Patent ID: 8836127

Claim:
A device, comprising a plurality of low k inter-metal dielectric (IMD) layers formed over a semiconductor substrate, the low k IMD layers having a dielectric constant less than 3.0, the substrate comprising at least one active device; at least one first IMD layer over the plurality of low k IMD layers, the at least one first IMD layer comprising a first via formed of a conductive material, the first IMD layer formed of a polyimide material having a coefficient of thermal expansion less than 25 ppm/° C. and an elastic Modulus greater than 3 Gpa, at least one second IMD layer above the at least one first IMD layer, the at least one second IMD layer comprising a first trench filled with a conductive material forming a first conductive line, the first conductive line conductively connected to the first via, wherein the second IMD layer is made of a material that is more susceptible to planarization than the first IMD layer.