Demonstration of Sputtering Atomic Layer Augmented Deposition: Aluminum Oxide-Copper Dielectric-Metal Nanocomposite Thin Films.

Abstract

Designing a thin-film structure often begins with choosing a film deposition method that employs a specific process by which chemical species are formed and transported; in other words, a film deposition system in which two deposition methods are hybridized should lead to new ways of designing thin-film structures. This premise inspires us to combine atomic layer deposition (ALD) and magnetron sputtering (SPU) within a single chamber-supttering atomic layer augmented deposition (SALAD). SALAD takes full advantage of both ALD's precise and accurate precursor delivery and SPU's versatility in choosing chemical elements. A SALAD system is designed based on knowledge obtained from computational fluid dynamics with the goal of conceiving a film deposition system that satisfies deposition conditions distinctive for both ALD and SPU. As a demonstration, the SALAD system is utilized to deposit a unique nanocomposite made of aluminum oxide (Alox) thin films by ALD and copper (Cu) thin films by SPU-AlOx-Cu nanocomposite thin films. Spectroscopic reflectivity collected on AlOx-Cu nanocomposite thin films shows unique dispersion features to which conventional effective medium theories used for describing optical properties of composites made of a dielectric host that contains metallic inclusions do not seem to simply apply.