A novel step stack NOR cell for low voltage flash
Seiki Ogura, A. Hori, Jun Kato, S. Odanaka, Keiichi Akamatsu, Masaki Yamanaka, M. Kojima, Hisakazu Kotani · 1998
In a stack NOR flash cell, a small vertical (step) channel has been added to the conventional horizontal channel, to reduce the operating voltages for CHE injection and FN ejection. Devices and processes have been optimized based on extensive 2D simulations, with hardware results showing a 1-1.5 V reduction in the drain voltage requirement, and more than one order of magnitude increase in injection efficiency.