新型稳定高迁移率二维半导体材料的界面工程及器件性能极限模拟

As Moore's Law is approaching its limit, new channel materials are in urgent need to continue Moore's prediction. Owing to the easy synthesis, simple composition, high mobility and proper bandgap, the novel two-dimensional (2D) layers, such as tellurene and PdSe2, are novel channel materials candidates in the field effect transistors. We plan to investigate the interfacial properties, transport properties and the devices of the monolayer and multilayer tellurene and PdSe2. Firstly, our project proposes to use the method of DFT and non-equilibrium Green's function to simulate the interface and then summary the principle about the tellurene and PdSe2 materials contact with metals. Secondly, we expect to decrease the Schottky barrier by inserting a 2D layer, such as honeycomb BN or graphene in systems of the tellurene- and PdSe2-Metal contact interfaces, which usually have a high Schottky barrier. At last, we plan to explore the performance limitation of transistors based on such two kinds of novel materials. We expect to get an optimal performance of tellurene and PdSe2 devices, especially the transport limits in the small scale from sub 10 nm to sub-5 nm. According to parameters required by the International Technology Roadmap for semiconductors (ITRS), such as the on/off ratio, SS, delay time, and etc., we can propose how to develop tellurene and PdSe2 devices in the next 10 years.

随着摩尔定律走到极限，新型沟道材料的开发迫在眉睫。稳定高迁移率二维半导体材料（VI族碲烯和五边形的PdSe2）有望成为下一代场效应晶体管的沟道材料。本项目拟以单层、多层的碲烯和PdSe2为例，研究与金属接触的界面、输运以及器件性能极限。运用密度泛函理论和非平衡格林函数方法模拟其界面，筛选得到肖特基势垒低的金属接触界面；通过对这类新型稳定高迁移率二维材料-金属进行界面插层修饰，探索降低肖特基势垒高度的新方法；研究这两类新型材料的晶体管在亚10nm下的性能极限。根据国际半导体线路图要求的开关比、亚阈值摆幅、延迟时间等关键参数设计满足未来十年需求的下一代器件。

随着摩尔定律走到极限，新型的沟道材料的开发迫在眉睫。稳定的二维半导体材料，如果其具有合适的带隙、高迁移率及稳定性，就可能具有成为下一代场效应晶体管沟道材料的潜力。我们采用密度泛函理论结合非平衡格林函数的方法，探索高迁移率稳定的二维半导体材料（In2Se3、Bi2O2Se、BiO2S2）和金属接触界面， 以降低势垒，我们预测了以单层WSe2、MoSi2N4、InP为沟道的场效应晶体管在亚10-5 nm尺度下性能极限并给出器件特征参数，同时预测了MoSi2N4/MoSi2As4单层材料的谷电子学性质。我们的研究结果为实验上设计满足国际半导体线路图的下一代场效应晶体管的选材提供有价值的理论参考。本项目取得多项原创性成果，已发表SCI论文8篇。其中一篇Physical Review B进入高被引论文。基于此项目研究内容负责人获得国家留学基金委公派博士后基金项目资助。