scholarly journals Using a Patterned Sapphire Template And The Lift-off Technique To Synthesize ZnO Nanoflower Arrays With Enhanced Photoluminescence Properties

2021 ◽  
Author(s):  
Hsien-Wei TSENG ◽  
Ching-Shan WANG ◽  
Fang-Hsing WANG ◽  
Han-Wen LIU ◽  
Cheng-Fu YANG
Keyword(s):  
Seed Layer ◽  
Focused Ion Beam ◽  
Sacrificial Layer ◽  
Ion Beam ◽  
Zinc Acetate Dihydrate ◽  
Zno Nanorods ◽  
Synthesis Temperature ◽  
Photoluminescence Properties ◽  
Synthesis Time ◽  
Lift Off

Abstract In this study, the hydrothermal method was used to synthesize ZnO nanorods and ZnO nanoflower arrays. Two different substrates were used to prepare the ZnO seed layer. For the p-type silicon <100> wafer, a prepared ZnO gel was deposited as the seed layer using the spin coating method. When a patterned sapphire recess-type substrate was used as a template, Al film, with a thickness of 120 nm, and OE-6370HF AB glue were used as a sacrificial layer and an imprinting lithography carrier for the ZnO seed layer, respectively. To prepare the array-patterned ZnO seed layers with a protrusion structure, a lift-off technique was used. A 0.2 M solution of zinc acetate dihydrate (Zn(CH3COO)2-2H2O) was used at a synthesis temperature of 90°C and a synthesis time of 10–60 min. Because the ZnO seed layer had a protrusion and matrix structure, the ZnO nanorods grew in the vertical bottom direction to form ZnO nanoflower arrays. X-ray diffraction patterns, scanning electron microscopy, and a focused ion beam system were used to analyze and compare the crystal characteristics and the heights and widths of the ZnO nanorods and ZnO nanoflower arrays. We found that the photoluminescence properties were enhanced in the ZnO nanoflower arrays compared with the ZnO nanorods.

Carbon Coating for Electron Beam Testing and Focus Ion Beam Reconfiguration

1996 ◽  
Author(s):  
P. Perdu ◽  
G. Perez ◽  
M. Dupire ◽  
B. Benteo
Keyword(s):  
Electron Beam ◽  
Sample Preparation ◽  
Carbon Coating ◽  
Focused Ion Beam ◽  
Sacrificial Layer ◽  
Ion Beam ◽  
Electrical Characterization ◽  
Fault Analysis ◽  
Voltage Contrast ◽  
The Right

Abstract To debug ASIC we likely use accurate tools such as an electron beam tester (Ebeam tester) and a Focused Ion Beam (FIB). Interactions between ions or electrons and the target device build charge up on its upper glassivation layer. This charge up could trigger several problems. With Ebeam testing, it sharply decreases voltage contrast during Image Fault Analysis and hide static voltage contrast. During ASIC reconfiguration with FIB, it could induce damages in the glassivation layer. Sample preparation is getting a key issue and we show how we can deal with it by optimizing carbon coating of the devices. Coating is done by an evaporator. For focused ion beam reconfiguration, we need a very thick coating. Otherwise the coating could be sputtered away due to imaging. This coating is use either to avoid charge-up on glassivated devices or as a sacrificial layer to avoid short circuits on unglassivated devices. For electron beam Testing, we need a very thin coating, we are now using an electrical characterization method with an insitu control system to obtain the right thin thickness. Carbon coating is a very cheap and useful method for sample preparation. It needs to be tuned according to the tool used.

Fabrication of large area nanogap electrodes for sensing applications

2013 ◽  
Vol 1530 ◽  
Author(s):  
A. Bendavid ◽  
L. Wieczorek ◽  
R. Chai ◽  
J. S. Cooper ◽  
B. Raguse
Keyword(s):  
Large Scale ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Fabrication Method ◽  
Large Area ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Lift Off ◽  
Nanogap Electrodes

ABSTRACTA large area nanogap electrode fabrication method combinig conventional lithography patterning with the of focused ion beam (FIB) is presented. Lithography and a lift-off process were used to pattern 50 nm thick platinum pads having an area of 300 μm × 300 μm. A range of 30-300 nm wide nanogaps (length from 300 μm to 10 mm ) were then etched using an FIB of Ga+ at an acceleration voltage of 30 kV at various beam currents. An investigation of Ga+ beam current ranging between 1-50 pA was undertaken to optimise the process for the current fabrication method. In this study, we used Monte Carlo simulation to calculate the damage depth in various materials by the Ga+. Calculation of the recoil cascades of the substrate atoms are also presented. The nanogap electrodes fabricated in this study were found to have empty gap resistances exceeding several hundred MΩ. A comparison of the gap length versus electrical resistance on glass substrates is presented. The results thus outline some important issues in low-conductance measurements. The proposed nanogap fabrication method can be extended to various sensor applications, such as chemical sensing, that employ the nanogap platform. This method may be used as a prototype technique for large-scale fabrication due to its simple, fast and reliable features.

