Nonvolatile Metal-Oxide-Semiconductor Capacitors with Ru-RuO_(x) Composite Nanodots Embedded in Atomic-Layer-Deposited Al_(2)O_(3) Films

摘要

Growth of Ru-RuO_(x) composite nanodots (RONs) on atomic-layer-deposited Al_(2)O_(3) films has been investigated using magnetic sputtering of a Ru target followed by postdeposition annealing. RONs with a density as high as approx2 X 10~(12) cm~(-2) were obtained together with good uniformity. Subsequently, metal-oxide-semiconductor capacitors with RONs embedded in Al_(2)O_(3) films have been electrically characterized for different configurations of tunneling layers (T)/blocking layers (B), and the underlying mechanisms of charge storage are discussed. For a 6-nm T/22-nm B device, a memory window of 3.7 V is achieved for a +-7 V programing/erasing voltage for 0.1 ms, and superior charge retention of more than 80percent is achieved after 10 years.