Semiclassical and Quantum Transport in CNTFETs Using Monte Carlo Simulation
Semiclassical and Quantum Transport in CNTFETs Using Monte Carlo Simulation
复制标题
使用蒙特卡罗模拟研究 CNTFET 中的半经典和量子输运
DOI：
10.1109/ted.2010.2096820
复制
发表时间：
2011
影响因子：
3.1
通讯作者：
P. Dollfus
中科院分区：
文献类型：
--
作者：
Huu;Damien Querlioz;S. Galdin;P. Dollfus
通过玻尔兹曼和维格纳蒙特卡罗模拟，包括声子散射，研究了准弹道输运和量子输运对碳纳米管场效应晶体管的工作和性能的影响。对栅长为10-100 nm的晶体管的半经典模拟表明，沟道栅极部分的输运具有很强的平衡性，而高能声子的发射只发生在沟道的漏端之外。对于栅长为25 nm的硅场效应晶体管，与未掺杂沟道相同的栅长时，弹道电子的比例达到了%，而不是通常的31%。对于大于20 nm的栅长，主要的量子输运效应是由于沟道漏极端的急剧势降而引起的载流子反射。尽管在比较Wigner函数和Boltzmann函数时观察到了很大的微观差异，但这种效应只是使量子电流在整个栅压范围内比半经典电流略小。对于较小的栅长，亚阈值范围内的源漏隧穿成为可能，这提高了量子模拟中的亚阈值斜率和截止电流。
The effects of quasi-ballistic and quantum transport on the operation and the performance of carbon nanotube FETs are examined by means of both Boltzmann and Wigner Monte Carlo simulations including phonon scattering. The semiclassical simulation of transistors of gate length in the range 10-100 nm shows the strong ballisticity of the transport in the gated part of the channel, while the emission of high-energy phonons occurs only beyond the drain end of the channel. For a gate length of 25 nm, the fraction of ballistic electrons reaches 89%, instead of typically 31% in the silicon FET of the same gate length with the undoped channel. For a gate length higher than 20 nm, the main quantum-transport effect is the reflection of carriers due to the sharp potential drop at the drain end of the channel. In spite of strong microscopic differences observed when comparing Wigner and Boltzmann functions, this effect just makes the quantum current slightly smaller than the semiclassical one on the full range of the gate voltage. For a smaller gate length, the source-drain tunneling becomes possible in the subthreshold regime, which enhances the subthreshold slope and the off-current in the quantum simulation.