Abnormal Threshold Voltage Shifts in P-Channel Low-Temperature Polycrystalline Silicon Thin Film Transistors Under Negative Bias Temperature Stress
| Autor: | Pyung Ho Choi, Jaehyeong Lee, Do Hyun Baek, Byoungdeog Choi, Sang Sub Kim |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Negative-bias temperature instability Condensed matter physics Transistor Low-temperature polycrystalline silicon Biomedical Engineering Bioengineering Nanotechnology General Chemistry Dielectric engineering.material Condensed Matter Physics Threshold voltage law.invention Stress (mechanics) Polycrystalline silicon law Thin-film transistor engineering General Materials Science |
| Zdroj: | Journal of Nanoscience and Nanotechnology. 15:7555-7558 |
| ISSN: | 1533-4880 |
| DOI: | 10.1166/jnn.2015.11167 |
| Popis: | In this research, we have investigated the instability of P-channel low-temperature polycrystalline silicon (poly-Si) thin-film transistors (LTPS TFTs) with double-layer SiO2/SiNX dielectrics. A negative gate bias temperature instability (NBTI) stress was applied and a turn-around behavior phenomenon was observed in the Threshold Voltage Shift (Vth). A positive threshold voltage shift occurs in the first stage, resulting from the negative charge trapping at the SiNX/SiO2 dielectric interface being dominant over the positive charge trapping at dielectric/Poly-Si interface. Following a stress time of 7000 s, the Vth switches to the negative voltage direction, which is “turn-around” behavior. In the second stage, the Vth moves from −1.63 V to −2 V, overwhelming the NBTI effect that results in the trapping of positive charges at the dielectric/Poly-Si interface states and generating grain-boundary trap states and oxide traps. |
| Databáze: | OpenAIRE |
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