REACTIVE ION ETCHING OF PBZR1-XTIXO3 AND RUO2 FILMS BY ENVIRONMENTALLY SAFE GASES

A new process for the reactive ion etching (RIE) of both PbZr1-xTixO3 (PZT) thin films and RuO2 electrodes is presented, employing etching g ases with low ozone depletion potential (ODP) and global warming poten tial (GWP). The etching process has been investigated as a function of etching time, discharge power density, chamber pressure, and additive gas. Etch rates were in the range of 250-650 Angstrom/min and 100-400 Angstrom/min for PZT and RuO2, respectively. A large etch selectivity between PZT and RuO2 was optimized. Etched surfaces exhibited smooth morphologies. Furthermore, the ferroelectric properties of PZT were no t altered significantly by the etching process. A surface residue cont aining Cl and F was found after etching, but this organic substance wa s totally removed by an after-etch bake. In addition, the etched profi le of the PZT films was studied through SEM.