Growth and characterization of (Ba0.5Sr0.5)TiO3 films epitaxially grown on (002) GaN/(0006) Al2O3 electrode

Epitaxial (Ba0.5Sr0.5)TiO3 (BST) films have been grown on an n-GaN/(0006) Al2O3 by pulsed-laser deposition. X-ray theta-2theta, omega-rocking curves, and phi-scans reveal the epitaxial growth of (111) BST/(002) GaN bilayers. The full-width at half-maximum (FWHM) of (111) BST deposited on GaN was 0.95degrees. The depth profile of the film was recorded by Auger electron spectroscopy (AES). The dielectric constant of the BST film was about 510 with a dielectric loss of 0.05 at 1 kHz. The memory window of the epitaxial BST film was about 2V for an applied voltage range of -8V to 3V.