Advanced Manufacturing, Electronics and Microsystems: TechConnect Briefs 2016Advanced Manufacturing, Electronics and Microsystems TechConnect Briefs 2016

WCM - Compact Modeling Chapter 8

Modeling Independent Multi-Gate MOSFET

J.P. Duarte, S. Khandelwal, H-L Chang, Y.S. Chauhan, C. Hu
University of California, Berkeley, United States

pp. 281 - 287


In this paper a fully-featured turn-key compact model for independent multi-gate MOSFETs is presented. This industry standard compact model is called BSIM-IMG. The two independent (front- and back-gate) control of the channel charge in these devices enables novel applications wherein back-gate can be in depletion or inversion, and BSIM-IMG accurately models these scenarios. Modeling of the channel-charge in this device requires a consistent solution of coupled Poisson’s equations at the front- and the back-gate. A consistent solution becomes very challenging because the solution lies in trigonometric and hyperbolic domains making the desired numerical robustness extremely difficult. We have developed an analytical solution which is numerically robust and passes important quality tests for an industry grade compact model. This solution composes the core of the new BSIM-IMG compact model. Using the core calculations, the source- and the drain-side charges are calculated and used to derive the long-channel drain-current. To represent a real device accurate modeling of the important physical effects such as drain-induced barrier lowering, velocity saturation, short-channel effects, self-heating effect, mobility-field dependence, substrate-depletion effect etc. are included in the model. For modeling radio-frequency (RF) behavior of these devices, the impact of gate- and substrate-network is also included. Furthermore, BSIM-IMG also includes the model for the flicker- and the thermal-noise behavior of these devices. We will discuss all the features of this model in this paper demonstrating readiness of BSIM-IMG model for use in developing process-design-kits (PDKs).