A modified constant field charge pumping method for sensitive profiling of near-junction charges

The functionality of nonvolatile memories with lateral multi-bit charge storage capabilities like NROM/TwinFlash is critically related to spatial separation of the injected charge quantities to discriminate different logical states. In this paper we develop an adapted methodology to extract local charge densities based on the constant field charge pumping method. Our method overcomes the problem of non self-consistency of conventional constant field charge pumping by determination of the spatial coordinate after every injection step. The method is demonstrated to directly extract the electron/hole mismatch after program and erase injection.