Extending storage dielectric scaling limit by reoxidizing nitrided NO dielectric for trench DRAM

摘要

[[abstract]]Conventional nitride/oxide (NO)-based storage dielectric has been demonstrated to possess the capability to extend its employment in trench dynamic random access memory (DRAM) by additional NH3 nitridation and in situ N2O reoxidation. Through this technique, cell capacitance could be enhanced by 12.2% as compared with NO dielectric while preserving tunneling current below 1 fA/cell. Even with NH3 nitridation and consequent well-known introduction of electron traps, the great improvement in tunneling leakage and reliability are exhibited after N2O treatment. With prominent electrical properties, this technique proves its eligibility for next-generation DRAM before the maturity of introduction of high-κ material into production