Abstract
The market demand for portable electric equipment increase dramatically year by year. Although Flash develop toward low cost and high density, following Moore’s law to continue the scaling due to the device fabrication and physics limitations of the device. The three-dimensional (3D) multi-layer-stack memory basing on poly-Si TFT is another path to ultra-high density memory. The conventional TANOS NVM behaves fast P/E operations because Al2O3 blocking layer increases the gate coupling ratio, and TaN immunizes the gate injection. The dielectric constant of the Al2O3 can be enlarged by rapid thermal annealing, but high temperature causes Al2O3 to crystallize, resulting in stored charge leaking to gate. Using sealing SiO2 or bandgap engineering (BE) can reduce this leakage, but those may sacrifice the coupling ratio and P/E speed. In this thesis, we propose TANOS TFT Flash memory with silicon nanocrystals (Si-NCs) as charge-trapping layer, and named it NCs-TANOS. NCs-TANOS can improve the progam/erase speed and reliability issues of the conventional TANOS NVM, and exhibits excellent high-temperature (850C) retention ( >108 sec for 5% charge loss). The excellent performance NCs-TANOS that provides a promising solution to overcome the limitation of the conventional NVM for future scaling, 3D stack NVM and next generation Flash memory application.