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.A semiconductor is a material that has an electrical conductivity between that of a conductor and an insulator, that is, generally in the range 103 siemens per centimeter to 10−8 S/cm.^ Generally falls between a metal and an insulator in conductivity.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Cite This Source Word Origin & History semiconductor 1838, "material whose electrical conductivity is between that of a conductor and that of an insulator," from semi- + conductor .
  • Semiconductor Definition | Definition of Semiconductor at Dictionary.com 20 January 2010 17:53 UTC dictionary.reference.com [Source type: Reference]

^ The conductivities of semiconductors are between these extremes.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

.Devices made from semiconductor materials are the foundation of modern electronics, including radio, computers, telephones, and many other devices.^ Semiconductor materials - Electronic properties .
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Semiconductor materials Electronic properties .
  • semiconductor (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Academic]

^ To help meet these challenges, the nationwide network of MEP centersstates has assisted more than 100,000 U.S. firms, including electronics and semiconductor manufacturers.
  • NIST and the Semiconductor Industry 20 January 2010 17:53 UTC www.nist.gov [Source type: Academic]

.Semiconductor devices include the various types of transistor, solar cells, many kinds of diodes including the light-emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits.^ Semiconductors are employed in the manufacture of various kinds of electronic devices, including diodes , transistors , and integrated circuits .
  • semiconductor (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Academic]

^ All solar cells are junction diodes.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Heterojunctions   Energy band diagrams    Device Application of PN Junction   Photodetector Solar Cell : design calculation  Rectifier LED Laser Diode  Applets on Transistors ( not completed ): n-channel MOSFET drain characteristics .    Device Fabrication and Processing Technology ( incomplete )  Self-aligned gate technology versus the conventional processing of MOSFET.  Problems general to Semiconductor Devices ( incomplete ) Space charge, electric field, and potential profile.
  • Semiconductor Applet Services 20 January 2010 17:53 UTC jas.eng.buffalo.edu [Source type: Academic]

.Solar photovoltaic panels are large semiconductor devices that directly convert light energy into electrical energy.^ A device that converts the energy of a fuel directly to electricity and heat, without combustion.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ And finally, 100W LED lighting applications will commonly occur in large panel LCD-TVs, video walls and industrial lighting.
  • The Source For Semiconductor Applications - SemiApps.com 20 January 2010 17:53 UTC www.semiapps.com [Source type: Reference]

^ The Companys power management semiconductor components controls, converts, protects and monitors the supply of power to the different elements within a range of electronic devices.
  • ON Semiconductor Corp. - Google Finance 20 January 2010 17:53 UTC www.google.com [Source type: General]

.An external electrical field may change a semiconductor's resistivity.^ In addition, students may pursue a minor field of study in Electrical Engineering, taking the three-course sequence of Solid-State Physics, Semiconductor Electronics and Semiconductor Devices.
  • Research Focus: Semiconductor Manufacturing 20 January 2010 17:53 UTC www.chemeng.ucla.edu [Source type: Academic]

.In a metallic conductor, current is carried by the flow of electrons.^ Because the resulting crystal has an excess of current-carrying electrons, each with a negative charge, it is known as "N-type" silicon.
  • Basic Semiconductor Crystal Structure 20 January 2010 17:53 UTC www.play-hookey.com [Source type: Original source]

^ Electric current in which electrons flow in one direction only.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Seebeck Effect - The generation of an electric current, when two conductors of different metals are joined at their ends to form a circuit, with the two junctions kept at different temperatures.

.In semiconductors, current can be carried either by the flow of electrons or by the flow of positively-charged "holes" in the electron structure of the material.^ Semiconductor materials - Electronic properties .
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Because the resulting crystal has an excess of current-carrying electrons, each with a negative charge, it is known as "N-type" silicon.
  • Basic Semiconductor Crystal Structure 20 January 2010 17:53 UTC www.play-hookey.com [Source type: Original source]

^ QR5u4 ) 42 mins ago irhm : Ch.5 Moving charges (currents), conductors, Ohm's law, Resistance, Semiconductors , Dielectrics and Capacitance.
  • Semiconductors - Business Exchange 20 January 2010 17:53 UTC bx.businessweek.com [Source type: FILTERED WITH BAYES]

.Common semiconducting materials are crystalline solids but amorphous and liquid semiconductors are known, such as mixtures of arsenic, selenium and tellurium in a variety of proportions.^ The elemental semiconductors are those composed of single species of atoms, such as silicon (Si), germanium (Ge), and tin (Sn) in column IV and selenium (Se) and tellurium (Te) in column VI of the periodic table .
  • semiconductor (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Academic]

^ Semiconductor Equipment & Materials are made by companies such as KLA-Tencor (KLAC) .
  • Industry:Foundry Semiconductors 20 January 2010 17:53 UTC www.wikinvest.com [Source type: News]

^ Solid-state materials are commonly grouped into three classes: insulators, semiconductors, and conductors.
  • semiconductor (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Academic]

.They share with better known semiconductors intermediate conductivity and a rapid variation of conductivity with temperature but lack the rigid crystalline structure of conventional semiconductors such as silicon and so are relatively insensitive to impurities and radiation damage.^ In semiconductors, thermal energy is enough to cause a small number of electrons to escape from the valence bonds between the atoms (the valence band ); they orbit instead in the higher-energy conduction band , in which they are relatively free.
  • Semiconductor Definition | Definition of Semiconductor at Dictionary.com 20 January 2010 17:53 UTC dictionary.reference.com [Source type: Reference]

