2002 年 43 巻 7 号 p. 1585-1592
A CVD-WN film is deposited as a barrier metal for copper interconnection using thermal CVD (Chemical Vapor Deposition) of WF6/NH3/SiH4 gases. Deposition of CVD-WN film with a resistivity of less than 300 \\microΩ·cm at a temperature of 400°C or less has been realized for the first time in the world. The deposited WN film is proved to be excellent in barrier properties and able to prevent Cu diffusion even with the film thickness of 6 nm as well. It is also proved that the CVD film is superior to a sputtered barrier metal in coverage and ECD (Electro-chemical deposition) filling properties. XPS analysis showed that adhesion of the CVD film to low-k materials is deteriorated by the existence of F at the interface between the WN film and low-k. Chemical surface pretreatment for low-k materials proves to restrain the pile-up of F at the interface and improve adhesion.
