FINE ZNO PATTERNING WITH CONTROLLED SIDEWALL-ETCH-FRONT SLOPE

摘要

This paper describes a wet etching technique that solves themajor difficulty of fine patterning a c-axis oriented polycrystallineZnO film. The technique, for the first time, allows the ZnO film tobe etched (1) with controlled etch rate ratio between the verticaland horizontal etch rates and (2) with controlled etch-front slope.The ratio between the vertical and horizontal etch rates is as highas 20 to 1, while the angle between the sidewall etch-front surfaceand the substrate surface can be electrically controlled between 73 and 106 . And ZnO films can now be patterned to fine features(even sub- m level) by a wet etchant.