Moore’s law has been predicted as the trend for silicon technology over the last four decades [1]. Along the way, it has provided the fundamental complementary metal–oxide–semiconductor (CMOS) technology for today’s global information society. It was thought that silicon will be the dominant technology for at least 10 more years [1]. However, some uncertainties in the behavior of transistors under extreme low dimensions make silicon questionable for future circuit technology [2]. Therefore, the end of the silicon era has been predicted for quite some time now due to technical reasons.