Influence of metal gate and capping film stress on TANOS cell performance

In this work it is shown that film stress in the gate stack of TANOS NAND memories plays an important role for cell device performance and reliability. Tensile stress induced by a TiN metal gate deteriorates TANOS cell retention compared to TaN gate material. However, the erase satn. level as well as cell endurance is improved by the use of a TiN gate. This trade-off between retention and erase satn. for TANOS cells is elaborated in detail.