Novel ultra-low voltage and high-speed programming/erasing schemes for SONOS flash memory with excellent data retention

Abstract

A novel cell operation scheme featuring low voltage, high speed, and excellent data retention has been proposed for SONOS flash memory First, in 1bit/cell operation, program is achieved by a back-bias assisted hot hole injection, while erase is achieved by forward-bias assisted electron injection. For a thick tunnel oxide (50A degrees), the ultra-low voltage (similar to 5V) and ultra-fast speed (<1 mu sec) operation has been the record reported to date. On the other hand, a 2 bit/cell operation is also demonstrated, in which very good retention can be achieved in comparison to conventional operation schemes, e.g., CHE (channel hot electron) or BTB(Band-to-band) tunneling etc.