Bottom Nitridation Engineering of Multi-Nitridation ONO Interpoly Dielectric for Highly Reliable and High Performance NAND Flash Memory
C. H. Liu, Y. M. Lin, D. Y. Yin, Gilbert Tseng, H. W. Liaw, H. C. Wei, S. H. Chen, Chih-Ming Chao, Hann-Ping Hwang, Saysamone Pittikoun, S. Aritome · 2009
The various methods of multi-nitridation ONO to improve NAND flash memory have been demonstrated in this paper. Excellent cell performance and reliability are obtained compared to convention ONO: (1) 1.9 V program voltage reduction owing to 23 A EOT (equivalant oxide thickness) reduction (2) More than 20% tighter cell Vt distribution width and 30% narrower Vth shift after 10 K cycling can be achieved by supressing ONO bird's beak encroachment of gate re-oxidation by floating gate (FG)/top oxide nitridation. MN-ONO is a promising technology for high density NAND flash beyond 40 nm generation.