Tin Oxide (SnO2) has established itself as excellent receptor in chemiresistive detection of ammonia gas in last two decades. There have been several routes developed to obtain a pristine SnO2 film over this time however, physical vapor deposition remains an attractive route for the same due to the control it provides for the growth and its scalability for industry scale production. In this work, we report on the effect of oxygen and argon ratio at different pressure in sputtering unit on the sensitivity of tin oxide. In particular, our investigation revealed that the device based on SnO2 thin film obtained at an sputtering pressure of 10 mTorr and Ar/O2 ratio of 50/50 possess highest response (~27.97% for 30 ppm of ammonia) at optimal temperature of 220 ℃. © 2020 Elsevier B.V.