Graphite approach to FPGAs

Researchers led by Rice University's Prof James Tour have shown how strips of graphite could be used to create reprogrammable gate arrays.

In a paper published in the online journal ACS Nano, Tour and postdoctoral associate Alexander Sinitskii show how they used industry standard lithographic techniques to deposit 10nm strips of amorphous graphite onto silicon.

The researchers then found that running a current through the10-atom-thick layer of graphite created a complete break in the circuit – literally, a gap in the strip a couple of nanometres wide. Another jolt repaired the break. Better yet, the process appears to be indefinitely repeatable.

As a result of Tour's work, NuPGA (new programmable gate arrays), a California company, has been formed to create a new breed of reprogrammable gate arrays.

The Tour lab and NuPGA, led by industry veteran Zvi Or-Bach (founder of eASIC and Chip Express), have applied for a patent based on the use of vertical arrays of graphite embedded in the vias in integrated circuits.

When current is applied to such a graphite-filled via, the graphite alternately splits and repairs itself, just like it does in strip form. Essentially, it becomes an 'antifuse', the basic element of one type of field programmable gate array (FPGA).

Currently, antifuse FPGAs can be programmed once. But this graphite approach could allow for the creation of FPGAs that can be reprogrammed at will.

The ACS Nano paper appears here: http://pubs.acs.org/doi/pdf/10.1021/nn9006225