scholarly journals Highly Rectifying Heterojunctions Formed by Annealed ZnO Nanorods on GaN Substrates

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 508 ◽  
Author(s):  
Stanislav Tiagulskyi ◽  
Roman Yatskiv ◽  
Hana Faitová ◽  
Šárka Kučerová ◽  
David Roesel ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Leakage Current ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Zno Nanorods ◽  
Carrier Injection ◽  
Ion Beam Lithography ◽  
Current Voltage ◽  
P Type ◽  
Surface Leakage

We study the effect of thermal annealing on the electrical properties of the nanoscale p-n heterojunctions based on single n-type ZnO nanorods on p-type GaN substrates. The ZnO nanorods are prepared by chemical bath deposition on both plain GaN substrates and on the substrates locally patterned by focused ion beam lithography. Electrical properties of single nanorod heterojunctions are measured with a nanoprobe in the vacuum chamber of a scanning electron microscope. The focused ion beam lithography provides a uniform nucleation of ZnO, which results in a uniform growth of ZnO nanorods. The specific configuration of the interface between the ZnO nanorods and GaN substrate created by the focused ion beam suppresses the surface leakage current and improves the current-voltage characteristics. Further improvement of the electrical characteristics is achieved by annealing of the structures in nitrogen, which limits the defect-mediated leakage current and increases the carrier injection efficiency.

Focused Ion Beam Study of Ni5Al Single Splat Microstructure

2006 ◽  
Vol 983 ◽  
Author(s):  
Yuhong Wu ◽  
Meng Qu ◽  
Lucille A Giannuzzi ◽  
Sanjay Sampath ◽  
Andrew Gouldstone
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Surface Engineering ◽  
Ion Beam ◽  
Deposition Process ◽  
Rapid Quenching ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Columnar Grains ◽  
Lift Off

AbstractThermally sprayed (TS) coatings are widely used for surface engineering across a range of industries, including aerospace, infrastructure and biomedical. TS materials are formed via the successive impingement, rapid quenching and build-up of molten powder particles on a substrate. The impacted ‘splats’ are thus the fundamental microstructural constituents of the coatings, and their intrinsic properties, as well as intersplat bonding and morphology, dictate coating behavior. Beyond the obvious practical considerations, from a scientific standpoint, splats represent a fascinating template for study, due to the highly non-equilibrium processing conditions (rapid deceleration from sub-sonic velocities, million-degree/sec cooling rates). In the literature, many studies of isolated splats on substrates have been carried out, but these have focused on overall morphology (disc-shape vs fragmented). Direct observations of microstructure, in particular cross-section, are limited in the specimen preparation stage due to splat size (tens of microns in diameter, 1-2 microns in thickness). However, Focused Ion Beam (FIB) techniques have allowed this problem to be addressed in a robust manner; in this paper we will discuss such approaches to observe Ni5Al splats on stainless steel substrates. Cross-sections through the splat and the substrate were created by recourse to ion milling and the ion beam itself provided good channeling contrast for grain imaging. The typical splat microstructure with sub-micron Ni(Al) columnar grains, a chill zone at the bottom and a lift off area is observed in high detail. In addition, an amorphous aluminum oxide top layer of 100-200 nm is partially present on top of the Ni(Al) columnar grains. At the splat/substrate interface, defects such as micro- and nano-scale pores were characterized for the first time and will be discussed. These observations provide insights into splat and interface formation during the deposition process and may drastically improve our current understanding of Ni5Al splat properties.

Effect of ZnO Seed Layer with Various Concentrations of Precursor on the Growth of ZnO Nanostructures

2016 ◽  
Vol 675-676 ◽  
pp. 237-240
Author(s):  
Nontakoch Siriphongsapak ◽  
Somyod Denchicharoen ◽  
Pichet Limsuwan
Keyword(s):  
Zinc Acetate ◽  
Seed Layer ◽  
Zinc Acetate Dihydrate ◽  
Zno Nanorods ◽  
Crystallographic Structure ◽  
Nitrate Hexahydrate ◽  
X Rays ◽  
Zno Nanostructures ◽  
Acetate Dihydrate ◽  
Seed Layers

In this work, Zinc oxide (ZnO) thin films were deposited on silicon and glass substrates using spin-coating method with different concentrations of precursor (zinc acetate dihydrate) and stabilizer (monoethanolamine). The concentrations of zinc acetate dihydrate and monoethanolamine in isopropanol were varied from 6 mM to 500 mM. Subsequently, the substrate with ZnO thin film as a seed layer was used to grow ZnO nanostructures by hydrothermal process with the same concentration of precursor (zinc nitrate hexahydrate), temperature, and time for each growth. The samples were characterized by field-emission scanning electron microscopy (FESEM), X-rays diffractometer (XRD), and UV-visible spectrophotometer (UV-vis) to study morphology, crystallographic structure, and optical property, respectively. The results showed that particle size, crystallinity, and transmittance of seed layers were changed with increasing concentrations of spin-coated precursor. Furthermore, the nanostructures were found that higher precursor concentration of seed layers affected the formation of ZnO nanorods to be nanosheets.

