Title |
Annealing Effects on Charge Trap Flash with TAHOS Structure |
Authors |
(Min Suk Song) ; (Hwiho Hwang) ; (Junsu Yu) ; (Sungmin Hwang) ; (Hyungjin Kim) |
DOI |
https://doi.org/10.5573/JSTS.2024.24.4.323 |
Keywords |
Flash memory; charge trap flash; post-deposition annealing; forming gas annealing |
Abstract |
Flash memory is gaining attention due to its scalability, high reliability, and multilevel capabilities. This study investigated the charge trapping characteristics of high permittivity HfO2 films with Al2O3 as a blocking oxide. TAHOS (TiN-Al2O3-HfO2-SiO2-Si) structure capacitors were fabricated to explore the annealing effects for charge trap flash (CTF) memory device applications. HfO2, serving as a charge trapping layer, offers the advantage of achieving a wide memory window owing to its high trap density. In this work, various characteristics related to memory cells were examined based on annealing temperature and gas type. Post-deposition annealing (PDA) was conducted from 900 °C to 1050 °C and forming gas annealing (FGA) was performed at 450 °C for 10 minutes using H2 gas. We analyzed the memory window and flat-band voltage distributions by measuring C-V characteristics. These results suggest that optimal annealing conditions can be helpful to improve memory characteristics in TAHOS stacked flash memories. |