Abstract
Firing processes of sol-gel derived hafnia films were investigated by temperature programmed desorption (TPD). The TPD analysis showed the evolutions of H2O, O2, NO and NO2 from the gel film. Since H2O evolved in the low temperature region, it was ascribed to physically adsorbed water of the gel film. The TPD curve for O2 showed two peaks at 265 and 570°C. XPS analysis of the gel and a film fired to 650°C in a TPD apparatus revealed the atomic ratio of Hf to O in the hafnia films to be 2.22 and 1.84, respectively. These results indicate that the hafnia film lacked O after being fired in vacuum. The evolved NO and NO2 were generated from HNO3 used in the sol preparation.
