Semiconductor ↔ relates to ↔ Geology

able to prepare it and characterize it in pure form. Its oxides form a family of anions known as silicates. Its melting and boiling points of 1414 °C and 3265 °C, respectively, are the second highest among all the metalloids and nonmetals, being surpassed only by boron. Silicon is the eighth most common element in the universe by mass, but very rarely occurs in its pure form in the Earth's crust. It is widely distributed throughout space in cosmic dusts, planetoids, and planets as various forms of silicon dioxide (silica) or silicates. More than 90% of the Earth's crust is composed of silicate minerals, making silicon the second most abundant element in the Earth's crust (about 28% by mass), after oxygen. Most silicon is used commercially without being separated, often with very little processing of the natural minerals. Such use includes industrial construction with clays, silica sand, and stone. Silicates are used in Portland cement for mortar and stucco, and mixed with silica sand and gravel to make concrete for walkways, foundations, and roads. They are also used in whiteware ceramics such as porcelain, and in traditional silicate-based soda–lime glass and many other specialty glasses. Silicon compounds such as silicon carbide are used as abrasives and components of high-strength ceramics. Silicon is the basis of the widely used synthetic polymers called silicones. The late 20th century to early 21st century has been described as the Silicon Age (also known as the Digital Age or Information Age) because of the large impact that elemental silicon has on the modern world economy. The small portion of very highly purified elemental silicon used in semiconductor electronics (<15%) is essential to the transistors and integrated circuit chips used in most modern technology such as smartphones and other computers. In 2019, 32.4% of the semiconductor market segment was for networks and communications devices, and the semiconductors industry is projected to reach $726.73 billion by 2027. Silicon is an essential element in biology. Only traces are required by most animals, but some sea sponges and microorganisms, such as diatoms and radiolaria, secrete skeletal structures made of silica.

Silicon is the eighth most abundant element in the universe, coming after hydrogen, helium, oxygen, carbon, neon, iron, and nitrogen. This differs from abundance of elements in Earth's crust due to substantial separation of the elements taking place during the formation of the Solar System. Silicon makes up 27.2% of the Earth's crust by weight, second only to oxygen at 45.5%, with which it always is associated in nature. Further fractionation took place in the formation of the Earth by planetary differentiation: Earth's core, which makes up 31.5% of the mass of the Earth, has approximate composition Fe25Ni2Co0.1S3; the mantle makes up 68.1% of the Earth's mass and is composed mostly of denser oxides and silicates, an example being olivine, (Mg,Fe)2SiO4; while the lighter siliceous minerals such as aluminosilicates rise to the surface and form the crust, making up 0.4% of the Earth's mass. The crystallisation of igneous rocks from magma depends on a number of factors; among them are the chemical composition of the magma, the cooling rate, and some properties of the individual minerals to be formed, such as lattice energy, melting point, and complexity of their crystal structure. As magma is cooled, olivine appears first, followed by pyroxene, amphibole, biotite mica, orthoclase feldspar, muscovite mica, quartz, zeolites, and finally, hydrothermal minerals. This sequence shows a trend toward increasingly complex silicate units with cooling, and the introduction of hydroxide and fluoride anions in addition to oxides. Many metals may substitute for silicon. After these igneous rocks undergo weathering, transport, and deposition, sedimentary rocks like clay, shale, and sandstone are formed. Metamorphism also may occur at high temperatures and pressures, creating an even vaster variety of minerals. There are four sources for silicon fluxes into the ocean: chemical weathering of continental rocks, river transport, dissolution of continental terrigenous silicates, and the reaction between submarine basalts and hydrothermal fluid which release dissolved silicon. All four of these fluxes are interconnected in the ocean's biogeochemical cycle as they all were initially formed from the weathering of Earth's crust. Approximately 300–900 megatonnes of aeolian dust is deposited into the world's oceans each year. Of that value, 80–240 megatonnes are in the form of particulate silicon. The total amount of particulate silicon deposition into the ocean is still less than the amount of silicon influx into the ocean via riverine transportation. Aeolian inputs of particulate lithogenic silicon into the North Atlantic and Western North Pacific oceans are the result of dust settling on the oceans from the Sahara and Gobi Desert, respectively.

