Ultra-smooth epitaxial Ge grown on Si(001) utilizing a thin C-doped Ge buffer layer

作者：Mantey J^*; Hsu W; James J; Onyegam E U; Guchhait S; Banerjee S K

来源：Applied Physics Letters, 2013, 102(19): 192111.

DOI：10.1063/1.4807500

Here, we present work on epitaxial Ge films grown on a thin buffer layer of C doped Ge (Ge:C). The growth rate of Ge:C is found to slow over time and is thus unsuitable for thick (>20 nm) layers. We demonstrate Ge films from 10 nm to >150 nm are possible by growing pure Ge on a thin Ge:C buffer. It is shown that this stack yields exceedingly low roughness levels (comparable to bulk Si wafers) and contains fewer defects and higher Hall mobility compared to traditional heteroepitaxial Ge. The addition of C at the interface helps reduce strain by its smaller atomic radius and its ability to pin defects within the thin buffer layer that do not thread to the top Ge layer.

• 出版日期2013-5-13