Electric Clock for NanoMagnet Logic Circuits - Field-Coupled Nanocomputing: Paradigms, Progress, and Perspectives - page 102

4 Conclusions
The clock solution here proposed represents an important breakthrough for
NanoMagnet Logic. It achieves two important results:
- It allows to develop a true low power system, considering also the losses in
the clock generation network.
- It can be fabricated with current technological processes because it is designed
around the constraints arisen by the fabrication processes themselves.
However, some problems require further investigations. From the technolog-
ical point of view issues related to the patterning of magnetic materials (for the
magnets fabrication) on a piezoelectric substrate must be solved. That means to
understand and to solve problems of the currently employed lithographic tech-
niques for magnetic layer patterning. Secondly, it is important to understand how
the physical properties of piezoelectric materials scale with dimensions. Proba-
bly a suitable compromise between performance and piezoelectric layer thickness
must be found.
Moreover, some important questions arise, and they must be investigated
both from a theoretical and experimental point of view. Are there any other
sources of energy loss that are not considered here (like unwanted leakage cur-
rents)? Are there problems of crosstalk between neighbor clock zones? It is know
that piezoelectric devices can work at frequency equal to tens of MHz, but what
is the real maximum frequency that can be achieved? Since this system is based
on mechanical deformations, do the vibrations caused by the environment influ-
ence it? Which is the expected reliability of this system?
We are trying to understand these problematics and to solve the related
problems. Our goal is to destroy one of the most important barrier for the
successful development of this technology, the clock power consumption, in order
to finally get the first full-magnetic devices.
Acknowledgements. We thank Nanofacility Piemonte and Compagnia di San Paolo
for the support. We would also like to thank ˇ Lab laboratory (Materials and Processes
for Micro & Nano Technologies - Chivasso) for the technical support in PZT deposition.
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