Effect of deposition time SnO2 thin film deposited using thermal CVD for humidity sensor application

The effect of SnO₂ thin film thickness as humidity sensor application has been investigated. In this paper, Humidity sensitivity of SnO₂ thin film at different thickness deposited by thermal chemical vapor deposition were presented. The electrical, optical and structural properties of SnO₂ thin film deposited at different deposition time using thermal chemical vapor deposition (CVD) were investigated. The thin films were characterized using current-voltage (I-V) measurement (Keithley 2400) and photoluminescence (PL) measurement (Horiba Jobin Yvon-DU420A-OE-325 system) for electrical and optical properties respectively. The structural propeties has been characterized using field emmision scanning electron microscopy (FESEM) (JEOL JSM 6701F). The humidity measurement were conducted on Au metal contact deposited on SnO₂ thin film that connected to a circuit using copper wire. The sensor were characterized using I-V measurement (Keithley 2400) in a humidity chamber (ESPEC SH-261) and the chamber has been set at same room temperature (25 °C) but different percent relative humidity (RH %) at 40 RH% to 90 RH. Deposition time for 60 minutes show high sensitivity . PL measurement revealed one peak at about between range red emission for all thin film. FESEM image show SnO₂ nanoparticle growth on the nucleation site of gold catalyst.