^ Silicon is the most commonly used semiconductor material today, along with various compound semiconductors.
  • Semiconductor Manufacturing 20 January 2010 17:53 UTC www.nydailynews.com [Source type: General]

^ Silicon Prices have been rising steadily due to increased demand for both semiconductors and other technology that uses silicon, such as Solar Power .
  • Industry:Foundry Semiconductors 20 January 2010 17:53 UTC www.wikinvest.com [Source type: News]

.Silicon is used to create most semiconductors commercially.^ Today, most semiconductor chips and transistors are created with silicon .
  • HowStuffWorks "How Semiconductors Work" 20 January 2010 17:53 UTC www.howstuffworks.com [Source type: General]

^ Silicon is the most common and familiar semiconductor.
  • Semiconductor Definition | Definition of Semiconductor at Dictionary.com 20 January 2010 17:53 UTC dictionary.reference.com [Source type: Reference]

^ Silicon is the most commonly used semiconductor material today, along with various compound semiconductors.
  • Semiconductor Manufacturing 20 January 2010 17:53 UTC www.nydailynews.com [Source type: General]

.Dozens of other materials are used, including germanium, gallium arsenide, and silicon carbide.^ Common semiconductors are silicon, germanium, gallium arsenide.
  • Semiconductor Definition | Definition of Semiconductor at Dictionary.com 20 January 2010 17:53 UTC dictionary.reference.com [Source type: Reference]

^ A class of materials, for instance silicon and germanium, whose electrical properties lie between those of conductors (such as copper and aluminum) and insulators (such as glass and rubber).
  • semiconductor,What is a semiconductor? - EE Times-Asia 20 January 2010 17:53 UTC www.eetasia.com [Source type: FILTERED WITH BAYES]

^ A layer of semiconductor material, such as copper indium diselenide, cadmium telluride, gallium arsenide, or amorphous silicon, a few microns or less in thickness, used to make photovoltaic cells.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

A pure semiconductor is often called an “intrinsic” semiconductor. .The conductivity, or ability to conduct, of common semiconductor materials can be drastically changed by adding other elements, called “impurities” to the melted intrinsic material and then allowing the melt to solidify into a new and different crystal.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ What happens if we go the other way, and introduce a 3-electron impurity into such a crystal?
  • Basic Semiconductor Crystal Structure 20 January 2010 17:53 UTC www.play-hookey.com [Source type: Original source]

^ Material that is solidified at such as rate that many small crystals (crystallites) form.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

This process is called "doping".[1]

Contents

Explaining semiconductor energy bands

There are three popular ways to classify the electronic structure of a crystal.
  • Band structure

Energy bands and electrical conduction

The electrons in semiconductors can have energies only within certain bands (i.e. ranges of levels of energy) between the energy of
the ground state, corresponding to electrons tightly bound to the atomic nuclei of the material, and the free electron energy,
which is the energy required for an electron to escape entirely from the material. The energy bands each correspond to a large
number of discrete quantum states of the electrons, and most of the states with low energy (closer to the nucleus) are full, up
to a particular band called the valence band. .Semiconductors and insulators are distinguished from metals because the valence band
in the semiconductor materials is nearly filled under usual operating conditions, thus causing more electrons to be available in
the "conduction band," which is the band immediately above the valence band.
^ Growing Semiconductor Packaging Materials Market under Pressure more .
  • Semiconductors - Business Exchange 20 January 2010 17:53 UTC bx.businessweek.com [Source type: FILTERED WITH BAYES]

^ Semiconductor materials - Electronic properties .
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Semiconductors are unique substances, which, under different conditions, can act as either conductors or insulators of electricity.
  • Semiconductor Processors 20 January 2010 17:53 UTC www.bls.gov [Source type: FILTERED WITH BAYES]

.The ease with which electrons in a semiconductor can be excited from the valence band to the conduction band depends on the band gap between the bands, and it is the size of this energy bandgap that serves as an arbitrary dividing line (roughly 4 eV) between semiconductors and insulators.^ The conductivities of semiconductors are between these extremes.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Generally falls between a metal and an insulator in conductivity.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ IMAGES Typical range of conductivities for insulators, semiconductors, and conductors.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

In the picture of covalent bonds, an electron moves by hopping to a neighboring bond. Because of the Pauli exclusion principle it has to be lifted into the higher anti-bonding state of that bond. .In the picture of delocalized states, for example in one dimension - that is in a nanowire, for every energy there is a state with electrons flowing in one direction and one state for the electrons flowing in the other.^ Electric current in which electrons flow in one direction only.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ The barrier inhibits the movement of electrons from one layer to the other, so that higher-energy electrons from one side diffuse preferentially through it in one direction, creating a current and thus a voltage across the cell.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ A semiconductor device with a junction and a built-in potential that passes current better in one direction than the other.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

