A method to improve the quality of 2.5 dimensional micro-and nano-structures produced by focused ion beam machining

Micron ◽  
2017 ◽  
Vol 101 ◽  
pp. 8-15 ◽  
Author(s):  
Daniele De Felicis ◽  
Muhammad Zeeshan Mughal ◽  
Edoardo Bemporad
Author(s):  
C. Rue ◽  
S. Herschbein ◽  
C. Scrudato ◽  
L. Fischer ◽  
A. Shore

Abstract The efficiency of Gas-Assisted Etching (GAE) and depositions performed using the Focused Ion Beam (FIB) technique is subject to numerous factors. Besides the wellknown primary parameters recommended by the FIB manufacturer (pixel spacing, dwell time, and gas pressures), certain secondary factors can also have a pronounced effect on the quality of these gas-assisted FIB operations. The position of the gas delivery nozzle during XeF2 mills on silicon is examined and was found to affect both the milling speed and the texture on the floor of the FIB trench. Limitations arising from the memory capacity of the FIB computer can also influence process times and trench quality. Exposing the FIB vacuum chamber to TMCTS during SiO2 depositions is found to temporarily impede the performance of subsequent tungsten depositions, especially following heavy or prolonged TMCTS exposure. A delay period may be required to achieve optimal tungsten depositions following TMCTS use. Finally, the focusing conditions of the ion beam are found to have a significant impact on the resistance of FIB-deposited metal films. This effect is attributed to partial milling of the deposition film due to the intense current density of the collimated ion beam. The resistances of metal depositions performed with intentionally defocused ion beams were found to be lower than those performed with focused beams.


2019 ◽  
Author(s):  
Genevieve Buckley ◽  
Gediminas Gervinskas ◽  
Cyntia Taveneau ◽  
Hari Venugopal ◽  
James C. Whisstock ◽  
...  

AbstractCryo-transmission electron tomography (cryo-ET) in association with cryo-focused ion beam (cryo-FIB) milling enables structural biology studies to be performed directly within the cellular environment. Cryo-preserved cells are milled and a lamella with a thickness of 200-300 nm provides an electron transparent window suitable for cryo-ET imaging. Cryo-FIB milling is an effective method, but it is a tedious and time-consuming process, which typically results in ~10 lamellae per day. Here, we introduce an automated method to reproducibly prepare cryo-lamellae on a grid and reduce the amount of human supervision. We tested the routine on cryo-preserved Saccharomyces cerevisiae and demonstrate that this method allows an increased throughput, achieving a rate of 5 lamellae/hour without the need to supervise the FIB milling. We demonstrate that the quality of the lamellae is consistent throughout the preparation and their compatibility with cryo-ET analyses.


2001 ◽  
Vol 691 ◽  
Author(s):  
Stephen B. Cronin ◽  
Yu-Ming Lin ◽  
Oded Rabin ◽  
Marcie R. Black ◽  
Gene Dresselhaus ◽  
...  

ABSTRACTWe developed a method for making 4-point contacts to Bi nanowires with a thick oxide coat using a combination of lithographic and focused ion beam (FIB) techniques. The resistivity of Bi nanowires with diameters in the range 70-200nm is found to increase with decreasing wire diameter. In contrast to bulk Bi, the temperature dependence of the resistivity is found to decrease monotonically with increasing temperature. The results are explained on the basis of increased scattering in the nanowire and the known temperature dependence of the electronic properties of bulk Bi. A large magneto-resistance was also measured, indicating a high crystalline quality of the nanowires. A large spread in the measured values of the resistivity indicates significant systematic error in the measurement technique. Possible sources for error are discussed.


2020 ◽  
Vol 21 (12) ◽  
pp. 2407-2417
Author(s):  
Ki-Hwan Jang ◽  
Hae-Sung Yoon ◽  
Hyun-Taek Lee ◽  
Eunseob Kim ◽  
Sung-Hoon Ahn

AbstractIn micro-/nano-scale, multi-material three-dimensional (3D), structuring has been a major research area for making various applications. To overcome dimensional and material limitations, several hybrid processes have been proposed. The hybrid processes were performed in the same or different numerically controlled stages. If the stages differed, the substrate was moved and locked to the stage before fabrication. During the locking, alignment error occurred. This error became problematic because this significantly compromised the quality of final structures. Here, an alignment method for a hybrid process consisted of a focused ion beam milling, aerodynamically focused nanoparticle printing, and micro-machining was developed. Two sets of collinear marks were placed at the edges of the substrate. Rotational and translational errors were calculated and compensated using the marks. Processes having different scales were bridged through this alignment method. Various materials were utilized, and accuracy was less than 50 nm when the length of the substrate was less than 13 mm. The alignment method was employed to fabricate a V-shaped structure and step-shaped structure using polymer, ceramic, and metal.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2871
Author(s):  
Qiuling Wen ◽  
Xinyu Wei ◽  
Feng Jiang ◽  
Jing Lu ◽  
Xipeng Xu

