Cycling endurance of NOR flash EEPROM cells under CHISEL programming operation - impact of technological parameters and scaling

The impact of technological parameter (channel doping, source/drain junction depth) variation and channel length scaling on the reliability of NOR flash EEPROM cells under channel initiated secondary electron (CHISEL) programming is studied. The best technology for CHISEL operation has been identified by using a number of performance metrics (cycling endurance of program/erase time, program/disturb margin) and scaling studies were done on this technology. It is explicitly shown that from a reliability perspective, bitcell optimization for CHISEL operation is quite different from that for channel hot electron (CHE) operation. Properly optimized bitcells show reliable CHISEL programming for floating gate length down to 0.2 μm.© IEE