|approved||osi_11_supplie_poster.pdf||2015-06-03 04:06:18||Oliver Supplie|
Author: Oliver Supplie
Requested Type: Poster
Submitted: 2015-05-27 15:35:08
Co-authors: M.M. May, O. Romanyuk, F. Grosse, C. Höhn, G. Steinbach, H. Stange, A. Nägelein, A. Müller, P. Kleinschmidt, S. Brückner, T. Hannappel
Here, we study the entire GaP/Si(100) MOVPE growth process, from preparation of single-domain Si(100) surfaces and GaP nucleation to GaP/Si(100) surface preparation, in situ with RAS. Almost single-domain Si(100) surfaces can successfully be prepared in ambient containing (Ga, P) background residuals . Antiphase disorder thus can be reliably suppressed. We obtain atomically ordered, single-domain GaP/Si(100) surfaces by pulsed GaP nucleation of a 2 nm thin epilayer and annealing with phosphorus stabilization . A terrace-related dielectric anisotropy evolves during nucleation and remains during further growth . By optical model calculations, we attribute this anisotropy to the heterointerface. Charge compensation at the heterointerface can be achieved by an equal number of Si–P and Si–Ga bonds . However, XPS measurements suggest a kinetically limited formation of a rather abrupt interface consisting of Si–P bonds . Such an interface agrees with the observed GaP sublattice orientation . Process conditions required for exactly oriented Si(100) surfaces promote diffusion of background residuals on the surface. Their (sub-monolayer) amount at the substrate prior to nucleation strongly affects the formation of the interface and the structure of the GaP epilayer .
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