A series of experiments have been conducted to evaluate the magnetotransport properties of RF diode sputter deposited giant magnetoresistive (GMR) multilayers with either copper or copper-silver-gold nonferromagnetic (NFM) conducting layers. The study revealed that RF diode deposited multilayers utilizing Cu80Ag15Au5 as the NFM conducting layer posses significantly superior giant magnetoresistance to otherwise identical device architectures that used pure copper as the NFM conducting layer. To explore the origin of this effect, copper and Cu80Ag15Au5 films of varying thickness have been grown under identical deposition conditions and their surface morphology and roughness investigated. Atomic force microscopy revealed significant roughness and the presence of many pinholes in thin pure copper films. The surface roughness of the Cu80Ag15Au5 layers was found to be much less than that of pure copper, and the alloying eliminated the formation of pinholes. Molecular statics estimates of activation barriers indicated that both silver and gold have significantly higher mobilities than copper atoms on a flat copper surface. However, gold is found to be incorporated in the lattice whereas silver tends to segregate (and concentrate) upon the free surface, enhancing its potency as a surfactant. The atomic scale mechanism responsible for silver's surface flattening effect has been explored.

Radio frequency (RF) diode sputtering has been used for the growth of giant magnetoresistive (GMR) metal multilayers. Control of the atomic-scale structure of the surfaces and interfaces within these films is critical for GMR applications. A systematic series of experiments have been conducted to evaluate the dependence of the magnetotransport properties upon the growth conditions (i.e. background pressure, input power) for NiFeCo/CoFe/CuAgAu spin valves during RF diode sputter deposition. By using computational fluid dynamics, plasma, molecular dynamics, and various Monte Carlo techniques, a multiscale modeling approach has investigated the atomic assembly events during film growth. Energetic metal atoms and inert gas ion fluxes are shown to have very strong effects upon interfacial structures. The insights gained have led to novel deposition strategy propopositions for interface morphology control.

Aluminum and copper nanolaminates have been fabricated at Jet Process Corporation using the novel, proprietary Jet Vapor DepositionTM (JVD)TM process. Laminates with a total thickness of 10 μm were made by depositing alternating layers ofapproximately equal thicknesses of copper and aluminum onto preheated silicon wafers at asubstrate temperature of ∼140 °C. The layer thicknesses were systematicallyvaried between 20 nm and 1 μm. The microstructure and properties of the laminates were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and nanoindentation methods. TEM has shown that the laminates have a strong {111} texture. The hardness results show that above a critical layer thickness of approximately 50 nm, the yield strength of the composites varies inversely with thelayer thickness, while the strength of nanolaminates with layer thicknesses smaller than the critical thickness is better explained by the Koehler model. An alternative model recently proposed by Embury and Hirth fits the data equally well.