Paper MC-TuM10
”More than Moore”: Could Silicene Be the Future of Electronics?

Tuesday, October 20, 2015, 11:00 am, Room 114

For more than forty years, the miniaturization of circuits by scaling down the transistor has been the principal driver for the semiconductor technology. As the number of components per chip increases, the total chip size has to be reduced within workable limits. Consequently, the technology roadmap for semiconductors or ”Moore's Law”(1), which states that the number of components integrated in a circuit would increase exponentially over time, has been successfully achieved by a continuous downscaling of the critical dimensions in the integrated circuit. Hence, since 1970, the number of components per chip has doubled every two years. However, we are nowadays nearing the basic limits of the scaling, thus for further improvement we may need ”More than Moore”(2). This new attractive trend adds value to devices by incorporating more functionalities to them, which do not necessarily scale according to Moore’s Law. Graphene is one of the best-placed novel materials to be included in a ”More than Moore” approach. A close relative of graphene, a 2D honeycomb lattice of Si atoms called Silicene has been recently reported as nanoribbons and single layers on silver (111) oriented monocrystals, (3,4). As silicon, unlike carbon, prefers sp3 hybridization instead of sp2 hybridization, silicone possess several stable buckled structures, which are compatible with the opening of a small gap (5). This ability makes silicene very attractive to be integrated to the already well-developed silicon-based electronics.

The task to create a new ”fabric” as silicene has been, however, very difficult because silicene does not exist in Nature and it is not as easy to form as graphene due surely to its particular electronic structure and larger atomic size. Over the last decade, research groups from around the world have claimed to have prepared silicene, a one atom-thick layer of silicon. However, just recently our team has created silicone single sheets of silicon on silver single crystal surfaces and has further characterized this novel material; using atomic resolution STM spectroscopy and high-resolution angle resolved photoemission, proving unambiguously the existence of one of the most stable phases of this unique material. (3)

REFERENCES

(1) Moore G.E., Electronics, Electronics, 38, 8 (1965); reproduced

in Proc. IEEE, 86, 82 (1998).

(2) ITRS website, http://www.itrs.net/home.html

(3) P. Vogt, et al., Phys. Rev. Lett. 108, 155501 (2012)

(4) P. De Padova et al., Appl. Phys. Lett. 96, 261905 (2010)

(5) S.S. Cahangirov, et at., Phys. Rev. Lett. 102, 236804 (2009)

(6) S.S. Cahangirov, et at., Phys. Rev. B 90,(3) ,035448( 2014)