.For a net current to flow some more states for one direction than for the other direction have to be occupied and for this energy is needed, in the semiconductor the next higher states lie above the band gap.^ Electric current in which electrons flow in one direction only.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ A semiconductor device with a junction and a built-in potential that passes current better in one direction than the other.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ More than two dozen GPS satellites orbit the Earth, transmitting radio signals which allow GPS receivers to determine their location, speed and direction.
  • SemiconductorStore.com > The Online Destination for New and Emerging Technology 20 January 2010 17:53 UTC www.semiconductorstore.com [Source type: General]

Often this is stated as: full bands do not contribute to the electrical conductivity. .However, as the temperature of a semiconductor rises above absolute zero, there is more energy in the semiconductor to spend on lattice vibration and — more importantly for us — on lifting some electrons into an energy states of the conduction band.^ However, completion of a 1-year certificate program in semiconductor technology or high-tech manufacturing, offered by some community colleges, may be sufficient.
  • Semiconductor Processors 20 January 2010 17:53 UTC www.bls.gov [Source type: FILTERED WITH BAYES]

^ There were also U.S. semiconductor operations in Japan; however, due to that nations restrictions on foreign direct investment, the U.S. presence there was minimal.

^ Solid-state materials are commonly grouped into three classes: insulators , semiconductors, and conductors.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

.The current-carrying electrons in the conduction band are known as "free electrons", although they are often simply called "electrons" if context allows this usage to be clear.^ Although also popularly know as computer chips, for their common usage in computer hardware industry, all electronic equipment in fact uses these silicon-based components.

^ To discuss how we can help your organization achieve high performance in electronics & high tech, call us toll- free at 1 (877) 889- 9009.
  • Accenture Services for the Semiconductor Industry 20 January 2010 17:53 UTC www.accenture.com [Source type: News]

Electrons excited to the conduction band also leave behind electron holes, or unoccupied states in the valence band. Both the conduction band electrons and the valence band holes contribute to electrical conductivity. .The holes themselves don't actually move, but a neighboring electron can move to fill the hole, leaving a hole at the place it has just come from, and in this way the holes appear to move, and the holes behave as if they were actual positively charged particles.^ The SIA moved to consolidate its position with other American electronic industry interests as well as any U.S. government officials that were not in accord with its actions.

.One covalent bond between neighboring atoms in the solid is ten times stronger than the binding of the single electron to the atom, so freeing the electron does not imply destruction of the crystal structure.^ A method of preventing oxidation (rusting) of exposed metal structures, such as bridges and pipelines, by imposing between the structure and the ground a small electrical voltage that opposes the flow of electrons and that is greater than the voltage present during oxidation.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ The Institute of Electronic Structure and Laser is one of the seven institutes which comprise FORTH. IESL is located on the grounds of FORTH in Crete, Greece .

^ At the same time, Japanese chip companies were selling to American electronics companies at a greater rate than ever before.

Holes: electron absence as a charge carrier

The motion of holes, which was introduced for semiconductors, can also be applied to metals, where the Fermi level lies within the conduction band. .With most metals the Hall effect reveals electrons to be the charge carriers, but some metals have a mostly filled conduction band, and the Hall effect reveals positive charge carriers, which are not the ion-cores, but holes.^ Superconductivity - The abrupt and large increase in electrical conductivity exhibited by some metals as the temperature approaches absolute zero.

Contrast this to some conductors like solutions of salts, or plasma. .In the case of a metal, only a small amount of energy is needed for the electrons to find other unoccupied states to move into, and hence for current to flow.^ The SIA moved to consolidate its position with other American electronic industry interests as well as any U.S. government officials that were not in accord with its actions.

^ Series Resistance - Parasitic resistance to current flow in a cell due to mechanisms such as resistance from the bulk of the semiconductor material, metallic contacts, and interconnections.

^ Second Law of Thermodynamics - This law states that no device can completely and continuously transform all of the energy supplied to it into useful energy.

Sometimes even in this case it may be said that a hole was left behind, to explain why the electron does not fall back to lower energies: It cannot find a hole. .In the end in both materials electron-phonon scattering and defects are the dominant causes for resistance.^ As a result, foundrieds are affected by issues on both ends of this chain, from Silicon Prices to end-user demand of electronics products.
  • Industry:Foundry Semiconductors 20 January 2010 17:53 UTC www.wikinvest.com [Source type: News]

^ But by the mid-1960s this began to change, and by the end of the 1970s, the Japanese had replaced American firms as the dominant firms in the U.S. consumer electronics market.

Fermi-Dirac distribution. States with energy ε below the Fermi energy, here µ, have higher probability n to be occupied, and those above are less likely to be occupied. Smearing of the distribution increases with temperature.
The energy distribution of the electrons determines which of the states are filled and which are empty. This distribution is described by Fermi-Dirac statistics. .The distribution is characterized by the temperature of the electrons, and the Fermi energy or Fermi level.^ It has a spectral, or wavelength, distribution that corresponds to different energy levels; short wavelength radiation has a higher energy than long-wavelength radiation.

