A Nitride-Oxide Blocking Layer For Scaled SONOS Non-Volatile Memory
Original Publication Date: 2002-Jan-11
Included in the Prior Art Database: 2002-Jan-11
SONOS (Silicon-Oxide-Nitride-Oxide-Silicon) and similar thin film storage non-volatile memory has been studied for greater than thirty years in the semiconductor industry1. Recently interest in SONOS has intensified due to the process simplicity, reduction of program/erase voltages, and scaling advantages. A limitation in scaling the thickness of the top (blocking) oxide of the dielectric stack is the need to prevent tunneling of electrons from the polysilicon gate to the nitride or oxynitride charge storage layer during the cell operation. This paper describes the use of a nitride-oxide blocking dielectric in order to further prevent tunneling from the gate while allowing additional scaling of the effective thickness.