SOI flash memory scaling limit and design consideration based on 2-D analytical modeling

In this paper, the short-channel effect in ultrathin body (UTB) SOI Flash memory cell induced by the floating-gate is investigated by a newly developed two-dimensional analytical model. A concept of effective natural length (A,ff) is introduced as a measure of the impact of the floating-gate on the scaling limit. Even though scaling the channel thickness can significantly reduce SCE in UTB MOSFETs, it becomes less effective in floating-gate device due to the floating polysilicon induced gate coupling. To minimize the floating-gate induced SCEs, the drain to floating-gate coupling has to be minimized.