Growth characteristics and film properties of gallium doped zinc oxide prepared by atomic layer deposition

Abstract

We carried out comprehensive studies on structural, optical, and electrical properties of gallium-doped zinc oxide (Ga:ZnO) films deposited by atomic layer deposition (ALD). The gallium(III) isopropoxide (GTIP) was used as a Ga precursor, which showed pure Ga2O3 thin film with high growth rate. Using this precursor, conductive Ga doped ZnO thin film can be successfully deposited. The electrical, structural and optical properties were systematically investigated as functions of the Ga doping contents and deposition temperature. The best carrier concentration and transmittance (7.2x10(20) cm(-3) and 83.5 %) with low resistivity (approximate to 3.5x10(-3) Omega cm) were observed at 5 at.% Ga doping concentration deposited at 250 degrees C. Also, low correlation of deposition temperature with the carrier concentration and film structure was observed. This can be explained by the almost same atomic radius of Ga and Zn atom.