Vertical Cell Array Using TCAT(Terabit Cell Array Transistor) Technology for Ultra High Density NAND Flash Memory

Vertical NAND flash memory cell array by TCAT (terabit cell array transistor) technology is proposed. Damascened metal gate SONOS type cell in the vertical NAND flash string is realized by a unique dasiagate replacementpsila process. Also, conventional bulk erase operation of the cell is successfully demonstrated. All advantages of TCAT flash is achieved without any sacrifice of bit cost scalability.