Atomistic impurity diffusion simulation of shallow junction fabrication processes and dopant-induced intrinsic fluctuations

Using a newly developed atomistic dopant diffusion simulator, sophisticated shallow junction fabrication processes, i.e. spike-anneal, flash-lamp anneal, and low temperature anneal, are studied. Based on a kinetic Monte Carlo procedure considering all possible charged species and Fermi-level effects on drift-diffusion and clustering reactions, and incorporating boron diffusion/activation kinetics obtained through ab-initio calculations, this simulator can reproduce various boron spike-anneal experiments without any arbitrary parameter fitting. This atomistic process simulator also enables us to calculate three dimensional dopant atom distribution for actual sub-100 nm MOSFETs. Coupling three-dimensional atomistic process/device simulators, a statistical simulation has been performed to evaluate the intrinsic fluctuation induced by discrete dopant atoms.