HDP-CVD deposition of low dielectric constant amorphous carbon film

The present invention generally provides a method for depositing a low dielectric constant amorphous carbon film on a substrate or other workpiece using high density plasma chemical vapor deposition (HDP-CVD) techniques. Specifically, the present invention provides a method for forming an amorphous carbon film having a low dielectric constant of less than about 3.0 and a high thermal stability at a temperature of at least about 400° C. In a preferred embodiment, the film is deposited using methane (CH4) and argon in a HDP-CVD reactor. The amorphous carbon film formed according to the invention is useful for many applications in ultra large scale integration (ULSI) structures and devices, such as for example, an inter-metal dielectric material and an anti-reflective coating useful for patterning sub-micron interconnect features.