An integrated circuit (IC), also known as a microchip or simply chip, is a compact assembly of electronic circuits formed from various electronic components, such as transistors, resistors, and capacitors, and their interconnections. These components are fabricated onto a thin, flat piece ("chip") of semiconductor material, most commonly silicon. Integrated circuits are integral to a wide variety of electronic devices (including computers, smartphones, and televisions) performing functions such as data processing, control, and storage. They have transformed the field of electronics by enabling device miniaturization, improving performance, and reducing cost. Compared to assemblies built from discrete components, integrated circuits are orders of magnitude smaller, faster, more energy-efficient, and less expensive, allowing for a very high transistor count. Its capability for mass production, its high reliability, and the standardized, modular approach of integrated circuit design facilitated rapid replacement of designs using discrete transistors. Today, ICs are present in virtually all electronic devices and have revolutionized modern technology. Products such as computer processors, microcontrollers, digital signal processors, and embedded processing chips in home appliances are foundational to contemporary society due to their small size, low cost, and versatility. Very-large-scale integration was made practical by technological advancements in semiconductor device fabrication. Since their origins in the 1960s, the size, speed, and capacity of chips have progressed enormously, driven by technical advances that fit more and more transistors on chips of the same size – a modern chip may have many billions of transistors in an area the size of a human fingernail. These advances, roughly following Moore's law, make the computer chips of today possess millions of times the capacity and thousands of times the speed of the computer chips of the early 1970s. ICs have three main advantages over circuits constructed out of discrete components: size, cost and performance. The size and cost are low because the chips, with all their components, are printed as a unit by photolithography rather than being constructed one transistor at a time. Furthermore, packaged ICs use much less material than discrete circuits. Performance is high because the IC's components switch quickly and consume comparatively little power because of their small size and proximity. The main disadvantage of ICs is the high initial cost of designing them and the enormous capital cost of factory construction. This high initial cost means ICs are only commercially viable when high production volumes are anticipated.
Terminology An "integrated circuit" is formally defined as:
A circuit in which all or some of the circuit elements are inseparably associated and electrically interconnected so that it is considered to be indivisible for the purposes of construction and commerce. In its strict sense, the term refers to a single-piece circuit construction – originally called a "monolithic integrated circuit" – consisting of an entire circuit built on a single piece of silicon. In general usage, "integrated circuit" can also apply to circuits constructed using technologies such as 3D IC, 2.5D IC, MCM, thin-film transistors, thick-film technology, or hybrid integrated circuits. The distinction between the strict and the broader definitions is often relevant in debates on whether Moore's law remains applicable.
History
The first integrated circuits
A precursor to the integrated circuit was small ceramic substrates known as micromodules, each containing a single miniaturized electronic component. These modules could be assembled and interconnected into a two- or three-dimensional compact grid. The idea, considered highly promising in 1957, was proposed to the U.S. Army by Jack Kilby, leading to the short-lived Micromodule Program (similar in spirit to 1951's Project Tinkertoy). However, as the project gained traction, Kilby devised a fundamentally new approach: the integrated circuit itself. Newly employed by Texas Instruments, Kilby recorded his initial ideas concerning the integrated circuit in July 1958, successfully demonstrating the first working example of an integrated circuit on 12 September 1958. In his patent application of 6 February 1959, Kilby described his new device as "a body of semiconductor material ... wherein all the components of the electronic circuit are completely integrated". The first customer for the new invention was the US Air Force. Kilby won the 2000 Nobel Prize in physics for his part in the invention of the integrated circuit. However, Kilby's invention was not a true monolithic integrated circuit chip, as it relied on external gold-wire connections, making large-scale production impractical. About six months later, Robert Noyce at Fairchild Semiconductor developed the first practical monolithic IC chip. The monolithic integrated circuit chip was enabled by the inventions of the planar process by Jean Hoerni and of p–n junction isolation by Kurt Lehovec. Hoerni's invention was built on Carl Frosch and Lincoln Derick's work on surface protection and passivation by silicon dioxide masking and predeposition, as well as Fuller, Ditzenberger's and others work on the diffusion of impurities into silicon. Unlike Kilby's germanium-based design, Noyce's version was fabricated from silicon using the planar process by his colleague Jean Hoerni, which allowed reliable on-chip aluminum interconnections. Modern IC chips are based on Noyce's monolithic design, rather than Kilby's early prototype. NASA's Apollo Program was the largest single consumer of integrated circuits between 1961 and 1965.
TTL integrated circuits
Transistor–transistor logic (TTL) was developed by James L. Buie in the early 1960s at TRW Inc. TTL became the dominant technology for digital integrated circuits during the 1970s to early 1980s.
Use of dozens of TTL integrated circuits was the standard method of construction for the processors of minicomputers and mainframe computers. Computers such as IBM 360 mainframes, PDP-11 minicomputers and the desktop Datapoint 2200 were built from bipolar integrated circuits, either TTL or the faster emitter-coupled logic (ECL).
MOS integrated circuits
… excerpt ends here. Continue reading the full article.
