Effect of SiN on Performance and Reliability of Charge Trap Flash (CTF) Under Fowler–Nordheim Tunneling Program/Erase Operation

Silicon-nitride trap layer stoichiometry in charge trap flash (CTF) memory strongly impacts electron and hole trap properties, memory performance, and reliability. Important tradeoffs between program/erase (P/E) levels (memory window), P- and E-state retention loss, and E-state window closure during cycling are shown. Increasing the Si richness of the SiN layer improves memory window, cycling endurance, and E-state retention loss but at the cost of higher P-state retention loss. The choice of SiN stoichiometry to optimize CTF memory performance and reliability is discussed.