Compliant substrates for materials on silicon

• Main Author: Black, Kate
• Published: University of Liverpool 2008
• Subjects: 671.735
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494119

This thesis describes the development of processes to fabricate compliant layers for the epitaxy of gallium nitride on silicon. A range of metalorganic chemical vapour deposition processes have been investigated. Three generic materials systems have been explored, namely: a perovskite-based rare earth aluminate; a rocksalt nitride system; and a hexagonal symmetry oxide based buffer layer. Single source precursors for the deposition of lanthanum- and praseodymium- aluminate have been demonstrated using LnAl(OPri)6(PriOH)]2 (Ln = La or Pr) for the first time. Annealing the films above 850°C crystallises them to form a rhombohedral perovskite phase. The growth of gallium nitride on these films has been investigated to establish their chemical stability. The GaN growth is textured and the interface between the oxide and GaN is abrupt indicating negligible interdiffusion. The promotion of better epitaxy via a SrO seed layer to inhibit adverse interfacial interactions is considered.