Integrated circuit

Last updated

Erasable Programmable Read-Only Memory (EPROM) integrated circuits. These packages have a transparent window that shows the die inside. The window is used to erase the memory by exposing the chip to ultraviolet light. Microchips.jpg
Erasable Programmable Read-Only Memory (EPROM) integrated circuits. These packages have a transparent window that shows the die inside. The window is used to erase the memory by exposing the chip to ultraviolet light.
Integrated circuit from an EPROM memory microchip showing the memory blocks, the supporting circuitry and the fine silver wires which connect the integrated circuit die to the legs of the packaging. EPROM Microchip SuperMacro.jpg
Integrated circuit from an EPROM memory microchip showing the memory blocks, the supporting circuitry and the fine silver wires which connect the integrated circuit die to the legs of the packaging.
Virtual detail of an integrated circuit through four layers of planarized copper interconnect, down to the polysilicon (pink), wells (greyish), and substrate (green) Siliconchip by shapeshifter.png
Virtual detail of an integrated circuit through four layers of planarized copper interconnect, down to the polysilicon (pink), wells (greyish), and substrate (green)

An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material that is normally silicon. The integration of large numbers of tiny transistors into a small chip results in circuits that are orders of magnitude smaller, cheaper, and faster than those constructed of discrete electronic components. The IC's mass production capability, reliability and building-block approach to circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs.

Electronic circuit electrical circuit with active components such as transistors, valves and integrated circuits; electrical network that contains active electronic components, generally nonlinear and require complex design and analysis tools

An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. To be referred to as electronic, rather than electrical, generally at least one active component must be present. The combination of components and wires allows various simple and complex operations to be performed: signals can be amplified, computations can be performed, and data can be moved from one place to another.

A semiconductor material has an electrical conductivity value falling between that of a metal, like copper, gold, etc. and an insulator, such as glass. Their resistance decreases as their temperature increases, which is behaviour opposite to that of a metal. Their conducting properties may be altered in useful ways by the deliberate, controlled introduction of impurities ("doping") into the crystal structure. Where two differently-doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers which include electrons, ions and electron holes at these junctions is the basis of diodes, transistors and all modern electronics. Some examples of semiconductors are silicon, germanium, and gallium arsenide. After silicon, gallium arsenide is the second most common semiconductor used in laser diodes, solar cells, microwave frequency integrated circuits, and others. Silicon is a critical element for fabricating most electronic circuits.

Silicon Chemical element with atomic number 14

Silicon is a chemical element with symbol Si and atomic number 14. It is a hard and brittle crystalline solid with a blue-grey metallic lustre; and it is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, and lead are below it. It is relatively unreactive. Because of its high chemical affinity for oxygen, it was not until 1823 that Jöns Jakob Berzelius was first able to prepare it and characterize it in pure form. Its melting and boiling points of 1414 °C and 3265 °C respectively are the second-highest among all the metalloids and nonmetals, being only surpassed by boron. Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure element in the Earth's crust. It is most widely distributed in dusts, sands, 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 after oxygen.

Contents

Integrated circuits were made practical by mid-20th-century technology 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 computer chips of today possess millions of times the capacity and thousands of times the speed of the computer chips of the early 1970s.

Semiconductor device fabrication process used to create the integrated circuits that are present in everyday electrical and electronic devices

Semiconductor device fabrication is the process used to create the integrated circuits that are present in everyday electrical and electronic devices. It is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer made of pure semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications.

Transistor semiconductor device used to amplify and switch electronic signals and electrical power

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.

Moores law heuristic law stating that the number of transistors on a circuit doubles every two years

Moore's law is the observation that the number of transistors in a dense integrated circuit doubles about every two years. The observation is named after Gordon Moore, the co-founder of Fairchild Semiconductor and CEO of Intel, whose 1965 paper described a doubling every year in the number of components per integrated circuit and projected this rate of growth would continue for at least another decade. In 1975, looking forward to the next decade, he revised the forecast to doubling every two years. The period is often quoted as 18 months because of a prediction by Intel executive David House.

