3D applicable ALD film for humidity detection

In this work, ALD films are developed by alternately applying semiconducting ZnO grains and dielectric Al2O3 grains which result in homogeneous composites with humiditysensitive properties. Various films, which differ in the grain size ratio of ZnO to Al2O3, are tested with 2D sensor structures. IV-t measurements during interaction of the films with applied water droplets reveal current and resistance changes of up to five orders of magnitude. 3D applicability of these humidity-sensitive films is proven by cross-sectional SEM images of an all-around coated silicon chip.