Charge centroid in MNOS devices

Abstract

A concise theoretical expression based on pronounced detrapping is derived for the charge‐vs‐centroid relationship of an MNOS structure subjected to constant current pulses which include the considerable injected charge levels encountered in practical memory device operation. Good agreement is found with available experimental charge‐vs‐centroid data obtained at various temperatures, thus enabling determination of Frenkel‐Poole coefficient and trap depth. Values so obtained agree with those for bulk silicon nitride. An analytical expression valid for any degree of detrapping is derived for change of centroid with charge in the limit of small injected charge levels. Implications of constant voltage versus constant current charging are discussed.