UV patternable metal organic systems for electroceramic films

This thesis concerns the development of a novel process for the production of thick PZT ceramic features by using a single deposition step and patterning of a photosensitive precursor solution. The preparation of thick films by a single deposition step using a precursor solution composed of PZT xerogel and 1,3 propanediol was examined initially. Viscosity measurements and particle size determination permitted the characteristics of the xerogel when re-dispersed in 1,3 propanediol to be determined. The results from the particle size measurements allowed the fluorescent behaviour of the PZT xerogel and PZT xerogel in 1,3 propanediol to be detected. This result was relevant in view of the use of PZT xerogel as part of a photosensitive system. The deposition and subsequent thermal treatment of the diol based solution allowed the preparation of uncracked ceramic films up to 0.3 jam thick. To overcome the limitation in the maximum thickness achievable by a single deposition step, and the requirement for a subsequent etching process, a photosensitive system was produced by dissolving a PZT xerogel in acrylic acid. The photosensitivity of the initial acrylic acid/PZT xerogel photosensitive system was improved by the addition of a photoinitiator. A procedure similar to a conventional photolithographic process was then developed and tailored to the newly developed system with the specific aim o f obtaining thick, uncracked ceramic features. Following deposition and exposure the patterned film was developed to obtain the image relief. The samples were only developed completely and rapidly in pure acetic acid at room temperature. As a result of the optimised photolithographic process and subsequent drying and firing it was possible to obtain two categories of uncracked ceramic features: structures with dimension ranging from 5 pm up to about 500 pm with a limit to uncracked thickness of 0 . 3 5 pm and structures approximately 2 pm thick with an uncracked feature limit size of about 3 pm. The procedure applied to the preparation of PZT features was found to be appropriate to the preparation of compositions other than PZT. A barium titanate (BT) photosensitive precursor solution was prepared and the deposited film was patterned by exposure to UV light. Following development and subsequent thermal treatments BT ceramic features were obtained.