Atomic layer deposition of hafnium silicate thin films using HfCl2[N-SiMe3)(2)](2) and H2O

Abstract

Hafnium silicate thin films were deposited on Si substrate for alternative gate dielectrics by atomic layer deposition (ALD) using a single metallorganic precursor, dichlorobis[bis(trimethylsilyl)amido]hafnium (HfCl2[N(SiMe3)(2)](2)), and H2O as an oxidant in the temperature range of 150-400 degreesC. The effect of pulse time for purge and precursor injection confirmed the self-limiting characteristic of ALD. Film growth rate and composition were investigated as a function of deposition temperature. Growth rate reached to a maximum value of 1.3 Angstrom/cycle at 250 degreesC and rapidly decreased to 0.3 Angstrom/cycle at 400 degreesC. The composition analysis of as-deposited films using X-ray photoelectron spectroscopy showed that the composition ratio of Si/(Hf + Si) increased linearly from 0.15 to 0.3 as the deposition temperature increased. (C) 2004 The Electrochemical Society.