A systematic study on group Ⅲ-nitride thin films with low temperature deposited via MOCVD

摘要

Wide bandgap semiconductor materials provide superior electrical, optical, and thermal properties that classical semiconductors, Si and GaAs, are unable to achieve. However, most commercially available substrates have large lattice and thermal expansion mismatches to Ⅲ-nitrides films. Thus a high quality buffer layer, grown at low temperatures, is essential in growing high quality Ⅲ-nitride films. This research provides a throughout study on Ⅲ-nitrides, such as AlN, GaN and AlGaN thin films, which were grown at low temperatures (400-600℃). Growth rate, stoichiometry and crystal structure of low temperature growth films will be reported by using several advanced post-growth analysis techniques. Temperature, pressure, and Ⅴ/Ⅲ molar ratio were also investigated to determine their effect on the film properties. From the study, a better understanding of the relationships between film properties and growth parameters will be achieved.