Alloys Elemental silicon is added to molten cast iron as ferrosilicon or silicocalcium alloys to improve performance in casting thin sections and to prevent the formation of cementite where exposed to outside air. The presence of elemental silicon in molten iron acts as a sink for oxygen, so that the steel carbon content, which must be kept within narrow limits for each type of steel, can be more closely controlled. Ferrosilicon production and use is a monitor of the steel industry, and although this form of elemental silicon is grossly impure, it accounts for 80% of the world's use of free silicon. Silicon is an important constituent of transformer steel, modifying its resistivity and ferromagnetic properties. The properties of silicon may be used to modify alloys with metals other than iron. "Metallurgical grade" silicon is silicon of 95–99% purity. About 55% of the world consumption of metallurgical purity silicon goes for production of aluminium-silicon alloys (silumin alloys) for aluminium part casts, mainly for use in the automotive industry. Silicon's importance in aluminium casting is that a significantly high amount (12%) of silicon in aluminium forms a eutectic mixture which solidifies with very little thermal contraction. This greatly reduces tearing and cracks formed from stress as casting alloys cool to solidity. Silicon also significantly improves the hardness and thus wear-resistance of aluminium. Metallurgical grade silicon is made by melting quartz or quartzite in a large arc furnace, in a carbothermal reduction process with carbon-containing material such as coal, coke or charcoal and woodchips for gas circulation. This production technique without iron is often used for polysilicon production for photovoltaics and also semiconductors. Electronics Silicon semiconductor devices enable modern information technology. The electronic applications are broad, including microelectronics, computing, optoelectronics, and nanotechnology. Among the many advantages of silicon for electronics are: low cost, formation of large pure single crystals, not brittle, conducts heat generated by electrical activity adequately, can be micro-structured and modified in layers, and its oxide is an excellent insulator. An estimated 15% of the world production of metallurgical grade silicon is refined to semiconductor purity. This is typically the "nine-9" or 99.9999999% purity, nearly defect-free single crystalline material. Monocrystalline silicon of such purity is usually produced by the Czochralski process, and is used to produce silicon wafers used in the semiconductor industry, in electronics, and in some high-cost and high-efficiency photovoltaic applications. Pure silicon is an intrinsic semiconductor, which means that unlike metals, it conducts electron holes and electrons released from atoms by heat. Intrinsic silicon's electrical conductivity increases with temperature due to the broadening of the Fermi-Dirac distribution. Pure silicon has too low a conductivity (i.e., too high a resistivity) to be used as a circuit element in electronics. In practice, pure silicon is doped with small concentrations of elements with differing valence electron count (typically boron and phosphorus), which greatly increase its conductivity and adjust its electrical response by controlling the number and type (positive or negative) of activated charge carriers. Such control is necessary for transistors, solar cells, semiconductor detectors, and other semiconductor devices used in the computer industry and other technical applications.

A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities ("doping") to its crystal structure. When two regions with different doping levels are present in the same crystal, they form a semiconductor junction. The term "semiconductors" is sometimes used to refer to semiconductor devices such as microchips and computer processors, which work using the physical properties of semiconductors. The behavior of charge carriers, which include electrons, ions, and electron holes, at these junctions is the basis of diodes, transistors, and most modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second-most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits, and others. Silicon is a critical element for fabricating most electronic circuits. Semiconductor devices can display a range of different useful properties, such as passing current more easily in one direction than the other, showing variable resistance, and having sensitivity to light or heat. Because the electrical properties of a semiconductor material can be modified by doping and by the application of electrical fields or light, devices made from semiconductors can be used for amplification, switching, and energy conversion. The term semiconductor is also used to describe materials used in high capacity, medium- to high-voltage cables as part of their insulation, and these materials are often plastic XLPE (cross-linked polyethylene) with carbon black. The conductivity of silicon can be increased by adding a small amount (of the order of 1 in 108) of pentavalent (antimony, phosphorus, or arsenic) or trivalent (boron, gallium, indium) atoms. This process is known as doping, and the resulting semiconductors are known as doped or extrinsic semiconductors. Apart from doping, the conductivity of a semiconductor can be improved by increasing its temperature. This is contrary to the behavior of a metal, in which conductivity decreases with an increase in temperature. The modern understanding of the properties of a semiconductor relies on quantum physics to explain the movement of charge carriers in a crystal lattice. Doping greatly increases the number of charge carriers within the crystal. When a semiconductor is doped by Group V elements, they will behave like donors creating free electrons, known as "n-type" doping. When a semiconductor is doped by Group III elements, they will behave like acceptors creating free holes, known as "p-type" doping. The semiconductor materials used in electronic devices are doped under precise conditions to control the concentration and regions of p- and n-type dopants. A single semiconductor device crystal can have many p- and n-type regions; the p–n junctions between these regions are responsible for the useful electronic behavior. Using a hot-point probe, one can determine quickly whether a semiconductor sample is p- or n-type. A few of the properties of semiconductor materials were observed throughout the mid-19th and first decades of the 20th century. The first practical application of semiconductors in electronics was the 1904 development of the cat's-whisker detector, a primitive semiconductor diode used in early radio receivers.

