A study of the structural and electronic properties of magnetron sputtered tin oxide films

Tin oxide (SnO_x) films have been deposited using a RF magnetron sputtering technique from a hot pressed SnO₂ target in an ambient mixture of argon and oxygen. Depending on the deposition parameters the structure of the films may be varied from amorphous to crystalline along with a consequent decrease in resistivity. An attempt has been made to understand the causes of formation of insulating and conducting films. By optimizing the oxygen partial pressure and substrate temperature, SnO_x films of resistivity 6.1*10^-3 Omega cm with a corresponding optical transmission approximately 95% and direct optical gap of 4.13 eV can be prepared. For films having a relatively high conductivity, a long exposure to the atmosphere changed their electronic properties which could be partially recovered by annealing. The effect of annealing SnO_x films in different ambients was studied.