Room-temperature rf magnetron sputtered ZnO for electromechanical devices

Zinc oxide has been deposited using an r.f. magnetron sputtering system, from metallic zinc and ceramic zinc oxide targets, in an atmosphere containing 0 to 100% oxygen. Substrate temperatures from 25 to 450 degrees C have been used and several samples have been annealed in air at 430 degrees C. Coming 7059 glass and stainless-steel wafers are used as substrate materials with prior- and post-deposited aluminium as the contacting material when necessary. Characterization of these films has included scanning electron microscopy, X-ray diffraction, resistivity and dielectric measurements, The high thermal-expansion coefficient of the stainless steel dictated the need for zinc oxide deposited at low temperatures. Good dielectric films of highly oriented zinc oxide are now being produced at room temperature and have been used to drive and pick up from a resonant structure. A theory for the deposition and growth mechanisms occurring at room temperature has been proposed.