Focused Ion Beam-Induced Carbon Deposition

1988 ◽  
Vol 131 ◽  
Author(s):  
L. R. Harriott ◽  
M. J. Vasile
Keyword(s):  
Molecular Weight ◽  
Focused Ion Beam ◽  
Carbon Deposition ◽  
Ion Beam ◽  
Ion Current ◽  
Gas Jet ◽  
High Molecular Weight Material ◽  
Beam Dose ◽  
Ion Current Density ◽  
Very High

ABSTRACTA process for repair of micron and submicron sized transparent defects on photomasks is described. Opaque films are deposited at the intersection of the flux of organic monomers from a gas jet and a 20 keV Ga ion beam. Focused ion beam-induced deposition differs from other ion-induced, electron beam and laser processes due to the very high ion current density and the sputtering of the material as it is being deposited. We have explored the deposition-sputtering rate competition for several precursor materials as a function of monomer flux and ion beam dose rate. Our results suggest a model for deposition which requires polymerization of the precursor through carbon-carbon double bonds to favor deposition over sputtering by creating high molecular weight material at the target.

Time Resolved Studies of Focused Ion Beam Induced Tungsten Deposition

2002 ◽  
Vol 749 ◽  
Author(s):  
H. Langfischer ◽  
S. Harasek ◽  
H. D. Wanzenboeck ◽  
B. Basnar ◽  
E. Bertagnolli
Keyword(s):  
Current Density ◽  
Focused Ion Beam ◽  
Metal Layer ◽  
Ion Beam ◽  
Ion Current ◽  
Transformation Rate ◽  
Average Current Density ◽  
Time Resolved ◽  
Tungsten Hexacarbonyl ◽  
Ion Current Density

ABSTRACTIn this study we investigate the nucleation and growth mechanisms of tungsten films processed by focused ion beam (FIB) induced chemical vapor deposition. For our investigation we use a 50 keV Ga+ ion beam focused on the substrate target and tungsten hexacarbonyl (W(CO)6) as precursor gas. Mediated by the substrate the energy of the impinging ions leads to the decomposition of the tungsten hexacarbonyl molecules adsorbed on the substrate into volatile parts and nonvolatile residues forming a metal deposit. Time resolved FIB secondary electron microscope imaging in combination with atomic force microscopy reveal first the formation of isolated nuclei and further their coalescence finally resulting in the formation of a contiguous metal layer. Despite the local impacts of the ion beam within the irradiated area of the substrate the localization of the nucleation spots is neither correlated to the spot centers nor to the scan path of the ion beam. After formation, the nanoscale tungsten nuclei preserve their positions and typical shapes during further deposition. Only after merging the nuclei to a contiguous tungsten layer, a further regime of growth sets on which is characterized by deposition of tungsten on a tungsten surface. In this regime the deposition process is determined by the total ion dose and the average current density the samples are subjected to. In this regime, deposition yields up to 3.5 atoms per incident gallium ion are achieved. The contiguous layer quality is determined by Auger electron analysis. The measured growth data were interpreted by adopting the analytic Ruedenauer Steiger approach mainly incorporating ion current density, precursor gas transformation rate, and ion induced sputtering. As a result, the critical ion current density, where ion sputtering exceeds deposition, was identified by the model. Because the model shows excellent agreement with the measurement it should be suitable for further survey concerning focused ion beam process development.

scholarly journals 4-Point Resistance Measurements of Individual Bi Nanowires

2001 ◽  
Vol 635 ◽  
Author(s):  
Stephen B. Cronin ◽  
Yu-Ming Lin ◽  
Pratibha L. Gai ◽  
Oded Rabin ◽  
Marcie R. Black ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
The Reformation ◽  
Bismuth Nanowires ◽  
Thick Oxide Layer ◽  
Bi Nanowire ◽  
Oxide Removal ◽  
Anodic Alumina Templates ◽  
Alternate Solution ◽  
Very High

AbstractWe have synthesized single crystal bismuth nanowires by pressure injecting molten Bi into anodic alumina templates. By varying the template fabrication conditions, nanowires with diameters ranging from 10 to 200nm and lengths of ~50[.proportional]m can be produced. We present a scheme for measuring the resistance of a single Bi nanowire using a 4-point measurement technique. The nanowires are found to have a 7nm thick oxide layer which causes very high contact resistance when electrodes are patterned on top of the nanowires. The oxide is found to be resilient to acid etching, but can be successfully reduced in high temperature hydrogen and ammonia environments. The reformation time of the oxide in air is found to be less than 1 minute. Focused ion beam milling is attempted as an alternate solution to oxide removal.