ICs have two main advantages over discrete circuits: cost and performance. Cost is 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 close proximity. The main disadvantage of ICs is the high cost to design them and fabricate the required photomasks. This high initial cost means ICs are only practical when high production volumes are anticipated.

Photolithography, also termed optical lithography or UV lithography, is a process used in microfabrication to pattern parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate. A series of chemical treatments then either engraves the exposure pattern into the material or enables deposition of a new material in the desired pattern upon the material underneath the photo resist. For example, in complex integrated circuits, a modern CMOS wafer will go through the photolithographic cycle up to 50 times.

Integrated circuit design Engineering process for electronic hardware

Integrated circuit design, or IC design, is a subset of electronics engineering, encompassing the particular logic and circuit design techniques required to design integrated circuits, or ICs. ICs consist of miniaturized electronic components built into an electrical network on a monolithic semiconductor substrate by photolithography.

Photomask opaque plate or film with holes or transparencies that allow light to shine through in a defined pattern

A photomask is an opaque plate with holes or transparencies that allow light to shine through in a defined pattern. They are commonly used in photolithography.

Terminology

An integrated circuit is defined as: [1]

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.

Circuits meeting this definition can be constructed using many different technologies, including thin-film transistors, thick-film technologies, or hybrid integrated circuits. However, in general usage integrated circuit has come to refer to the single-piece circuit construction originally known as a monolithic integrated circuit. [2] [3]

Thin-film transistor

A thin-film transistor (TFT) is a special kind of field-effect transistor made by depositing thin films of an active semiconductor layer as well as the dielectric layer and metallic contacts over a supporting substrate. A common substrate is glass, because the primary application of TFTs is in liquid-crystal displays (LCDs). This differs from the conventional transistor, where the semiconductor material typically is the substrate, such as a silicon wafer.

Thick-film technology is used to produce electronic devices such as surface mount devices, hybrid integrated circuits and sensors.

Hybrid integrated circuit

A hybrid integrated circuit (HIC), hybrid microcircuit, hybrid circuit or simply hybrid is a miniaturized electronic circuit constructed of individual devices, such as semiconductor devices and passive components, bonded to a substrate or printed circuit board (PCB). A PCB having components on a Printed Wiring Board (PWB) is not considered a hybrid circuit according to the definition of MIL-PRF-38534.

Arguably, the first examples of integrated circuits would include the Loewe 3NF. [4] Although far from a monolithic construction, it certainly meets the definition given above.

Loewe 3NF

The Loewe 3NF was an early attempt to combine several functions in one electronic device.

Invention

Early developments of the integrated circuit go back to 1949, when German engineer Werner Jacobi (Siemens AG) [5] filed a patent for an integrated-circuit-like semiconductor amplifying device [6] showing five transistors on a common substrate in a 3-stage amplifier arrangement. Jacobi disclosed small and cheap hearing aids as typical industrial applications of his patent. An immediate commercial use of his patent has not been reported.

Amplifier electronic device that can increase the power of a signal

An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the power of a signal. It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is a circuit that has a power gain greater than one.

Hearing aid electroacoustic device

A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss. Hearing aids are classified as medical devices in most countries, and regulated by the respective regulations. Small audio amplifiers such as PSAPs or other plain sound reinforcing systems cannot be sold as "hearing aids".

The idea of the integrated circuit was conceived by Geoffrey Dummer (1909–2002), a radar scientist working for the Royal Radar Establishment of the British Ministry of Defence. Dummer presented the idea to the public at the Symposium on Progress in Quality Electronic Components in Washington, D.C. on 7 May 1952. [7] He gave many symposia publicly to propagate his ideas and unsuccessfully attempted to build such a circuit in 1956.

A precursor idea to the IC was to create small ceramic squares (wafers), each containing a single miniaturized component. Components could then be integrated and wired into a bidimensional or tridimensional compact grid. This idea, which seemed very promising in 1957, was proposed to the US Army by Jack Kilby and led to the short-lived Micromodule Program (similar to 1951's Project Tinkertoy). [8] [9] [10] However, as the project was gaining momentum, Kilby came up with a new, revolutionary design: the IC.

