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 Reaction control of metal-assisted chemical etching for silicon-based zone plate nanostructures

RSC Advances ◽  
2018 ◽  
Vol 8 (23) ◽  
pp. 12628-12634 ◽  
Author(s):  
Rabia Akan ◽  
Karolis Parfeniukas ◽  
Carmen Vogt ◽  
Muhammet S. Toprak ◽  
Ulrich Vogt
Keyword(s):  
Reaction Kinetics ◽  
Chemical Etching ◽  
Zone Plate ◽  
X Ray ◽  
Zone Plates ◽  
Aspect Ratios ◽  
Metal Assisted Chemical Etching ◽  
Silicon Based

Specially designed X-ray zone plates with high aspect-ratios have been fabricated via metal-assisted chemical etching, by controlling the reaction kinetics.

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 Investigation of Metal-Assisted Chemical Etching for Fabrication of Silicon-Based X-Ray Zone Plates

2018 ◽  
Vol 24 (S2) ◽  
pp. 290-291 ◽  
Author(s):  
Rabia Akan ◽  
Karolis Parfeniukas ◽  
Carmen Vogt ◽  
Muhammet S. Toprak ◽  
Ulrich Vogt
Keyword(s):  
Chemical Etching ◽  
X Ray ◽  
Zone Plates ◽  
Metal Assisted Chemical Etching ◽  
Silicon Based

A facile and low-cost route to high-aspect-ratio microstructures on silicon via a judicious combination of flow-enabled self-assembly and metal-assisted chemical etching

2016 ◽  
Vol 4 (38) ◽  
pp. 8953-8961 ◽  
Author(s):  
Liyi Li ◽  
Bo Li ◽  
Chuchu Zhang ◽  
Chia-Chi Tuan ◽  
Zhiqun Lin ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Self Assembly ◽  
Chemical Etching ◽  
Low Cost ◽  
Cost Strategy ◽  
Metal Assisted Chemical Etching ◽  
Low Cost Strategy

A viable and low-cost strategy for fabricating high-aspect-ratio microstructures on silicon (Si) based on a judicious combination of flow-enabled self-assembly (FESA) and metal-assisted chemical etching (MaCE) is reported.

Low Cost and High‐Aspect Ratio Micro/Nano Device Fabrication by Using Innovative Metal‐Assisted Chemical Etching Method

2019 ◽  
Vol 21 (8) ◽  
pp. 1900490 ◽  
Author(s):  
Nguyen Van Toan ◽  
Xiaoyue Wang ◽  
Naoki Inomata ◽  
Masaya Toda ◽  
Ioana Voiculescu ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Chemical Etching ◽  
Low Cost ◽  
Device Fabrication ◽  
Etching Method ◽  
Metal Assisted Chemical Etching

scholarly journals Optimization of Metal-Assisted Chemical Etching for Deep Silicon Nanostructures

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2806
Author(s):  
Rabia Akan ◽  
Ulrich Vogt
Keyword(s):  
Aspect Ratio ◽  
Reaction Kinetics ◽  
Chemical Etching ◽  
Mechanical Stability ◽  
Zone Plate ◽  
Processing Temperature ◽  
Brick Wall ◽  
Wide Range ◽  
Metal Assisted Chemical Etching ◽  
Si Nanostructures

High-aspect ratio silicon (Si) nanostructures are important for many applications. Metal-assisted chemical etching (MACE) is a wet-chemical method used for the fabrication of nanostructured Si. Two main challenges exist with etching Si structures in the nanometer range with MACE: keeping mechanical stability at high aspect ratios and maintaining a vertical etching profile. In this work, we investigated the etching behavior of two zone plate catalyst designs in a systematic manner at four different MACE conditions as a function of mechanical stability and etching verticality. The zone plate catalyst designs served as models for Si nanostructures over a wide range of feature sizes ranging from 850 nm to 30 nm at 1:1 line-to-space ratio. The first design was a grid-like, interconnected catalyst (brick wall) and the second design was a hybrid catalyst that was partly isolated, partly interconnected (fishbone). Results showed that the brick wall design was mechanically stable up to an aspect ratio of 30:1 with vertical Si structures at most investigated conditions. The fishbone design showed higher mechanical stability thanks to the Si backbone in the design, but on the other hand required careful control of the reaction kinetics for etching verticality. The influence of MACE reaction kinetics was identified by lowering the oxidant concentration, lowering the processing temperature and by isopropanol addition. We report an optimized MACE condition to achieve an aspect ratio of at least 100:1 at room temperature processing by incorporating isopropanol in the etching solution.

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 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.

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