Patent ID: 7378350

Claim:
A method of making a BEOL interconnect structure including a porous or dense low k dielectric having low via contact resistance comprising the steps of: a) forming a porous or dense low k dielectric layer on a substrate; b) forming single or dual damascene etched openings in said porous or dense low k dielectric; c) placing said substrate in a process chamber on a cold chuck at a temperature about −200° C. to about 25° C.; d) adding to said process chamber a condensable cleaning agent (CCA) to condense a layer of CCA within said single or dual damascene etched openings in said porous or dense low k dielectric, said condensable cleaning agent (CCA) is selected from the group consisting of a metal hydride, a metal fluoride, an organic fluorine compound, an inorganic fluorine compound, a source of both hydrogen and silicon, and a combination thereof; and e) the layer of the condensable cleaning agent (CCA) while the substrate remains cold at a temperature of about −200° C. to about 25° C.