Sensitivity of Ag/Al Interface Specific Resistances to Interfacial Intermixing

TL;DR

This study measures the Ag/Al interface resistance and finds it highly sensitive to interfacial disorder, with experimental values exceeding predictions for perfect interfaces, indicating a significant impact of intermixing and disorder on interface properties.

Contribution

The paper provides experimental measurements of Ag/Al interface resistance and demonstrates the strong influence of interfacial intermixing on resistance values and anisotropy ratios.

Findings

Measured 2AR(Ag/Al)(111) = 1.4 fΩ·m^2, twice the perfect interface prediction.

Large resistance suggests interface thickness ≥ 4 ML with intermixing.

Interfacial disorder reduces anisotropy ratio from >4 to <2.

Abstract

We have measured an Ag/Al interface specific resistance, 2AR(Ag/Al)(111) = 1.4 fOhm-m^2, that is twice that predicted for a perfect interface, 50% larger than for a 2 ML 50%-50% alloy, and even larger than our newly predicted 1.3 fOhmm^2 for a 4 ML 50%-50% alloy. Such a large value of 2ARAg/Al(111) confirms a predicted sensitivity to interfacial disorder and suggests an interface greater than or equal to 4 ML thick. From our calculations, a predicted anisotropy ratio, 2AR(Ag/Al)(001)/2AR(Ag/Al)(111), of more then 4 for a perfect interface, should be reduced to less than 2 for a 4 ML interface, making it harder to detect any such anisotropy.