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Thomas Farinha

Epitaxial MgO Films Grown on GaN by Atomic Layer Deposition: Growth Temperature Dependence and Thermal Stability

Department: Materials Science and Engineering
Advisor: Nicholas Strandwitz

MgO is currently being researched for its use as a high-k dielectric material in GaN-based electronic devices. MgO grows epitaxially on GaN via several growth techniques thus providing a potentially high quality interface for GaN-based devices. The structural quality of the MgO epilayer and the interface are highly important, yet little is known about the influence of initial surface chemistry and deposition temperature. In this study, MgO thin films were grown on GaN by atomic layer deposition (ALD) at temperatures ranging from 100°C to 325°C and the structural quality was assessed through x-ray diffraction (XRD) and reflectivity. In situ heating during XRD measurements from 300 °C to 1075°C indicated a change in the structure of the MgO and may represent an upper limit for the thermal stability of this interface. These studies lay the foundation for well-defined dielectric layers on gallium nitride and are relevant for lighting, power electronics, and computing applications.

About Thomas Farinha:
Thomas Farinha is a senior student in the Lehigh University DMSE and is currently working towards acquiring a B.S. in Materials Science and Engineering and a minor in Nanotechnology. He performs undergraduate research with Dr. Nicholas Strandwitz regarding the deposition of thin films. Tom has been studying the quality and crystalline character of MgO thin films deposited on GaN as a function of deposition and annealing temperatures. He is a Rossin Junior Fellow and is a member of the engineering honor society Tau Beta Pi. He was involved in the Lehigh Aerospace Club for three years and is planning to attend graduate school to complete a PhD program in Materials Science and Engineering.