Abstract

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.

© 2013 Optical Society of America

Sub-50 nm patterning by immersion interference lithography using a Littrow prism as a Lloyd’s interferometer

Johannes de Boor, Dong Sik Kim, and Volker Schmidt
Opt. Lett. 35(20) 3450-3452 (2010)

Period-chirped gratings fabricated by laser interference lithography with a concave Lloyd’s mirror

Hanbit Kim, Hyunho Jung, Dong-Hyun Lee, Kyu Back Lee, and Heonsu Jeon
Appl. Opt. 55(2) 354-359 (2016)

Three-beam interference lithography: upgrading a Lloyd's interferometer for single-exposure hexagonal patterning

Johannes de Boor, Nadine Geyer, Ulrich Gösele, and Volker Schmidt
Opt. Lett. 34(12) 1783-1785 (2009)

Self-processing solgel material for one-step fabrication of micrometer-period sinusoidal phase gratings using the Lloyd’s mirror scheme

Miao He, Jing Bu, Xiaocong Yuan, Hanben Niu, and Xiang Peng
Opt. Lett. 30(20) 2772-2774 (2005)

Patterning nanoscale crossed grating with high uniformity by using two-axis Lloyd’s mirrors based interference lithography

Gaopeng Xue, Haiou Lu, Xinghui Li, Qian Zhou, Guanhao Wu, Xiaohao Wang, Qihang Zhai, and Kai Ni
Opt. Express 28(2) 2179-2191 (2020)