The information technology (IT) industry is confronting an acute problem in the form of increasing power and energy consumption by electronic products, which is projected to have dramatic impact on the global energy crisis. This is partly due to the fact that a significant fraction of the energy consumption in the IT industry results from the computing components? (such as servers) energy need, which in turn, depends on the power consumption of the various integrated circuits in these components. Hence, designing low-power and energy-efficient integrated circuits or Green Electronics constitutes a key area for sustaining the irreversible growth of the global IT industry. Achieving energy-efficiency is also of critical importance for all electronic circuits used in mobile applications for increasing the battery life.
Energy-efficiency can be achieved by lowering both dynamic and leakage power consumption. However, lowering of power using traditional techniques becomes increasingly difficult beyond the 22 nanometer technology node. This is due to the fact that in such nanoscale devices, the most effective knob used for lowering power, namely the power supply voltage, cannot be scaled as rapidly as in earlier technology generations without incurring significant performance penalty arising from the inability to simultaneously reduce the threshold voltage. Simultaneous scaling of threshold voltage, which is essential for maintaining a certain ON to OFF ratio of the device currents (that is essential in digital circuits where the transistors are used as switches), leads to a substantial increase in the sub-threshold leakage (OFF state) current, owing to the non-abrupt nature of the switching characteristics of MOSFETs, thereby making the devices very energy inefficient.
This project aims to address this critical issue at the most fundamental level by designing circuits and systems enabled by novel electronic devices whose switching behaviors are near-ideal, that is, they can move from ON to OFF state and vice-versa, almost instantly. In particular, the PIs plan to design and fabricate ultra energy-efficient heterojunction Tunneling Field-Effect Transistors (T-FETs) that employ a fundamentally different injection mechanism in the form of band-to-band tunneling (BTBT) to achieve near ideal switching. They also plan to develop necessary modeling/simulation, and optimization techniques for these devices, and explore circuits and systems specifically enabled by these devices to demonstrate unprecedented power and energy savings in electronic products.
This collaborative four-year project brings together an outstanding team of scientists for addressing one of the fundamental limitations of MOSFETs and is expected to have wide implications for the semiconductor and electronics industries. The project is expected to help digital switches and circuits (including high-performance microprocessors) to attain their ultimate limits (in terms of density and performance) and also open new opportunities in embedded memories (including DRAMs and Flash) and remote sensors, thereby maintaining U.S. competitiveness in the worldwide semiconductor market. Broader impact of the proposed research is also well recognized, particularly in the light of emerging 3-D ICs, where integration of low leakage and relatively temperature insensitive T-FETs could be exploited to build next-generation high-performance and low-power integrated circuits. The overall program also ties research to education at all levels (K-12, undergraduate, graduate, continuing-ed) partly via participation in programs designed by education professionals, besides focusing on recruitment and retention of underrepresented groups in nanoscience and engineering.
