Defect Reduction and Its Mechanism of Selective Ge Epitaxy in Trenches on Si(001) Substrates using Aspect Ratio Trapping

摘要

Defect-free germanium has been demonstrated in SiO_2 trenches on silicon via aspect ratio trapping, whereby defects arising from lattice mismatch are trapped by laterally confining sidewalls. Results were achieved through a combination of conventional patterning of SiO_2, and selective growth of Ge as thin as 450 nm. It was revealed that facets, when formed early on in the growth process, play a dominant role in determining the configurations of threading dislocations in the films. This approach shows great promise for the integration of Ge and/or IIIV materials, sufficiently large for key device applications, onto silicon substrates