Dual-damascene interconnects without an etch stop layer by alternating ILDs

摘要

A dual-damascene process where first alternate ILDs are made of a first material and second alternate ILDs are made of a second material. Each material is etchable at a faster rate than the other in the presence of different etchant such as for an organic polymer and an inorganic low k material. This allows the ILDs to be deposited alternately on one another without an etchant stop layer thereby reducing capacitance.