Atomic layer deposition of SnO2 thin films using tetraethyltin and H2O2

Abstract

The atomic layer deposition (ALD) of SnO2 films has drawn interest from many researchers as a way to enhance the performance of functional materials for emerging applications such as transistors, sensors, and transparent electrodes. Among the critical issues in the exploitation of SnO2 ALD in industrial applications is the lack of commercially available Sn precursors. Here, we demonstrate an ALD process for SnO2 films using commercially available tetraethyltin (TET) as a precursor. H2O2 is used as the oxygen source to overcome the lack of reactivity between TET and H2O, consequently the reaction of TET and H2O2 results in the growth of SnO2 films. The ALD process has a wide ALD window of 250-400 degrees C. In the range of the growth temperature, the grown films show a high density of similar to 6.2 g/cm(3) and an optical band gap of 3.7-3.9 eV, which is comparable to that of bulk SnO2. Negligible impurities remained in the films grown over the entire temperature range. The crystallization behavior and electrical properties of the SnO2 films were examined as well. The ability of this ALD process to produce high-quality SnO2 films with a commercially available tin precursor will allow it to be exploited in various applications.