Sapphire substrates with different crystal orientations are widely used in optoelectronic applications. In this work, focused ion beam (FIB) milling of single-crystal sapphire with A-, C-, and M-orientations was performed. The material removal rate (MRR) and surface roughness (Sa) of sapphire with the three crystal orientations after FIB etching were derived. The experimental results show that: The MRR of A-plane sapphire is slightly higher than that of C-plane and M-plane sapphires; the Sa of A-plane sapphire after FIB treatment is the smallest among the three different crystal orientations. These results imply that A-plane sapphire allows easier material removal during FIB milling compared with C-plane and M-plane sapphires. Moreover, the surface quality of A-plane sapphire after FIB milling is better than that of C-plane and M-plane sapphires. The theoretical calculation results show that the removal energy of aluminum ions and oxygen ions per square nanometer on the outermost surface of A-plane sapphire is the smallest. This also implies that material is more easily removed from the surface of A-plane sapphire than the surface of C-plane and M-plane sapphires by FIB milling. In addition, it is also found that higher MRR leads to lower Sa and better surface quality of sapphire for FIB etching.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1789 ◽  
Author(s):  
Liangliang Yang ◽  
Jiangtao Wei ◽  
Zhe Ma ◽  
Peishuai Song ◽  
Jing Ma ◽  
...  

Micro/nano structures have unique optical, electrical, magnetic, and thermal properties. Studies on the preparation of micro/nano structures are of considerable research value and broad development prospects. Several micro/nano structure preparation techniques have already been developed, such as photolithography, electron beam lithography, focused ion beam techniques, nanoimprint techniques. However, the available geometries directly implemented by those means are limited to the 2D mode. Laser machining, a new technology for micro/nano structural preparation, has received great attention in recent years for its wide application to almost all types of materials through a scalable, one-step method, and its unique 3D processing capabilities, high manufacturing resolution and high designability. In addition, micro/nano structures prepared by laser machining have a wide range of applications in photonics, Surface plasma resonance, optoelectronics, biochemical sensing, micro/nanofluidics, photofluidics, biomedical, and associated fields. In this paper, updated achievements of laser-assisted fabrication of micro/nano structures are reviewed and summarized. It focuses on the researchers’ findings, and analyzes materials, morphology, possible applications and laser machining of micro/nano structures in detail. Seven kinds of materials are generalized, including metal, organics or polymers, semiconductors, glass, oxides, carbon materials, and piezoelectric materials. In the end, further prospects to the future of laser machining are proposed.


2018 ◽  
Author(s):  
Michael W. Martynowycz ◽  
Wei Zhao ◽  
Johan Hattne ◽  
Grant J. Jensen ◽  
Tamir Gonen

AbstractMicrocrystal electron diffraction (MicroED) allows for macromolecular structure solution from nanocrystals. To create crystals of suitable size for MicroED data collection, sample preparation typically involves sonication or pipetting a slurry of crystals from a crystallization drop. The resultant crystal fragments are fragile and the quality of the data that can be obtained from them is sensitive to subsequent sample preparation for cryoEM as interactions in the water-air interface can damage crystals during blotting. Here, we demonstrate the use of a focused ion beam to generate lamellae of macromolecular protein crystals for continuous rotation MicroED that are of ideal thickness, easy to locate, and require no blotting optimization. In this manner, crystals of nearly any size may be scooped and milled to ideal dimensions prior to data collection, thus streamlining the methodology for sample preparation for MicroED.


Author(s):  
Jiyoung Chang ◽  
Jongbaeg Kim ◽  
Byung-Kwon Min ◽  
Sang Jo Lee ◽  
Liwei Lin

Schemes for in-situ resonant frequency tuning of nano scale vibrating structures using Focused Ion Beam (FIB) sputtering and FIB-Chemical Vapor Deposition (CVD) are presented. This approach introduces precisely controlled permanent increase or decrease of resonant frequencies on processed nano structures, enabling the frequency adjustment when the desired resonant frequency is higher or lower than the actual frequency of the fabricated resonators. The vibration is induced by electrostatic force between resonator and stator using 0~10V AC input and all the processes including fabrication of nanostructure, electrostatic actuation, vibration observation and frequency tuning in either higher or lower direction were successfully conducted in single FIB chamber. The range of the frequency tuned from 600kHz initial resonant frequency is +6kHz with -1.9μm and -65kHz with +1.1μm length change of the nano-resonator respectively. Structural FEM analysis result is compared with the experimental result.


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