Influence of Ion Current Density on the Surface Morphology of AZ31 Magnesium Alloy Irradiated by High-Intensity Pulsed Ion Beam

2011 ◽  
Vol 391-392 ◽  
pp. 868-871
Author(s):  
Peng Li ◽  
Y.X. Wang ◽  
L. Xue
Keyword(s):  
Magnesium Alloy ◽  
Current Density ◽  
Ion Beam ◽  
Surface Profile ◽  
Ion Current ◽  
Az31 Magnesium Alloy ◽  
Horizontal Wave ◽  
Surface Profiles ◽  
Surface Morphologies ◽  
Ion Current Density

HIPIB irradiation into AZ31 magnesium alloy is performed at ion current density of 100-300 A/cm2 with 1 shot. The surface morphologies and surface profiles of the irradiated AZ31 magnesium alloy samples are characterized by scanning electron microscopy (SEM) and profilometer, respectively. It is found that HIPIB irradiation leads to the formation of crater in local region of irradiated samples, and crater density increases with increasing ion current density. Both the surface roughness that reflects the vertical wave of surface profile and the mean spacing of surface profile irregularities that reflects the horizontal wave of surface profile increase as ion current density increases. These results are in agreement with the SEM observation on the irradiated surface.

scholarly journals Focused Ion Beam Processing of Superconducting Junctions and SQUID Based Devices

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
David C. Cox ◽  
John C. Gallop ◽  
Ling Hao
Keyword(s):  
Quantum Interference ◽  
Focused Ion Beam ◽  
Large Range ◽  
Ion Beam ◽  
Lead Times ◽  
Length Scale ◽  
Superconducting Quantum Interference Devices ◽  
Research Areas ◽  
New Research ◽  
Very High

AbstractFocused ion beam (FIB) has found a steady and growing use as a tool for fabrication, particularly in the length-scale of micrometres down to nanometres. Traditionally more commonly used for materials characterisation, FIB is continually finding new research areas in a growing number of laboratories. For example, over the last ten years the number of FIB instruments in the U.K. alone has gone from single figures, largely supplied by a single manufacturer, to many tens of instruments supplied by several competing manufacturers. Although the smaller of the two research areas, FIB fabrication has found itself to be incredibly powerful in the modification and fabrication of devices for all kinds of experimentation. Here we report our use of FIB in the production of Superconducting QUantum Interference Devices (SQUIDs) and other closely related devices for metrological applications. This is an area ideally suited to FIB fabrication as the required precision is very high, the number of required devices is relatively low, but the flexibility of using FIB means that a large range of smallbatch, and often unique, devices can be constructed quickly and with very short lead times.

Evaluating Angular Ion Current Density for Atomically Defined Nanotips

2014 ◽  
Vol 20 (5) ◽  
pp. 1514-1520 ◽  
Author(s):  
Radovan Urban ◽  
Robert A. Wolkow ◽  
Jason L. Pitters
Keyword(s):  
Current Density ◽  
Ion Beam ◽  
Beam Profile ◽  
Ion Current ◽  
Beam Diameter ◽  
Gas Field ◽  
Gaussian Shape ◽  
Gaussian Profile ◽  
Ion Current Density

AbstractIn this paper we investigate methods to characterize angular current density from atomically defined gas field ion sources. We show that the ion beam emitted from a single apex atom is described by a two-dimensional Gaussian profile. Owing to the Gaussian shape of the beam and the requirement to collect the majority of the ion current, fixed apertures have inhomogeneous illumination. Therefore, angular current density measurements through a fixed aperture record averaged angular current density. This makes comparison of data difficult as averaged angular current density depends on aperture size. For the same reasons, voltage normalization cannot be performed for fixed aperture measurements except for aperture sizes that are infinitely small. Consistent determination of angular current density and voltage normalization, however, can be achieved if the beam diameter as well as total ion current are known. In cases where beam profile cannot be directly imaged with a field ion microscope, the beam profile could be extracted from measurements taken at multiple acceleration voltages and/or with multiple aperture sizes.

