Investigation on the role of nitrogen in crystallization of Sb-rich phase change materials

To better understand the role of nitrogen (N) during crystallization of Sb-rich phase change materials, a study was conducted using Sb and Sb70 Te30 as host materials of N. Crystallization of the as-sputtered Sb-N films of varying N content was examined to reveal that Sb-N bonds are formed in the as-sputtered states, enhancing amorphous phase stability increasingly with N content. Crystallization appeared to proceed with irreversible dissociation of these bonds to form N₂ molecules that may then exist stably during the subsequent memory operations. N₂ molecules are considered to play as growth-retarding agents as demonstrated with memory operations of N-doped Sb70 Te30.