Growth Optimization, Morphological, Electrical and Sensing Characterization of V2O5 Films for SO2Sensor Chip

In this work, we investigate the Sulphur dioxide (SO
₂
) sensing characteristics of reactive-ion magnetron sputtered vanadium oxide (V
₂
O
₅
) film of different thicknesses, followed by morphological and electrical characterization. Later, sensing material is integrated on MEMS platform to develop a sensor chip to integrated with electronics to enable portable, real-time monitoring of gas. Sputtered films are studied for their sensing characteristics at different operating conditions to realize the optimum thickness film to integrate it with CMOS platform. SO
₂
limit of detection (LOD) and the detection precision is quantified as 38 ppb [(R
_a
- R
_g
)/R
_a
× 100% = 0.7] and ~10 ppb using optimized ~ 61 nm V
₂
O
₅
film. The film is found to be more selective towards SO
₂
gas as against CO, CO
₂
and NO
₂
gases. This optimized film is successfully integrated on the sensor platform, with the chip size of 1 mm
²
, with an inbuilt microheater power consumption of ~22 mW (at 326°C), to provide a localized uniform temperature to sensor film.