Mitigating Electromigration in Physical Design
摘要
The goal of this chapter is to summarize the state-of-the-art in electromigration (EM)-mitigating effects. Sections 4.2–4.7 describe in detail all known EM-inhibiting effects upon which an “electromigration awareness” is based. We also consider material-related options to reduce EM, like surface passivation (Sect. 4.8), and the use of EM-robust materials, such as carbon nanotubes (Sect. 4.9). We determine parameters for every measure, which enable them to be used easily; we also provide detailed advice for applying each method. We show how approved current densities can thus be increased at critical points, for example, by means of local layout modifications. The presented measures provide circuit designers with a suite of options to prevent EM damage in present, and future, technology nodes. Ultimately, the challenge is to avoid exceeding permissible current densities by selectively increasing the permissible boundaries.