[F-5] 3D NAND Flash Memory

[F-5-03] Performance Improvement by Applying High-k Materials for 3D NAND Memory Block Oxide with a Lower Thermal Budget

〇Sara Aoki¹, Loan Nguyenhong¹, Muneyuki Otani², Naonori Fujiwara², Genji Nakamura¹ (1. Tokyo Electron Ltd. (Japan), 2. Tokyo Electron Technology Solutions Ltd. (Japan))

Presentation style: On-site (in-person)

https://doi.org/10.7567/SSDM.2022.F-5-03

Alternative materials for Al2O3 used in block oxide in 3D NAND were investigated. Memory characteristics of ZrO2, HfO2, and HfSiO (Si: Hf = 6:94) were thoroughly examined considering the thermal budget. Materials with higher k-values outperformed Al2O3 in terms of window performance due to the improved erase characteristics. It was also discovered that the thermal processing after high-k deposition affects memory qualities and that lower thermal processing temperatures result in better memory characteristics. Degradation of characteristics during high temperature annealing is assumed to be due to mixing that occurred at the interface. The effect of distortion of band structure and increase of defects due to mixing on memory characteristics and its mechanism are discussed.