A novel high-density embedded AND-type split gate flash memory

A new high-density AND-type split gate (ASG) flash memory realized by the Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 mu m embedded flash process has been successfully demonstrated and fabricated. This ASG flash memory has a pair of symmetric floating gates for performance of 2 bits/cell. By device and process optimization, this cell can operate via highly efficient source side injection (SSI) and Fowler-Nordheim (FN) tunneling mechanisms for program and erase, respectively. Moreover, ASG flash memory significantly shrinks 50% of the unit cell size by sharing word line (WL) and eliminating bit line (BL) contact. Since the ASG flash memory cell and process used are inherited from proven split-gate technology, this work also provides a highly reliable solution for high-density embedded flash application. (C) 2014 The Japan Society of Applied Physics