Every atom counts

With CMOS scaling to nanometre dimensions near the end of the roadmap, atomic scale effects will introduce increasingly large variations between the characteristics of individual transistors, hampering their integration into Giga-transistor chips. Device characteristics mismatch are starting to affect already the function and the reliability not only of analogue but also digital circuits and systems. The designer should be acutely aware of the forthcoming problems. A shift to fault-tolerant design, that includes support for redundancy, self-organising and reconfigurable architectures and intensive on-chip testing will be needed to combat the increasing levels of intrinsic parameter fluctuations that will accompany transistor scaling in the next two decades.