The authors report on optimization of the Hf-Al oxide (HfAlO) buffer-layer deposition conditions in a Pt/SrBi2Ta2O9/HfAlO/Si field effect transistor intended for nonvolatile memory applications. The N-2 pressure during pulsed-laser deposition of the HfAlO buffer layer is found to primarily affect the subthreshold swing and the width of the memory window with no significant impact on the data retention behavior of the devices. Scanning transmission electron microscopy was used to investigate the gate stack structure and the electrical properties are correlated with the observed structural variations. (C) 2008 American Vacuum Society.