Formation of SiCH ₆-mediated Ge quantum dots with strong field emission properties by ultrahigh vacuum chemical vapor deposition

Pretreatment of silicon surface with SiCH6 was used to modify the Stranski-Krastanow growth mode of Ge on Si(001) at 550 °C by ultrahigh vacuum chemical vapor deposition. With the appropriate SiCH6 mediation, the elongated Ge hut clusters can be transformed to highly uniform multifaceted domes with a high Ge composition at the core. These SiCH6 -mediated Ge dots have an average diameter and height of 38 and 7 nm, respectively. The modified growth mode for the formation of SiCH6 -mediated Ge dots can be attributed to (i) an almost hydrogen-passivated Si surface to limit the nucleation sites for dot formation and (ii) the incorporation of Ge atoms, repelled by the C-rich areas, into the existing Ge dots. The results also demonstrate that SiCH6 -mediated dots exhibit the improved field emission characteristics compared to shallow Ge huts.