, medium- to high-voltage cables as part of their insulation, and these materials are often plastic XLPE (cross-linked polyethylene) with carbon black. The conductivity of silicon can be increased by adding a small amount (of the order of 1 in 108) of pentavalent (antimony, phosphorus, or arsenic) or trivalent (boron, gallium, indium) atoms. This process is known as doping, and the resulting semiconductors are known as doped or extrinsic semiconductors. Apart from doping, the conductivity of a semiconductor can be improved by increasing its temperature. This is contrary to the behavior of a metal, in which conductivity decreases with an increase in temperature. The modern understanding of the properties of a semiconductor relies on quantum physics to explain the movement of charge carriers in a crystal lattice. Doping greatly increases the number of charge carriers within the crystal. When a semiconductor is doped by Group V elements, they will behave like donors creating free electrons, known as "n-type" doping. When a semiconductor is doped by Group III elements, they will behave like acceptors creating free holes, known as "p-type" doping. The semiconductor materials used in electronic devices are doped under precise conditions to control the concentration and regions of p- and n-type dopants. A single semiconductor device crystal can have many p- and n-type regions; the p–n junctions between these regions are responsible for the useful electronic behavior. Using a hot-point probe, one can determine quickly whether a semiconductor sample is p- or n-type. A few of the properties of semiconductor materials were observed throughout the mid-19th and first decades of the 20th century. The first practical application of semiconductors in electronics was the 1904 development of the cat's-whisker detector, a primitive semiconductor diode used in early radio receivers.

Semiconductors are defined by their unique electric conductive behavior, somewhere between that of a conductor and an insulator. The differences between these materials can be understood in terms of the quantum states for electrons, each of which may contain zero or one electron (by the Pauli exclusion principle). These states are associated with the electronic band structure of the material. Electrical conductivity arises due to the presence of electrons in states that are delocalized (extending through the material), however in order to transport electrons a state must be partially filled, containing an electron only part of the time. If the state is always occupied with an electron, then it is inert, blocking the passage of other electrons via that state. The energies of these quantum states are critical since a state is partially filled only if its energy is near the Fermi level (see Fermi–Dirac statistics). High conductivity in a material comes from it having many partially filled states and much state delocalization. Metals are good electrical conductors and have many partially filled states with energies near their Fermi level. Insulators, by contrast, have few partially filled states, their Fermi levels sit within band gaps with few energy states to occupy. Importantly, an insulator can be made to conduct by increasing its temperature: heating provides energy to promote some electrons across the band gap, inducing partially filled states in both the band of states beneath the band gap (valence band) and the band of states above the band gap (conduction band). An (intrinsic) semiconductor has a band gap that is smaller than that of an insulator and at room temperature, significant numbers of electrons can be excited to cross the band gap. A pure semiconductor, however, is not very useful, as it is neither a very good insulator nor a very good conductor. However, one important feature of semiconductors (and some insulators, known as semi-insulators) is that their conductivity can be increased and controlled by doping with impurities and gating with electric fields. Doping and gating move either the conduction or valence band much closer to the Fermi level and greatly increase the number of partially filled states. Some wider-bandgap semiconductor materials are sometimes referred to as semi-insulators. When undoped, these have electrical conductivity nearer to that of electrical insulators, however they can be doped (making them as useful as semiconductors). Semi-insulators find niche applications in micro-electronics, such as substrates for HEMT. An example of a common semi-insulator is gallium arsenide. Some materials, such as titanium dioxide, can even be used as insulating materials for some applications, while being treated as wide-gap semiconductors for other applications. Charge carriers (electrons and holes) The partial filling of the states at the bottom of the conduction band can be understood as adding electrons to that band. The electrons do not stay indefinitely (due to the natural thermal recombination) but they can move around for some time. The actual concentration of electrons is typically very dilute, and so (unlike in metals) it is possible to think of the electrons in the conduction band of a semiconductor as a sort of classical ideal gas, where the electrons fly around freely without being subject to the Pauli exclusion principle. In most semiconductors, the conduction bands have a parabolic dispersion relation, and so these electrons respond to forces (electric field, magnetic field, etc.) much as they would in a vacuum, though with a different effective mass. Because the electrons behave like an ideal gas, one may also think about conduction in very simplistic terms such as the Drude model, and introduce concepts such as electron mobility. For partial filling at the top of the valence band, it is helpful to introduce the concept of an electron hole. Although the electrons in the valence band are always moving around, a completely full valence band is inert, not conducting any current. If an electron is taken out of the valence band, then the trajectory that the electron would normally have taken is now missing its charge. For the purposes of electric current, this combination of the full valence band, minus the electron, can be converted into a picture of a completely empty band containing a positively charged particle that moves in the same way as the electron. Combined with the negative effective mass of the electrons at the top of the valence band, we arrive at a picture of a positively charged particle that responds to electric and magnetic fields just as a normal positively charged particle would do in a vacuum, again with some positive effective mass.

