Micro-machined WO3-based sensors with improved characteristics

Characteristics of WO3-based micro-machined sensors prepared using modified technologies of sensing layer deposition have been studied. The sensing films were deposited using two sputtering regimes. The first one included three interruptions of the deposition process. The second one comprised a deposition by using a floating regime that included three interruptions as well. In the first two interruptions the sputtering power was 100 W and in the last one the sputtering power was set to 280 W. Additionally to the operations of film deposition, annealing and lift-off processes were optimized. The micro-sensors showed high sensitivity and selectivity to oxidizing gases. The stability of the micro-sensors has been investigated as well. An explanation for the high sensitivity and selectivity of these new micro-sensors is presented in this study.