AN INTEGRAL-EQUATION APPROACH TO ELECTROMIGRATION UNDER ARBITRARY TIME-DEPENDENT STRESS

We present an integral equation reformulation of the drift-diffusion e quation for modeling void buildup in integrated circuit interconnects due to the electromigration of aluminum atoms, The method can deal wit h arbitrary time-dependent current stress and offers a number of advan tages over the conventional finite-difference approach. in particular, the boundary conditions are included in an intuitive and straightforw ard fashion. By way of illustration we identify the conditions under w hich the time-to-failure scales as r(-2) for unidirectional square-wav e stress of duty cycle r. (C) 1996 American Institute of Physics.