Chen Changdong, Yang Bo-Ru, Li Gongtan, Zhou Hang, Huang Bolong, Wu Qian, Zhan Runze, Noh Yong-Young, Minari Takeo, Zhang Shengdong, Deng Shaozhi, Sirringhaus Henning, Liu Chuan
State Key Lab of Opto-Electronic Materials & Technologies, Guangdong Province Key Lab of Display Material and Technology, School of Electronics and Information Technology, Shunde International Joint Research Institute Sun Yat-Sen University Guangdong 510275 China.
Shenzhen Key Lab of Thin Film Transistor and Advanced Display, Peking University Shenzhen Graduate School Peking University Shenzhen 518055 China.
Adv Sci (Weinh). 2019 Jan 25;6(7):1801189. doi: 10.1002/advs.201801189. eCollection 2019 Apr 3.
For newly developed semiconductors, obtaining high-performance transistors and identifying carrier mobility have been hot and important issues. Here, large-area fabrications and thorough analysis of InGaZnO transistors with enhanced current by simple encapsulations are reported. The enhancement in the drain current and on-off ratio is remarkable in the long-channel devices (e.g., 40 times in 200 µm long transistors) but becomes much less pronounced in short-channel devices (e.g., 2 times in 5 µm long transistors), which limits its application to the display industry. Combining gated four-probe measurements, scanning Kelvin-probe microscopy, secondary ion mass spectrometry, X-ray photoelectron spectroscopy, and device simulations, it is revealed that the enhanced apparent mobility up to several tens of times is attributed to the stabilized hydrogens in the middle area forming a degenerated channel area while that near the source-drain contacts are merely doped, which causes artifact in mobility extraction. The studies demonstrate the use of hydrogens to remarkably enhance performance of oxide transistors by inducing a new mode of device operation. Also, this study shows clearly that a thorough analysis is necessary to understand the origin of very high apparent mobilities in thin-film transistors or field-effect transistors with advanced semiconductors.
对于新开发的半导体而言，获得高性能晶体管并确定载流子迁移率一直是热门且重要的问题。在此，报道了通过简单封装实现大面积制备以及对具有增强电流的铟镓锌氧化物晶体管进行全面分析的情况。漏极电流和开/关比的增强在长沟道器件中十分显著（例如，在200 µm长的晶体管中增强了40倍），但在短沟道器件中则变得不太明显（例如，在5 µm长的晶体管中增强了2倍），这限制了其在显示行业的应用。结合栅控四探针测量、扫描开尔文探针显微镜、二次离子质谱、X射线光电子能谱以及器件模拟，结果表明，高达数十倍的增强表观迁移率归因于中间区域稳定的氢形成了简并沟道区域，而源极 - 漏极接触附近区域仅仅是掺杂，这导致了迁移率提取中的假象。这些研究证明了利用氢通过诱导新的器件工作模式来显著提高氧化物晶体管的性能。此外，这项研究清楚地表明，对于理解采用先进半导体的薄膜晶体管或场效应晶体管中非常高的表观迁移率的起源，进行全面分析是必要的。