Very high-resolution focused ion beam nanolithography improvement: A new three-dimensional patterning capability

1999 ◽  
Vol 17 (6) ◽  
pp. 3132 ◽  
Author(s):  
J. Gierak ◽  
E. Cambril ◽  
M. Schneider ◽  
C. David ◽  
D. Mailly ◽  
...  
Keyword(s):  
High Resolution ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Very High

scholarly journals Two-dimensional focusing of self-magnetically insulated “Plasma Focus Diode”

1989 ◽  
Vol 7 (2) ◽  
pp. 287-303 ◽  
Author(s):  
Katsumi Masugata ◽  
Hironobu Isobe ◽  
Keigo Aga ◽  
Masami Matsumoto ◽  
Shigeo Kawata ◽  
...  
Keyword(s):  
Current Density ◽  
Plasma Focus ◽  
Ion Beam ◽  
Ion Current ◽  
Anode Surface ◽  
Beam Power ◽  
Simple Type ◽  
Experimental Conditions ◽  
Simulation Code ◽  
Ion Current Density

A new and simple type of self-magnetically insulated, vacuum ion diode named “Plasma Focus Diode” has been successfully developed with a large solid angle of irradiation and low divergence angle. The diode has a pair of coaxial cylindrical electrodes similar to a Mather-type plasma focus device. Ion-current density of 1·9 kA/cm2 has been obtained on the anode surface under the experimental conditions of diode voltage ∼1·4 MV, diode current ∼180 kA, and pulse width ∼75 ns. The generated ion beam has been two-dimensionally focused (line focusing) with a focusing radius of ∼0·18 mm, giving a maximum ion current density and beam power density at the axis of ∼0·14 MA/cm2 and ∼0·18 TW/cm2, respectively. The motion of electrons in the gap has been numerically simulated by use of a newly developed particle-in-cell computer simulation code, and good agreement has been obtained between the simulation and the experiment.

Nanoscale Tomographic Imaging using Focused Ion Beam Sputtering, Secondary Electron Imaging and Secondary Ion Mass Spectrometry

2001 ◽  
Vol 7 (S2) ◽  
pp. 934-935
Author(s):  
Robert Hull ◽  
Derren Dunn ◽  
Alan Kubis
Keyword(s):  
Mass Spectrometry ◽  
Secondary Electron ◽  
Focused Ion Beam ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Beam ◽  
3D Structure ◽  
Ion Current ◽  
Ion Mass Spectrometry ◽  
Electron Imaging ◽  
Secondary Ion

As the importance of nano-scaled structures in both science and engineering increases, techniques for reconstructing three-dimensional structural, crystallographic and chemical relationships become increasingly important. in this paper we described a technique which uses focused ion beam (FIB) sputtering to expose successive layers of a 3D sample, coupled with secondary electron imaging and secondary ion mass spectrometry of each sputtered surface. Computer interpolation of these different slice images then enables reconstruction of the 3D structure and chemistry of the sample. These techniques are applicable to almost any inorganic material, at a spatial resolution of tens of nanometers, and fields of view up to (tens of μm).The FIB instrument used in this study is an FEI 200 with a minimum ion probe diameter < 10 nm, an ion current density ∼ 10 A/cm2, a maximum ion current of 11 nA, and a standard Ga+ ion energy of 30 keV. Our instrument is equipped with a continuous dynode electron multiplies (CDEM) for secondary electron imaging and a quadrupole mass spectrometer for secondary ion mass spectroscopy (SIMS) / element specific mapping. Gallium ions of this energy will ablate any material, with sputter yields typically of order ten, corresponding to a material removal rate of order 1 μm3nA−1s−1.

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