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

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.