Independently Driven DG MOSFETs for Mixed-Signal Circuits: Part I—Quasi-Static and Nonquasi-Static Channel Coupling

Abstract

The two tightly coupled channels in independently driven double-gate (IDDG) MOSFET offer new opportunities in constructing mixed-signal circuit modules. Understanding of channel coupling in various bias and frequency regimes is imperative to conceptualize the circuit design and optimization. In Part I, we will investigate both quasi-static and nonquasi-static channel coupling in IDDG through capacitance simulation. The charge reshuffling between channels provides effective coupling at high frequency when source/drain (S/D) carriers cannot respond spontaneously to the applied gate signals, which opens up new high-frequency circuit possibilities beyond the S/D transit time set by the lithography limit. The bias and frequency regions that enhance channel coupling are identified. The transition frequency related to channel charge reshuffling is investigated for its dependence on device geometry. Operational principles and practical limitations are discussed. In Part II, we will present the circuit design examples based on the interchannel coupling.