MOCVD and characterization of Hf-silicate thin films using HTB and TEMAS

Abstract

Hafnium silicate (HfSixOy) films were deposited by metal-organic chemical vapor deposition (MOCVD) using a combination of precursors: hafnium tetra-tert-butoxide [Hf(OC(CH3)(3))(4), HTB] and tetrakis-ethylmethylamino silane [Si(N(C2H5)(CH3))(4), TEMAS]. The activation energy was independent on the ratio of precursor amounts in the surface reaction regime. The grown films showed Hf-rich characteristics and the impurity concentrations were less than 1 at.% (below detection limits). Hafnium silicate films were amorphous up to 700 degrees C annealing. Hf/(Hf+Si) composition ratio and dielectric constant (k) of the Hf-silicate films decreased by increasing the growth temperature above 270 degrees C. (C) 2007 Elsevier B.V. All rights reserved.