Editing Semiconductor (section)

{{Short description|Material that has electrical conductivity intermediate to that of a conductor and an insulator}}
{{For-multi|devices using semiconductors and their history|Semiconductor device|other uses}}
[[File:Monokristalines Silizium für die Waferherstellung.jpg|thumb|upright=0.8|An [[boule (crystal)|ingot]] of [[monocrystalline silicon]]]]
{{Semiconductor manufacturing processes}}

A '''semiconductor''' is a material with [[electrical conductivity]] between that of a [[Electrical conductor|conductor]] and an [[Insulator (electricity)|insulator]].<ref>{{cite web |last=Tatum |first=Jeremy |date=13 December 2016 |title=Resistance and Temperature |url=https://phys.libretexts.org/Bookshelves/Electricity_and_Magnetism/Electricity_and_Magnetism_(Tatum)/04%3A_Batteries_Resistors_and_Ohm's_Law/4.03%3A_Resistance_and_Temperature |access-date=2023-12-22 |website=LibreTexts}}</ref> Its conductivity can be modified by adding impurities ("[[doping (semiconductor)|doping]]") to its [[crystal structure]]. When two regions with different doping levels are present in the same crystal, they form a [[semiconductor junction]]. 

The behavior of [[charge carrier]]s, which include [[electron]]s, [[ion]]s, and [[electron hole]]s, at these junctions is the basis of [[diode]]s, [[transistor]]s, 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 diode]]s, [[solar cell]]s, microwave-frequency [[integrated circuit]]s, and others. Silicon is a critical element for fabricating most [[electronic circuit]]s.

[[Semiconductor device]]s 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 cable]]s as part of their insulation, and these materials are often plastic XLPE ([[cross-linked polyethylene]]) with carbon black.<ref>{{cite book | url=https://books.google.com/books?id=X8QfRT_SYDgC&dq=carbon+black+cable&pg=PA20 | title=Submarine Power Cables: Design, Installation, Repair, Environmental Aspects | isbn=978-3-642-01270-9 | last1=Worzyk | first1=Thomas | date=11 August 2009 | publisher=Springer }}</ref>

The conductivity of silicon is increased by adding a small amount (of the order of 1 in 10<sup>8</sup>) of pentavalent ([[antimony]], [[phosphorus]], or [[arsenic]]) or trivalent ([[boron]], [[gallium]], [[indium]]) atoms.<ref>{{Cite web |title=Electrical Conduction in Semiconductors |url=https://www.mks.com/n/electrical-conduction-semiconductors |access-date=2024-04-01 |website=www.mks.com}}</ref> This process is known as doping, and the resulting semiconductors are known as doped or [[extrinsic semiconductor]]s. 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.<ref>{{Cite web |date=2015-01-12 |title=Joshua Halpern |url=https://chem.libretexts.org/Courses/Howard_University/General_Chemistry%3A_An_Atoms_First_Approach/Unit_5%3A_States_of_Matter/Chapter_12%3A_Solids/Chapter_12.06%3A_Metals_and_Semiconductors |access-date=2024-04-01 |website=Chemistry 003 |language=en}}</ref>

The modern understanding of the properties of a semiconductor relies on [[quantum physics]] to explain the movement of charge carriers in a [[crystal structure|crystal lattice]].<ref name=Feynman>{{cite book |last1=Feynman |first1=Richard |title=Feynman Lectures on Physics |url=https://feynmanlectures.caltech.edu}}</ref> Doping greatly increases the number of charge carriers within the crystal. When a semiconductor is doped by Group V elements, they will behave like [[Donor (semiconductors)|donors]] creating free [[electron]]s, known as "[[extrinsic semiconductor#N-type semiconductors|n-type]]" doping. When a semiconductor is doped by Group III elements, they will behave like [[acceptor (semiconductors)|acceptors]] creating free holes, known as "[[extrinsic semiconductor#P-type semiconductors|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 junction]]s 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.<ref>{{cite web |title=2.4.7.9 The "hot-probe" experiment |url=https://ecee.colorado.edu/~bart/book/hotprobe.htm |website=ecee.colorado.edu |access-date=27 November 2020 |archive-date=6 March 2021 |archive-url=https://web.archive.org/web/20210306224540/https://ecee.colorado.edu/~bart/book/hotprobe.htm |url-status=dead }}</ref>

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 [[wireless telegraphy|radio]] receivers. Developments in quantum physics led in turn to the invention of the [[transistor]] in 1947<ref>{{cite book |last1=Shockley |first1=William |title=Electrons and holes in semiconductors: with applications to transistor electronics |date=1950 |publisher=R. E. Krieger Pub. Co |isbn=978-0-88275-382-9}}</ref> and the [[integrated circuit]] in 1958.