Title :
A novel high-κ SONOS memory using TaN/Al2O3/Ta2O5/HfO2/Si structure for fast speed and long retention operation
Author :
Wang, Xuguang ; Kwong, Dim-Lee
Author_Institution :
Spansion LLC, Sunnyvale, CA, USA
Abstract :
A novel high-κ silicon-oxide-nitride-oxide-silicon (SONOS)-type memory using TaN/Al2O3/Ta2O5/HfO2/Si (MATHS) structure is reported for the first time. Such MATHS devices can keep the advantages of our previously reported TaN/HfO2/Ta2O5/HfO2/Si device structure to obtain a better tradeoff between long retention and fast programming as compared to traditional SONOS devices. While at the same time by replacing hafnium oxide (HfO2) with aluminum oxide (Al2O3) for the top blocking layer, better blocking efficiency can be achieved due to Al2O3´s much larger barrier height, resulting in greatly improved memory window and faster programming. The fabricated devices exhibit a fast program and erase speed, excellent ten-year retention and superior endurance up to 105 stress cycles at a tunnel oxide of only 9.5 Å equivalent oxide thickness.
Keywords :
aluminium compounds; dielectric materials; elemental semiconductors; hafnium compounds; random-access storage; semiconductor heterojunctions; silicon; tantalum compounds; TaN-Al2O3-Ta2O5-HfO2-Si; barrier height; blocking efficiency; high-k dielectrics; high-k silicon-oxide-nitride-oxide-silicon-type memory; metal-oxide-nitride-oxide-silicon; nonvolatile memory; stress cycle; tunnel oxide; Aluminum oxide; Dielectrics; Flash memory; Hafnium oxide; Leakage current; MONOS devices; Mathematical programming; Nonvolatile memory; SONOS devices; Stress; high-; nonvolatile memory; silicon-oxide-nitride-oxide-silicon (SONOS)/metal–oxide–nitride–oxide–silicon (MONOS);
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2005.860637
