Combining advanced photoelectron spectroscopy approaches to analyse deeply buried GaP(As)/Si(100) interfaces: Interfacial chemical states and complete band energy diagrams

• Published in: arXiv.org 2022-06
• Main Authors: Romanyuk, O, Paszuk, A, Gordeev, I, Wilks, R G, Ueda, S, Hartmann, C, Félix, R, Bär, M, Schlueter, C, Gloskovskii, A, Bartoš, I, Nandy, M, Houdková, J, Jiříček, P, Jaegermann, W, Hofmann, J P, Hannappel, T
• Format: Article
• Language: English
• Subjects: Antiphase boundaries; Arsenic; Doping; Epitaxial growth; Gallium phosphides; Heterostructures; Ion beams; Metalorganic chemical vapor deposition; Photoelectrons; Silicon substrates; Spectrum analysis; Thick films; Valence band; Vapor phase epitaxy; Vapor phases; X ray photoelectron spectroscopy
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2206.08819

The epitaxial growth of the polar GaP(100) on the nonpolar Si(100) substrate suffers from inevitable defects at the antiphase domain boundaries, resulting from mono-atomic steps on the Si(100) surface. Stabilization of Si(100) substrate surfaces with arsenic 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(100) substrates with different types of doping, miscuts, and As-surface termination by metalorganic vapor phase epitaxy. The GaP(As)/Si(100) 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 arsenic atoms in the GaP lattice (0.2-0.3 at.%) and a localization of As atoms at the GaP(As)/Si(100) interface (1 at.%). Deconvolution of core level peaks revealed interface core level shifts. In As core levels, chemical shifts between 0.5-0.8 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 heterostructure was deduced.