Device and Technology Challenges for Nanoscale CMOS

With the introduction of 90 nm node technology, silicon CMOS is already at the nanoscale. There is no doubt that the semiconductor industry desires to stay on the historical rate of cost/performance/density improvement as exemplified by the International Technology Roadmap for Semiconductors (ITRS). The challenges for continued device scaling are daunting. At the highest level, the challenges are: (1) delivering cost/performance improvement while at the same time containing power consumption/dissipation, (2) control of device variations, and (3) device/circuit/system co-design and integration. New devices and new materials offer new opportunities for solving the challenges of continued improvement. In this talk, we give an overview of the device options being considered for CMOS logic technologies from 45 nm to 22 nm and beyond. Technology options include the use of device structures (multi-gate FET) and transport-enhanced channel materials (strained Si, Ge). Beyond the 22 nm node, research are underway to explore even more adventurous options such as III-V compound semiconductors as channel materials, metal Schottky source/drain. Beyond that time horizon, there is the question of whether new materials and fabrication methods such as carbon nanotubes, semiconductor nanowires and self-assembly techniques will make an impact in nanoscale CMOS technologies. We survey the state-of-the-art of these emerging devices and technologies and discuss the research opportunities going forward. We conclude with a discussion of the interaction between device design and the circuit/system architecture and how this interaction will change the landscape of technology development in the future.