  Nano Electro Mechanical (NEM) contact switches have been widely studied as
one of the alternative for classical field effect transistor (FET). An ideal
NEM contact switch with hysteresis free switching slope (SS) of 0 mV/dec is
desired to achieve the ultimate scaling of the complementary metal oxide
semiconductor (CMOS) integrated circuits (IC) but never realized. Here we show,
low pull-in voltage, hysteresis free graphene based NEM contact switch with hBN
as a contact larger. The hysteresis voltage is greatly reduced by exploiting
the weak adhesion energy between the graphene and hexagonal boron nitride
(hBN). The graphene NEM contact switch with hBN as contact exhibits low pull-in
voltage of < 2 V, high contact life time of more than 6x10^4 switching cycles,
ON/OFF ratio of 10^4 orders of magnitude and hysteresis voltage of as small as
< 0.1 V. Our G-hBN NEM contact switch can be potentially used in ultra-low
power energy efficient CMOS IC's.
