Effect of interface roughness on the carrier transport in germanium MOSFETs investigated by Monte Carlo method

• Published in: Chinese physics B Vol. 19; no. 5; pp. 536 - 541
• Main Author: 杜刚 刘晓彦 夏志良 杨竞峰 韩汝琦
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.05.2010
• Subjects: Channels; Computer simulation; Germanium; Interface roughness; Monte Carlo methods; MOSFETs; Silicon; Transport properties; 半导体场效应晶体管; 双栅MOSFET; 承运人; 界面粗糙度; 蒙特卡罗法; 通道长度
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/19/5/057304

Interface roughness strongly influences the performance of germanium metal-organic-semiconductor field effect transistors （MOSFETs）. In this paper, a 2D full-band Monte Carlo simulator is used to study the impact of interface roughness scattering on electron and hole transport properties in long- and short- channel Ge MOSFETs inversion layers. The carrier effective mobility in the channel of Ge MOSFETs and the in non-equilibriurn transport properties are investigated. Results show that both electron and hole mobility are strongly influenced by interface roughness scattering. The output curves for 50 nm channel-length double gate n and p Ge MOSFET show that the drive currents of n- and p-Ge MOSFETs have significant improvement compared with that of Si n- and p-MOSFETs with smooth interface between channel and gate dielectric. The 82% and 96% drive current enhancement are obtained for the n- and p-MOSFETs with the completely smooth interface. However, the enhancement decreases sharply with the increase of interface roughness. With the very rough interface, the drive currents of Ge MOSFETs are even less than that of Si MOSFETs. Moreover, the significant velocity overshoot also has been found in Ge MOSFETs.