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I will review some old and some recent work on the fundamental (and not so fundamental) limits imposed by physics of electron devices on their density and power consumption. In particular, I will discuss:
reversible computing, that allows one to beat the apparent Maxwell's-demon (E > kBTln2) and uncertainty-relation (E > /£n) "limits" for energy dissipation E per logic operation, and
quantum-mechanical effects that impose limits on shrinking of both field-effect and single-electron transistors.
I will argue that the impact of scaling limitations is grossly exacerbated by the economics of the current microcircuit fabrication paradigm. This problem may be overcome by transfer from the purely CMOS technology to hybrid "CMOL" integrated circuits. Such a circuit would combine an advanced (e.g., 45-nm) CMOS subsystem capped with two levels of mutually perpendicular nanowires. The nanowires are bridged with specially designed molecules that would self-assemble on them from solution. CMOL circuits may allow to combine advantages of their nanoscale components (e.g., reliability of CMOS circuits and miniscule footprint of molecular devices) and circumvent their drawbacks (e.g., low voltage gain of molecular devices), while keeping the fabrication facilities costs within reasonable limits. Possible architectures of CMOL circuits, and their speed vs. power consumption tradeoffs will be reviewed in brief.
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