Tuning the dielectric properties of hafnium silicate films

The influence of Si concentration in hafnium silicate dielectrics on thermal stability and dielectric permittivity was analyzed. A phase diagram was developed using GIXRD and FTIR measurement. The stabilization of the higher-k cubic/tetragonal phase for annealing temperatures up to 1000 degrees C with a steady increase in capacitance was demonstrated for Hf0.94Si0.06O2 films. It was also shown that the stabilization of nano-crystalline Hf0.80Si0.20O2 films can be realized for annealing temperatures up to 900 degrees C. The influence of TiN electrodes on the dielectric constant and the leakage current characteristic was also investigated. A permittivity increase for annealing temperatures up to 1000 degrees C without degradation of leakage current was shown. (C) 2007 Elsevier B.V. All rights reserved.