Patent ID: 8399349

Claim:
A process for forming an air gap, the process comprising: (a)providing a substrate; (b)depositing a sacrificial layer comprising silicon; (c)depositing a composite layer with a porogen and at least one silica-containing precursor or organosilicate glass(OSG) precursor; (d) applying energy to the substrate having the sacrificial layer and the composite layer to remove the porogen to form a porous layer; and (e)contacting the substrate having the sacrificial layer and the porous layer with a fluorine containing reagent under reduced pressure capable of diffusing through the porous layer to selectively remove the sacrificial layer to form air gaps; wherein depositing step (b) is via a process selected from the group consisting of a chemical vapor deposition (CVD) and a plasma enhanced chemical vapor deposition (PECVD); and depositing step (c) is via a process selected from the group consisting of chemical vapor deposition (CVD), spin-on coating, dip coating and mist deposition.