Increased sensitivity of a gas sensor by controlled extension of TiO2 active area

In this article we deal with the preparation of nanostructured patterns of sputtered thin-film titanium dioxide surfaces. Such nanostructured surfaces are implemented into sensoric structures and are measured for the presence of gases, for detection of which we used a thin layer of polycrystalline TiO2 deposited on a resistive layer of SiO2. The basic principle of gas detection is the change in conductivity of thin TiO2 layer after gas exposure, and controlled geometrical extension of this area is the basic mechanism for increasing the sensor’s sensitivity. Another possibility to extend the surface of a gas sensor is by ICP etching through a suitable masking material or, eventually, a combination of both mentioned techniques. In order to increase the active area of TiO2 we compare here samples prepared by cylindrical and cuboidal geometries of the sensor’s active surface and show TiO2 surface modifications after their ICP plasma treatment.