FIB Sample Preparation of Polymer Thin Films on Hard Substrates Using the Shadow-FIB Method

2009 ◽  
Vol 17 (6) ◽  
pp. 20-23 ◽  
Author(s):  
Suhan Kim ◽  
Gao Liu ◽  
Andrew M. Minor
Keyword(s):  
Thin Film ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Sacrificial Layer ◽  
Ion Beam ◽  
Initial Sample ◽  
Cross Sectional ◽  
Site Specific ◽  
Transmission Electron ◽  
Hard Substrates

Focused ion beam (FIB) instrumentation has proven to be extremely useful for preparing cross-sectional samples for transmission electron microscopy (TEM) investigations. The two most widely used methods involve milling a trench on either side of an electron-transparent window: the “H-bar” and the “lift-out” methods [1]. Although these two methods are very powerful in their versatility and ability to make site-specific TEM samples, they rely on using a sacrificial layer to protect the surface of the sample as well as the removal of a relatively large amount of material, depending on the size of the initial sample. In this article we describe a technique for making thin film cross-sections with the FIB, known as Shadow FIBing, that does not require the use of a sacrificial layer or long milling times [2].

scholarly journals Effect of Different Seed Solutions on the Morphology and Electrooptical Properties of ZnO Nanorods

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. Kashif ◽  
U. Hashim ◽  
M. E. Ali ◽  
Syed M. Usman Ali ◽  
M. Rusop ◽  
...  
Keyword(s):  
Seed Layer ◽  
Zinc Acetate Dihydrate ◽  
Zno Nanorods ◽  
Forward Bias ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Acetate Dihydrate ◽  
Common Precursor ◽  
Current Voltage ◽  
Electrooptical Properties

The morphology and electrooptical properties of ZnO nanorods synthesized on monoethanolamine-based seed layer and KOH-based seed layer were compared. The seed solutions were prepared in monoethanolamine in 2-methoxyethanol and potassium hydroxide in methanol, respectively. Zinc acetate dihydrate was as a common precursor in both solutions. The nanorod-ZnOs were synthesized via the spin coating of two different seed solutions on silicon substrates followed by their hydrothermal growth. The scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL), and Raman studies revealed that the ZnO nanorods obtained from monoethanolamine-based seed layer had fewer defects, better crystals, and better alignment than those realized via KOH-based seed layer. However, the current-voltage (I-V) characteristics demonstrated better conductivity of the ZnO nanorods obtained via KOH-based seed layer. The current measured in forward bias was 4 mA and 40 μA for ZnO-nanorods grown on KOH-based seed layer and monoethanolamine-based with the turn on voltage of approximately 1.5 V and 2.5 V, respectively, showing the feasibility of using both structures in optoelectric devices.

scholarly journals The study of photoluminescence properties of AlGaAs/GaAs heterostructure after Ga+ focused ion beam etching

2018 ◽  
Vol 1124 ◽  
pp. 051016
Author(s):  
G V Voznyuk ◽  
I V Levitskii ◽  
M I Mitrofanov ◽  
M N Mizerov ◽  
D N Nikolaev ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Photoluminescence Properties ◽  
Ion Beam Etching

DIRECT FORMATION OF NANOPORE ARRAY VIA FOCUSED ION BEAM FINE MILLING AND SURFACE COATING TECHNIQUES

2006 ◽  
Vol 05 (04n05) ◽  
pp. 529-534 ◽  
Author(s):  
YONGQI FU ◽  
BRYAN KOK ANN NGOI ◽  
WEI ZHOU ◽  
THIAN FATT LOH
Keyword(s):  
Thin Film ◽  
Focused Ion Beam ◽  
Sacrificial Layer ◽  
Ion Beam ◽  
Film Coating ◽  
Milling Process ◽  
Transmission Electron ◽  
Direct Formation ◽  
Nanopore Arrays ◽  
Bottom Side

A nanopore array with diameter of ~30 nm was fabricated by use of focused ion beam (FIB) scanning and thin film coating on Si (100). A thin film of SiO 2 with thickness of 200 nm (used as a sacrificial layer) was coated by physical evaporation deposition (PVD) first. Next, the thin films of poly-silicon with thickness of 50 nm were coated on double side of the substrate. A window with an area of 2 × 2 mm 2 was opened by reactive ion etching from bottom side and reached to the thin film of SiO 2. After that, a fine controlled FIB milling with bitmap function (milling according to a designed pattern in a defined area) was used to scan the area. Signal is obtained by a sensor inside the vacuum chamber collecting secondary electrons emitted from the sputtered material when the beam reach the layer of SiO 2. Stopping the milling process at this moment, the nanopore array was derived after removing the sacrificial layer by wet chemical etching. The nanopore arrays were characterized using transmission electron microscopy (TEM) after the FIB drilling.

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