Black's equation for today's ULSI interconnect Electromigration reliability — A revisit

Abstract

Electromigration (EM) is an important failure mechanism in Ultra-Large-Scale Integration (ULSI) interconnections. The Black's equation is a simple empirical EM model, which is widely accepted in the industry as the most common method to extrapolate the median time to failure (MTF) from the accelerated test condition to the normal operating condition. Although the empirical model of the Black's equation is simple in implementation, its validity has been a great controversy in the literature and will be described later. In this work, we revisit the Black's equation for its success in the industry and its validity. In the presence of the additional driving forces and other important Electromigration physics which are not considered in the Black's equation for today ULSI interconnects, the application of the Black's equation for today's ULSI interconnects become inaccurate as shown experimentally. An alternative model based on the physics-based Electromigration simulation and Eyring model in extrapolation is proposed in this work.