While growth of wide bandgap semiconductor materials on crystalline oxides (sapphire, lithium gallate, lithium aluminate, zinc oxide and others) has become routine, growth of crystalline oxides on wide bandgap, materials remains challenging and minimally explored. The potential payoff in terms of enhanced device performance, increased functionality and reliability warrants examining this option. This presentation aims at targeting key areas, where crystalline oxides could improve wide bandgap semiconductor device performance. Some of these include the use of ferroelectric oxides for power switching applications, oxides with anisotropic dielectric constants for high voltage termination and oxides with large electric flux density near breakdown. Unique polarization engineered structures are described that are enabled by using lithographically defined poled regions in a ferroelectric substrate. The desired crystalline oxide properties, potential implementation challenges and potential pitfalls will be discussed. (C) 2003 Published by Elsevier Ltd.