Wong Hei, Kakushima Kuniyuki
Department of Electrical Engineering, City University of Hong Kong, Hong Kong, China.
Frontier Research Center, Tokyo Institute of Technology, Yokohama 226-8502, Japan.
Nanomaterials (Basel). 2023 Jan 19;13(3):411. doi: 10.3390/nano13030411.
This work reports, for the first time, the phenomenon of lateral Poole-Frenkel current conduction along the dielectric/Si interface of a silicon nanowire metal-oxide semiconductor (MOS) transistor. This discovery has a great impact on the study of device characteristic modeling and device reliability, leading to a new kind of electronic device with a distinct operation mechanism for replacing the existing MOS transistor structure. By measuring the current-voltage characteristics of silicon nanowire MOS transistors with different nanowire widths and at elevated temperatures up to 450 K, we found that the current level in the conventional ohmic region of MOS transistors, especially for the transistors with a nanowire width of 10 nm, was significantly enhanced and the characteristics are no longer linear or in an ohmic relationship. The enhancement strongly depended on the applied drain voltage and strictly followed the Poole-Frenkel emission characteristics. Based on this discovery, we proposed a new type of MOS device: a Poole-Frenkel emission MOS transistor, or PF-MOS. The PF-MOS uses the high defect state Si/dielectric interface layer as the conduction channel and is expected to possess several unique features that have never been reported. PF-MOS could be considered as the ultimate MOS structure from a technological point of view. In particular, it eliminates the requirement of a subnanometer gate dielectric equivalent oxide thickness (EOT) and eradicates the server mobility degradation issue in the sub-decananometer nanowires.
这项工作首次报道了沿硅纳米线金属氧化物半导体（MOS）晶体管的电介质/硅界面横向的普尔-弗伦克尔电流传导现象。这一发现对器件特性建模和器件可靠性研究产生了重大影响，催生了一种具有独特工作机制的新型电子器件，有望取代现有的MOS晶体管结构。通过测量不同纳米线宽度且温度高达450K的硅纳米线MOS晶体管的电流-电压特性，我们发现MOS晶体管传统欧姆区域内的电流水平，特别是对于纳米线宽度为10nm的晶体管，显著增强，且特性不再呈线性或欧姆关系。这种增强强烈依赖于所施加的漏极电压，并严格遵循普尔-弗伦克尔发射特性。基于这一发现，我们提出了一种新型MOS器件：普尔-弗伦克尔发射MOS晶体管，即PF-MOS。PF-MOS将高缺陷态的硅/电介质界面层用作传导通道，预计具有一些从未报道过的独特特性。从技术角度来看，PF-MOS可被视为终极MOS结构。特别是，它消除了对亚纳米级栅极电介质等效氧化层厚度（EOT）的要求，并解决了亚十纳米级纳米线中严重的迁移率退化问题。