College of Western Idaho (CWI) is a public community college in Southwest Idaho with its primary campus locations in Boise and Nampa. CWI also offers classes at several community locations throughout the Treasure Valley. It is one of four comprehensive community colleges along with the College of Eastern Idaho, College of Southern Idaho and North Idaho College, in Idaho and is governed by a five-member board of trustees elected at large by voters in Ada and Canyon counties. CWI offers over 120 programs in the areas of Academic Transfer, Dual Credit, Career and Technical Education, Workforce Development, and Adult Education. In fall of 2023, CWI served 21,359 credit students and 14,951 noncredit students. CWI reported the gender of their students to be 55% female and 45% male.

e 55% female and 45% male. Idaho residents comprised 98% of CWI's student population and Ada County residents were 49%, while 28% were Canyon County residents. History Prior to the creation of CWI, Boise was one of the largest metropolitan statistical areas in the United States without a community college. CWI was created on May 22, 2007, when voters of Canyon and Ada counties passed a measure to allow the formation of the new community college district. In June 2007, the Albertson Foundation announced it was donating $10 million to help found the college. In July 2007, the Idaho State Board of Education selected an initial five-member board of trustees. The following month Boise State University faculty member Dennis Griffin was named to a two-year term as the college's first president and CWI began offering academic classes on January 20, 2009, with an enrollment of over 1,100 students. In the summer of 2009 the professional-technical programs from Boise State University's Selland College of Applied Technology transitioned to CWI. By the fall 2009 semester, CWI enrollment had expanded to over 3,600 students. In January 2010, CWI applied for accreditation from the Northwest Commission on Colleges and Universities (NWCCU). NWCCU granted candidacy status at the associate degree level in 2012 and initial accreditation in 2016. President Griffin retired in August 2009 and was succeeded by Bert Glandon. After serving as president for 12 years, Glandon retired from CWI on May 15, 2021. The college's board of trustees named Denise Aberle-Cannata the interim president. CWI Board of Trustees extended an offer to Gordon Jones on Dec. 9, 2021 to be the next president at College of Western Idaho. Gordon Jones accepted the position of President at CWI and began his tenure as the third president in CWI's history on Jan.

