scholarly journals Branched High Aspect Ratio Nanostructures Fabricated by Focused Helium Ion Beam Induced Deposition of an Insulator

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 232
Author(s):  
Frances I. Allen
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Ion Beam ◽  
Single Step ◽  
Direct Write ◽  
Step Method ◽  
Helium Ion ◽  
Nanofabrication Technique ◽  
Selective Placement ◽  
Branched Nanostructures

Helium ion beam induced deposition using the gaseous precursor pentamethylcyclopentasiloxane is employed to fabricate high aspect ratio insulator nanostructures (nanopillars and nanocylinders) that exhibit charge induced branching. The branched nanostructures are analyzed by transmission electron microscopy. It is found that the side branches form above a certain threshold height and that by increasing the flow rate of the precursor, the vertical growth rate and branching phenomenon can be significantly enhanced, with fractalesque branching patterns observed. The direct-write ion beam nanofabrication technique described herein offers a fast single-step method for the growth of high aspect ratio branched nanostructures with site-selective placement on the nanometer scale.

Proton Beam Nano-Machining: End Station Design and Testing

2003 ◽  
Vol 777 ◽  
Author(s):  
J.A. van Kan ◽  
A.A. Bettiol ◽  
F. Watt
Keyword(s):  
Aspect Ratio ◽  
Proton Beam ◽  
High Aspect Ratio ◽  
Ion Beam ◽  
Spot Size ◽  
High Energy ◽  
Direct Write ◽  
Proton Beam Energy ◽  
National University ◽  
Physics Department

AbstractA new nuclear nanoprobe facility has been developed at the Centre for Ion Beam Applications (CIBA) in the Physics Department of the National University of Singapore. This facility is the first of its type dedicated to proton beam micromachining on a micron as well as a nano scale. The design and performance of the facility, which is optimized for 3D lithography with MeV protons, is discussed here. The system has been designed to be compatible with Si wafers up to 6”.The production of good quality high aspect ratio microstructures requires a lithographic technique capable of producing microstructures with smooth vertical sidewalls. In proton beam micromachining, a high energy (e.g. 2 MeV) proton beam is focused to a sub-100 nm spot size and scanned over a resist material (e.g. SU-8 and polymethylmethacrylate (PMMA)). When a proton beam interacts with matter it follows an almost straight path, the depth of which is dependent on the proton beam energy. These features enable the production of nanometer sized polymer structures. Experiments have shown that post-bake and curing steps are not required in this SU-8 process, reducing the effects of cracking and internal stress in the resist. Since proton beam micromachining is a fast direct write lithographic technique it has high potential for the production of high-aspect-ratio nano-structures.

High aspect ratio AFM Probe processing by helium-ion-beam induced deposition

Microscopy ◽  
2014 ◽  
Vol 63 (suppl 1) ◽  
pp. i30.2-i30 ◽  
Author(s):  
Keiko Onishi ◽  
Hongxuan Guo ◽  
Syoko Nagano ◽  
Daisuke Fujita
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Ion Beam ◽  
Helium Ion ◽  
Afm Probe

Fluorocarbon Precursor for High Aspect Ratio via Milling in Focused Ion Beam Modification of Integrated Circuits

2004 ◽  
Author(s):  
Valery Ray
Keyword(s):  
Side Effects ◽  
Aspect Ratio ◽  
Integrated Circuits ◽  
High Aspect Ratio ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Enabling Technology ◽  
Si Substrate ◽  
Ion Beam Modification ◽  
The Past

Abstract Gas Assisted Etching (GAE) is the enabling technology for High Aspect Ratio (HAR) circuit access via milling in Focused Ion Beam (FIB) circuit modification. Metal interconnect layers of microelectronic Integrated Circuits (ICs) are separated by Inter-Layer Dielectric (ILD) materials, therefore HAR vias are typically milled in dielectrics. Most of the etching precursor gases presently available for GAE of dielectrics on commercial FIB systems, such as XeF2, Cl2, etc., are also effective etch enhancers for either Si, or/and some of the metals used in ICs. Therefore use of these precursors for via milling in dielectrics may lead to unwanted side effects, especially in a backside circuit edit approach. Making contacts to the polysilicon lines with traditional GAE precursors could also be difficult, if not impossible. Some of these precursors have a tendency to produce isotropic vias, especially in Si. It has been proposed in the past to use fluorocarbon gases as precursors for the FIB milling of dielectrics. Preliminary experimental evaluation of Trifluoroacetic (Perfluoroacetic) Acid (TFA, CF3COOH) as a possible etching precursor for the HAR via milling in the application to FIB modification of ICs demonstrated that highly enhanced anisotropic milling of SiO2 in HAR vias is possible. A via with 9:1 aspect ratio was milled with accurate endpoint on Si and without apparent damage to the underlying Si substrate.

FABRICATION OF ARRAY MICROSTRUCTURES USING SERIAL AND PARALLEL LOCALIZED ELECTRODEPOSITION

2009 ◽  
Vol 08 (03) ◽  
pp. 323-332 ◽  
Author(s):  
RA'A SAID ◽  
NIDAL ALSHWAWREH ◽  
YOUSEF HAIK
Keyword(s):  
Tissue Engineering ◽  
Aspect Ratio ◽  
Antenna Arrays ◽  
High Aspect Ratio ◽  
High Frequency ◽  
Neural Recording ◽  
Single Step ◽  
Fabrication Technique ◽  
Ultra High Frequency

To add to the development efforts in enhancing the capabilities of localized electrodeposition (LED) fabrication technique, this paper presents serial and parallel deposition algorithms to fabricate array microstructures. Such arrays can be implemented as microsensors in neural recording applications or as antenna arrays in ultra high frequency applications. Also, magnetic tip microarrays for tissue engineering can be realized. In the case of serial fabrication, an array of high aspect ratio microstructures is realized using the conventional single-tip microelectrode while implementing a multistep fabrication algorithm. In this algorithm, the fabricated microstructure elements within the array are realized one at a time. In the parallel deposition algorithm, the array is realized using a multitip array microelectrode while implementing a single step fabrication algorithm. In this algorithm, the microstructure elements within the array are fabricated simultaneously. The proposed algorithms are compared through a demonstration of fabricated array microstructures.

Focused Ion Beam: Advanced Technique for Device Modification

1994 ◽  
Vol 337 ◽  
Author(s):  
Marsha Abramo ◽  
Loren Hahn
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Semiconductor Materials ◽  
Advanced Technique ◽  
Aspect Ratios ◽  
Chip Technology ◽  
Design Changes ◽  
Critical Feedback

ABSTRACTFocused ion beam (FIB) technology is used to modify circuits for early-product design debug; it also has the capability to create probe points to underlying metallurgy, allowing device characterization while maintaining full functionality. These techniques provide critical feedback to designers for rapid verification of proposed design changes.Current FIB technology has its limitations because of redeposition of sputtered material; this phenomena may induce vertical electrical shorts and limit the achievable aspect ratio of a milled via to 6:1. Therefore, innovative enhancements are required to provide modification capability on planar chip technology which may utilize up to five levels of metallurgy. The ability to achieve high-aspect-ratio milling is required to access underlying circuitry. Vias with aspect ratios of 10:1 are necessary in some cases.This paper reviews a gas-assisted etching (GAE) process that enhances FIB milling by volatilizing the sputtered material, examines the results obtained from utilizing the GAE process for high-aspect-ratio milling, and discusses selectivity of semiconductor materials (silicon, aluminum, tungsten and silicon dioxide).

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