Mechanism of High Qualified Mn-Co-Ni-O Thin Films Grown at Low Temperature

Abstract

High quality of Mn-Co-Ni-O (MCNO) thin films were prepared by radio frequency (RF) magnetron sputtering deposition at a very low temperature of ≤450 ℃. The structure and electrical transport of films under different growth temperatures and annealing conditions were investigated. It was found that the film can be transformed from a mixed conduction mechanism to a single variable-range hopping conduction mechanism under appropriate growth temperature and annealing conditions. The optimized Mn3+/Mn4+ ratio in the film is close to 1, which is corresponding to the best probability of small polaron hopping, lowest activation energy, lowest room temperature resistivity, large negative resistance temperature coefficient, and the specific preferred (400) orientation. The electrical properties of the film is similar to that prepared under high temperature condition, which promotes the integration of MCNO to the present mature silicon technology. Our results provide an important avenue for the development of infrared focal plane arrays.

Keywords: Low Temperature growth, RF magnetron sputtering, High qualified Mn-Co-Ni-O, Small polaron hopping conduction, Electrical transport mechanism