Explanation of the Charge-Trapping Properties of Silicon Nitride Storage Layers for NVM Devices Part I: Experimental Evidences From Physical and Electrical Characterizations

In part I of this paper, we study the physicochemical structure and the electrical properties of low-pressure-chemical-vapor-deposited silicon nitride (SiN) aimed to serve as storage layers for nonvolatile memory applications. An in-depth material analysis has been carried out together with a comprehensive electrical characterization on two samples fabricated with recipes yielding rather standard SiN and Si-rich SiN. The investigation points out the impact of SiN stoichiometry and hydrogen content on the electrical characteristics of gate stacks designed in view of channel hot-electron/hole-injection program/erase (P/E) operation and tunnel P/E operation. The extensive and detailed characterization establishes a sound experimental basis for the development of the physics-based trap models proposed in the companion paper.