Simulation of Capacitance-Voltage characteristics of Ultra-thin Metal-Oxide-Semiconductor Structures with Embedded Nanocrystals

This paper presents an approach to model quantum mechanical effects in solid-state devices such as Metal Oxide Semiconductor (MOS) capacitor with and without nanocrystal in the oxide at the device simulation level. This quantum-mechanical model is developed to understand finite inversion layer width and threshold voltage shift. It allows a consistent determination of the physical oxide thickness based on an agreement between the measured and modeled C-V curves. However, as for thinner oxides finite inversion layer width effects become more severe, quantum-mechanical model predicts higher threshold voltage than the classical model. The inversion-layer charge density and MOS capacitance in multidimensional MOS structures are simulated with various substrate doping profiles and gate bias voltages. The effectiveness of the QM correct method for modeling quantum effects in ultrathin oxide MOS structures is also investigated. The CV characteristic is used as a tool to compare results of the QM correction with that of the Schrödinger–Poisson (SP) solution and Classical solution The variation of (different parameters) for various doping profiles at different gate voltages is investigated.