Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
Opt Lett. 2013 Jul 15;38(14):2531-4. doi: 10.1364/OL.38.002531.
We have developed a liquid immersion Lloyd's mirror interference lithography system to fabricate subwavelength periodic nanostructures. In this approach, we construct the Lloyd's mirror interferometer within a liquid medium to increase the ambient index. The light wavelength is scaled by the refractive index of the immersion fluid, reducing the minimum interference pattern period and increasing the spatial resolution. The all-liquid system ensures continuous fluid contact with the sample without an external mechanism, allows rapid adjustment of pattern period with subwavelength resolution, and retains the passive vibration-correction capability of Lloyd's mirror interferometers. Using this approach, we have successfully fabricated a grating structure with 112 nm period using a laser with 325 nm wavelength, attaining a numerical aperture of 1.45. The proposed immersion strategy can be adapted to improve pattern resolution of more complex interference lithography systems.
我们开发了一种液体浸没 Lloyd 镜干涉光刻系统，用于制造亚波长周期性纳米结构。在这种方法中，我们在液体介质中构建 Lloyd 镜干涉仪以增加环境折射率。光波长通过浸没液体的折射率进行缩放，从而减小最小干涉图案周期并提高空间分辨率。全液体系统确保了与样品的连续流体接触，而无需外部机构，允许以亚波长分辨率快速调整图案周期，并保留 Lloyd 镜干涉仪的被动振动校正能力。使用这种方法，我们成功地使用波长为 325nm 的激光制造了周期为 112nm 的光栅结构，实现了数值孔径为 1.45 的效果。所提出的浸入策略可以进行改进，以提高更复杂的干涉光刻系统的图案分辨率。
