Chemically Assisted ion-Beam Etching of Sol-Gel Derived Pzt, Plzt And LITaO3 Thin Films for Silicon Based Device Integration

Abstract

AbstractWet chemical, reactive ion etching and reactive ion-beam etching of sol-gel prepared PZT (54/46) [Pb(Zr,Ti)O3], Lanthanum doped PZT [PLZT (9/65/35)] and LiTaO3 have been investigated. Wet chemical etching using an HCI-HF solution, reactive-ion etching using a SF6 plasma and chemically assisted ion-beam etching (CAIBE) using a xenon plasma and chlorine reactive gas were used. Etch rates for each method were determined and the ability to define small features in the thin film ferroelectric was investigated. It was found that for structures smaller than approximately 20 × 20 μm2, chemically assisted ion beam etching provided by far the best results. 3 × 3 μm2 capacitor and 2 μm wide optical waveguide structures in PZT, PLZT respectively, were successfully fabricated using a CAIBE system. An etch depth monitor enabled accurate in-situ etch rate monitoring of the PLZT and PZT thin films.