Fabrication of periodic square arrays by angle-resolved nanosphere lithography

• Main Authors: Lee, Kwang Hong, Chen, Qiu Ling, Yip, Chan Hoe, Yan, Qingfeng, Wong, Chee Cheong
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Microelectronics
• Online Access: https://hdl.handle.net/10356/90934; http://hdl.handle.net/10220/6813
• Institution: Nanyang Technological University

We investigate the fabrication of periodic square arrays of solid gold islands by angle-resolved nanosphere lithography (ARNSL) in conjunction with thermal evaporation and etching. By varying θ (the tilt angle between the direction of gold deposition beam and the substrate surface normal) and (the substrate rotation angle about the beam axis), adjacent islands on a deposited hexagonal gold array will have a constant and periodic difference in height. Upon etching, this height bias will result in the shorter structures being removed to produce an array with a different symmetry from the original hexagonal symmetry of the parent mask. By depositing at three directions of = 0°, 120° and −120° with a constant θ = 20°, experimental results show that deposited two-dimensional gold periodic arrays will have a measurable difference in height between adjacent islands. Etching of the resulting patterns produced periodic near-square arrays with triangular nanostructures. Thus the combination of ARNSL and etching can allow selective periodic nanostructures to be removed, increasing the diversity of array symmetries available through nanosphere lithography.