The study of electronic conduction in amorphous thin films of Al-In₂O₃-Al structure deposited by thermal evaporation

Abstract

A discussion of electronic conduction in amorphous thin films of Al-In₂O₃-Al structure is presented. Particular attention is given to the question of film thickness, substrate temperature during deposition and post-deposition annealing, since these conditions are known to have a profound effect on the structure and electrical properties of the films. The effects of temperature on the V-I characteristics and effects of frequency on conductivity and capacitance of the Al-In₂O₃-Al structure are also reported. Activation energies for conduction processes are estimated and the results are discussed in terms of the hopping model. The conduction at higher temperature is seemingly a contact-limited, i.e. Schottky type process, so a transition from hopping to free-band conduction takes place. The capacitance decreases with the rise of frequency and the lowering of temperature. The values of dielectric constants are estimated and the results are discussed in terms of Schottky type of conduction. The increase in conductivity with the increase in temperature during measurements of electrical properties, film thickness, substrate temperature and post deposition annealing is reported and results are discussed in terms of current theory.