CMOS-Compatible Catalyst for MacEtch: Titanium Nitride-Assisted Chemical Etching in Vapor phase for High Aspect Ratio Silicon Nanostructures

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

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

MRS Proceedings ◽

10.1557/opl.2012.1663 ◽

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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Pattern Collapse of High-Aspect-Ratio Silicon Nanostructures - A Parametric Study

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.255.136 ◽

2016 ◽

Vol 255 ◽

pp. 136-140 ◽

Cited By ~ 6

Author(s):

Nandi Vrancken ◽

Guy Vereecke ◽

Stef Bal ◽

Stefanie Sergeant ◽

Geert Doumen ◽

...

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Silicon Nanostructures ◽

Complete Structure ◽

Chemically Modified ◽

Chemically Modified Surfaces ◽

Modified Surfaces ◽

Wet Processing ◽

Modification Of The Surface

This work focuses on capillary-induced collapse of high-aspect-ratio silicon nanopillars. Modification of the surface chemistry is demonstrated to be an efficient approach for reducing capillary forces and consequently reduce pattern collapse. Special effort is spent on determination of the wetting state of chemically modified surfaces as complete structure wetting is of utmost importance in wet processing. In light of this, an ATR-FTIR based method has been developed to unambiguously distinguish between wetting and non-wetting states.

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Fabrication of Ultra-High Aspect Ratio (>420:1) Al2O3 Nanotube Arraysby Sidewall TransferMetal Assistant Chemical Etching

Micromachines ◽

10.3390/mi11040378 ◽

2020 ◽

Vol 11 (4) ◽

pp. 378 ◽

Cited By ~ 2

Author(s):

Hailiang Li ◽

Changqing Xie

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Chemical Etching ◽

Atomic Layer ◽

Nanotube Arrays ◽

Al2o3 Layer ◽

Practical Applications ◽

Aspect Ratios ◽

Layer Deposition

We report a robust, sidewall transfer metal assistant chemical etching scheme for fabricating Al2O3 nanotube arrays with an ultra-high aspect ratio. Electron beam lithography followed by low-temperature Au metal assisted chemical etching (MacEtch) is used to pattern high resolution, high aspect ratio, and vertical silicon nanostructures, used as a template. This template is subsequently transferred by an atomic layer deposition of the Al2O3 layer, followed by an annealing process, anisotropic dry etching of the Al2O3 layer, and a sacrificial silicon template. The process and characterization of the Al2O3 nanotube arrays are discussed in detail. Vertical Al2O3 nanotube arrays with line widths as small as 50 nm, heights of up to 21 μm, and aspect ratios up to 420:1 are fabricated on top of a silicon substrate. More importantly, such a sidewall transfer MacEtch approach is compatible with well-established silicon planar processes, and has the benefits of having a fully controllable linewidth and height, high reproducibility, and flexible design, making it attractive for a broad range of practical applications.

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