A Simplified Current-Voltage (I-V) Characteristics Model with Quantum Mechanical Effects for n-channel MOSFET

摘要

The CMOS (complementary-metal-oxide-silicon) scaling rules require that advanced MOSFETs (metal-oxide-silicon field-effect transistors) be fabricated with ultra-thin gate dielectrics as the channel length reduces to the nanometer scale. MOSFET performance degradation (reduced channel current and gate capacitance) occurs due to polysilicon depletion and quantum mechanical effects [1, 2]. Accurate Current-Voltage (I-V) and Capacitance-Voltage (C-V) characteristics of the device for SPICE (Simulation Program with Integrated Circuit Emphasis) application are required, and as a consequence these effects need careful modeling. Furthermore the model characteristics have to be in a simple form to reduce circuit simulation time. The focus of this paper is on modeling the I-V characteristics with quantum effects for n-channel MOSFETs that are referenced to the substrate terminal. Transistor I-V models developed in [3] and [4] are simplified into a polynomial function using the technique introduced in [5]. Preliminary I-V simulation and comparison give good results (see Figures 1 and 2).