Ion beam
Encyclopedia
An ion beam is a type of charged particle beam
consisting of ions. Ion beams have many uses in electronics manufacturing
(principally ion implantation
) and other industries. A variety of ion beam sources
exist, some derived from the mercury vapor thrusters
developed by NASA
in the 1960s.
is the duoplasmatron
. Ion beams can be used for sputtering
or ion beam etching and for ion beam analysis
.
Ion beam application, etching, or sputtering
, is a technique conceptually similar to sandblasting, but using individual atoms in an ion beam to ablate a target. Reactive ion etching
is an important extension that uses chemical reactivity to enhance the physical sputtering effect.
In a typical use in semiconductor manufacturing, a mask
is used to selectively expose a layer of photoresist
on a substrate
made of a semiconductor
material such as a silicon dioxide
or gallium arsenide wafer. The wafer is developed, and for a positive photoresist, the exposed portions are removed in a chemical process. The result is a pattern left on the surface areas of the wafer that had been masked from exposure. The wafer is then placed in a vacuum chamber
, and exposed to the ion beam. The impact of the ions erodes the target, abrading away the areas not covered by the photoresist.
Focused Ion Beam
(FIB) instruments are also used in the design verification and/or failure analysis
of semiconductor devices. Engineering prototype devices may be modified using the ion beam in order to rewire the electrical circuit. The technique may be effectively used to avoid performing a new mask run for the purpose of testing design changes. A device edit (FIB milling operation) is accomplished by focusing the ion beam on selected regions of the device in order to mill through metal or polysilicon structures. In addition to milling, it is also possible to use the ion beam to force the deposit of new conductive lines on the surface of the device. This is accomplished by injecting chemicals into the ion stream near the device surface. The interaction between the ions and the chemicals result in chemical deposition on the surface. This process is typically referred to as a FIB deposit operation.
Sputtering is also used in materials science to thin samples or specific regions of samples for transmission electron microscope analysis, or for extending surface analytical techniques such as secondary ion mass spectrometry
or electron spectroscopy (XPS
, AES
) so that they can depth profile them.
a broad or focused ion beam
is used to study mechanisms of inter- and intra- cellular communication, signal transduction
and DNA damage and repair
.
, most often in the treatment of cancer.
has been shown to be effective in the area of active space debris removal as well as asteroid deflection.
s are used in atomic physics
, nuclear physics
and particle physics
.
is theoretically possible, but has not been demonstrated. See particle beam weapon
for more information on this type of weapon.
The current ion beams today would barely cause a human to flinch or even notice a touch if hit. The ions only stay in a beam shape if under ultra-high vacuum (UHV) conditions, making its use as a weapon futile. However, if one is trying to destroy single cells, the ion beam may be one's "weapon of choice."
In science fiction
, weaponised ion beam generators are usually dubbed ion cannon
s.
Charged particle beam
A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same velocity . The kinetic energies of the particles are typically measured in keV or MeV, much larger than the energies of particles at ambient temperature...
consisting of ions. Ion beams have many uses in electronics manufacturing
Electronics manufacturing
The industrial electronics manufacturing process for the electronic assemblies found in many of today's electronic devices, is a multi-step process.-Component and PCB manufacturing:...
(principally ion implantation
Ion implantation
Ion implantation is a materials engineering process by which ions of a material are accelerated in an electrical field and impacted into another solid. This process is used to change the physical, chemical, or electrical properties of the solid...
) and other industries. A variety of ion beam sources
Ion source
An ion source is an electro-magnetic device that is used to create charged particles. These are used primarily to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines.- Electron ionization :...
exist, some derived from the mercury vapor thrusters
Ion thruster
An ion thruster is a form of electric propulsion used for spacecraft propulsion that creates thrust by accelerating ions. Ion thrusters are categorized by how they accelerate the ions, using either electrostatic or electromagnetic force. Electrostatic ion thrusters use the Coulomb force and...
developed by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
in the 1960s.
Ion beam etching or sputtering
One type of ion beam sourceIon source
An ion source is an electro-magnetic device that is used to create charged particles. These are used primarily to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines.- Electron ionization :...
is the duoplasmatron
Duoplasmatron
Duoplasmatron, an invention of Manfred von Ardenne, is a type of ion beam source. The duoplasmatron operates as follows: a cathode filament emits electrons into a vacuum chamber. A gas such as argon is introduced in very small quantities into the chamber, where it becomes charged or ionized through...
