PNNL

Abstract

Isotopic labeling experiments (18O2) have been carried out to understand the film-formation reactions in the MOCVD growth of (Ba,Sr)TiO3 films. Time-of-flight secondary ion mass spectrometry reveals both M18O and M16O (M=Ba, Sr, Ti) in the BST films, indicating that the oxygen in the BST films originates from both the gas phase oxidants(18 O), and the precursor ligands (16 O). Use of 50 % 18 O2-50%N2 16 O mixture results in a reduction of 18 O incorporation in the BST film, indicative direct involvment of N2O in the film-formation reactions. Addition of N2O in O2 appears to improve film surface morphology and step coverage.