.Under absolute zero conditions the Fermi energy can be thought of as the energy up to which available electron states are occupied.^ The ratio of the electric energy produced by a photovoltaic device (under one-sun conditions) to the energy from sunlight incident upon the cell.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ In this project, we have similarly integrated available physical models with neural networks to provide more robust models of process behavior under a variety of deposition conditions.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

At higher temperatures, the Fermi energy is the energy at which the probability of a state being occupied has fallen to 0.5.
.The dependence of the electron energy distribution on temperature also explains why the conductivity of a semiconductor has a strong temperature dependency, as a semiconductor operating at lower temperatures will have fewer available free electrons and holes able to do the work.^ The conductivity of a semiconductor is generally sensitive to temperature, illumination, magnetic fields , and minute amounts of impurity atoms.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ People interested in becoming semiconductor processors—either operators or technicians—need strong technical skills, an ability to solve problems intuitively, and an ability to work in teams.
  • Semiconductor Processors 20 January 2010 17:53 UTC www.bls.gov [Source type: FILTERED WITH BAYES]

^ SEMATECH is a consortium of American semiconductor manufacturers working with government and academia to sponsor and conduct research aimed at assuring leadership in semiconductor manufacturing technology for the U.S. semiconductor industry.

Energy–momentum dispersion

In the preceding description an important fact is ignored for the sake of simplicity: the dispersion of the energy. .The reason that the energies of the states are broadened into a band is that the energy depends on the value of the wave vector, or k-vector, of the electron.^ Second Law of Thermodynamics - This law states that no device can completely and continuously transform all of the energy supplied to it into useful energy.

The k-vector, in quantum mechanics, is the representation of the momentum of a particle.
The dispersion relationship determines the effective mass, m*, of electrons or holes in the semiconductor, according to the formula:
 m^{*} = \hbar^2 \cdot \left[ {{d^2 E(k)} \over {d k^2}} \right]^{-1}.
.The effective mass is important as it affects many of the electrical properties of the semiconductor, such as the electron or hole mobility, which in turn influences the diffusivity of the charge carriers and the electrical conductivity of the semiconductor.^ Many of the compound semiconductors have electrical and optical properties that are absent in silicon.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Semiconductor materials - Electronic properties .
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ The Semiconductor Electronics Division within the Electronics and Electrical Engineering Laboratory at NIST. provides leadership in developing the semiconductor measurement infrastructure essential to improving U.S. economic competitiveness.

Typically the effective mass of electrons and holes are different. This affects the relative performance of p-channel and n-channel IGFETs.[2]
The top of the valence band and the bottom of the conduction band might not occur at that same value of k. Materials with this situation, such as silicon and germanium, are known as indirect bandgap materials. .Materials in which the band extrema are aligned in k, for example gallium arsenide, are called direct bandgap semiconductors.^ A layer of semiconductor material, such as copper indium diselenide, cadmium telluride, gallium arsenide, or amorphous silicon, a few microns or less in thickness, used to make photovoltaic cells.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Certain semiconductors, including silicon, gallium arsenide, copper indium diselenide, and cadmium telluride, are uniquely suited to the photovoltaic conversion process.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]
  • S 20 January 2010 17:53 UTC www.electromn.com [Source type: Reference]

.Direct gap semiconductors are particularly important in optoelectronics because they are much more efficient as light emitters than indirect gap materials.^ As discrete components, they have found use in power devices, optical sensors, and light emitters, including solid-state lasers.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ A semiconductor device with a junction and a built-in potential that passes current better in one direction than the other.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ They have a wide range of current- and voltage-handling capabilities, with current ratings from a few nanoamperes (10 −9 ampere) to more than 5,000 amperes and voltage ratings extending above 100,000 volts.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

Carrier generation and recombination

.When ionizing radiation strikes a semiconductor, it may excite an electron out of its energy level and consequently leave a hole.^ Affected by the worsening recession, it may take up to five years for the semiconductor market to return to revenue levels of the previous years, Gartner said in a survey.
  • semiconductor | ITworld 20 January 2010 17:53 UTC www.itworld.com [Source type: News]

^ It has a spectral, or wavelength, distribution that corresponds to different energy levels; short wavelength radiation has a higher energy than long-wavelength radiation.

^ Student: T. Brown Advisors: G. May, A. Brown Sponsor: AFRL The electronic properties of many compound semiconductor devices are highly dependent on heterointerface structure and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

This process is known as electron–hole pair generation. .Electron-hole pairs are constantly generated from thermal energy as well, in the absence of any external energy source.^ Synchronous Generator - An electrical generator that runs at a constant speed and draws its excitation from a power source external or independent of the load or transmission network it is supplying.

^ Solar Thermal Electric Systems - Solar energy conversion technologies that convert solar energy to electricity, by heating a working fluid to power a turbine that drives a generator.

.Electron-hole pairs are also apt to recombine.^ Photons are created by electron-hole recombination in the laser.
  • Transient Response of a Semiconductor Laser - Wolfram Demonstrations Project 20 January 2010 17:53 UTC demonstrations.wolfram.com [Source type: FILTERED WITH BAYES]

.Conservation of energy demands that these recombination events, in which an electron loses an amount of energy larger than the band gap, be accompanied by the emission of thermal energy (in the form of phonons) or radiation (in the form of photons).^ It has a spectral, or wavelength, distribution that corresponds to different energy levels; short wavelength radiation has a higher energy than long-wavelength radiation.

