1. Introduction
Many technological fields are experiencing one major revolution, coming from the possibility of manipulating and assembling objects at the nanometer scale. With the term “nanotechnology” we roughly refer to the possibility of manipulating objects at the nanometer scale. In the last decades, we have been facing huge advances in CMOS technology, which enabled the mass production of powerful small electronic devices. At the basis of such creations, there is the introduction of silicon transistors. Technological advances have then made it possible to build ever smaller, faster and cheaper devices [1].