Journal of Crystal Growth, Vol.441, 78-83, 2016
Direct MOCVD epitaxy of GaAsP on SiGe virtual substrate without growth of SiGe
GaAsP has important applications for solar cells and light-emitting diodes on silicon substrates. Here we demonstrate that GaAsP can be directly grown by metal-organic chemical vapor deposition on previously-prepared lattice-matched SiGe virtual substrates, without prior in-situ growth of SiGe. By optimizing the growth pressure and AsH3 pre-exposure time, the surface morphology of GaAsP is improved and the pinhole densities are reduced by two orders of magnitude from 2.4 x 10(7)/cm(2) to 1.2 x 10(5)/cm(2). The physics is suggested to be an optimization between complete As-termination and AsH3 etching effect of SiGe surface. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:Metalorganic vapor phase epitaxy;Semiconducting III-V materials;Semiconducting gallium compounds;Semiconducting silicon compounds;Light emitting diodes