Fabrication of periodic square arrays by angle-resolved nanosphere lithography

• Published in: Microelectronic engineering 2010-10, Vol.87 (10), p.1941-1944
• Main Authors: Lee, Kwang Hong, Chen, Qiu Ling, Yip, Chan Hoe, Yan, Qingfeng, Wong, Chee Cheong
• Format: Article
• Language: English
• Subjects: Angle-resolved nanosphere lithography (ARNSL); Applied sciences; Arrays; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition; Electronics; Etching; Exact sciences and technology; Gold; Gold etching; Lithography; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of nanofabrication; Microelectronic fabrication (materials and surfaces technology); Nanocomposites; Nanolithography; Nanomaterials; Nanopowders; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Square array; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2009.11.169

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 ϕ (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 ϕ = 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.