The electronics revolution of the past 50 years has its roots in two scientific and technological areas. On the one hand, there have been tremendous advancements in our understanding of the physics of metals, dielectrics, and semiconductors, leading to the development of devices such as the transistor. On the other hand, a variety of processing techniques such as thin-film growth and deposition, ion implantation, and photolithography have allowed the massive integration of electronic functionality within a very small area, leading to microprocessors and high-density memory, among other innovations.