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CMU-CS-02-181
Computer Science Department
School of Computer Science, Carnegie Mellon University
CMU-CS-01-114
What Makes a Good Molecular-Scale Computer Device?
Seth Copen Goldstein, Dan Rosewater
March 2001
An updated version of this report now appears as
CMU-CS-02-181 (September 2002)
CMU-CS-01-114.ps
CMU-CS-01-114.pdf
Keywords: Chemically assembled electronic nanotechnology,
two-terminal devices, molecular latch, resonant tunneling diodes,
clocking scheme
The lithographically-produced CMOS transistor has been the key
technology that has enabled the information revolution. However, in
the near future the limitations, both technical and economic,
introduced by lithographic fabrication may inhibit further decreases
in feature size. Chemically assembled electronic nanotechnology
(CAEN) is a promising alternative to CMOS for constructing circuits
with device sizes in the tens of nanometers, far smaller than is
thought possible using lithography. In this paper we examine and
contrast the constraints imposed by lithographic versus CAEN
fabrication; the key limitation is that three-terminal devices, such
as transistors, will be impractical at the nanoscale. We
demonstrate that these constraints can be satisfied by outlining an
architecture that uses only two-terminal CAEN devices to compute
without transistors. One crucial requirement of this design circuit
is that it be able to restore signals to a reference state without
transistors. We present preliminary results for a molecular latch,
constructed from molecular resonant tunneling diodes (RTDs) that can
perform signal restoration, I/O isolation, and voltage buffering
without transistors at the nanoscale.
19 pages
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