Silver metal organic chemical vapor deposition for advanced silver metallization

The use of silver interconnects enables higher speed for silicon integrated circuits. The formation of Ag interconnects requires sequential deposition of a continuous barrier layer followed by silver deposition and chemical-mechanical polishing (CMP). In this article, various organometallic precursors (hfac)Ag(1,5-COD), (fod)Ag(PEt3) and (hfac)Ag(VTES) for the metal organic chemical vapor deposition (MOCVD) of silver on a TiN adhesion layer were evaluated and their deposition characteristics was studied. It was confirmed that Ag could be deposited at a substrate temperature as low as 180 °C with (hfac)Ag(VTES). The silver thin film was deposited at a precursor vaporization temperature of 50 °C and a substrate temperature of 220-250 °C, resulting in Ag film with resistivity around 1.8-2.0 μΩ cm.