[F-5] 3D NAND Flash Memory

[F-5-04] Microscopic Physical Origin of Charge Traps in 3D NAND Flash Memories

〇Fugo Nanataki¹, Jun-ichi Iwata^2,3, Kenta Chokawa⁴, Masaaki Araidai^1,4, Atsushi Oshiyama⁴, Kenji Shiraishi^1,4 (1. Univ. of Nagoya (Japan), 2. Tokyo Inst. of Tech. (Japan), 3. Quemix Inc. (Japan), 4. Inst. of Materials and Systems for Sustainability (Japan))

Presentation style: On-site (in-person)

https://doi.org/10.7567/SSDM.2022.F-5-04

We investigated hydrogen (H) impurity and nitrogen (N) vacancy complexes by the first-principles calculations to clarify the origin of charge traps inside SiN layer in 3D-NAND flash memories. We revealed that N vacancies attract H impurities. One Si dangling bond on N vacancies (VN) is saturated with one H atom and other two Si atoms form Si-Si bond (VN-H complex). We also examined the electronic structures and stable charge states of VN-H complexes and revealed that the complex can capture charge. In conclusion, we have found that VN and a H impurity are likely to form a VN-H complex and that the VN-H complex is the origin of charge traps in 3D NAND flash memories.