Effect of substrate doping on threshold voltages of buried channel pMOSFET based on strained-SiGe technology
来源期刊：中南大学学报(英文版)2014年第6期
论文作者：WANG Bin(王斌) ZHANG He-ming(张鹤鸣) HU Hui-yong(胡辉勇) ZHANG Yu-ming(张玉明) ZhOU Chun-yu(周春宇) LI Yu-chen(李妤晨)
文章页码：2292 - 2297
Key words：buried pMOSFET; strained SiGe; plateau; threshold voltage; substrate doping; Ge fraction
Abstract: The effect of substrate doping on the threshold voltages of buried channel pMOSFET based on strained-SiGe technology was studied. By physically deriving the models of the threshold voltages, it is found that the layer which inversely occurs first is substrate doping dependent, giving explanation for the variation of plateau observed in the C-V characteristics of this device, as the doping concentration increases. The threshold voltages obtained from the proposed model are -1.2805 V for buried channel and -2.9358 V for surface channel at a lightly doping case, and -3.41 V for surface channel at a heavily doping case, which agrees well with the experimental results. Also, the variations of the threshold voltages with several device parameters are discussed, which provides valuable reference to the designers of strained-SiGe devices.
WANG Bin(王斌), ZHANG He-ming(张鹤鸣), HU Hui-yong(胡辉勇), ZHANG Yu-ming(张玉明), ZhOU Chun-yu(周春宇), LI Yu-chen(李妤晨)
(Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of Ministry of Education
(School of Microelectronics, Xidian University), Xi’an 710071, China)
Abstract:The effect of substrate doping on the threshold voltages of buried channel pMOSFET based on strained-SiGe technology was studied. By physically deriving the models of the threshold voltages, it is found that the layer which inversely occurs first is substrate doping dependent, giving explanation for the variation of plateau observed in the C-V characteristics of this device, as the doping concentration increases. The threshold voltages obtained from the proposed model are -1.2805 V for buried channel and -2.9358 V for surface channel at a lightly doping case, and -3.41 V for surface channel at a heavily doping case, which agrees well with the experimental results. Also, the variations of the threshold voltages with several device parameters are discussed, which provides valuable reference to the designers of strained-SiGe devices.
Key words:buried pMOSFET; strained SiGe; plateau; threshold voltage; substrate doping; Ge fraction
