Analysis and modeling of dual-gate MOSFET's

Dual-gate MOS transistors (both as discrete devices and as circuit elements are extremely attractive for a variety of applications where electronic gain control capability, low feedback parameters, low noise and cross modulation, reduced short-channel effects, or high breakdown voltage are required. In this paper, the operation and physical characteristics of dual-gate MOSFET's are investigated. An accurate model is developed, which enables the simulation of behavior of the device with respect to bias conditions, by means of a simple iterative algorithm. Using this model, the static characteristics are analyzed in detail, special emphasis being directed toward the properties of the drain conductance and transconductances in the various operational modes. Second order effects, not taken into account in the model, are discussed. The boundaries of the operating regions also are calculated by means of simple analytic models. Extensive experimental verification is made through measurements conducted on various dual-gate transistor structures fabricated by a shadowed-gap/lift-off process.