Anti-reflectance investigation of a micro-nano hybrid structure fabricated by dry/wet etching methods

Abstract

Black silicon fabrication and manipulation have been well reported by institutes around the world and are quite useful for solar absorption and photovoltaic conversion. In this study, silicon micro-nano hybrid structures were fabricated, and the morphologies of the hybrid structures were analyzed. This paper studied nanostructures formed on tips, pits and a flat surface using a dry etching method and a wet etching method. In terms of nanostructure morphology, nanostructures etched by the wet etching method (13 μm) were taller than those etched by the dry etching method (1 μm), but the wet etched morphology was less organized. After the nanostructures were grown, six samples with nano sturctures and three samples with micro sturctures were measured by a photometer for reflectivity testing. The nine samples were compared and analyzed using the integral of reflectivity and solar emissivity at the earth’s surface. The results show that the nanostructures grown on a tip surface using the wet etching method had the minimum reflectivity in the wavelength range of 300 nm–1100 nm, in consideration of the forbidden energy gap of silicon.

Thermal Drift Investigation of an SOI-Based MEMS Capacitive Sensor with an Asymmetric Structure

“…The most difficult process is to deeply etch the bulk silicon structure using inductively coupled plasma (ICP) to get a high aspect ratio. At present, high-precision deep etching methods have been applied, and high aspect ratio structures [26] and shaped three-dimensional structures [27,28] can be obtained by etching. The literature [26] completed the optimization of the parameters of the ICP etching process through a large number of contrasting experiments and formed the etching experience formula of single crystal silicon structures of different widths and depths.…”

Deep Reactive Etching of Silica with SF6/H2 Plasma

“…Today, these structures have different uses as antibacterial surfaces, drug analysis, supercapacitor fabrication, photovoltaic devices, microelectromechanical systems, self-cleaning surfaces, and heat transfer [18,19,21,22]. Based on the reports, it is claimed that unpleasant particles and contaminations lead to the grass formation mechanism which may be because of dusts, the remnant of the metal masking lay-ers, unacceptable surface cleaning, and any origin of accidental micro-masks [21].…”

Anti-Reflectance Optimization of Secondary Nanostructured Black Silicon Grown on Micro-Structured Arrays

“…In order to fabricate hemispherical shape pits and volcanic shape tips, etching gas and high energy density SF 6 /O 2 plasma should not only react with the silicon in the vertical direction but also in the horizontal direction. In previous work, the etching rate ratios in the vertical direction and horizontal direction were measured by considering the different pattern sizes of the masks [ 70 , 71 ]. Therefore, the sizes of the masks were designed according to the results of the etching rate ratio.…”

“…1 to No. 5 tip and pits samples might show different results of depth, which were studied in previous research [ 70 , 71 ]. Therefore, Table 2 indicates the design number of the depths of each sample in Table 1 .…”