Reactive sputtered TiO2 thin film humidity sensor with negative substrate bias

This study has demonstrated a simple fabrication process of a thin film cer amic relative humidity sensing chip at low temperature, 500 degreesC. This process window to optimize sensitivity and hysteresis performance of the se nsor has been studied using negative sputtering substrate bias and annealin g duration. This proposed optimizing method yields an adjustable rutile/ana tase phase ratio of titanium oxide. It shows improvement to the hysteresis of sensors and obtains good sensitivity, which is greater than four-orders of magnitude change in de current over 11-97% relative humidity. (C) 2001 E lsevier Science B.V. All rights reserved.