Stability and sensitivity of ammonia sensor based on porous silicon coated tin oxide
Porous silicon (pSi) with 86% porosity was fabricated from arsenic doped crystalline silicon wafer with (100) orientation. Porous silicon layers were produced via electrochemical anodization of Si wafer. After anodization, tin oxide (SnO2) was sprayed onto the surface of pSi. Then, aluminum (Al) contacts were deposited on the surface of pSi coated tin oxide via rf magnetron sputtering for electrical connection. The response of the fabricated sensor to ammonia vapor with different concentration was studied. The sensitivity and the stability of the sensor have been characterized and analyzed as a function of gas concentration and incubation period.