Formation of an oxide-free GeTiO2 interface by atomic layer deposition on brominated Ge

Abstract

Atomic layer deposition (ALD) of titanium dioxide (Ti O2) high- κ dielectric films on brominated Ge substrates using titanium tetrachloride and water has been studied. A strong temperature dependence was observed for the Ti O2 deposition rate. An accelerated growth rate was measured for the first 15 ALD cycles at 300 °C; this effect is attributed to bromine desorption and resultant deposition on halide-free Ge. Results suggest that Ti O2 films were deposited with no interfacial oxide layer at 300 °C. The films were in a crystalline anatase phase at 300 °C, and were amorphous when deposited at 100 °C. © 2008 American Institute of Physics.