Silicon/silicide grown out of nanoporous gold nanoparticles

Ordered arrays of nanoporous gold nanoparticles were fabricated via a combination of solid‐state dewetting of Au/Ag bilayers on pre‐patterned SiO 2 /Si substrates and a subsequent dealloying process. AuAg alloy nanoparticles were formed after dewetting, and a subsequent dealloying process leads to the formation of nanoporous gold nanoparticles. The dewetting was carried at 700, 800, and 900 °C, respectively. The growth of Si or silicide particles occurred after dewetting at 800 and 900 °C, and these particles remains even after the dealloying process. This growth is supposed to occur via a solid–liquid–solid (SLS) mechanism, and mainly Ag serves as catalyst. A 20 nm thick thermal SiO 2 is sufficient to avoid this reaction between the Au/Ag bilayers and the Si substrate when the dewetting temperature is 700 °C.