Romanyuk, O.; Paszuk, A.; Gordeev, I.; Wilks, R.G.; Ueda, S.; Hartmann, C.; Félix, R.; Bär, M.; Schlueter, C.; Gloskovskii, A.; Bartos, I.; Nandy, M.; Houdková, J.; Jirícek, P.; Jaegermann, W.; Hofmann, J.P.; Hannappel, T.: Combining advanced photoelectron spectroscopy approaches to analyse deeply buried GaP(As)/Si(1 0 0) interfaces: Interfacial chemical states and complete band energy diagrams. Applied Surface Science 605 (2022), p. 154630/1-11
10.1016/j.apsusc.2022.154630
Open Access Version (externer Anbieter)
Abstract:
The epitaxial growth of the polar GaP(1 0 0) on the nonpolar Si(1 0 0) substrate suffers from inevitable defects at the antiphase domain boundaries (APDs), resulting from mono-atomic steps on the Si(1 0 0) surface. Stabilization of Si(1 0 0) substrate surfaces with As is a promising technological step enabling the preparation of Si substrates with double atomic steps and reduced density of the APDs. In this paper, 4–50-nm-thick GaP epitaxial films were grown on As-terminated Si(1 0 0) substrates with different types of doping, miscuts, and As-surface termination by metalorganic vapor phase epitaxy (MOVPE). The GaP(As)/Si(1 0 0) heterostructures were investigated by X-ray photoelectron spectroscopy (XPS) combined with gas cluster ion beam (GCIB) sputtering and by hard X-ray photoelectron spectroscopy (HAXPES). We found residuals of As atoms in the GaP lattice (∼0.2–0.3 at.%) and a localization of As atoms at the GaP(As)/Si(1 0 0) interface (∼1 at.%). Deconvolution of core level peaks revealed interface core level shifts. In As core levels, chemical shifts between 0.5 and 0.8 eV were measured and identified by angle-resolved XPS measurements. Similar valence band offset (VBO) values of 0.6 eV were obtained, regardless of the doping type of Si substrate, Si substrate miscut or type of As-terminated Si substrate surface. The band alignment diagram of the GaP(As)/Si(1 0 0) heterostructure was deduced.