نبيطة

(تم التحويل من جهاز شبه موصل)
Outlines of some packaged semiconductor devices

النبائط Semiconductor device أو الشوائب هي مكونات الكترونية تصنع من مواد شبه موصلة يمكن معالجتها لتصبح موصلة عن طريق التشويب بواسطة التطعيم بما يسمى عميل إشابة عبر إضافة كمية قليلة من مادة مانحة تحتوي 5 إلكترونات مثل الأنتيمون أو الفوسفور أو الزرنيخ من عناصر المجموعة الخامسة بالجدول الدوري و بهذه الطريقة تصبح بلورة المادة المشوبة حينها بلورة شبه موصل سالب أما إذا أضيف للبلورة النقية مادة تحتوي ذراتها على ثلاثة الكترونات فعندها ستشكل الالكترونات الثلاث رابطة تساهمية مع الكترونات الذرات المجاورة و تبقى الرابطة الرابعة غير مكتملة مما يؤدي إلى تكون فجوة و تسمى البلورة من هذا النوع بلورة شبه موصل موجب

يمكن التحكم بالموصلية الكهربائية للنبائط عن طريق المجال الكهربائي أو الضوء أو الحرارة و تحل الآن النبائط الإلكترونية محل الصمامات المفرغة بسبب قدرتها على التوصيل الكهربائي في الحالة الصلبة بعكس الصمامات التي تعتمد الحالة الغازية للتوصيل الكهربي

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أنواع النبائط

منها ما هو ثنائي الأطراف ( يتكون من عنصرين) مثل :

و منه ثلاثية الأطراف (يتكون من ثلاثة عناصر) مثل :


تاريخ تطوير النبائط

Cat's-whisker detector

Semiconductors had been used in the electronics field for some time before the invention of the transistor. Around the turn of the 20th century they were quite common as detectors in radios, used in a device called a "cat's whisker" developed by Jagadish Chandra Bose and others. These detectors were somewhat troublesome, however, requiring the operator to move a small tungsten filament (the whisker) around the surface of a galena (lead sulfide) or carborundum (silicon carbide) crystal until it suddenly started working.[1] Then, over a period of a few hours or days, the cat's whisker would slowly stop working and the process would have to be repeated. At the time their operation was completely mysterious. After the introduction of the more reliable and amplified vacuum tube based radios, the cat's whisker systems quickly disappeared. The "cat's whisker" is a primitive example of a special type of diode still popular today, called a Schottky diode.

Metal rectifier

Another early type of semiconductor device is the metal rectifier in which the semiconductor is copper oxide or selenium. Westinghouse Electric (1886) was a major manufacturer of these rectifiers.

الحرب العالمية الثانية

During World War II, radar research quickly pushed radar receivers to operate at ever higher frequencies and the traditional tube-based radio receivers no longer worked well. The introduction of the cavity magnetron from Britain to the United States in 1940 during the Tizard Mission resulted in a pressing need for a practical high-frequency amplifier.[بحاجة لمصدر]

On a whim, Russell Ohl of Bell Laboratories decided to try a cat's whisker. By this point, they had not been in use for a number of years, and no one at the labs had one. After hunting one down at a used radio store in Manhattan, he found that it worked much better than tube-based systems.

Ohl investigated why the cat's whisker functioned so well. He spent most of 1939 trying to grow more pure versions of the crystals. He soon found that with higher-quality crystals their finicky behavior went away, but so did their ability to operate as a radio detector. One day he found one of his purest crystals nevertheless worked well, and it had a clearly visible crack near the middle. However, as he moved about the room trying to test it, the detector would mysteriously work, and then stop again. After some study he found that the behavior was controlled by the light in the room – more light caused more conductance in the crystal. He invited several other people to see this crystal, and Walter Brattain immediately realized there was some sort of junction at the crack.

Further research cleared up the remaining mystery. The crystal had cracked because either side contained very slightly different amounts of the impurities Ohl could not remove – about 0.2%. One side of the crystal had impurities that added extra electrons (the carriers of electric current) and made it a "conductor". The other had impurities that wanted to bind to these electrons, making it (what he called) an "insulator". Because the two parts of the crystal were in contact with each other, the electrons could be pushed out of the conductive side which had extra electrons (soon to be known as the emitter), and replaced by new ones being provided (from a battery, for instance) where they would flow into the insulating portion and be collected by the whisker filament (named the collector). However, when the voltage was reversed the electrons being pushed into the collector would quickly fill up the "holes" (the electron-needy impurities), and conduction would stop almost instantly. This junction of the two crystals (or parts of one crystal) created a solid-state diode, and the concept soon became known as semiconduction. The mechanism of action when the diode off has to do with the separation of charge carriers around the junction. This is called a "depletion region".

