Facile fabrication and integration of patterned nanostructured TiO 2 for microsystems applications

Abstract

A simple technique to fabricate integrated crack-free and crystalline nanostructured titania (ns-titania) in microsystems devices is presented. In this technique, crack elimination is achieved by oxidizing Ti films, pre-patterned below a threshold dimension, in aqueous hydrogen peroxide solution. Amorphous ns-titania with walls of pores having thicknesses and pore diameters ranging from 25 nm-50 nm and 50 nm-200 nm, respectively, is formed after oxidation and transformed to anatase after thermal annealing. We demonstrate the functionality of ns-titania formed and compatibility of this technique with microsystems device manufacturing practices by fabricating a prototype device for gas sensing using integrated ns-titania features as sensing elements. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.