An electrical shield is provided in a non-volatile memory (NVM) cell
structure to protect the cell's floating gate from any influence
resulting from charge redistribution in the vicinity of the floating gate
during a programming operation. The shield may be created from the second
polysilicon layer or other conductive material covering the floating
gate. The shield may be grounded. Alternately, it may be connected to the
cell's control gate electrode resulting in better coupling between the
floating gate and the control gate. It is not necessary that the shield
cover the floating gate completely, the necessary protective effect is
achieved if the coupling to the dielectric layers surrounding the
floating gate is reduced.