| abstract |
Due to the coupling of the electric field based on the charges accumulated in the adjacent charge storage elements, a shift may occur in the apparent charges stored in the charge storage elements of the nonvolatile memory. To compensate for this coupling, the programming process for a given memory cell can take into account the programmed state that is the target of one or more adjacent memory cells. The amount of programming is verified after each programming pulse, and the standard verify level for the programming cell depends on the target state. The verify level is offset even lower depending on the amount of perturbation from neighboring cells that can be determined by their target state. The verify level is preferably virtually offset by biasing adjacent word lines instead of actually offsetting the standard verify level. In order to soft-program erased cells, adjacent cells on both adjacent word lines are taken into account. |