Program and erase of NAND memory arrays

Abstract

The purpose of NAND Flash memories as a non-volatile memory is to store the user data for years without requiring a supply voltage. The state of the art memory cell for this purpose in NAND Flash is the 1T floating gate memory cell, which is based on a MOSFET. In contrast to the 1T1C DRAM cell, which consists of an access transistor and a separate capacitance as charge storage node, the 1T floating gate cell is a MOSFET whose gate dielectric is split with a charge storage node in between. This charge storing node, usually made of poly-silicon, is electrically isolated completely by the surrounding dielectrics. Its stored charges represent the information, and may be altered according to the user data by the program operation. © 2010 Springer Science+Business Media B.V.