Jack Kilby's original integrated circuit Kilby solid circuit.jpg
Jack Kilby's original integrated circuit

Newly employed by Texas Instruments, Kilby recorded his initial ideas concerning the integrated circuit in July 1958, successfully demonstrating the first working integrated example on 12 September 1958. [11] In his patent application of 6 February 1959, [12] Kilby described his new device as "a body of semiconductor material … wherein all the components of the electronic circuit are completely integrated." [13] The first customer for the new invention was the US Air Force. [14]

Kilby won the 2000 Nobel Prize in Physics for his part in the invention of the integrated circuit. [15] His work was named an IEEE Milestone in 2009. [16]

Half a year after Kilby, Robert Noyce at Fairchild Semiconductor developed a new variety of integrated circuit, more practical than Kilby's implementation. Noyce's design was made of silicon, whereas Kilby's chip was made of germanium. Noyce credited Kurt Lehovec of Sprague Electric for the principle of p–n junction isolation, a key concept behind the IC. [17] This isolation allows each transistor to operate independently despite being part of the same piece of silicon.

Fairchild Semiconductor was also home of the first silicon-gate IC technology with self-aligned gates, the basis of all modern CMOS integrated circuits. The technology was developed by Italian physicist Federico Faggin in 1968. In 1970, he joined Intel in order to develop the first single-chip central processing unit (CPU) microprocessor, the Intel 4004, for which he received the National Medal of Technology and Innovation in 2010. The 4004 was designed by Busicom's Masatoshi Shima and Intel's Ted Hoff in 1969, but it was Faggin's improved design in 1970 that made it a reality. [18]

Advances

Advances in IC technology, primarily smaller features and larger chips, have allowed the number of transistors in an integrated circuit to double every two years, a trend known as Moore's law. This increased capacity has been used to decrease cost and increase functionality. In general, as the feature size shrinks, almost every aspect of an IC's operation improves. The cost per transistor and the switching power consumption per transistor goes down, while the memory capacity and speed go up, through the relationships defined by Dennard scaling. [19] Because speed, capacity, and power consumption gains are apparent to the end user, there is fierce competition among the manufacturers to use finer geometries. Over the years, transistor sizes have decreased from 10s of microns in the early 1970s to 10 nanometers in 2017 [20] with a corresponding million-fold increase in transistors per unit area. As of 2016, typical chip areas range from a few square millimeters to around 600 mm2, with up to 25 million transistors per mm2. [21]

The expected shrinking of feature sizes and the needed progress in related areas was forecast for many years by the International Technology Roadmap for Semiconductors (ITRS). The final ITRS was issued in 2016, and it is being replaced by the International Roadmap for Devices and Systems. [22]

Initially, ICs were strictly electronic devices. The success of ICs has led to the integration of other technologies, in an attempt to obtain the same advantages of small size and low cost. These technologies include mechanical devices, optics, and sensors.

As of 2018, the vast majority of all transistors are fabricated in a single layer on one side of a chip of silicon in a flat 2-dimensional planar process. Researchers have produced prototypes of several promising alternatives, such as:

Design

The cost of designing and developing a complex integrated circuit is quite high, normally in the multiple tens of millions of dollars. [31] Therefore, it only makes economic sense to produce integrated circuit products with high production volume, so the non-recurring engineering (NRE) costs are spread across typically millions of production units.

Modern semiconductor chips have billions of components, and are too complex to be designed by hand. Software tools to help the designer are essential. Electronic Design Automation (EDA), also referred to as Electronic Computer-Aided Design (ECAD), [32] is a category of software tools for designing electronic systems, including integrated circuits. The tools work together in a design flow that engineers use to design and analyze entire semiconductor chips.

Types

A CMOS 4511 IC in a DIP Cmosic.JPG
A CMOS 4511 IC in a DIP

Integrated circuits can be classified into analog, [33] digital [34] and mixed signal, [35] consisting of both analog and digital signaling on the same IC.

Digital integrated circuits can contain anywhere from one [36] to billions [21] of logic gates, flip-flops, multiplexers, and other circuits in a few square millimeters. The small size of these circuits allows high speed, low power dissipation, and reduced manufacturing cost compared with board-level integration. These digital ICs, typically microprocessors, DSPs, and microcontrollers, work using boolean algebra to process "one" and "zero" signals.

