Integration of Porous Silicon with Sol-Gel Derived Ceramic Films

摘要

Direct integration of sol-gel derived ceramic films with porous silicon, without buffer layers, has been demonstrated. The effects of ceramic type, solvent type, solution concentration, as well as, porous silicon layer thickness, porosity and preparation conditions, on the quality and microstructure of sol-gel films/porous silicon integrated systems have been studied. The following ceramic compositions have been applied to porous silicon as protective coatings: PZT (PbZr_(0.3)Ti_(0.7)O_3), PLZT (Pb_(0.925)La_(0.055)Zr_(0.3)Ti_(0.7)O_3), ZrO_2, TiO_2, with 2-methoxyethanol and 2-ethoxyethanol solvents, 0.5 and 0.1 M precursor solution concentrations. The LSCO (La_(0.5)Sr_(0.5)CO_(.3)) water based sol-gels have been deposited for electroconductive purposes. The best compositions for integration, giving transparent, mirror-like, uniform ceramic films with fine morphology and strong adhesion, were found to be the TiO_2 and ZrO_2 as well as, the diluted (0.1 M) PZT (PbZr_(0.3)Ti_(0.7)O_3) sol-gel precursors. Conductive LSCO sol-gel derived films showed improved wetting and stronger adhesive interaction with porous silicon, as compared to polished silicon wafers.