The Influence of the pressure and time deposition to sensitivity of the SnO₂ thin films gas sensor

Research on the influence of pressure and time deposition on the sensitivity of gas sensor fabricated using technique DC Sputtering has been done. The variation of pressure were 3 ×10^-2, 4×10^-2, 5×10^-2, 6×10^-2 and 7×10^-2 Torr and time variation were 30, 60, 90, and 120 minutes, DC high voltage was 2 kV and temperature deposition was 250 °C. The results showed that SnO₂ thin films with parameter process voltage 2 kV, current 10 mA, pressure 7×10^-2 Torr, time 120 minutes and temperature deposition was 250 °C have optimum sensitivity to detect : C₂H₅OH, NH₃, CO dan HNO₃ gas. Results showed that the optimum sensitivity for gas C₂H₅OH was 46.95 % and NH₃ 41.91 %. Measured at 5.529 ppm. SEM-EDS analysis showed that at this condition the thickness of SnO₂ thin film was in order of ± 4.5 μm, while the content of oxygen (O) and Sn were 69.32 % and 30.60 % respectively. (author)