| Summary: | 碩士 === 大同大學 === 光電工程研究所 === 103 === In this work, the fabrication of SnSex and (001)-oriented SnSe2 thin films on c-sapphire by molecular beam epitaxy (MBE) was studied. The growth processes were monitored by in situ reflection high energy electron diffraction (RHEED). Streaky RHEED patterns of SnSe2 show the films were flat. The lattice constant of a-axis was approximately 3.71 ± 0.1Å, which is consistent with that of SnSe2 crystalline. The crystal structure was also observed by X-ray diffraction (XRD) analysis for lattice constant c of 6.15Å, the c/a = 1.685. The SnSex films were measured by using Raman spectrum, SEM and four point probe method for components, morphology and electric properties. In addition, the relationship between stoichiometry and substrate temperature was investigated by X-ray photoelectron spectroscope (XPS). At temperature < 400℃, SnSe2 phase films was grown. The growth conditions of SnSex thin film were observed in this research, the optimization conditions of SnSe2 thin films are substrate temperature = 300℃, Tin cell temperature = 980℃, Selenium cell temperature = 203℃. At the conditions, the SnSe2 single phase thin films were deposited successfully.
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