Focused ion beam - Wikipedia


focused ion beam technology and applications

Ions of keV energies incident on a solid surface produce a number of effects: several atoms are sputtered off, several electrons are emitted, chemical reactions may be induced, atoms are displaced from their equilibrium positions, and ions implant themselves in the solid, altering its properties. Apr 11,  · Prior to her retirement in , her primary areas of interest were in microelectronic application development and technology transfer related to plasma and ion beam physics for failure analysis applications. She has authored and co-authored numerous conference papers . Aug 29,  · Focused Ion Beam Systems: Basics and Applications [Nan Yao] on *FREE* shipping on qualifying offers. The focused ion beam (FIB) system is an important tool for understanding and manipulating the structure of materials at the nanoscale. Combining this system with an electron beam creates a DualBeam - a single system that can function as an imaging5/5(1).

Focused-ion-beam technology and applications (Technical Report) |

Ion sources based on elemental gold and iridium are also available. In a gallium LMIS, gallium metal is placed in contact with a tungsten needle, and heated gallium wets the tungsten and flows to the tip of the needle, where the opposing forces of surface tension and electric field form the gallium into a cusp shaped tip called a Taylor cone.

The huge electric field at this small tip greater than 1 x volts per centimeter causes ionization and field emission of the gallium atoms. Source ions are then generally accelerated to an energy of 1—50 keV kiloelectronvoltsand focused onto the sample by electrostatic lenses. LMIS produce high current density ion beams with very small energy spread. A modern FIB can deliver tens of nanoamperes of current to a sample, or can image the sample with a spot size on the order of a few nanometers, focused ion beam technology and applications.

More recently, instruments using plasma beams of noble gas ions, focused ion beam technology and applications, such as Xenon, have become available more widely. FIB systems operate in a similar fashion to a scanning electron microscope SEM except, focused ion beam technology and applications, rather than a beam of electrons and as the name implies, FIB systems use a finely focused beam of ions usually gallium that can be operated at low beam focused ion beam technology and applications for imaging or at high beam currents for site specific sputtering or milling.

As the primary beam rasters on the sample surface, the signal from the sputtered ions or secondary electrons is collected to form an image. At higher primary currents, a great deal of material can be removed by sputtering, allowing precision milling of the specimen down to focused ion beam technology and applications sub micrometer or even a nano scale. If the sample is non-conductive, a low energy electron flood gun can be used to provide charge neutralization. In this manner, by imaging with positive secondary ions using the positive primary ion beam, even highly insulating samples may be imaged and milled without a conducting surface coating, as would be required in an SEM.

Until recently, the overwhelming usage of FIB has been in the semiconductor industry. Such applications as defect analysis, circuit modification, photomask repair and transmission electron microscope TEM sample preparation of site specific locations on integrated circuits have become commonplace procedures. The latest FIB systems have high resolution imaging capability; this capability coupled with in situ sectioning has eliminated the need, in many cases, to examine FIB sectioned specimens in a separate SEM instrument.

FIB imaging[ edit ] At lower beam currents, FIB imaging resolution begins to rival the more familiar scanning electron microscope SEM in terms of imaging topography, however the FIB's two imaging modes, focused ion beam technology and applications, using secondary electrons and secondary ions, both produced by the primary ion beam, offer many advantages over SEM.

Correlative Light-Ion Microscopy of cells on glass. Color image obtained by fluorescence microscope, black-and-white image obtained by Scanning Ion Microscope and London skyline milled by Focused Ion Beam. As a result, grain morphology can be readily imaged without resorting to chemical etching. Grain boundary contrast can also be enhanced through careful selection of imaging parameters.

FIB secondary ion images also reveal chemical differences, and are especially useful in corrosion studies, as secondary ion yields of metals can increase by three orders of magnitude in the presence of oxygen, clearly revealing the presence of corrosion.

When the high-energy gallium ions strike the focused ion beam technology and applications, they will sputter atoms from the surface. Gallium atoms will also be implanted into the top few nanometers of the surface, and the surface will be made amorphous. Because of the sputtering capability, the FIB is used as a micro- and nano-machining tool, to modify or machine materials at the micro- and nanoscale.

FIB micro machining has become a broad field of its own, but nano machining with FIB is a field that is still developing. Commonly the smallest beam size for imaging is 2.

FIB tools are designed to etch or machine surfaces, an ideal FIB might machine away one atom layer without any disruption of the atoms in the next layer, or any residual disruptions above the surface. Yet currently because of the sputter the machining typically roughens surfaces at the sub-micrometer length scales. FIB-assisted chemical vapor deposition occurs when a gas, such as tungsten hexacarbonyl W CO 6 is introduced to the vacuum chamber and allowed to chemisorb onto the sample.

