Off-state degradation with ac bias in PMOSFET

• Published in: Microelectronics and reliability Vol. 65; pp. 16 - 19
• Main Authors: Park, Segeun, Jung, Hyuckchai, Oh, Jeonghoon, Kim, Ilgweon, Hong, Hyoungsun, Jin, Gyoyoung, Roh, Yonghan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2016
• Subjects: ac bias; HEIP; Hot electron; Off-state; PMOSFET; ac bias; Hot electron; PMOSFET; HEIP; Off-state
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/j.microrel.2016.08.007

For the first time, the current failure of p-channel MOSFETs used for the sub-wordline driver of state-of-the-art DRAM chips was investigated during off-state switching cycles. With increasing switching speed for the sub-wordline driver, the subthreshold leakage current of p-channel MOSFETs increased, and resulted in serious stand-by current failure. The model proposed in this work suggested that the off-state degradation of p-channel MOSFETs with ac bias will intensify as the dimensions of devices decrease due to both the high electric field and the high operating frequency. The roles of various device parameters- such as gate length, gate-tab width, doping concentration at the source/drain extensions, operating temperature and operating frequency- on the degradation of p-channel MOSFETs were investigated.
•For the first time, off-state degradation with ac bias in PMOS is investigated.•The sub-threshold leakage current of PMOS increased after off-state degradation with ac bias.•We suggested the degradation model of off-state degradation with ac bias.•The roles of various device parameters on the degradation of p-channel MOSFETs were investigated.