High performance multi-bit nonvolatile HfO2 nanocrystal memory using spinodal phase separation of hafnium silicate

Abstract

In this paper, we exploit a novel technique for preparing high density HfO2 nanocrystals with an average size < 10nm using spinodal phase separation of Hf-silicate thin film by 900degreesC rapid thermal annealing for nonvolatile memories. The density can be as high as 0.9similar to1.9x10(12)cm(-2). Owing to the fact that HfO2 nanocrystals are well embedded inside SiO2 matrix and their sufficiently deep energy level, we, for the first time, have demonstrated superior characteristics of the nanocrystal memory in terms of considerably large memory window, high speed program/erase (1mus/0.1ms), long retention time greater than 10(8)s for 10% charge loss, excellent endurance after 10(6) P/E cycles, negligible read/write disturbances and multi-bit operation.