History Prior to the creation of CWI, Boise was one of the largest metropolitan statistical areas in the United States without a community college. CWI was created on May 22, 2007, when voters of Canyon and Ada counties passed a measure to allow the formation of the new community college district. In June 2007, the Albertson Foundation announced it was donating $10 million to help found the college. In July 2007, the Idaho State Board of Education selected an initial five-member board of trustees. The following month Boise State University faculty member Dennis Griffin was named to a two-year term as the college's first president and CWI began offering academic classes on January 20, 2009, with an enrollment of over 1,100 students. In the summer of 2009 the professional-technical programs from Boise State University's Selland College of Applied Technology transitioned to CWI. By the fall 2009 semester, CWI enrollment had expanded to over 3,600 students. In January 2010, CWI applied for accreditation from the Northwest Commission on Colleges and Universities (NWCCU). NWCCU granted candidacy status at the associate degree level in 2012 and initial accreditation in 2016. President Griffin retired in August 2009 and was succeeded by Bert Glandon. After serving as president for 12 years, Glandon retired from CWI on May 15, 2021. The college's board of trustees named Denise Aberle-Cannata the interim president. CWI Board of Trustees extended an offer to Gordon Jones on Dec. 9, 2021 to be the next president at College of Western Idaho. Gordon Jones accepted the position of President at CWI and began his tenure as the third president in CWI's history on Jan.

ern Oregon to Boise, and is the most populated area in Idaho. Historically, the valley had been known as the Lower Snake River Valley or the Boise River Valley. Pete Olesen, president of the valley's association of local Chambers of Commerce, coined the name "Treasure Valley" in 1959 to reflect the treasure chest of resources and opportunities that the region offered. The valley has a very diverse terrain, from sage flatlands, to mesas, agricultural areas, and urbanized areas.

The Treasure Valley is a valley in the western United States, primarily in southwestern Idaho, where the Payette, Boise, Weiser, Malheur, and Owyhee rivers drain into the Snake River. It includes all the lowland areas from Vale in rural eastern Oregon to Boise, and is the most populated area in Idaho. Historically, the valley had been known as the Lower Snake River Valley or the Boise River Valley. Pete Olesen, president of the valley's association of local Chambers of Commerce, coined the name "Treasure Valley" in 1959 to reflect the treasure chest of resources and opportunities that the region offered. The valley has a very diverse terrain, from sage flatlands, to mesas, agricultural areas, and urbanized areas.

eflect the treasure chest of resources and opportunities that the region offered. The valley has a very diverse terrain, from sage flatlands, to mesas, agricultural areas, and urbanized areas. As the Boise Metropolitan Area grows, more and more undeveloped and agricultural land is being urbanized. History Settling the region The tribes that roamed the area, specifically, were the Northern Paiute and Shoshone. In 1834, Thomas McKay built the original Fort Boise, in the area near present-day Parma, which was run for a time by Francois Payette. It later was moved because of flooding troubles and was abandoned in 1854. The Oregon Trail runs through the Treasure Valley. The valley was settled for the most part by ranchers and farmers, initially to supply the gold and silver mining communities in the higher elevations nearby: Idaho City in the Boise Basin and Silver City in the Owyhees. A new Fort Boise was constructed by the U.S. Army in 1863 in present-day Boise, from which the city grew.

, and service sectors, including companies such as Micron Technology and Hewlett-Packard. The city is home to the Boise Art Museum, Idaho State Capitol, the annual Treefort Music Fest, and the Basque Block. History Etymology The origin of the name is uncertain. One account credits Capt. B. L. E. Bonneville of the U.S. Army as its source. After trekking for weeks through dry and rough terrain, his exploration party reached an overlook with a view of the Boise River Valley. The place where they stood is called Bonneville Point, located on the Oregon Trail east of the city. According to the story, a French-speaking guide, overwhelmed by the sight of the verdant river, yelled "Les bois! Les bois!" ("The woods! The woods!")—and the name stuck. The name may also derive from earlier mountain men who named the river that flows through the city. In the 1820s, French Canadian fur trappers associated with the British-owned Hudson's Bay Company set trap lines in the vicinity. Set in a high-desert area, the tree-lined valley of the Boise River became a distinct landmark, an oasis dominated by cottonwood trees.

Downtown Boise is Boise's cultural center and home to many small businesses as well as a growing number of high-rises. While downtown Boise lacks a major retail/dining focus like Seattle and Portland, the area has a variety of shops and growing option for dining choices. Centrally, 8th Street contains a pedestrian zone with sidewalk cafes and restaurants. The neighborhood has many local restaurants, bars, and boutiques and supports a vibrant nightlife. The area contains the Basque Block, which gives visitors a chance to learn about and enjoy Boise's Basque heritage.

