Effects of nitride trap layer properties on location of charge centroid in charge-trap flash memory

Abstract

In this study, the effects of nitride trap layer properties on location of charge centroid in charge-trap flash (CTF) memory are closely investigated. In the operations of CTF memories, charges tunnel into the nitride layer through thin oxide, unlike the floating-gate (FG) type flash memory where the charges are stored in the conductive poly-crystalline Si. Deeper understanding of distribution of the trapped charges should be beneficial in setting up an accurate compact model of CTF memory cell, where the charge centroid becomes a very practical means by which a rather large number of trapped electrons can be dealt in the more mathematical manner as a whole electron cloud. The relation between charge centroid and program voltage (Kpgm) depending on nitride layer properties is analytically studied.