In TANOS stuctures in retention, the major decrease in theprogrammed threshold voltage is found to be caused by the Vtsensing (IdVg measurements) rather than by intrinsic charge loss(when no bias is applied). This Vt decrease can be understoodwithin the process of the temperature-activated charge transportthrough the Al2O3 blocking oxide. The charge loss can beminimized when Vt sensing time is decreased down to microseconds. Blocking oxides engineered by adding a thin SiO2 layerat the SiN/AlO interface demonstrate significant suppression of thecharge loss.
Charge loss in TANOS devices caused by Vt sensing measurements during retention / H., Park; G., Bersuker; D., Gilmer; K. Y., Lim; M., Jo; H., Hwang; Padovani, Andrea; Larcher, Luca; Pavan, Paolo; W., Taylor; P. D., Kirsch. - STAMPA. - (2010), pp. 1-2. (Intervento presentato al convegno IEEE International Memory Workshop tenutosi a Seul (Korea) nel May 2010) [10.1109/IMW.2010.5488409].