Ultrahigh-aspect-ratio SiO2 deeply etched periodic structures with smooth surfaces for photonics applications

Abstract

One-dimensional SiO 2 deeply etched periodic structures were fabricated. The fabrication process was based on an anisotropic Si etching, followed by a direct oxidation of the etched Si structure. The obtained submicron-scale SiO 2 periodic structure had an ultrahigh aspect ratio of 16 for the etched space and an etching depth of as large as 12.5 m. The etched depth was limited only by the etching mask. Therefore, increasing the mask thickness, or replacing it with a much harder mask material, should result in a much larger aspect ratio and etching depth. This structure also had an excellent vertical profile of less than 0.5°and extremely smooth surfaces of only 0.6 nm rms suitable for use in various applications, particularly in photonics fields that require a broad band performance, ranging from ultraviolet to near infrared.

High Aspect Ratio Nanoimprint Mold-Cavity Filling and Stress Simulation Based on Finite-Element Analysis

“…Nanoimprint lithography (NIL), which overcomes the limitations of conventional optic lithography, is a low-cost and high-throughput technique for manufacturing nanoscale patterns. Fabrication of three-dimensional (3D) high aspect ratio (HAR) nanopatterns has a broad range of applications in many fields, such as superhydrophobic structures [ 1 ], optics [ 2 ], electronics [ 3 ], and biology [ 4 ].…”

Fabrication of high aspect ratio (> 100:1) nanopillar array based on thiol-ene

“…Due to allowing higher device densities, nanopillars have already been utilized in a broad range of applications in electronics [4,5], optics [6], chemical analysis [7], and sensors [8]. In particular, devices for high frequencies based on diffraction (e.g.…”

Ultrahigh aspect ratio etching of silicon in SF6-O2 plasma: The clear-oxidize-remove-etch (CORE) sequence and chromium mask

“…Aspect ratio is defined as the depth of a trench/hole or height of a plate/pillar divided by its width/diameter. In addition to large scale integrated circuit manufacturing, HAR structures are increasingly requested in applications such as biological or chemical sensors, [1][2][3][4] electronic devices, [5][6][7] energy conversion and solar cells, 8,9 photon-absorbent surfaces, 10 confined phonon or photonic devices, 11,12 and quantum-based devices. 13 The success of HAR etching depends on controlling the lateral etch rate while keeping or enhancing the vertical etch rate.…”