^ British thermal unit (BTU) --The amount of heat energy required to raise the temperature of one pound of water from 60 degrees F to 61 degrees F at one atmosphere pressure.
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^ While these materials offer significant advantages in the form of band gap engineering, a better understanding of the processes occurring during the growth of the interfaces will allow for improvements in device performance and manufacturing.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

In some states, the generation and recombination of electron–hole pairs are in equipoise. The number of electron-hole pairs in the steady state at a given temperature is determined by quantum statistical mechanics. .The precise quantum mechanical mechanisms of generation and recombination are governed by conservation of energy and conservation of momentum.^ The numerical model begins by solving differential equations originating from the transport equations (conservation of mass, momentum, energy, and chemical species) using finite difference methods.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

.As the probability that electrons and holes meet together is proportional to the product of their amounts, the product is in steady state nearly constant at a given temperature, providing that there is no significant electric field (which might "flush" carriers of both types, or move them from neighbour regions containing more of them to meet together) or externally driven pair generation.^ The semiconductor market is moving toward two major product types: commodity and application specific.

^ Because there is no combustion, fuel cells give off few emissions; because there are no moving parts, fuel cells are quiet.
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^ We determine dielectric constant and loss tangent as a function of the type of polymer material, the volume fraction of ceramic in the polymer matrix, and the polymer cure time and temperature.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

.The product is a function of the temperature, as the probability of getting enough thermal energy to produce a pair increases with temperature, being approximately exp(−EG/kT), where k is Boltzmann's constant, T is absolute temperature and EG is band gap.^ We determine dielectric constant and loss tangent as a function of the type of polymer material, the volume fraction of ceramic in the polymer matrix, and the polymer cure time and temperature.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ Superconductivity - The abrupt and large increase in electrical conductivity exhibited by some metals as the temperature approaches absolute zero.

^ Superconducting Magnetic Energy Storage (SMES) - SMES technology uses the superconducting characteristics of low-temperature materials to produce intense magnetic fields to store energy.

The probability of meeting is increased by carrier traps—impurities or dislocations which can trap an electron or hole and hold it until a pair is completed. Such carrier traps are sometimes purposely added to reduce the time needed to reach the steady state.

Semi-insulators

Some materials are classified as semi-insulators. These have electrical conductivity nearer to that of electrical insulators. Semi-insulators find niche applications in micro-electronics, such as substrates for HEMT. .An example of a common semi-insulator is gallium arsenide.^ Gallium arsenide (GaAs), for example, is a binary III-V compound, which is a combination of gallium (Ga) from column III and arsenic (As) from column V. .
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

[3]

Doping

.The property of semiconductors that makes them most useful for constructing electronic devices is that their conductivity may easily be modified by introducing impurities into their crystal lattice.^ The most common semiconductor material used in making photovoltaic devices.
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^ The U.S. also experienced a shift of electronics production to other countries, but most of the shift occurred in the early 2000’s after the 2001 semiconductor downturn.

^ Ion Implantation Updated 11-10-2009 Ion implantation is used to alter the surface properties of semiconductor materials.

.The process of adding controlled impurities to a semiconductor is known as doping.^ Experiments will be performed using solid-source molecular beam epitaxy, a semiconductor growth technique that controls thickness, doping, and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Since they can be used to build predictive models from multivariate sensor data generated by process monitors, neural nets have also been applied to the control of semiconductor manufacturing processes.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

.The amount of impurity, or dopant, added to an intrinsic (pure) semiconductor varies its level of conductivity.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

Doped semiconductors are often referred to as extrinsic. .By adding impurity to pure semiconductors, the electrical conductivity may be varied not only by the number of impurity atoms but also, by the type of impurity atom and the changes may be thousand folds and million folds.^ For example, the addition of less than 0.01 percent of a particular type of impurity can increase the electrical conductivity of a semiconductor by four or more orders of magnitude ( i.e., 10,000 times).
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ The conductivity of a semiconductor is generally sensitive to temperature, illumination, magnetic fields , and minute amounts of impurity atoms.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Semiconductor - Any material that has a limited capacity for conducting an electric current.

.For example, 1 cm3 of a metal or semiconductor specimen has a number of atoms on the order of 1022.^ For example, the addition of less than 0.01 percent of a particular type of impurity can increase the electrical conductivity of a semiconductor by four or more orders of magnitude ( i.e., 10,000 times).
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Silicon - A chemical element, of atomic number 14, that is semi-metallic, and an excellent semiconductor material used in solar photovoltaic devices; commonly found in sand.

.Since every atom in metal donates at least one free electron for conduction in metal, 1 cm3 of metal contains free electrons on the order of 1022.^ Insulators, such as fused quartz and glass, have very low conductivities, on the order of 10 −18 to 10 −10 siemens per centimetre; and conductors, such as aluminum, have high conductivities, typically from 10 4 to 10 6 siemens per centimetre.
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

.At the temperature close to 20 °C , 1 cm3 of pure germanium contains about 4.2×1022 atoms and 2.5×1013 free electrons and 2.5×1013 holes (empty spaces in crystal lattice having positive charge) The addition of 0.001% of arsenic (an impurity) donates an extra 1017 free electrons in the same volume and the electrical conductivity increases about 10,000 times."^ For example, the addition of less than 0.01 percent of a particular type of impurity can increase the electrical conductivity of a semiconductor by four or more orders of magnitude ( i.e., 10,000 times).
  • semiconductor device (electronics) -- Britannica Online Encyclopedia 20 January 2010 17:53 UTC www.britannica.com [Source type: Reference]

^ Our sales were up over a billion for the first time ever and they were up from about $730 million a year before which was over 40% increase.
  • Semiconductor Stock, Varian Semiconductor Equipment (VSEA-NASDAQ) 20 January 2010 17:53 UTC www.ceocfointerviews.com [Source type: General]

^ Semiconductor Intelligence estimates the SEMI forecast will result in an increase of about 70 thousand wafers in 2010, about the same as in 2008.

