Relationships Between Morphology and Stress-State of Gold-Silver Alloys and Nanoporous Gold Blanket Films

Abstract

Gold-silver alloy films deposited on silicon wafers were annealed at temperatures between 100{degree sign}C and 400{degree sign}C, and subsequently dealloyed. The grain morphology and stress-state evolution of the samples before and after dealloying were studied by scanning electron microscopy and wafer curvature measurements. The residual stress in alloy films was augmented through thermal treatment; however, the subsequent dealloying step mitigated the residual stress without introducing significant changes in pore morphology. Possible mechanisms for stress and morphology evolution are reported.