An method including forming multiple interconnect levels on top of one another, each level comprising a metal interconnect and a crack stop both embedded in a dielectric layer, and a dielectric capping layer directly on top of the dielectric layer and directly on top of the metal interconnect, the crack stop is an air gap which intersects an interface between the dielectric layer and the dielectric capping layer of each interconnect level, and forming a through substrate via through the multiple interconnect levels adjacent to, but not in direct contact with, the crack stop, the crack stop of each interconnect level is directly between the metal interconnect of each interconnect level and the through substrate via to prevent cracks caused during fabrication from propagating away from the through substrate via and damaging the metal interconnect.