Description
Nanosphere lithography (NSL) is a versatile and well-known method, which is suitable for the fabrication nanostructures over a large area The NSL offers several advantages over the other lithographical methods such as high throughput, while also being low-cost [1]. NSL is commonly used to fabricate an array of ordered triangular nanostructures, which originate from deposited metal material onto the interstices between the closely packed spheres [2]. The size and density of the triangular nanostructures depend on the size of the nanospheres used. In this work the polystyrene spheres ranging from 2 µm to 200 nm in diameter were used to fabricate an array of GaN triangular nanostructures.
The whole fabrication process consists of deposition of the polystyrene spheres over the GaN sample, followed by metal deposition to cover the whole sample and the spheres lift-off to expose the material beneath. The sample is then etched SiCl4/Ar plasma to facilitate formation of the trigonal nanostructure [3].
[1] P. COLSON, C. HENRIST, and R. CLOOTS, ‘Nanosphere Lithography: A Powerful Method for the Controlled Manufacturing of Nanomaterials’. Journal of Nanomaterials. Jan. 2013, vol. 2013, no. 1, p. 948510. Available from: https://doi.org/10.1155/2013/948510. J. GUANG et al. ‘Flexible and Speedy Preparation of
[2] J. GUANG et al. ‘Flexible and Speedy Preparation of Large-Scale Polystyrene Monolayer through HemisphericalDepression-Assisted Self-Assembling and Vertical Lifting’. ACS Appl. Polym. Mater. Apr. 2023, vol. 5, no. 4, pp. 2674–2683. Available from: https://doi.org/10.1021/acsapm.2c02245.
[3] S. J. PEARTON, R. J. SHUL, and F. REN. ‘A Review of Dry Etching of GaN and Related Materials’. MRS Internet j. nitride semicond. res. 2000, vol. 5, no. 1, p. e11. Available from: https://doi.org/10.1557/S1092578300000119.