Assessing simultaneous effect of Ar/O2 ratio and process pressure on ammonia sensing properties of reactive DC magnetron sputtered SnO2 thin films

• Published in: Materials letters 2021-03, Vol.286, p.129239, Article 129239
• Main Authors: Prajesh, Rahul, Jha, Ravindra Kumar, Saini, Vikas, Nahid, Mohd, Goyal, Vinay, Chaudhury, Pubali, Bhargava, Jitendra, Sharma, Ashok Kumar, Agarwal, Ajay
• Format: Article
• Language: English
• Subjects: Ammonia; Argon; Electronic materials; Magnetic properties; Materials science; Physical vapor deposition; Sensors; Sputtering; Thin films; Tin dioxide; Tin oxide; Tin oxides
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.129239

•SnO2 thin films were prepared by reactive DC magnetron sputtering.•In the deposition process, ratio of Ar and O2 was varied with the process pressure.•Ar:O2 ratio and pressure was found to affect crystallinity and sensing behavior.•SnO2 deposited with Ar/O2 (50:50) at 10 mTorr pressure showed optimal sensing.•The response of the optimized film was found to be 27.97% @ 30 ppm of NH3 at 220 ℃. 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 ℃.