| Summary: | 碩士 === 國立清華大學 === 光電工程研究所 === 105 === In this thesis, structures made of III-V semiconductor Gallium Antimonide (GaSb) on silicon substrate by Rapid-Melt-Growth (RMG) method are investigated. Due to the relatively low melting point of GaSb (712 ℃) and small bandgap, it is an ideal material to be applied for Si photonics as a light source and can be fabricated through the RMG process. However, III-V compounds are different from group IV, hence there are still many issues required to be overcome, such as such as lattice mismatch (13%), thermal expansion mismatch between GaSb and Si.
In general, growing III-V semiconductor typically relies on either Molecular Beam Epitaxy (MBE) or Metal-organic Chemical Vapor Deposition (MOCVD), which requires expensive tools and critical processes, especially for heterogeneous epitaxial growth of III-V on Si. In this study, Ga (7N) and Sb (6N) are co-evaporated by the E-gun and thermal evaporator to be the precursor for the following annealing process. Despite the quality of the precursor film can’t compare with the material directly made by MBE or MOCVD, this study is to demonstrate a monocrystalline, high-quality GaSb structure implemented via the RMG method.
To get the best material quality, we study several key process conditions of RMG, including the ratio of Ga and Sb in precursor, crucible material, annealing temperature and annealing time. Then the material is characterized by Photoluminescence (PL), Transmission Electron Microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), Selective Area Diffraction pattern (SAD) and so on. Finally, we find the best process condition to make GaSb on Si substrate.
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