Optimization of Pt and PZT Films for Ferroelectric-Gate Thin Film Transistors

摘要

The polycrystalline Pt film with an excellent (111) orientation and a small grain size of about 30 nm was successfully prepared on a SiO_2/Si substrate by the new structured-sputtering system. By optimizing annealing process and using the highly (111)-oriented Pt film as a bottom electrode, an epitaxial-grade (111)-oriented PZT film was suc-cessfully prepared by the sol-gel method. Operation of the ferroelectric-gate thin film transistor (FGT) with indium-tin-oxide (ITO) channel, which was based on the optimum Pt and PZT films, has been verified. The FGT device exhibited good properties and performance with high "on/off" current ratio (～10~5), adequate memory window (1.2 V) and small swing factor (～88 mV/decade).