A True 6F2 NOR Flash Memory Cell Technology - Impact of Floating Gate B4-Flash on NOR Scaling

This paper describes a true 6F2 B4-Flash (Back Bias assisted Band-to-Band tunneling induced Hot Electron injection Flash) memory cell, which is one half of conventional NOR cell, for the first time as a floating gate NOR cell. 6F2 B4-Flash cells featuring a self-aligned STI and self aligned contact architectures have been fabricated by a 90nm process and was confirmed sufficient performance for NOR array operation. The cell size of 0.0486um2 of 90nm 6F2 is the smallest NOR cell in the 90nm generation. B4-HE programming scheme, in which the voltage between drain and source sets to 1.8V, allows more aggressive gate length scaling than for conventional CHE programming cells, consequently gate length has been scaled down to 78nm.