Influence of SiN composition on program and erase characteristics of SANOS-type flash memories

Composition of the silicon-nitride charge trap layer strongly impacts electron and hole trap properties. This significantly impacts charge trap flash memory performance and reliability. Important trade-offs between program/erase (P/E) levels (memory window) and retention loss is shown and critical trends identified. Increasing the Si-richness of the SiN layer improves memory window by increasing erase efficiency. E-state retention characteristics are improved but at the expense of higher P-state retention loss.