A series of samples of nanocrystalline zinc oxide films was fabricated by reactive magnetron sputtering under different regimes, heating up to 200-250 ° C and subsequent annealing. The effect of relative humidity in the range of 25-80% on the resistance of zinc oxide films was investigated. The character of the dependence of fabrication regimes on film resistance at different relative humidities was detected. The optimum conditions of insensitive to relative humidity zinc oxide films formation was obtained.
Keywords: nanocrystalline films, zinc oxide, magnetron sputtering, electrical resistance, relative humidity
Results of researches of gas sensitive properties of zinc oxide films grown by reactive rf magnetron sputtering was shown. Process parameters, affected on the gas-sensitive ratio, response time, recovery time and the type of electrical conductivity of obtained films were identified. Optimal modes of magnetron sputtering of zinc oxide for implementing gas sensors (RF sputtering Zn target in a gas mixture of oxygen and argon at a concentration of 80% oxygen, a chamber pressure of 0.8 Pa and the magnetron power 100 W) were established. Avarage response time on NO2 gas was 5-15 sec. The obtained values of the gas-sensitivity were in the range 30-67% for NO2 concentrations from 20 to 100 ppm, CO and CO2 from 50 to 100 ppm and 81-97% for higher gas concentrations from 500 to 1000 ppm.
Keywords: Nanotechnology, magnetron sputtering, zinc oxide, thin films, gas sensitivity