The Properties of Hexagonal ZnO Sensing Thin Film Grown by DC Sputtering on (100) Silicon Substrate

Abstract

This research was proposed to utilize sputtering system to fabricate sensing material of electronics nose of humidity sensor, and expected to use it in nano and multiple biosensor system with intelligent functions in new generation. The first test was material measurement for zinc oxides (ZnO) deposited on (100) Si substrate in variable thin film thickness and epitaxial growth time. The second test was that the variable growth time will be selected to study characteristics of the sensing material in humidity sensors by measurement of resistance and capacitance. The ZnO nanostructure-like were synthesized on silicon wafer with native buffer layer by the DC sputtering method, and the optimum growth conditions based on growth temperature, oxygen flow rate, and growth time, have been found. We discussed some issue of growth rate, resistivity of thin film, and crystalline of nanostructure, and also explained the sensing mechanism of ZnO hexagonal nanostructure in impedance measurement. It is experimentally demonstrated that the ZnO hexagonal nanostructures have potential growth by DC sputtering growth method on silicon wafer with native oxidation at room temperature. This grown ZnO epitaxial layers would be used in application of sensors.