Introduction
The most recent International Technology Roadmap for Semiconductors [1] of the Semiconductor Industry Association (SIA) basically affirms the desire of the industry to stay on Moore's Law [2]. The phenomenal progress signified by the Moore's Law has been achieved through scaling of the complementary MOSFET (CMOS) [3]–[5]. Scaling CMOS towards the 25 nm channel length generation requires innovations to circumvent barriers due to the fundamental physics that constrains the conventional MOSFET. These innovations generally fall into two categories: (1) adopt a new device structure, and (2) employ a new material set.