Compare and Contrast HiSIM-LDMOS and BSIM based compact model of High Voltage MOSFETs for Analog Applications
A. Young, J. Hall, Z. Luo, Y. Xiao, D. Connerney
Fairchild Semiconductor, US
Keywords: hisim, hisim-ldmos, bsim, ldmos, high-voltage, drift resistor, scalability, mixed-signal, analog, comparison, predictability, performance, convergence, transient simulation, cadence spectre, application
Abstract:A pair of scalable spectre models, one utilizes the Surface Potential based HiSIM-LDMOS model, and the other, the conventional Vth-based BSIM3v3 model, were extracted based on a test vehicle designed with both Drain-Extended CMOS and LDMOS Transistors. Both devices were designed with a single fixed channel length but varying drift length and width. The test vehicle is processed using Fairchild Semiconductor’s state-of-the-art 0.35µm, Analog BiCMOS Process with 4-levels of Metal. Both devices were well characterized and corresponding spectre models were extracted. The key difference between the HiSIM-LDMOS and BISM based models is that BSIM based model required an additional Behavioral Element to model the drift resistor where the potential based HiSIM-LDMOS does not. The two models are then compared and contrasted in two major areas: 1) Model Accuracies, including LDR (Length of the drift region) scaling, device Width scaling, drift resistance scaling, etc. 2) Model Performance in an actual CAD Environment, Cadence ADE running MMSIM 7.0 in this case, including simulation speeds, convergent-ability, relative accuracies under both DC and Transient Simulations. Finally, conclusions are presented to reflect the viability of each model in the current Analog-Mixed-Signal Applications and Designs.