Functional materials integrated on III-V semiconductors

The integration of ferroelectric oxides on semiconductors has been achieved through the use of molecular beam epitaxy and solution spin coating. The oxide layers were determined to be single phase and crystalline and were oriented with the (1 0 0) along the growth direction. Epitaxial SrTiO₃ and BaTiO₃ buffer layers were grown on GaAs and Si using a unique MBE process for nucleation that suppressed the formation of interfacial oxide. The deposition of ferroelectric Pb(Zr)TiO₃, on STO buffered Si and GaAs was carried out using solution spin coating. The nucleation of the oxide growth by solution spin coating was promoted by the crystallinity of the surface structure of the SrTiO₃ buffer layer. Ab initio Density Functional Theory calculations were used to determine the interfacial structure and band alignments for the STO/GaAs and BTO/GaAs interfaces. Initial electrical characterization of the PZT grown on GaAs was determined by measuring the polarization versus electric field which suggests evidence of ferroelectricity.