摘要
This letter investigates abnormal negative threshold voltage shifts under positive bias stress in input/output (I/O) TiN/HfO2 n-channel metal-oxide-semiconductor field-effect transistors using fast I-V measurement. This phenomenon is attributed to a reversible charge/discharge effect in pre-existing bulk traps. Moreover, in standard performance devices, threshold-voltage (Vt) shifts positively during fast I-V double sweep measurement. However, in I/O devices, Vt shifts negatively since electrons escape from bulk traps to metal gate rather than channel electrons injecting to bulk traps. Consequently, decreasing pre-existing bulk traps in I/O devices, which can be achieved by adopting HfxZr1-xO 2 as gate oxide, can reduce the charge/discharge effect.
原文 | English |
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文章編號 | 113503 |
期刊 | Applied Physics Letters |
卷 | 104 |
發行號 | 11 |
DOIs | |
出版狀態 | Published - 17 3月 2014 |