Atomistic Design of Guiding Principles for High Quality Metal-Oxide-Nitride-Oxide-Semiconductor Memories: First Principles Study of H and O Incorporation Effects for N Vacancies in SiN Charge Trap Layers

We theoretically investigate H- and O-incorporation effects on memory characteristics of N vacancies in the SiN layer of metal-oxide-nitride-oxide-semiconductor (MONOS) type memory. The present calculations show that N vacancy maintains high program/erase (P/E) cycle endurance characteristics, regardless of the existence of H and O atoms. It is also found that the incorporation of an H atom is energetically favorable for N vacancy, whereas the incorporation of such an atom is unfavorable for O-incorporated N vacancy. The present results indicate clearly that realistic process conditions, in which incorporation of H and O atoms is inevitable, do not affect memory characteristic of MONOS-type memory having N vacancies in the SiN layer, and, therefore, such a memory is desirable and feasible for future memories. (C) 2011 The Japan Society of Applied Physics