Epitaxial Si encapsulation of highly misfitting SiC quantum dot arrays formed on Si (001)

This work examines Si overgrowth to encapsulate 3C-SiC quantum dot arrays epitaxially grownon Si substrates. Using transmission electron microscopy, we show how the crystalline quality of the Si cap depends on the growth conditions. Overgrowth at 300 °C leads to a planar,epitaxial Si cap, but with small crystallographic rotations in the cap above each quantum dot. At 400 °C growth temperature, Si exhibits reduced sticking to the SiC, leading to a non-planar cap. However, a two-step process, with thin layer grown at 250 °C followed by growth at 500 °C, leads to a planar cap with a much-reduced density of defects.