. Ion beams can be used for sputtering
Sputtering
Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. It is commonly used for thin-film deposition, etching and analytical techniques .-Physics of sputtering:...
or ion beam etching and for ion beam analysis
Ion beam analysis
Ion beam analysis is an important family of modern analytical techniques involving the use of MeV ion beams to probe the composition and obtain elemental depth profiles in the near-surface layer of solids. All IBA methods are highly sensitive and allow the detection of elements in the...
.
Ion beam application, etching, or sputtering
Sputtering
Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. It is commonly used for thin-film deposition, etching and analytical techniques .-Physics of sputtering:...
, is a technique conceptually similar to sandblasting, but using individual atoms in an ion beam to ablate a target. Reactive ion etching
Reactive ion etching
Reactive-ion etching is an etching technology used in microfabrication. It uses chemically reactive plasma to remove material deposited on wafers. The plasma is generated under low pressure by an electromagnetic field...
is an important extension that uses chemical reactivity to enhance the physical sputtering effect.
In a typical use in semiconductor manufacturing, a mask
Mask
A mask is an article normally worn on the face, typically for protection, disguise, performance or entertainment. Masks have been used since antiquity for both ceremonial and practical purposes...
is used to selectively expose a layer of photoresist
Photoresist
A photoresist is a light-sensitive material used in several industrial processes, such as photolithography and photoengraving to form a patterned coating on a surface.-Tone:Photoresists are classified into two groups: positive resists and negative resists....
on a substrate
Wafer (electronics)
A wafer is a thin slice of semiconductor material, such as a silicon crystal, used in the fabrication of integrated circuits and other microdevices...
made of a semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
material such as a silicon dioxide
Silicon dioxide
The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...
or gallium arsenide wafer. The wafer is developed, and for a positive photoresist, the exposed portions are removed in a chemical process. The result is a pattern left on the surface areas of the wafer that had been masked from exposure. The wafer is then placed in a vacuum chamber
Vacuum chamber
A vacuum chamber is a rigid enclosure from which air and other gases are removed by a vacuum pump. The resulting low pressure, commonly referred to as a vacuum, allows researchers to conduct physical experiments or to test mechanical devices which must operate in outer space...
, and exposed to the ion beam. The impact of the ions erodes the target, abrading away the areas not covered by the photoresist.
Focused Ion Beam
Focused ion beam
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. An FIB setup is a scientific instrument that resembles a scanning...
(FIB) instruments are also used in the design verification and/or failure analysis
Failure analysis
Failure analysis is the process of collecting and analyzing data to determine the cause of a failure. It is an important discipline in many branches of manufacturing industry, such as the electronics industry, where it is a vital tool used in the development of new products and for the improvement...
of semiconductor devices. Engineering prototype devices may be modified using the ion beam in order to rewire the electrical circuit. The technique may be effectively used to avoid performing a new mask run for the purpose of testing design changes. A device edit (FIB milling operation) is accomplished by focusing the ion beam on selected regions of the device in order to mill through metal or polysilicon structures. In addition to milling, it is also possible to use the ion beam to force the deposit of new conductive lines on the surface of the device. This is accomplished by injecting chemicals into the ion stream near the device surface. The interaction between the ions and the chemicals result in chemical deposition on the surface. This process is typically referred to as a FIB deposit operation.
Sputtering is also used in materials science to thin samples or specific regions of samples for transmission electron microscope analysis, or for extending surface analytical techniques such as secondary ion mass spectrometry
Secondary ion mass spectrometry
Secondary ion mass spectrometry is a technique used in materials science and surface science to analyze the composition of solid surfaces and thin films by sputtering the surface of the specimen with a focused primary ion beam and collecting and analyzing ejected secondary ions...
or electron spectroscopy (XPS
X-ray photoelectron spectroscopy
X-ray photoelectron spectroscopy is a quantitative spectroscopic technique that measures the elemental composition, empirical formula, chemical state and electronic state of the elements that exist within a material...
, AES
Auger electron spectroscopy
Auger electron spectroscopy is a common analytical technique used specifically in the study of surfaces and, more generally, in the area of materials science...
) so that they can depth profile them.
Biology
In radiobiologyRadiobiology
Radiobiology , as a field of clinical and basic medical sciences, originated from Leopold Freund's 1896 demonstration of the therapeutic treatment of a hairy mole using a new type of electromagnetic radiation called x-rays, which was discovered 1 year previously by the German physicist, Wilhelm...
a broad or focused ion beam
Microbeam
A microbeam is a narrow beam of radiation, of micrometer or sub-micrometer dimensions. Together with integrated imaging techniques, microbeams allow precisely defined quantities of damage to be introduced at precisely defined locations...
is used to study mechanisms of inter- and intra- cellular communication, signal transduction
Signal transduction
Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response...
and DNA damage and repair
DNA repair
DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1...
