Multi-station sequential curing of dielectric films

The present invention provides improved methods of preparing a low-k dielectric material on a substrate. The methods involve multiple operation ultraviolet curing processes in which UV intensity, wafer substrate temperature, UV spectral distribution, and other conditions may be independently modulated in each operation. Operations may be pulsed or even be concurrently applied to the same wafer. In certain embodiments, a film containing a structure former and a porogen is exposed to UV radiation in a first operation to facilitate removal of the porogen and create a porous dielectric film. In a second operation, the film is exposed to UV radiation to increase cross-linking within the porous film.