DESIGN OF A TEST STRUCTURE TO EVALUATE ELECTRO-THERMOMIGRATION IN POWER ICS

The design of a novel test structure to study the influence of electro migration and thermomigration in the large dimension metal lines used in power integrated circuits is reported. Incorporated into the test s tructure are a heating element and a number of temperature monitors, t o enhance the thermal gradient and to measure it, respectively. Therma l simulations have been performed and compared with the electrical cha racterization carried out on a set of test structures. The agreement b etween simulation end electrical measurements has been proved confirmi ng the validity of the test structure as a vehicle for a deeper unders tanding of the reliability of the line under the influence of thermal gradients. Copyright (C) 1996 Elsevier Science Ltd