Compact Modeling of the Dynamic Behaviour of MOSFETS

摘要

Various ways of modeling semiconductor devices are discussed and a review of theanalytical DC modeling of MOSFETs is presented. A short channel DC model used is discussed. The modeling of the dynamic behavior of the ideal part of the transistor using the quasi static approximation is discussed and a method to partition the channel charge in a source and drain charge, necessary for application in circuit simulation, is presented. Expressions for the charges are derived and resulting explicit expressions for the capacitances are presented. A practical compact charge and capacitance model for MOSFETs is discussed taking into account effects such as velocity saturation, the bulk effect and channel length modulation. The model is extended by taking into account parasitic elements inherent to the actual transistor. A high frequency applications model is derived. The models are compared with measurement results for several transistors with different gate lengths.