Chemical Vapor Deposition of Ru and Its Application in (Ba,Sr)TiO₃ Capacitors for Future Dynamic Random Access Memories

Abstract

Ru films were fabricated by chemical vapor deposition using Ru(C 5 H 5 ) 2 and O 2 . The deposition of Ru film was controlled by the surface reaction kinetics as the rate limiting step with activation energy of 2.48 eV below 250°C and by the mass transport process above 250°C. Ru films had a polycrystalline structure and showed low resistivity of about 12 µΩcm. Ru films deposited at 230°C showed excellent step coverage. We applied Ru films prepared by chemical vapor deposition to the bottom electrode of a Ba 0.25 Sr 0.75 TiO 3 capacitor and obtained good electrical characteristics.