Quantum Mechanical Simulation for Ultra-thin High-k Gate Dielectrics Metal Oxide Semiconductor Field Effect Transistors

High-k dielectric materials are being considered as replacement for SiO2 as the gate dielectric while retaining the low equivalent oxide thickness (EOT) required next generation metal oxide semiconductor field effect transistors (MOSFETs). In this paper, we simulate the capacitance – voltage (C-V) of n-type MOSFET devices with different high-k dielectric insulator numerically. According to the results, high-k dielectric materials maintain the capacitance and provide a robust physical thickness preventing tunneling current. Quantum mechanism must be considered in the simulation or a 9.3 % overestimation of capacitance will be observed in an extreme case. Capacitance of high-k dielectrics couldn’t be estimated by capacitance of insulator with EOT directly because a 13 % difference is observed. To obtain an accurate result, a self-consistent Schrödinger – Poisson equation should be solved. Key-Words: Quantum confinement effects, Schrödinger equation, High-k dielectric, MOSFET devices, Capacitance, Equivalent oxide thickness, Ultra thin oxide.