scholarly journals Metal assisted chemical etching of silicon in the gas phase: a nanofabrication platform for X-ray optics

2020 ◽  
Vol 5 (5) ◽  
pp. 869-879 ◽  
Author(s):  
Lucia Romano ◽  
Matias Kagias ◽  
Joan Vila-Comamala ◽  
Konstantins Jefimovs ◽  
Li-Ting Tseng ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Gas Phase ◽  
Chemical Etching ◽  
Pt Catalyst ◽  
Ray Optics ◽  
X Ray ◽  
Metal Assisted Chemical Etching

Gas-MacEtch of Si with a Pt catalyst allows vertical etching nanostructures with an extreme aspect ratio up to 10 000 : 1.

scholarly journals Microfabrication of X-ray Optics by Metal Assisted Chemical Etching: A Review

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 589 ◽  
Author(s):  
Lucia Romano ◽  
Marco Stampanoni
Keyword(s):  
Aspect Ratio ◽  
Chemical Etching ◽  
Microelectromechanical Systems ◽  
Fresnel Zone ◽  
New Technology ◽  
Etching Technique ◽  
Ray Optics ◽  
X Ray ◽  
Metal Assisted Chemical Etching ◽  
Optics Fabrication

High-aspect-ratio silicon micro- and nanostructures are technologically relevant in several applications, such as microelectronics, microelectromechanical systems, sensors, thermoelectric materials, battery anodes, solar cells, photonic devices, and X-ray optics. Microfabrication is usually achieved by dry-etch with reactive ions and KOH based wet-etch, metal assisted chemical etching (MacEtch) is emerging as a new etching technique that allows huge aspect ratio for feature size in the nanoscale. To date, a specialized review of MacEtch that considers both the fundamentals and X-ray optics applications is missing in the literature. This review aims to provide a comprehensive summary including: (i) fundamental mechanism; (ii) basics and roles to perform uniform etching in direction perpendicular to the <100> Si substrate; (iii) several examples of X-ray optics fabricated by MacEtch such as line gratings, circular gratings array, Fresnel zone plates, and other X-ray lenses; (iv) materials and methods for a full fabrication of absorbing gratings and the application in X-ray grating based interferometry; and (v) future perspectives of X-ray optics fabrication. The review provides researchers and engineers with an extensive and updated understanding of the principles and applications of MacEtch as a new technology for X-ray optics fabrication.

scholarly journals Metal-Assisted Chemical Etching and Electroless Deposition for Fabrication of Hard X-ray Pd/Si Zone Plates

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 301 ◽  
Author(s):  
Rabia Akan ◽  
Thomas Frisk ◽  
Fabian Lundberg ◽  
Hanna Ohlin ◽  
Ulf Johansson ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Chemical Etching ◽  
Electroless Deposition ◽  
Low Cost ◽  
Zone Plate ◽  
X Ray ◽  
Zone Plates ◽  
Aspect Ratios ◽  
Plate Design ◽  
Metal Assisted Chemical Etching

Zone plates are diffractive optics commonly used in X-ray microscopes. Here, we present a wet-chemical approach for fabricating high aspect ratio Pd/Si zone plate optics aimed at the hard X-ray regime. A Si zone plate mold is fabricated via metal-assisted chemical etching (MACE) and further metalized with Pd via electroless deposition (ELD). MACE results in vertical Si zones with high aspect ratios. The observed MACE rate with our zone plate design is 700 nm/min. The ELD metallization yields a Pd density of 10.7 g/cm 3 , a value slightly lower than the theoretical density of 12 g/cm 3 . Fabricated zone plates have a grid design, 1:1 line-to-space-ratio, 30 nm outermost zone width, and an aspect ratio of 30:1. At 9 keV X-ray energy, the zone plate device shows a first order diffraction efficiency of 1.9%, measured at the MAX IV NanoMAX beamline. With this work, the possibility is opened to fabricate X-ray zone plates with low-cost etching and metallization methods.

scholarly journals Passivation of high aspect ratio silicon nanowires by using catalytic chemical vapor deposition for radial heterojunction solar cell application

RSC Advances ◽  
2017 ◽  
Vol 7 (71) ◽  
pp. 45101-45106 ◽  
Author(s):  
Gangqiang Dong ◽  
Yurong Zhou ◽  
Hailong Zhang ◽  
Fengzhen Liu ◽  
Guangyi Li ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Aspect Ratio ◽  
Silicon Nanowires ◽  
Vapor Deposition ◽  
High Aspect Ratio ◽  
Chemical Etching ◽  
Chemical Vapor ◽  
Solar Cell Application ◽  
Catalytic Chemical Vapor Deposition ◽  
Metal Assisted Chemical Etching

High aspect ratio silicon nanowires (SiNWs) prepared by metal-assisted chemical etching were passivated by using catalytic chemical vapor deposition (Cat-CVD).

Wafer-Scale, Highly-Ordered Silicon Nanowires Produced by Step-and-Flash Imprint Lithography and Metal-Assisted Chemical Etching

2012 ◽  
Vol 1512 ◽  
Author(s):  
Jian-Wei Ho ◽  
Qixun Wee ◽  
Jarrett Dumond ◽  
Li Zhang ◽  
Keyan Zang ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Cross Sections ◽  
Silicon Nanowires ◽  
High Aspect Ratio ◽  
Chemical Etching ◽  
Semiconductor Device ◽  
Imprint Lithography ◽  
Wafer Level ◽  
Conventional Photolithography ◽  
Metal Assisted Chemical Etching

ABSTRACTA combinatory approach of Step-and-Flash Imprint Lithography (SFIL) and Metal-Assisted Chemical Etching (MacEtch) was used to generate near perfectly-ordered, high aspect ratio silicon nanowires (SiNWs) on 4" silicon wafers. The ordering and shapes of SiNWs depends only on the SFIL nanoimprinting mould used, thereby enabling arbitary SiNW patterns not possible with nanosphere and interference lithography (IL) to be generated. Very densely packed SiNWs with periodicity finer than that permitted by conventional photolithography can be produced. The height of SiNWs is, in turn, controlled by the etching duration. However, it was found that very high aspect ratio SiNWs tend to be bent during processing. Hexagonal arrays of SiNW with circular and hexagonal cross-sections of dimensions 200nm and less were produced using pillar and pore patterned SFIL moulds. In summary, this approach allows highlyordered SiNWs to be fabricated on a wafer-level basis suitable for semiconductor device manufacturing.

Metal-assisted chemical etching for very high aspect ratio grooves inn-type silicon wafers

2014 ◽  
Vol 24 (12) ◽  
pp. 125026 ◽  
Author(s):  
Katherine Booker ◽  
Maureen Brauers ◽  
Erin Crisp ◽  
Shakir Rahman ◽  
Klaus Weber ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Chemical Etching ◽  
Silicon Wafers ◽  
Type Silicon ◽  
Metal Assisted Chemical Etching ◽  
Very High
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