Lattice-Matched Gaas/Ca0.45Sr0.55F2/Ge(100) Heterostrucuures Grown By Molecular Beam Epitaxy

Abstract
Epitaxial, lattice-matched GaAs/Ca0.45Sr0.55/F2 heterostructures were grown on Ge(100) substrates by molecular beam epitaxy. The films were analyzed by Rutherford backscattering and secondary ion mass spectroscopy to determine crystallinity and Ge outdiffusion. The Xmin (channeling over random yield) of a 1.5 μm-thick GaAs film grown on the fluoride is 0.075, indicating reasonably good epitaxy. After rapid thermal annealing, the crystallinity of higher-Xmin films improves, and Ge diffuses only 200 A into the fluoride, indicating that a thin fluoride layer is an effective barrier to Ge outdiffusion.