Top–down fabrication of sub-nanometre semiconducting nanoribbons


Developments in semiconductor technology are propelling the dimensions of devices down to 10 nm, but facing great challenges in manufacture at the sub-10 nm scale. Nanotechnology can fabricate nanoribbons from two-dimensional atomic crystals, such as graphene, with widths below the 10 nm threshold, but their geometries and properties have been hard to control at this scale. Here we find that robust ultrafine molybdenum-sulfide ribbons with a uniform width of 0.35 nm can be widely formed between holes created in a MoS2 sheet under electron irradiation. In situ high-resolution transmission electron microscope characterization, combined with first-principles calculations, identifies the sub-1 nm ribbon as a Mo5S4 crystal derived from MoS2, through a spontaneous phase transition. Further first-principles investigations show that the Mo5S4 ribbon has a band gap of 0.77 eV, a Young’s modulus of 300GPa and can demonstrate 9% tensile strain before fracture. The results show a novel top–down route for controllable fabrication of functional building blocks for sub-nanometre electronics.

Link to the article

纳米制造技术有望实现亚纳米级突破

本报讯 目前,以光刻、电子束刻蚀等能量束刻蚀技术为主的纳米制造技术已经突破20纳米节点,最前沿的技术正在渐渐向10纳米分辨率趋近,但要达到可控制造10纳米特征尺寸的结构尚面临巨大挑战且成本极高。

《自然通讯》日前发表了由中国南京航空航天大学机械结构力学与控制国家重点实验室,与东南大学、南京大学和浙江大学共同完成的一项有关纳米技术制造研究理论的成果。研究人员发现用电子束刻蚀二硫化钼单层材料时,电子束引起的相邻孔洞在聚合前会发生自发相变,生成尺寸均一、高强韧(30GPa拉伸强度、9%断裂应变)、具备半导体特征(能隙0.77电子伏特)的0.35纳米宽的四硫化五钼纳米带,在电子束下比完整的二硫化钼母材还要稳定并可以大量产生。研究人员从理论上预测二硫族过渡金属都有类似的可加工性质,这一技术有望将纳米制造技术从10纳米以上突破到亚纳米级。(潘锋)

《中国科学报》 (2013-05-07 第2版 国际)

Link to the news report on Sciencenet