Multi-layer spacer technology for flash EEPROM

摘要

A method is provided for forming multi-layer spacer GELS) for flash EEPROM devices. A composite tetraethyl orthosilicate-silicon nitride (TEOS/Si3N4) layer is deposited over the floating gate and anisotropically etched to form the MLS. The resulting MLS is better controlled dimensionally with the attendant advantage, therefore, of better definition of gate and channel lengths in the memory cell for more predictable and better programming and erase performance of EEPROMS.