HIGH-TEMPERATURE ETCHING OF PZT PT/TIN STRUCTURE BY HIGH-DENSITY ECR PLASMA/

Submicron patterning technologies for the PZT/Pt/Ti/TiN/Ti structure w ith a spin on glass (SOG) mask were demonstrated using a high-density ECR plasma and a high substrate temperature above 300 degrees C. A 30% -Cl-2/Ar gas was used to etch a lead zirconate titanate (PZT) film. No deposits remained, which resulted in an etched profile of more than 8 0 degrees. A 40%-O-2/Cl-2 gas was used to etch a Pt film. The etching was completely stopped at the Ti layer. 30-nm-thick deposits remained on the sidewall. They were removed after dipping in hydrochloric acid. The etched profile of a Pt film was more than 80 degrees. The Ti/TiN/ Ti layer was etched with pure Cl-2 gas. The size shift from the SOG ma sk was less than 0.1 mu m. Interdiffusion between SOG and PZT was not detected by transmission electron microscopy and energy dispersive x-r ay spectroscopy (TEM-EDX) analysis.