A comparison of diol and methanol-based chemical solution deposition routes for PZT thin film fabrication

Abstract

For decoupling capacitor fabrication, solution deposition routes that yield film thicknesses of 0.5 to 1.0 μm per coating are required for economic viability. Films fabricated from propanediol-based solutions appear to meet this manufacturing requirement. To develop an effective deposition route based on this solvent, the processing characteristics of diol-based films were compared to films deposited from a “traditional” solution deposition approach, the IMO-chelate method. Differences in processing behavior were related to solvent and oligomer properties through optical microscopy and ellipsometry measurements. Films deposited from diol solutions remain “wet” throughout the initial phase of the fabrication process, and because of surface tension effects, tend to dewet the substrate, introducing non-uniformities into the film. A low temperature heat treatment process was employed to minimize this degradation in uniformity. The dielectric and ferroelectric properties of the diol derived films were tested and were found to be comparable to those of the films prepared by the traditional solution deposition method.

Key Words:

• CSD
• PZT
• diol
• thick coatings
• decoupling capacitors