By: X.C. Wang, H.Y. Zheng, C. W. Tan, F. Wang, H. Y. Yu, K. L. Pey
Singapore Institute of Manufacturing Technology (SIMTech), Singapore
School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore
Modern technology requires the ability of creating smaller and smaller devices. Whether it is for information storage, high definition displays or sensor arrays, there are increasing demands for techniques able to define features smaller than micrometers or even just a few nanometers across. Several technologies such as electron beam lithography, X-ray lithography, nanoimprinting, and optical near-field lithography etc, have widely been investigated for nanofabrication. However, they all have some disadvantages especially in terms of cost flexibility, and complexity. Electron beam lithography is characterized by low sample throughput, high sample cost, modest feature shape control and excellent feature size control, whereas x-ray lithography is characterized by initial high capital costs but high sample throughput. Conventional optical lithography is relatively cheap and adaptable, but, its minimum feature size is limited by optical diffraction.