Southeast Boise ranges from Boise State University to Micron Technology between Federal Way and the Boise River. Its oldest neighborhood, Original South Boise, was platted in 1890, and accordingly has variegated housing (assiduously maintained by zoning); it consists of 33 blocks bordered by W Beacon Street, S Boise Avenue, and S Broadway Avenue, and hence is a triangular neighborhood immediately adjoining BSU. The rest of Southeast Boise was developed over the decades, largely by a variety of suburban-style homes. Columbia Village subdivision and the older Oregon Trail Heights were the first major planned communities in Southeast Boise with an elementary and middle school all within walking distance from all homes. The subdivision is at the intersections of Interstate 84, Idaho 21, and Federal Way (former U.S. Highway), which are all major arteries to get anywhere in Boise. The subdivision, a baseball complex, and swimming pools were developed around the Simplot Sports complex. The fields are built over an old landfill and dump, and the fields and gravel parking lot allow radon gases to escape through the ground. The most recent planned community is the 35-acre (14 ha) Bown Crossing, which has easy access to the Boise Greenbelt. On August 25, 2008, at about 7:00 pm, a fire started near Amity and Holcomb during a major windstorm. It destroyed ten houses and damaged nine.

Kuna ( KYOO-nə) is a city in Ada County, Idaho. It is part of the Boise metropolitan area. The population was 24,011 at the time of the 2020 census. Kuna is one of the fastest-growing areas in Idaho, having nearly tripled in population between 2000 and 2010 and a nearly additional 60 percent gain between 2010 and 2020.

History Kuna originated as a railroad stop with coach transport to Boise. It is popularly believed, as cited by the Kuna Chamber of Commerce, that the translation of the name "Kuna" means "the end of the trail", but Charles S. Walgamott cites the origin of the name as a Shoshone Indian word meaning "green leaf, good to smoke." The Western Heritage Historic Byway, designated as a national as well as a state scenic byway, travels around a number of historic sites in the area. Geography Kuna's business center is approximately 18 miles (29 km) southwest of downtown Boise, the state capital. According to the United States Census Bureau, the city has a total area of 18.18 square miles (47.09 km2), of which 18.08 square miles (46.83 km2) is land and 0.10 square miles (0.26 km2) is water. South of Kuna is the Kuna Caves, a lava tube. A small seasonal creek, Indian Creek, runs through the city. It is now used as an irrigation canal, filled by the New York Canal from the Boise River Diversion Dam.

Geography Kuna's business center is approximately 18 miles (29 km) southwest of downtown Boise, the state capital. According to the United States Census Bureau, the city has a total area of 18.18 square miles (47.09 km2), of which 18.08 square miles (46.83 km2) is land and 0.10 square miles (0.26 km2) is water. South of Kuna is the Kuna Caves, a lava tube. A small seasonal creek, Indian Creek, runs through the city. It is now used as an irrigation canal, filled by the New York Canal from the Boise River Diversion Dam. One of the few small floatable waterways in the region, Indian Creek is a favorite swimming spot for local residents. Demographics 2020 census As of the 2020 census, Kuna had a population of 24,011. The median age was 30.9 years. 31.8% of residents were under the age of 18 and 8.1% of residents were 65 years of age or older. For every 100 females there were 97.8 males, and for every 100 females age 18 and over there were 96.2 males age 18 and over. 97.1% of residents lived in urban areas, while 2.9% lived in rural areas. There were 7,736 households in Kuna, of which 48.2% had children under the age of 18 living in them. Of all households, 62.3% were married-couple households, 11.6% were households with a male householder and no spouse or partner present, and 17.4% were households with a female householder and no spouse or partner present. About 13.9% of all households were made up of individuals and 4.6% had someone living alone who was 65 years of age or older. There were 7,948 housing units, of which 2.7% were vacant. The homeowner vacancy rate was 0.8% and the rental vacancy rate was 5.9%. As of the 2020 census, the median income for a household in the city was $68,017. Families had a median income of $75,296 versus $91,364 for married-couple families and $33,512 for nonfamily households.