.
Medicine
Ion beams are also used in particle therapyParticle therapy
Particle therapy is a form of external beam radiotherapy using beams of energetic protons, neutrons, or positive ions for cancer treatment. The most common type of particle therapy as of 2009 is proton therapy. Although a photon, used in x-ray or gamma ray therapy, can also be considered a...
, most often in the treatment of cancer.
Space Applications
Ion beam produced by ion and plasma thrusters on board a spacecraft can be used to transmit a force to a nearby object (e.g. another spacecraft, an asteroid, etc.) that is irradiated by the beam. This innovative propulsion technique named Ion Beam ShepherdIon Beam Shepherd
An Ion Beam Shepherd is a concept in which the orbit and/or attitude of a spacecarft or a generic orbiting body is modified by having a beam of quasi-neutral plasma impinging against its surface to create a force and/or a torque on the target...
has been shown to be effective in the area of active space debris removal as well as asteroid deflection.
High-energy ion beams
High-energy ion beams produced by particle acceleratorParticle accelerator
A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...
s are used in atomic physics
Atomic physics
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and...
, nuclear physics
Nuclear physics
Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those...
and particle physics
Particle physics
Particle physics is a branch of physics that studies the existence and interactions of particles that are the constituents of what is usually referred to as matter or radiation. In current understanding, particles are excitations of quantum fields and interact following their dynamics...
.
Weaponry
The use of ion beams as a particle beam weaponParticle beam weapon
A particle beam weapon uses an ultra-high-energy beam of atoms or electrons to damage a material target by hitting it, and thus disrupting its atomic and molecular structure. A particle beam weapon is a type of directed-energy weapon, which directs energy in a particular direction by a means of...
is theoretically possible, but has not been demonstrated. See particle beam weapon
Particle beam weapon
A particle beam weapon uses an ultra-high-energy beam of atoms or electrons to damage a material target by hitting it, and thus disrupting its atomic and molecular structure. A particle beam weapon is a type of directed-energy weapon, which directs energy in a particular direction by a means of...
for more information on this type of weapon.
The current ion beams today would barely cause a human to flinch or even notice a touch if hit. The ions only stay in a beam shape if under ultra-high vacuum (UHV) conditions, making its use as a weapon futile. However, if one is trying to destroy single cells, the ion beam may be one's "weapon of choice."
In science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
, weaponised ion beam generators are usually dubbed ion cannon
Ion cannon
In science fiction, an ion cannon is a beam weapon that fires beams of ions . Due to its power, it is usually classified as a superweapon. An ion cannon is a type of particle cannon; only the particles used are ionized...
s.
See also
- Ion sourceIon sourceAn ion source is an electro-magnetic device that is used to create charged particles. These are used primarily to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines.- Electron ionization :...
- MicrobeamMicrobeamA microbeam is a narrow beam of radiation, of micrometer or sub-micrometer dimensions. Together with integrated imaging techniques, microbeams allow precisely defined quantities of damage to be introduced at precisely defined locations...
- Manfred von ArdenneManfred von ArdenneManfred von Ardenne was a German research and applied physicist and inventor. He took out approximately 600 patents in fields including electron microscopy, medical technology, nuclear technology, plasma physics, and radio and television technology...
Inventor of the Duoplasmatron - Particle beamParticle beamA particle beam is a stream of charged or neutral particles which may be directed by magnets and focused by electrostatic lenses, although they may also be self-focusing ....
- Particle therapyParticle therapyParticle therapy is a form of external beam radiotherapy using beams of energetic protons, neutrons, or positive ions for cancer treatment. The most common type of particle therapy as of 2009 is proton therapy. Although a photon, used in x-ray or gamma ray therapy, can also be considered a...
- Harold R. KaufmanHarold R. KaufmanHarold R. Kaufman is an American physicist, noted for his development of electrostatic ion thrusters for NASA during the 1950s and '60s...
Inventor of the mercury-vapor thruster - On-Line Isotope Mass SeparatorOn-Line Isotope Mass SeparatorThe On-Line Isotope Mass Separator, also known as the ISOLDE Radioactive Ion Beam Facility, is a facility located at CERN on the PS Booster...
- Ion Beam ShepherdIon Beam ShepherdAn Ion Beam Shepherd is a concept in which the orbit and/or attitude of a spacecarft or a generic orbiting body is modified by having a beam of quasi-neutral plasma impinging against its surface to create a force and/or a torque on the target...
- List of plasma (physics) applications articles