Dopants

.The materials chosen as suitable dopants depend on the atomic properties of both the dopant and the material to be doped.^ Ion Beam Analysis (IBA) is based on the interaction, at both the atomic and the nuclear level, between accelerated charged particles and the bombarded material.

.In general, dopants that produce the desired controlled changes are classified as either electron acceptors or donors.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

.A donor atom that activates (that is, becomes incorporated into the crystal lattice) donates weakly-bound valence electrons to the material, creating excess negative charge carriers.^ The transduction operation is based on the piezoelectric effect, in which an acoustical pressure applied to a polarized ZnO crystal results in a mechanical deformation, creating an electrical charge.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ The anode creates a galvanic cell in which magnesium or zinc will be corroded more quickly than the metal of the tank giving the tank a negative charge and preventing corrosion.

These weakly-bound electrons can move about in the crystal lattice relatively freely and can facilitate conduction in the presence of an electric field. (The donor atoms introduce some states under, but very close to the conduction band edge. Electrons at these states can be easily excited to the conduction band, becoming free electrons, at room temperature.) Conversely, an activated acceptor produces a hole. Semiconductors doped with donor impurities are called n-type, while those doped with acceptor impurities are known as p-type. The n and p type designations indicate which charge carrier acts as the material's majority carrier. The opposite carrier is called the minority carrier, which exists due to thermal excitation at a much lower concentration compared to the majority carrier.
.For example, the pure semiconductor silicon has four valence electrons.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

.In silicon, the most common dopants are IUPAC group 13 (commonly known as group III) and group 15 (commonly known as group V) elements.^ Silicon - A chemical element, of atomic number 14, that is semi-metallic, and an excellent semiconductor material used in solar photovoltaic devices; commonly found in sand.

.Group 13 elements all contain three valence electrons, causing them to function as acceptors when used to dope silicon.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Reference Shelf for Particle-Solid Interactions - This site contains information useful for researchers in the field of interactions of ions, electrons, and energetic photons with solids.

^ Silicon - A chemical element, of atomic number 14, that is semi-metallic, and an excellent semiconductor material used in solar photovoltaic devices; commonly found in sand.

Group 15 elements have five valence electrons, which allows them to act as a donor. .Therefore, a silicon crystal doped with boron creates a p-type semiconductor whereas one doped with phosphorus results in an n-type material.^ The transduction operation is based on the piezoelectric effect, in which an acoustical pressure applied to a polarized ZnO crystal results in a mechanical deformation, creating an electrical charge.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

Carrier concentration

.The concentration of dopant introduced to an intrinsic semiconductor determines its concentration and indirectly affects many of its electrical properties.^ Using this methodology, we will determine proper combinations of polymer/ceramic materials and processing conditions to achieve desirable electrical properties.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ Student: T. Brown Advisors: G. May, A. Brown Sponsor: AFRL The electronic properties of many compound semiconductor devices are highly dependent on heterointerface structure and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

The most important factor that doping directly affects is the material's carrier concentration. .In an intrinsic semiconductor under thermal equilibrium, the concentration of electrons and holes is equivalent.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

That is,
n = p = n_i.\
If we have a non-intrinsic semiconductor in thermal equilibrium the relation becomes:
n_0 \cdot p_0 = n_i^2\
where n0 is the concentration of conducting electrons, p0 is the electron hole concentration, and ni is the material's intrinsic carrier concentration. .Intrinsic carrier concentration varies between materials and is dependent on temperature.^ However, there are several limitations in VFM processing, including: lack of reliable temperature measurement techniques, uncertain process characterization methods, incomplete understanding of the interactions between microwaves and materials, and a lack of control over the various processes occurring.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

Silicon's ni, for example, is roughly 1.5×1010 cm−3 at 300 kelvins (room temperature).
In general, an increase in doping concentration affords an increase in conductivity due to the higher concentration of carriers available for conduction. .Degenerately (very highly) doped semiconductors have conductivity levels comparable to metals and are often used in modern integrated circuits as a replacement for metal.^ Experiments will be performed using solid-source molecular beam epitaxy, a semiconductor growth technique that controls thickness, doping, and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ University of Cambridge , Cavendish Laboratory The Semiconductor Physics group investigates fundamental electronic phenomena using advanced, often unique, semiconductor structures.

.Often superscript plus and minus symbols are used to denote relative doping concentration in semiconductors.^ Experiments will be performed using solid-source molecular beam epitaxy, a semiconductor growth technique that controls thickness, doping, and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ The use of Neural networks for the diagnosis of semiconductor manufacturing processes and equipment is relatively new.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

For example, n+ denotes an n-type semiconductor with a high, often degenerate, doping concentration. Similarly, p- would indicate a very lightly doped p-type material. .It is useful to note that even degenerate levels of doping imply low concentrations of impurities with respect to the base semiconductor.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

In crystalline intrinsic silicon, there are approximately 5×1022 atoms/cm³. .Doping concentration for silicon semiconductors may range anywhere from 1013 cm−3 to 1018 cm−3.^ The latest autumn forecasts from market research firms and industry associations expect the 2009 semiconductor market will decline from 10% to 13% from 2008.

