Swathi Vunnam

Date of Graduation

Summer 2009


Master of Science in Materials Science


Physics, Astronomy, and Materials Science

Committee Chair

Shyang Huang


oxide heterostructure, buffer layer, molecular beam epitaxy, magnesium oxide, silicon carbide, ultra high vacuum

Subject Categories

Materials Science and Engineering


The integration of complex oxides on wide bandgap semiconductors is required for future generation of high frequency, high power, and robust devices. High quality oxide thin films can be integrated on silicon based semiconductors by the new oxide-MBE technology. However, the growth of multifunctional oxide heterostructure is not easy due to different properties of each oxide film. By using a buffer layer, it is possible to produce a desired epitaxial oxide layer on a particular substrate without damaging either the substrate or the overlayer. Magnesium oxide (MgO) is a large bandgap insulator. Having a rock salt structure, it is a good buffer layer for complex oxide overlayers. Substrate selection is very important because matching in lattice parameters and crystal structure influences the crystal growth of the thin film. Due to its hexagonal crystal structure, 6H-SiC is an appropriate substrate for the growth of epitaxial MgO thin film using a molecular beam epitaxy deposition technique. In this project, appropriate substrate preparation methods and MgO growth processes were investigated. In order to grow the thin films, MBE components were designed and ultra high vacuum (UHV) was achieved. Finally, growth of MgO thin film on a 6H-SiC substrate has been achieved.


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