Electrically alterable non-volatile memory with n-bits per memory cell

摘要

The bit storage density of an Electrically Alterable Non-Volatile Memory (EANVM) cell is improved by increasing the number of bits that are stored on an individual memory cell, without increasing the size and complexity of the memory cell, by allowing a non-volatile memory cell to assume 2 n discrete memory states. A multi-bit memory cell uses a floating gate FET which is electrically programmed to 2 n different thresholds. The 2 n different conductivity states of the FET are provided as information storage states for the cell.