the interface between Ge wetting layers and Ge dots. The C atoms are considered to induce a local strain field by forming Ge–C bonding. Such strain field enhanced dome formation even at low temperature (<500 °C). Optimization of experimental conditions enabled precise control of the Ge dome size in the range of 30–40 nm with the density of 1010 cm−2. The Ge domes thus prepared exhibited intensive photoluminescence (PL) compared to those prepared by a conventional self-assembling technique.