Metal-Organic Chemical Vapor Deposition and Characterization of Strontium Bismuth Tantalate (SBT) Thin Films

The metal-organic chemical vapor deposition (MOCVD) of ferroelectric thin films is being widely investigated for the manufacture of devices requiring a high density of volatile or non-volatile memory which goes beyond the limits of current mass production techniques. One of the more important challenges in the MOCVD of multi-component oxide thin films is the precise control of stoichiometry which relates directly to the films' electrical characteristics. A novel approach to liquid precursor delivery embodied in the AIXTRON TriJetTM liquid delivery system is reported. Physical and electrical properties of thin films as well as deposition characteristics as a function of various process parameters are described in detail. Most notably 2Pr=13 µC/cm2 at 5 V with leakage current density Jl=1E-8 A/cm2 @≤5 V were obtained. In addition, films with excellent thickness uniformity with 3σ=2.25% at 180 nm were deposited on 6'' Pt/TiOx/Si wafers. Finally, near 100% step coverage with a maximum 2:1 aspect ratio (0.5 µm) was achieved.