Development of the diode

Armed with the knowledge of how these new diodes worked, a vigorous effort began to learn how to build them on demand. Teams at Purdue University, Bell Labs, MIT, and the University of Chicago all joined forces to build better crystals. Within a year germanium production had been perfected to the point where military-grade diodes were being used in most radar sets.

تطوير الترانزستور

After the war, William Shockley decided to attempt the building of a triode-like semiconductor device. He secured funding and lab space, and went to work on the problem with Brattain and John Bardeen.

The key to the development of the transistor was the further understanding of the process of the electron mobility in a semiconductor. It was realized that if there were some way to control the flow of the electrons from the emitter to the collector of this newly discovered diode, an amplifier could be built. For instance, if contacts are placed on both sides of a single type of crystal, current will not flow between them through the crystal. However, if a third contact could then "inject" electrons or holes into the material, the current would flow.

Actually doing this appeared to be very difficult. If the crystal were of any reasonable size, the number of electrons (or holes) required to be injected would have to be very large, making it less than useful as an amplifier because it would require a large injection current to start with. That said, the whole idea of the crystal diode was that the crystal itself could provide the electrons over a very small distance, the depletion region. The key appeared to be to place the input and output contacts very close together on the surface of the crystal on either side of this region.

Brattain started working on building such a device, and tantalizing hints of amplification continued to appear as the team worked on the problem. Sometimes the system would work but then stop working unexpectedly. In one instance a non-working system started working when placed in water. Ohl and Brattain eventually developed a new branch of quantum mechanics, which became known as surface physics, to account for the behavior. The electrons in any one piece of the crystal would migrate about due to nearby charges. Electrons in the emitters, or the "holes" in the collectors, would cluster at the surface of the crystal where they could find their opposite charge "floating around" in the air (or water). Yet they could be pushed away from the surface with the application of a small amount of charge from any other location on the crystal. Instead of needing a large supply of injected electrons, a very small number in the right place on the crystal would accomplish the same thing.

Their understanding solved the problem of needing a very small control area to some degree. Instead of needing two separate semiconductors connected by a common, but tiny, region, a single larger surface would serve. The electron-emitting and collecting leads would both be placed very close together on the top, with the control lead placed on the base of the crystal. When current flowed through this "base" lead, the electrons or holes would be pushed out, across the block of the semiconductor, and collect on the far surface. As long as the emitter and collector were very close together, this should allow enough electrons or holes between them to allow conduction to start.

أول ترانزستور

A stylized replica of the first transistor

The Bell team made many attempts to build such a system with various tools but generally failed. Setups, where the contacts were close enough, were invariably as fragile as the original cat's whisker detectors had been, and would work briefly, if at all. Eventually, they had a practical breakthrough. A piece of gold foil was glued to the edge of a plastic wedge, and then the foil was sliced with a razor at the tip of the triangle. The result was two very closely spaced contacts of gold. When the wedge was pushed down onto the surface of a crystal and voltage was applied to the other side (on the base of the crystal), currently started to flow from one contact to the other as the base voltage pushed the electrons away from the base towards the other side near the contacts. The point-contact transistor had been invented.

While the device was constructed a week earlier, Brattain's notes describe the first demonstration to higher-ups at Bell Labs on the afternoon of 23 December 1947, often given as the birthdate of the transistor. What is now known as the "p–n–p point-contact germanium transistor" operated as a speech amplifier with a power gain of 18 in that trial. John Bardeen, Walter Houser Brattain, and William Bradford Shockley were awarded the 1956 Nobel Prize in physics for their work.

أصل كلمة "ترانزستور"

Bell Telephone Laboratories needed a generic name for their new invention: "Semiconductor Triode", "Solid Triode", "Surface States Triode" [ك‍], "Crystal Triode" and "Iotatron" were all considered, but "transistor", coined by John R. Pierce, won an internal ballot. The rationale for the name is described in the following extract from the company's Technical Memoranda (May 28, 1948) [26] calling for votes:

Transistor. This is an abbreviated combination of the words "transconductance" or "transfer", and "varistor". The device logically belongs in the varistor family, and has the transconductance or transfer impedance of a device having gain, so that this combination is descriptive.


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التحسينات في تصميم الترانزستور

Shockley was upset about the device being credited to Brattain and Bardeen, who he felt had built it "behind his back" to take the glory. Matters became worse when Bell Labs lawyers found that some of Shockley's own writings on the transistor were close enough to those of an earlier 1925 patent by Julius Edgar Lilienfeld that they thought it best that his name be left off the patent application.

