A semiconductor processing system with ultra low-K dielectric is provided including providing a substrate having an electronic circuit, forming an ultra low-K dielectric layer, having porogens, over the substrate, blocking an incoming radiation from a first region of the ultra low-K dielectric layer, evaporating the porogens from a second region of the ultra low-K dielectric layer by projecting the incoming radiation on the second region, and removing the ultra low-K dielectric layer in the first region with a developer.