2018 Fiscal Year Annual Research Report
|Research Institution||The University of Tokyo |
KE MENGNAN 東京大学, 工学系研究科, 特別研究員(DC2)
|Project Period (FY)
2018-04-25 – 2020-03-31
|Keywords||Ge / MOS interfaces / slow traps / reliability|
|Outline of Annual Research Achievements
Journal M. Ke, M. Takenaka, and S. Takagi, “Slow trap properties and generation in Al2O3/GeOx/Ge MOS interfaces formed by plasma oxidation process”, ACS Appl. Electron. Mater., 2019, 1 (3), pp 311-317
Conference M. Ke, P. Cheng, K. Kato, M. Takenaka and S. Takagi, “Characterization and understanding of slow traps in GeOx-based n-Ge MOS interfaces”, 2018 IEEE International Electron Devices Meeting (IEDM), 34.3, Hilton Hotel, San Fransicco, December 1-5 (2018)
|Current Status of Research Progress
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
We have revealed that slow traps are additionally generated during the PPO process near conduction band side.It has also been found that the main slow traps of electrons, responsible for the hysteresis in the Al2O3/GeOx/n-Ge interfaces, can locate near the GeOx/Ge interfaces, while the main slow traps for holes, responsible for the hysteresis in the Al2O3/GeOx/p-Ge interfaces, can locate near the Al2O3/GeOx interfaces. Moreover, under low Eox, only electrons in Ge are trapped into slow traps during C-V measurements. Under high Eox, on the other hand, hot holes created probably in the gate metal are injected into dielectrics and trapped into hole traps. These trapped holes do not come out and cause the negative VFB shift as fixed positive charges.
|Strategy for Future Research Activity
In order to achieve high performance Ge MOSFETs with high reliability, further study about Ge MOS interfaces is still needed. Such as, large degradation and long term reliability problem of Ge MOSFETs, the slow trap origins in Ge MOS interfaces in details, how to decrease the slow trap density and improve the reliability of Ge MOSFETs with a good performance, the process and fabrications.
I will study the physical characterization of slow traps in Ge MOS interfaces and try to reducing its density in the future.
Research Products (2 results)