Three-dimensional self-consistent simulation of the charging time response in silicon nanocrystal flash memories

A numerical model to calculate the tunneling time from the channel of a metal-oxide-semiconductor device into a silicon nanocrystal embedded in SiO ₂ is presented. Self-consistent simulations of the Kohn-Sham and Poisson equations are performed to study the role of the size, shape, barrier thickness of a quantum dot (QD). We found that the charging process is very sensitive to the shape of the QD, resulting in changes of several orders of magnitude in the electron transfer and retention times.