Physical Modeling for Programming of TANOS Memories in the Fowler–Nordheim Regime

Abstract

This paper presents a physics-based model that is able to describe the TANOS memory programming transients in the Fowler-Nordheim uniform tunneling regime across the bottom-oxide layer. The model carefully takes into consideration the trapping/detrapping processes in the nitride, the limited number of traps available for charge storage, and their spatial and energetic distribution. Results are in good agreement with experimental data on TANOS devices with different gate-stack compositions, considering a quite extended range of gate biases and times. The reduced gate-bias sensitivity of the programming transients with respect to the floating-gate cell is explained in terms of a finite number of nitride traps and a thinner extension of the nitride trapping region as the gate bias is increased. The model represents a valid contribution for the investigation of the achievable performances of the TANOS technology.