Understanding the clean interface between covalent Si and ionic Al2O3.
The atomic and electronic structures of the (001)-Si/(001)-gamma-Al(2)O(3) heterointerface are investigated by first principles total energy calculations combined with a newly developed "modified basin-hopping" method. It is found that all interface Si atoms are fourfold coordinated due to the formation of Si-O and unexpected covalent Si-Al bonds in the new abrupt interface model. And the interface has perfect electronic properties in that the unpassivated interface has a large LDA band gap and no gap levels. These results show that it is possible to have clean semiconductor-oxide interfaces.
National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
H J
HJ
Xiang
Juarez L F
JL
Da Silva
Howard M
HM
Branz
Su-Huai
SH
Wei