RF-sputtered ferroelectric barium titanate films on silicon

Abstract

Polycrystalline films of BaTi0₃ with ferroelectric properties are regularly observed for films thicker than 1000 Å which have been rf-sputtered deposited at 5 Å/min onto silicon substrates at temperatures above 500°C. A 2000 Å thick film deposited under these conditions typically exhibits a counter-clockwise hysteresis curve, a leakage current below 10⁻⁵ C/cm², a remanent polarization persisting for two days, and a dielectric constant vs. temperature relationship which peaks at 135°C. The nature of the BaTi0₃ - silicon system has been extensively characterized by supporting studies.