Investigation into trap-assisted tunneling drain leakage current in NMOSFETs

• Published in: 2009 IEEE 8th International Conference on ASIC pp. 1031 - 1034
• Main Authors: Xing Dezhi, Liu Hongxia, Li Kaicheng
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.10.2009
• Subjects: band-band tunneling; Degradation; Electron traps; hot carrier; Hot carriers; interface trap-assisted tunneling drain leakage current; Leakage current; MOSFETs; NMOSFETs; Semiconductor device testing; Solid state circuits; Stress; Temperature; Tunneling
• ISBN: 9781424438693; 1424438691; 1424438683; 9781424438686
• ISSN: 2162-7541; 2162-755X
• DOI: 10.1109/ASICON.2009.5351513

The impact of hot carrier stress on drain leakage current becomes more severe in ultra-deep submicron NMOSFETs. The mechanisms and characteristics of trap-assisted tunneling drain leakage current (I TAT ) degradation are investigated. Both interface trap and oxide trapped charge are analyzed. The experimental results show that the hot carrier stress makes I TAT degradation have a strong dependence on the oxide thickness. In thin gate oxide (3.84 nm) NMOSFETs, Itat degradation is attributed mostly to interface trap creation, while in thicker oxide (7.64 nm) NMOSFETs, I TAT exhibits two stages degradation, a power law degradation rate in the initial stage due to interface trap generation, followed by an accelerated degradation rate in the second stage caused by oxide trapped charge creation.