RGTO: a new technique for preparing SnO/sub 2/ sputtered thin film as gas sensors

Abstract

A technique for the preparation of SnO/sub 2/ thin films by means of RF magnetron sputtering is presented. This technique, rheotaxial growth and thermal oxidation (RGTO), makes it possible to obtain thin films formed by polycrystalline grains, connected by necks and with high surface areas. SnO/sub 2/ thin films grown with this method and 300 nm thick show high sensitivity to such gases as H/sub 2/, C/sub 4/H/sub 10/, and C/sub 2/H/sub 5/OH. SEM (scanning electron microscope) analysis shows that these films are formed by grains with a diameter of 500-1500 mm which are randomly connected. XRD (X-ray diffraction) analysis shows that the SnO/sub 2/ thin films are preferentially oriented in the