The compatibility of ZnO piezoelectric film with micromachining process

This paper presents the compatibility of ZnO piezoelectric films with the process of micromachining. As a reactive material, ZnO films are sensitive to temperature, acids, bases, and even water. These films may easily be damaged in the subsequent process steps. Therefore, different from most of the present investigations that focus on how to fabricate ZnO films with good performance, this paper discusses how to protect ZnO films against degradation in subsequent micromachining processes. The main micromachining processes related to ZnO films, including cleaning, photolithography, etching, photoresist stripping, metal layer patterning, passivation and dielectric layer deposition, and reaction ion etching (RIE), are investigated. How these subsequent micromachining processes change ZnO films performance and how to minimize or avoid such performance changes is presented. Some suggestions about the subsequent micromachining process steps are given. (C) 2003 Elsevier Science B.V. All rights reserved.