Browsing by Author "Liao, Yu-Chiao"

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Criteria for Plasmon-Enhanced Electron Drag in Si Metal-Oxide-Semiconductor Devices
(2015-03-01)
Chen, Ming-Jer
;
Hsieh, Shang-Hsun
;
Liao, Yu-Chiao
;
Chen, Chuan-Li
;
Tsai, Ming-Fu
Plasmons in the highly doped source and drain regions of silicon field-effect transistors can strongly drag channel electrons via long-range collective Coulomb interactions and cause deteriorations in overall device performances. To examine such interactions, two different methods have been published: 1) sophisticated device simulations and 2) carefully calibrated experiments. To provide a more transparent understanding, we propose a third method in terms of two criteria: 1) one for the occurrence of the plasmon resonance and 2) the other for the strength of the plasmons. The former is determined based on our published dragged mobility data due to the interface plasmons and the bulk plasmons in gate. The latter makes use of our more recently experimentally extracted potential fluctuations due to plasmons in crystalline silicon. The effects of the temperature on the criteria are considered. It is a straightforward task to confirm that for a channel density larger than approximately 5 x 10(12) cm(-2), the source and drain plasmons act as key limiters in silicon device scaling. Therefore, the underlying device physics, modeling, simulations, experimental analyses, and data interpretation may be inaccurate if the limiting factors are not incorporated.
Probing Long-Range Coulomb Interactions in Nanoscale MOSFETs
(2013-12-01)
Chen, Ming-Jer
;
Chang, Li-Ming
;
Wei, Sih-Yun
;
Chen, Wan-Li
;
Yeh, Ting-Hsien
We have recently experimentally probed long-range Coulomb interactions due to plasmons in polysilicon gate of long-channel (1 mu m) MOSFETs. In this letter, we further probe those due to plasmons in the highly doped source and drain. Test vehicles include four more samples from the same manufacturing process but with small channel lengths (down to 33 nm). I-V's of devices are measured at two drain voltages of 0.05 and 1 V, in a temperature range of 292-380 K. Inverse modeling technique is applied to furnish calibrated doping profiles. The inversion layer electron effective mobility is thereby extracted, showing a decreasing trend with decreasing channel length. Such differences reflect more additional scatterers in the shorter devices. Mobility components limited by these additional scatterers are assessed using Matthiessen's rule. From the extracted temperature dependencies, we infer that the strength of source/drain plasmons increases with decreasing channel length. The errors of Matthiessen's rule are adequately dealt with. Corroborative evidence is given as well.