By focused ion beam technology and applications an area with the beam, the precursor gas will be decomposed into volatile and non-volatile components; the non-volatile component, such as tungsten, remains on the surface as a deposition.

This is useful, as the deposited metal can be used as a sacrificial layer, to protect the underlying sample from the destructive sputtering of the beam. Focused ion beam technology and applications nanometers to hundred of micrometers in length, tungsten metal deposition allows metal lines to be put right where needed. Other materials such as platinumcobalt, carbon, gold, etc. The high level of surface interaction is exploited in patterned doping of semiconductors.

FIB is also used for maskless implantation. Other techniques, such as ion milling or electropolishing can be used to prepare such thin samples. However, the nanometer-scale resolution of the FIB allows the exact region of interest to be chosen, such as perhaps a grain boundary or defect in a material. This is vital, for example, in integrated circuit failure analysis.

If a particular transistor out of several million on a chip is bad, the only tool capable of preparing an electron microscope sample of that single transistor is the FIB. This damaged layer can be minimized by FIB milling with lower beam voltages, or focused ion beam technology and applications further milling with a low-voltage argon ion beam after completion of the FIB process, focused ion beam technology and applications.

The ejected secondary ions are collected and analyzed after the surface of the specimen has been sputtered with a primary focused ion beam. FIB Tomography[ edit ] The focused ion beam has become a powerful tool for site-specific 3D imaging of sub-micron features in a sample.

In this FIB tomography technique, the sample is sequentially milled using an ion beam perpendicular to the specimen while imaging the newly exposed surface using an electron beam. This so called, slice and view approach allows larger scale nano-structures to be characterized across the many imaging modes available to an SEM, including secondary electron, backscattered electron, and energy dispersive x-ray measurement.

The process is destructive, since the specimen is being sequentially milled away after each image is collected. The collected series of images is then reconstructed to a 3D volume by registering the image stack and removing artifacts. The predominant artifact that degrades FIB tomography is ion mill curtaining, where mill patterns form large aperiodic stripes in each image.

The ion mill curtaining can be removed using destriping algorithms. Orloff MIT, J. Melngailis Helium ion microscope HeIM [ edit ] Another ion source seen in commercially available instruments is a helium ion source, focused ion beam technology and applications, which is inherently less damaging to the sample than Ga ions although it will still sputter small amounts of material especially at high magnifications and long scan times.

As the sample surface is sputtered away at a rate proportional to the sputtering yield and the ion flux ions per area per timethe Ga is implanted further into the sample, and a steady-state profile of Ga is reached.

This implantation is often a problem in the range of the semiconductor where silicon can focused ion beam technology and applications amorphised by the gallium. In order to get an alternative solution to Ga LMI sources, mass-filtered columns have been developed, based on a Wien filter technology.

Mass selection in the FIB column The principle of a Wien filter is based on the equilibrium of the opposite forces induced by perpendicular electrostatic and a magnetic fields acting on accelerated particles.

The proper mass trajectory remains straight and passes through the mass selection aperture while the other masses are stopped. Larger ions can be used to make rapid milling before refining the contours with smaller ones.

Users also benefits from the possibility to dope their samples with elements of suitable alloy sources. The latter property has found great interests in the investigation of magnetic materials and devices. Khizroev and Litvinov have shown, with the help of magnetic force microscopy MFMthat there is a critical dose of ions that a magnetic material can be exposed to without experiencing a change in the magnetic properties.

Exploiting FIB from such an unconventional perspective is especially favourable today when the future of so many novel technologies depends on the ability focused ion beam technology and applications rapidly fabricate prototype nanoscale magnetic devices.


Ion beam - Wikipedia


focused ion beam technology and applications


Recent advances in focused ion beam technology and applications. (ASPIS) has been investigated as a high brightness ion source for nano applications such as focused ion beam (FIB) and nano. Focused ion beam, also known as FIB, is a technique used particularly in the semiconductor industry, materials science and increasingly in the biological field for site-specific analysis, deposition, and ablation of materials. A FIB setup is a scientific instrument that resembles a scanning electron microscope (SEM). The anode spot plasma ion source (ASPIS) has been investigated as a high brightness ion source for nano applications such as focused ion beam (FIB) and nano medium energy ion scattering (nano-MEIS). The generation of anode spot is found to enhance brightness of ion beam since the anode spot increases plasma density near the extraction aperture.