Programming and erase with floating-body for high density low voltage flash EEPROM fabricated on SOI wafers

Abstract

The new portable computing and telecommunications market requires high performance, low power, high density electrically reprogrammable non-volatile memories. Memories integrated with information handling circuits on SOI wafers can offer significant advantages for high speed computation, better isolation, lower leakage, better noise immunity, and excellent CMOS latch-up margin. A NOR Virtual Ground (NVG) flash memory cell fabricated on an SOI wafer is considered. The fabrication process for NVG on SOI can be unchanged if the silicon thickness of the SOI wafer is properly chosen and doped, such that the N+ bit-line (Source/Drain) touches the oxide layer. One important feature of cells on SOI is that it is difficult to ground the p-body of cell and it will be left floating during all memory operations. Therefore, it is important to study the effect of the floating body on channel-hot-electron (CHE) programming and Fowler-Nordheim (F-N) channel erase used in NVG flash memory.