^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ More integrated components per area of silicon and reduced circuit geometries are the overriding benefits as lasers enable a complete range of semiconductor fabrication processes.
  • Coherent Inc. : Semiconductor and Microelectronics Fabrication 20 January 2010 17:53 UTC www.coherent.com [Source type: FILTERED WITH BAYES]

Doping concentration above about 1018 cm−3 is considered degenerate at room temperature. .Degenerately doped silicon contains a proportion of impurity to silicon in the order of parts per thousand.^ A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (e.g., phosphorous in silicon).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

This proportion may be reduced to parts per billion in very lightly doped silicon. .Typical concentration values fall somewhere in this range and are tailored to produce the desired properties in the device that the semiconductor is intended for.^ Laser technology's role in semiconductor and microelectronics fabrication is growing exponentially as manufacturers seek to produce smaller, more powerful, reliable devices.
  • Coherent Inc. : Semiconductor and Microelectronics Fabrication 20 January 2010 17:53 UTC www.coherent.com [Source type: FILTERED WITH BAYES]

^ Student: T. Brown Advisors: G. May, A. Brown Sponsor: AFRL The electronic properties of many compound semiconductor devices are highly dependent on heterointerface structure and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

Effect on band structure

Band diagram of PN junction operation in forward bias mode showing reducing depletion width. Both p and n junctions are doped at a 1e15/cm3 doping level, leading to built-in potential of ~0.59V. Reducing depletion width can be inferred from the shrinking charge profile, as fewer dopants are exposed with increasing forward bias [1].
.Doping a semiconductor crystal introduces allowed energy states within the band gap but very close to the energy band that corresponds to the dopant type.^ (PV) cell --The smallest semiconductor element within a PV module to perform the immediate conversion of light into electrical energy (dc voltage and current).
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Doping of Semiconductors by Ion Implantation - Pennsylvania State University .

In other words, donor impurities create states near the conduction band while acceptors create states near the valence band. The gap between these energy states and the nearest energy band is usually referred to as dopant-site bonding energy or EB and is relatively small. For example, the EB for boron in silicon bulk is 0.045 eV, compared with silicon's band gap of about 1.12 eV. Because EB is so small, it takes little energy to ionize the dopant atoms and create free carriers in the conduction or valence bands. .Usually the thermal energy available at room temperature is sufficient to ionize most of the dopant.^ British thermal unit (BTU) --The amount of heat energy required to raise the temperature of one pound of water from 60 degrees F to 61 degrees F at one atmosphere pressure.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

Dopants also have the important effect of shifting the material's Fermi level towards the energy band that corresponds with the dopant with the greatest concentration. .Since the Fermi level must remain constant in a system in thermodynamic equilibrium, stacking layers of materials with different properties leads to many useful electrical properties.^ In this case the heterostructure devices, which include material systems such as AlGaAs/GaAs, must be precisely etched following their removal from the growth substrate.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ Systems that are installed at or near the location where the electricity is used, as opposed to central systems that supply electricity to grids.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ Ion Implantation Updated 11-10-2009 Ion implantation is used to alter the surface properties of semiconductor materials.

For example, the p-n junction's properties are due to the energy band bending that happens as a result of lining up the Fermi levels in contacting regions of p-type and n-type material.
This effect is shown in a band diagram. The band diagram typically indicates the variation in the valence band and conduction band edges versus some spatial dimension, often denoted x. The Fermi energy is also usually indicated in the diagram. Sometimes the intrinsic Fermi energy, Ei, which is the Fermi level in the absence of doping, is shown. .These diagrams are useful in explaining the operation of many kinds of semiconductor devices.^ Molecular beam epitaxy (MBE) is a versatile thin film growth technique used in the development of advanced III-V semiconductor devices.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ Student: T. Brown Advisors: G. May, A. Brown Sponsor: AFRL The electronic properties of many compound semiconductor devices are highly dependent on heterointerface structure and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

Preparation of semiconductor materials

.Semiconductors with predictable, reliable electronic properties are necessary for mass production.^ Student: T. Brown Advisors: G. May, A. Brown Sponsor: AFRL The electronic properties of many compound semiconductor devices are highly dependent on heterointerface structure and composition.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

The level of chemical purity needed is extremely high because the presence of impurities even in very small proportions can have large effects on the properties of the material. .A high degree of crystalline perfection is also required, since faults in crystal structure (such as dislocations, twins, and stacking faults) interfere with the semiconducting properties of the material.^ Material that is solidified at such as rate that many small crystals (crystallites) form.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ The models are required by semiconductor manufacturers in order to predict process behavior under an exhaustive set of operating conditions, and with a very high degree of precision.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ Electronic Structure Group , Department of Physics, Boston University, We perform interdisciplinary research on the electronic properties of novel materials that are of scientific and technological importance.

