Intrinsic failure mechanisms are operative within the silicon chip or die. The sources that cause such failures may be defects in the silicon wafer (e.g., dislocations, stacking faults) or defects introduced during subsequent processing. Included are failure mechanisms in grown or deposited insulators, metallizations, contacts to devices, and so on. Such failures are associated with the "front end" or chip processing stage of manufacturing.
Extrinsic failures are identified with the interconnection and packaging stages of manufacturing (i.e., the "back end").