Coupled electromagnetic and device level investigations of metal-insulator-semiconductor interconnects.
详细信息
文摘
Metal-insulator-semiconductor (MIS) interconnects are the most fundamental component in the modern integrated circuits. Their electrical performance is of critical importance. Most existing approaches for analysis of MIS interconnects are solely based on using Maxwell's equations with the semiconductor substrate modeled as a lossy medium. The nonlinear nature of semiconductor substrate has been generally ignored by previous research.;In order to understand the physical mechanisms behind effects such as field-carrier interactions, substrate noise, semiconductor nonlinearity, losses, dispersion, slow-wave behavior, and external bias dependence, it is necessary to describe the semiconductor as nonlinear solid state plasma. In this thesis, device level frequency domain (DLFD) simulation is proposed for studying wave propagation along MIS interconnects. Based on these device level simulations, a rigorous circuit extraction scheme is then developed for modeling MIS interconnects.;Nonlinearity of semiconductor substrates is included by combining the motion equations of charged carriers and Maxwell's equations. The set of combined nonlinear equations is then transformed into the frequency domain, which leads to sets of nonlinear equations for the fundamental mode and its harmonics. Finally, the sets of nonlinear equations in the frequency domain are discretized using the finite element method and solved using Newton's iterations. Special numerical enhancements are implemented to speed up the computational convergence and handle the boundary layer nature of the problem under study. This device level simulation provides knowledge on field-carrier interactions, semiconductor substrate losses and nonlinearity, as well as slow-wave, external bias, and screening effects of charged carriers. In particular, this device level simulation enables a rigorous full wave study of nonlinearity effects that arise from semiconductor substrates.;Based on the device level simulation results, a rigorous circuit model of MIS interconnects is extracted using an energy-based approach. The new equivalent circuit model provides a generalized nonlinear and electronically tunable circuit model, suitable for both small-signal and large-signal analyses.;Numerical examples are included to illustrate capabilities and efficiency of both the proposed device level simulation and circuit extraction schemes. Good agreement is observed between the results obtained from the proposed schemes and those from the measurements or the published data from previous research.