The die from an Intel 8742, an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip Intel 8742 153056995.jpg
The die from an Intel 8742, an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip

Among the most advanced integrated circuits are the microprocessors or " cores ", which control everything from personal computers and cellular phones to digital microwave ovens. Digital memory chips and application-specific integrated circuits (ASICs) are examples of other families of integrated circuits that are important to the modern information society.

In the 1980s, programmable logic devices were developed. These devices contain circuits whose logical function and connectivity can be programmed by the user, rather than being fixed by the integrated circuit manufacturer. This allows a single chip to be programmed to implement different LSI-type functions such as logic gates, adders and registers. Current devices called field-programmable gate arrays (FPGAs) can (as of 2016) implement the equivalent of millions of gates and operate at frequencies up to 1 GHz. [37]

Analog ICs, such as sensors, power management circuits, and operational amplifiers (op-amps), work by processing continuous signals. They perform functions like amplification, active filtering, demodulation, and mixing. Analog ICs ease the burden on circuit designers by having expertly designed analog circuits available instead of designing a difficult analog circuit from scratch.

ICs can also combine analog and digital circuits on a single chip to create functions such as analog-to-digital converters and digital-to-analog converters. Such mixed-signal circuits offer smaller size and lower cost, but must carefully account for signal interference. Prior to the late 1990s, radios could not be fabricated in the same low-cost CMOS processes as microprocessors. But since 1998, a large number of radio chips have been developed using CMOS processes. Examples include Intel's DECT cordless phone, or 802.11 (Wi-Fi) chips created by Atheros and other companies. [38]

Modern electronic component distributors often further sub-categorize the huge variety of integrated circuits now available:

Manufacturing

Fabrication

Rendering of a small standard cell with three metal layers (dielectric has been removed). The sand-colored structures are metal interconnect, with the vertical pillars being contacts, typically plugs of tungsten. The reddish structures are polysilicon gates, and the solid at the bottom is the crystalline silicon bulk. Silicon chip 3d.png
Rendering of a small standard cell with three metal layers (dielectric has been removed). The sand-colored structures are metal interconnect, with the vertical pillars being contacts, typically plugs of tungsten. The reddish structures are polysilicon gates, and the solid at the bottom is the crystalline silicon bulk.
Schematic structure of a CMOS chip, as built in the early 2000s. The graphic shows LDD-MISFET's on an SOI substrate with five metallization layers and solder bump for flip-chip bonding. It also shows the section for FEOL (front-end of line), BEOL (back-end of line) and first parts of back-end process. Cmos-chip structure in 2000s (en).svg
Schematic structure of a CMOS chip, as built in the early 2000s. The graphic shows LDD-MISFET's on an SOI substrate with five metallization layers and solder bump for flip-chip bonding. It also shows the section for FEOL (front-end of line), BEOL (back-end of line) and first parts of back-end process.

The semiconductors of the periodic table of the chemical elements were identified as the most likely materials for a solid-state vacuum tube . Starting with copper oxide, proceeding to germanium, then silicon, the materials were systematically studied in the 1940s and 1950s. Today, monocrystalline silicon is the main substrate used for ICs although some III-V compounds of the periodic table such as gallium arsenide are used for specialized applications like LEDs, lasers, solar cells and the highest-speed integrated circuits. It took decades to perfect methods of creating crystals with minimal defects in semiconducting materials' crystal structure.

Semiconductor ICs are fabricated in a planar process which includes three key process steps  photolithography, deposition (such as chemical vapor deposition), and etching. The main process steps are supplemented by doping and cleaning.

Mono-crystal silicon wafers are used in most applications (or for special applications, other semiconductors such as gallium arsenide are used). The wafer need not be entirely silicon. Photolithography is used to mark different areas of the substrate to be doped or to have polysilicon, insulators or metal (typically aluminium or copper) tracks deposited on them. Dopants are impurities intentionally introduced to a semiconductor to modulate its electronic properties. Doping is the process of adding dopants to a semiconductor material.

