3D simulations of ultra-small MOSFETs: The role of the short range Coulomb interactions and discrete impurities on device terminal characteristics

We have developed a three-dimensional particle based simulator with a coupled molecular dynamics routine that avoids the "double-counting " of the long-range portion of the Coulomb force. As opposed to drift-diffusion based simulators, the Monte Carlo simulator can accurately model high field transport in semiconductor devices, while enabling the real-space treatment of the interactions, in-cluding multi-ion and particle contributions, through the coupled molecular dynamics scheme. The inclusion of the electron-electron and electron-ion interactions was shown to play an important role in device simulations. The drain current for MOSFET devices was significantly decreased when the Coulomb forces were added. Using this simula-tor, random dopant ions in the channel have shown to cre-ate fluctuations in the drain current of deep sub-micron MOSFETS as well as fluctuations in the device threshold voltage