Atomic layer deposition of gadolinium scandate films with high dielectric constant and low leakage current

GdScO3 films were deposited on hydrogenated silicon substrates by atomic layer deposition. The films were pure and amorphous, both as-deposited and after a 5 min anneal at 950 degrees C. Cross-sectional transmission electron microscopy revealed a sharp, smooth interface between GdScO3 and Si. Capacitance and leakage current measurements on metal oxide semiconductor capacitors made from atomic layer deposited WN/GdScO3 stacks showed that the amorphous GdScO3 films have a high dielectric constant (similar to 22), low fixed charge density, and low interface trap density. A film with 1 nm equivalent oxide thickness also demonstrated that the leakage current density is less than 2 mA/cm(2) at 1 V gate bias. (c) 2006 American Institute of Physics.