Analytic Carrier-Based Charge and Capacitance Model for Long-Channel Undoped Surrounding-Gate MOSFETs

Three terminal charges and nine intrinsic capacitances associated to the gate, source, and drain terminals of long-channel undoped surrounding-gate (SRG) MOSFETs are derived physically from an exact analytical solution of the channel current-continuity principle and channel charge-partition scheme in this paper. Although requiring lengthy and complex mathematical expressions, all explicit solutions for the capacitances can be obtained analytically. The validity of the analytical solutions is confirmed by comparing model predictions with simulation data obtained using the 3-D numerical solvers. The explicit expressions to the terminal charges and transcapacitance not only lead to a clearer understanding of SRG MOSFET device physics but also provide a better infrastructure to develop a complete carrier-based model for the SRG-MOSFET-based circuit simulation