A COMPARISON OF DIOL AND METHANOL-BASED CHEMICAL SOLUTION DEPOSITION ROUTES FOR PZT THIN-FILM FABRICATION

For decoupling capacitor fabrication, solution deposition routes that yield film thicknesses of 0.5 to 1.0 mu m per coating are required for economic viability. Films fabricated from propanediol-based solutions appear to meet this manufacturing requirement. To develop an effectiv e deposition route based on this solvent, the processing characteristi cs of diol-based films were compared to films deposited from a ''tradi tional'' solution deposition approach, the IMO-chelate method. Differe nces in processing behavior were related to solvent and oligomer prope rties through optical microscopy and ellipsometry measurements. Films deposited from diol solutions remain ''wet'' throughout the initial ph ase of the fabrication process, and because of surface tension effects , tend to dewet the substrate, introducing non-uniformities into the f ilm. A low temperature heat treatment process was employed to minimize this degradation in uniformity. The dielectric and ferroelectric prop erties of the diol derived films were tested and were found to be comp arable to those of the films prepared by the traditional solution depo sition method.