Stabilization of fluorine-containing low-k dielectrics in a metal/insulator wiring structure by ultraviolet irradiation

The present invention relates to metal/insulator interconnect structures found in Very Large Scale Integrated (VLSI) and Ultra Large Scale Integrated (ULSI) devices and packaging, and more particularly to interconnect structures comprising fluorine-containing, low dielectric constant (low-k) dielectrics. Dielectric treatment methods for mitigating reliability problems associated with out-diffusion of fluorine from the low-k dielectric into other parts of such structures are taught. A method for providing regions of substantially lower fluorine content in a fluorine containing dielectric is described incorporating exposing a region to ultraviolet radiation and annealing at an elevated temperature to remove partially disrupted fluorine from the region. The invention overcomes the problem of fluorine from a fluorine containing dielectric reacting with other materials while maintaining a bulk dielectric material of sufficiently high or original fluorine content to maintain an effective low dielectric constant in semiconductor chip wiring interconnect structures.