Phase-gradient atomic layer deposition of TiO2 thin films by plasma-induced local crystallization

Atomic layer deposition (ALD) is a thin-film fabrication method that can be used to deposit films with precise thickness controllability and uniformity. The low deposition temperature of ALD, however, often interrupts the facile crystallization of films, resulting in inferior optical and electrical properties. In this study, the extremely localized crystallization of TiO2 thin films was demonstrated by per-cycle plasma treatment during the plasmaenhanced ALD process. By layering crystalline and amorphous films, a phase-gradient TiO2 film with precisely modulated optical and electrical properties was fabricated. Moreover, the ratio between the amorphous and crystalline layer thicknesses for a high dielectric constant and low leakage current density was optimized.

Automated summary

This study demonstrates a method to achieve localized crystallization of TiO2 thin films through plasma treatment, and modulates the optical and electrical properties by fabricating phase-gradient TiO2 films, optimizing the ratio between amorphous and crystalline layer thicknesses.