Epitaxial Films of Silicon on Spinel by Vacuum Evaporation

Abstract

By using the vacuum evaporation method single‐crystal silicon films have been epitaxially grown on (111) spinel substrates at the substrate temperature range of 850° to 1000°C with the deposition rate of a few angstroms per second. Antimony‐doped n‐type epitaxial films of silicon having the carrier concentration ranging from 1.3×10¹⁶ to 2.1×10¹⁸ cm⁻³ were obtained by evaporating antimony during the evaporation of undoped silicon with the resistivity of 1600 Ω·cm. The Hall effect and the resistivity measurements on those films were carried out over the temperature range from 77°K to room temperature. Electron Hall mobilities of films over 800 cm²/V·sec at room temperature were achieved. It was found that these film mobilities corresponded to approximately 75% of the mobilities expected on the bulk silicon with similar carrier concentrations, and that electron Hall mobilities of the n‐type films with the carrier concentrations over 3×10¹⁷ cm⁻³ corresponded to about 100% of those of bulk silicon. It was also found that the n‐type epitaxial films of silicon as well as the p‐type epitaxial films of silicon grown on (111) spinel substrates had higher Hall mobilities than those grown on (0001) and (1̄012) sapphire substrates with the deposition rate of a few angstroms per second by using the vacuum evaporation method.