This work examines Si overgrowth to encapsulate 3C-SiC quantum dot arrays epitaxially grown on Si substrates. Using transmission electron microscopy we show how the crystalline quality of the Si cap depends on the growth conditions. Overgrowth at 300ºC leads to a planar, epitaxial Si cap, but with small crystallographic rotations in the cap above each quantum dot. At 400ºC 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 250ºC followed by growth at 500ºC, leads to a planar cap with a much-reduced density of defects.
Citation: Applied Physics Letters
Pub Type: Journals