Title :
Study of P/E Cycling Endurance Induced Degradation in SANOS Memories Under NAND (FN/FN) Operation
Author :
Sandhya, C. ; Oak, Apoorva B. ; Chattar, Nihit ; Ganguly, Udayan ; Olsen, C. ; Seutter, S.M. ; Date, L. ; Hung, R. ; Vasi, Juzer ; Mahapatra, Souvik
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol. Bombay, Mumbai, India
fDate :
7/1/2010 12:00:00 AM
Abstract :
Program/Erase (P/E) cycling endurance in poly-Si/Al2O3/SiN/SiO2/Si (SANOS) memories is systematically studied. Cycling-induced trap generation, memory window (MW) closure, and eventual stack breakdown are shown to be strongly influenced by the material composition of the silicon nitride (SiN) charge trap layer. P/E pulsewidth and amplitude, as well as starting program and erase flatband voltage (VFB) levels (therefore the overall MW), are shown to uniquely impact stack degradation and breakdown. An electron-flux-driven anode hole generation model is proposed, and trap generation in both SiN and tunnel oxide are used to explain stack degradation and breakdown. This paper emphasizes the importance of SiN layer optimization for reliably sustaining large MW during P/E operation of SANOS memories.
Keywords :
NAND circuits; field effect memory circuits; NAND operation; P/E pulsewidth; SANOS memories; cycling endurance induced degradation; cycling-induced trap generation; electron-flux-driven anode hole generation model; erase flatband voltage level; eventual stack breakdown; impact stack degradation; material composition; memory window closure; program/erase cycling endurance; silicon nitride charge trap layer; tunnel oxide; Breakdown voltage; Composite materials; Degradation; Dielectrics; Electric breakdown; Electron traps; Nanoelectronics; Silicon compounds; Space vector pulse width modulation; Stress; Charge trap flash (CTF); SANOS; SONOS; endurance; erase; impact ionization; memory window; program; retention; silicon nitride (SiN);
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2010.2048404
