Molecular Beam Epitaxy Fabrication of SrTiO₃ and Bi₂Sr₂CaCu₂O₈ Heterostructures Using a Novel Reflection High-Energy Electron Diffraction Monitoring Technique

Abstract

SrTiO 3 and Bi 2 Sr 2 CaCu 2 O 8 layered structures were continuously grown by the molecular beam epitaxy technique with in situ reflection high-energy electron diffraction (RHEED). By using a new RHEED picture subtraction technique, we could display intensity changes due to only the topmost layer. This method allows us to sensitively detect roughness on the atomic scale and excess phase formation. The SrTiO 3 layer could be grown by sequential shuttering as well as coevaporation. A heterostructure with a 60 Å Bi 2 Sr 2 CaCu 2 O 8 film had a superconducting transition temperature of 53 K.