title: Simple fabrication of antireflective silicon subwavelength structure with self-cleaning properties.
abstract: A subwavelength structure (SWS) was formed via a simple chemical wet etching using a gold (Au) catalyst. Single nano-sized Au particles were fabricated by metallic self-aggregation. The deposition and thermal annealing of the thin metallic film were carried out. Thermal annealing of a thin metallic film enables the creation of metal nano particles by isolating them from each other by means of the self-aggregation of the metal. After annealing, the samples were soaked in an aqueous etching solution of hydrofluoric acid and hydrogen peroxide. When silicon (Si) was etched for 2 minutes using the Au nano particles, the reflectance was decreased almost 0% over the entire wavelength range from 300 to 1300 nm due to its deep and steeply double tapered structure. When given varying incident angle degrees from 30 degrees to 60 degrees, the reflectance was also maintained at less than 3%. Following this, the etched silicon was treated with a plasma-polymerized fluorocarbon (PPFC) film of about 5 nm using an ICP reactor for surface modification. The result of this surface treatment, the contact angle increased significantly from 27.5 degrees to 139.3 degrees. The surface modification was successful and maintained almost 0% reflectance because of the thin film deposition.
authors.affiliation: School of Information and Communication Engineering, INHA University, Incheon 402-751, South Korea.
authors.forename: Bo-Soon
authors.initials: BS
authors.lastname: Kim
authors.forename: Won-Ki
authors.initials: WK
authors.lastname: Ju
authors.forename: Min-Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Cheon
authors.initials: C
authors.lastname: Lee
authors.forename: Seung-Gol
authors.initials: SG
authors.lastname: Lee
authors.forename: O
authors.initials: O
authors.lastname: Beom-Hoan
mesh_terms: D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012031:Refractometry; D012542:Scattering, Radiation; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D012825:Silicon