Shockley was incensed, and decided to demonstrate who was the real brains of the operation.[بحاجة لمصدر] A few months later he invented an entirely new, considerably more robust, bipolar junction transistor type of transistor with a layer or 'sandwich' structure, used for the vast majority of all transistors into the 1960s.

With the fragility problems solved, the remaining problem was purity. Making germanium of the required purity was proving to be a serious problem and limited the yield of transistors that actually worked from a given batch of material. Germanium's sensitivity to temperature also limited its usefulness. Scientists theorized that silicon would be easier to fabricate, but few investigated this possibility. Former Bell Labs scientist Gordon K. Teal was the first to develop a working silicon transistor at the nascent Texas Instruments, giving it a technological edge. From the late 1950s, most transistors were silicon-based. Within a few years transistor-based products, most notably easily portable radios, were appearing on the market. "Zone melting", a technique using a band of molten material moving through the crystal, further increased crystal purity.

شبه الموصل المعدن-أكسيد

In the 1950s, Mohamed Atalla investigated the surface properties of silicon semiconductors at Bell Labs, where he proposed a new method of semiconductor device fabrication, coating a silicon wafer with an insulating layer of silicon oxide so that electricity could reliably penetrate to the conducting silicon below, overcoming the surface states that prevented electricity from reaching the semiconducting layer. This is known as surface passivation, a method that became critical to the semiconductor industry as it made possible the mass production of silicon integrated circuits (ICs). Building on his surface passivation method, he developed the metal oxide semiconductor (MOS) process, which he proposed could be used to build the first working silicon field-effect transistor (FET).[2][3] The led to the invention of the MOSFET (MOS field-effect transistor) by Mohamed Atalla and Dawon Kahng in 1959.[4][5] With its scalability,[6] and much lower power consumption and higher density than bipolar junction transistors,[7] the MOSFET became the most common type of transistor in computers, electronics,[3] and communications technology such as smartphones.[8] The US Patent and Trademark Office calls the MOSFET a "groundbreaking invention that transformed life and culture around the world".[8]

CMOS (complementary MOS) was invented by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963.[9] The first report of a floating-gate MOSFET was made by Dawon Kahng and Simon Sze in 1967.[10] FinFET (fin field-effect transistor), a type of 3D multi-gate MOSFET, was developed by Digh Hisamoto and his team of researchers at Hitachi Central Research Laboratory in 1989.[11][12]

انظر أيضاً

المراجع

  1. ^ Ernest Braun & Stuart MacDonald (1982). Revolution in Miniature: The History and Impact of Semiconductor Electronics. Cambridge University Press. pp. 11–13. ISBN 978-0-521-28903-0.
  2. ^ "Martin Atalla in Inventors Hall of Fame, 2009". Retrieved 21 June 2013.
  3. ^ أ ب "Dawon Kahng". National Inventors Hall of Fame. Retrieved 27 June 2019.
  4. ^ "1960 - Metal Oxide Semiconductor (MOS) Transistor Demonstrated". The Silicon Engine. Computer History Museum.
  5. ^ Lojek, Bo (2007). History of Semiconductor Engineering. Springer Science & Business Media. pp. 321-3. ISBN 9783540342588.
  6. ^ Motoyoshi, M. (2009). "Through-Silicon Via (TSV)" (PDF). Proceedings of the IEEE. 97 (1): 43–48. doi:10.1109/JPROC.2008.2007462. ISSN 0018-9219. S2CID 29105721. Archived from the original (PDF) on 2019-07-19.
  7. ^ "Transistors Keep Moore's Law Alive". EETimes. 12 December 2018. Retrieved 18 July 2019.
  8. ^ أ ب "Remarks by Director Iancu at the 2019 International Intellectual Property Conference". United States Patent and Trademark Office. June 10, 2019. Retrieved 20 July 2019.
  9. ^ "1963: Complementary MOS Circuit Configuration is Invented". Computer History Museum. Retrieved 6 July 2019.
  10. ^ D. Kahng and S. M. Sze, "A floating gate and its application to memory devices", The Bell System Technical Journal, vol. 46, no. 4, 1967, pp. 1288–1295
  11. ^ "IEEE Andrew S. Grove Award Recipients". IEEE Andrew S. Grove Award. Institute of Electrical and Electronics Engineers. Retrieved 4 July 2019.
  12. ^ "The Breakthrough Advantage for FPGAs with Tri-Gate Technology" (PDF). Intel. 2014. Archived (PDF) from the original on 2022-10-09. Retrieved 4 July 2019.