Crystalline faults are a major cause of defective semiconductor devices. The larger the crystal, the more difficult it is to achieve the necessary perfection. .Current mass production processes use crystal ingots between 100 mm and 300 mm (4-12 inches) in diameter which are grown as cylinders and sliced into wafers.^ Established technology for production, using smaller wafer diameters.
  • Crystec 20 January 2010 17:53 UTC www.crystec.com [Source type: Reference]

.Because of the required level of chemical purity and the perfection of the crystal structure which are needed to make semiconductor devices, special methods have been developed to produce the initial semiconductor material.^ The most common semiconductor material used in making photovoltaic devices.
  • Big Frog Mountain- Solar Electric Glossary Of Terminology Used In Renewable Or Alternative Energy Systems 20 January 2010 17:53 UTC bigfrogmountain.com [Source type: Reference]

^ ON Semiconductor needed to replace its manual and imprecise methods to gain control of its current inventory and begin to strategically forecasting future demand.
  • Optimizing Inventory at ON Semiconductor 20 January 2010 17:53 UTC www.i2.com [Source type: General]

^ Principles of Semiconductor Devices - The goal of this text is to provide the basic principles of common semiconductor devices, with a special focus on Metal-Oxide-Semiconductor Field-Effect-Transistors (MOSFETs).

.A technique for achieving high purity includes growing the crystal using the Czochralski process.^ The MBE process can be monitored in-situ using reflection high-energy electron diffraction (RHEED).
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ Successful failure diagnosis is also achieved using NN-DS technique: a single false alarm occurs in 19 possible failure scenarios.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ The proposed modeling technique uses principal component analysis (PCA) to reduce the dimensionality of the RHEED data set, and the reduced data set is used to train neural nets to model the process responses.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

An additional step that can be used to further increase purity is known as zone refining. In zone refining, part of a solid crystal is melted. The impurities tend to concentrate in the melted region, while the desired material recrystalizes leaving the solid material more pure and with fewer crystalline faults.
.In manufacturing semiconductor devices involving heterojunctions between different semiconductor materials, the lattice constant, which is the length of the repeating element of the crystal structure, is important for determining the compatibility of materials.^ This project involves the examination of growth processes during formation of the interface in heterostructure devices in order to improve device performance, reliability, and manufacturability.
  • Semiconductor Manufacturing: Overview 20 January 2010 17:53 UTC users.ece.gatech.edu [Source type: Academic]

^ For ON Semiconductor, having the correct inventory on hand can make the difference between a sale and a dissatisfied customer.
  • Optimizing Inventory at ON Semiconductor 20 January 2010 17:53 UTC www.i2.com [Source type: General]

^ Laser technology's role in semiconductor and microelectronics fabrication is growing exponentially as manufacturers seek to produce smaller, more powerful, reliable devices.
  • Coherent Inc. : Semiconductor and Microelectronics Fabrication 20 January 2010 17:53 UTC www.coherent.com [Source type: FILTERED WITH BAYES]

See also

References

  1. ^ International Union of Pure and Applied Chemistry. "semiconductor". Compendium of Chemical Terminology Internet edition.
  2. ^ Muller, Richard S.; Theodore I. Kamins (1986). Device Electronics for Integrated Circuits (2d ed.). New York: Wiley. p. 427. ISBN 0-471-88758-7. 
  3. ^ J. W. Allen (1960). "Gallium Arsenide as a semi-insulator". Nature 187: 403–405. doi:10.1038/187403b0. 
Notes
  • A. A. Balandin and K. L. Wang (2006), Handbook of Semiconductor Nanostructures and Nanodevices (5-Volume Set), American Scientific Publishers. ISBN 1-58883-073-X
  • Sze, Simon M. (1981). Physics of Semiconductor Devices (2nd ed.). John Wiley and Sons (WIE). ISBN 0-471-05661-8. 
  • Turley, Jim (2002). The Essential Guide to Semiconductors. Prentice Hall PTR. ISBN 0-13-046404-X. 
  • Yu, Peter Y.; Cardona, Manuel (2004). .Fundamentals of Semiconductors : Physics and Materials Properties.^ Ion Implantation Updated 11-10-2009 Ion implantation is used to alter the surface properties of semiconductor materials.

    ^ University of Cambridge , Cavendish Laboratory The Semiconductor Physics group investigates fundamental electronic phenomena using advanced, often unique, semiconductor structures.

    ^ Semiconductor Materials Characteristics and Properties by Ioffe Institute .

    Springer. .ISBN 3-540-41323-5. 
  • Ben G. Steetman and Sanjay Kumar Banerjee (2006), Solid State Electronic Devices, Pearson Education Inc.^ Introduction to Solid-State Devices and Power Supplies.

    ^ Chalmers University of Technology Department of Solid State Electronics .

    ISBN 0-13-149726-X

External links

.

Simple English

A semiconductor is a solid whose electrical conductivity falls between that of conductors and insulators and its electrical conductivity can be controlled by adding impurities. The electrical conductivity can be changed a great deal with a high level of control. Semiconductors like silicon can be made into transistors, which are small amplifiers. Transitors are used in computers, mobile phones, digital audio players and many other electronic devices. Silicon is the most important commercial semiconductor, though many others are used.

Like other solids, the electrons in semiconductors can have energies only within certain bands (ie. ranges of energy levels) between the energy of the ground state, corresponding to electrons tightly bound to the atomic nuclei of the material, and the free electron energy, which is the energy required for an electron to escape entirely from the material. Semi-Conductors have many different applications.

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