Nonvolatile Poly-Si TFT Charge-Trap Flash Memory With Engineered Tunnel Barrier

Abstract

Tunnel-barrier-engineered thin-film transistor (TFT) memory (TBE-TFT memory) devices on glass substrates were fabricated using low-temperature processes. An amorphous silicon film on the glass substrate was crystallized using excimer laser annealing for system-on-panel applications. The engineered tunnel barrier of VARIOT type (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> /SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) with a high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> charge-trapping layer and an Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> blocking layer was applied to TBE-TFT memory devices in order to enhance the memory performance of TBE-TFT memory devices. As a result, the poly-Si TFT charge-trap Flash memory with an engineered tunnel barrier exhibited excellent memory characteristics, such as large memory window (9.5 V), long retention time, and endurance.