Terahertz CMOS integrated circuits

Abstract

Advances in circuit techniques, aided by continued lithographic scaling, will deliver CMOS technology capable of operation in the submillimeter-wave bands. Many building blocks operating at near-THz frequencies in silicon-based technologies (SiGe and CMOS) have appeared in the recent literature. Although many significant challenges remain, these results suggest that CMOS THz ICs are an inevitability. Applications that reside in the "terahertz gap," mapped against the projected capabilities of CMOS, provide a context for identifying the most important remaining problems. The lack of efficient, high-power (watt-level) sources remains the most conspicuous impediment to further progress. The talk concludes with an examination of the potential of vacuum electronic devices to solve the transmit power problem.

Emerging Transistor Technologies Capable of Terahertz Amplification: A Way to Re-Engineer Terahertz Radar Sensors

“…CMOS is favored owing to the low cost of fabrication and high level of achievable integration. According to Lee [71], the maximum f T of a CMOS technology can be approximated (to the first order) by the formula f T = 10 (THz·nm)/ L , where L is the gate length in nanometer, meaning that the f T of a 5 nm technology could be 2 THz, if the length can be feasibly decreased to such low levels. Considering the challenges of transistor optimization listed in Section 2.2, reaching such frequencies even at such short lengths is unlikely.…”