Evaluation of Microstructure Evolution of Al-1%SI-0.5%CU Thin Film Induced By Post Deposition Processing

Abstract

AbstractThe evolution of grain structure of AI-1%Si-0.5%Cu film, deposited by sputtering at 150'C substrate temperature has been evaluated, comparing as deposited film microstructure and grain structure at the end of process, both on large metal areas and on narrow strips. Microstructure has been characterized by means of FIB, TEM and XRD analyses. Grain size evolution resulted to be strongly dependent from the type of substrate. In particular TiN substrate appeared to greatly inhibit AlSiCu grain growth. This behavior was attributed to the formation of Ti9AI23 intermetallic compound during the alloy thermal treatment, that pins grain boundaries thus limiting Al grain boundary mobility.