Effects of Dopant-Segregated Profiles on Schottky Barrier Charge-Trapping Flash Memories

摘要

This paper numerically elucidates the effects of dopant-segregated (DS) profiles on the cell operations for Schottky barrier charge-trapping Flash memories. Various DS profiles were employed to examine the cell conduction, programming, and erasing. The DS profile has a key function in determining the injected mechanisms and locations of cell programming and erasing. The heavy DS layer, concentration of $1times 10^{20}~{rm cm}^{-3}$ , induces the DS Schottky barrier cell to become a conventional-like drain-side injection cell, thereby producing similar programming and erasing characteristics as those of a traditional doped source/drain cell. The light DS profile, concentration lower than $3times 10^{19}~{rm cm}^{-3}$ , retains the DS-structured cell as an intrinsic Schottky barrier-like source-side injection cell. Because the intrinsic Schottky barrier cells generate most of the efficient programming/erasing injections with minimized short-channel effects, it is dispensable to incorporate the DS profiles in Schottky barrier charge-trapping cells.