Since a CMOS device only draws current on the transition between logic states, CMOS devices consume much less current than bipolar junction transistor devices.

A random-access memory is the most regular type of integrated circuit; the highest density devices are thus memories; but even a microprocessor will have memory on the chip. (See the regular array structure at the bottom of the first image.[ which? ]) Although the structures are intricate – with widths which have been shrinking for decades – the layers remain much thinner than the device widths. The layers of material are fabricated much like a photographic process, although light waves in the visible spectrum cannot be used to "expose" a layer of material, as they would be too large for the features. Thus photons of higher frequencies (typically ultraviolet) are used to create the patterns for each layer. Because each feature is so small, electron microscopes are essential tools for a process engineer who might be debugging a fabrication process.

Each device is tested before packaging using automated test equipment (ATE), in a process known as wafer testing, or wafer probing. The wafer is then cut into rectangular blocks, each of which is called a die . Each good die (plural dice, dies, or die) is then connected into a package using aluminium (or gold) bond wires which are thermosonically bonded [39] to pads, usually found around the edge of the die. Thermosonic bonding was first introduced by A. Coucoulas which provided a reliable means of forming these vital electrical connections to the outside world. After packaging, the devices go through final testing on the same or similar ATE used during wafer probing. Industrial CT scanning can also be used. Test cost can account for over 25% of the cost of fabrication on lower-cost products, but can be negligible on low-yielding, larger, or higher-cost devices.

As of 2016, a fabrication facility (commonly known as a semiconductor fab) can cost over US$8 billion to construct. [40] The cost of a fabrication facility rises over time because of increased complexity of new products. This is known as Rock's law. Today, the most advanced processes employ the following techniques:

Packaging

A Soviet MSI nMOS chip made in 1977, part of a four-chip calculator set designed in 1970 RUS-IC.JPG
A Soviet MSI nMOS chip made in 1977, part of a four-chip calculator set designed in 1970

The earliest integrated circuits were packaged in ceramic flat packs, which continued to be used by the military for their reliability and small size for many years. Commercial circuit packaging quickly moved to the dual in-line package (DIP), first in ceramic and later in plastic. In the 1980s pin counts of VLSI circuits exceeded the practical limit for DIP packaging, leading to pin grid array (PGA) and leadless chip carrier (LCC) packages. Surface mount packaging appeared in the early 1980s and became popular in the late 1980s, using finer lead pitch with leads formed as either gull-wing or J-lead, as exemplified by the small-outline integrated circuit (SOIC) package – a carrier which occupies an area about 30–50% less than an equivalent DIP and is typically 70% thinner. This package has "gull wing" leads protruding from the two long sides and a lead spacing of 0.050 inches.

In the late 1990s, plastic quad flat pack (PQFP) and thin small-outline package (TSOP) packages became the most common for high pin count devices, though PGA packages are still used for high-end microprocessors.

Ball grid array (BGA) packages have existed since the 1970s. Flip-chip Ball Grid Array packages, which allow for much higher pin count than other package types, were developed in the 1990s. In an FCBGA package the die is mounted upside-down (flipped) and connects to the package balls via a package substrate that is similar to a printed-circuit board rather than by wires. FCBGA packages allow an array of input-output signals (called Area-I/O) to be distributed over the entire die rather than being confined to the die periphery. BGA devices have the advantage of not needing a dedicated socket, but are much harder to replace in case of device failure.

Intel transitioned away from PGA to land grid array (LGA) and BGA beginning in 2004, with the last PGA socket released in 2014 for mobile platforms. As of 2018, AMD uses PGA packages on mainstream desktop processors, [43] BGA packages on mobile processors, [44] and high-end desktop and server microprocessors use LGA packages. [45]

Electrical signals leaving the die must pass through the material electrically connecting the die to the package, through the conductive traces (paths) in the package, through the leads connecting the package to the conductive traces on the printed circuit board. The materials and structures used in the path these electrical signals must travel have very different electrical properties, compared to those that travel to different parts of the same die. As a result, they require special design techniques to ensure the signals are not corrupted, and much more electric power than signals confined to the die itself.

When multiple dies are put in one package, the result is a system in package, abbreviated SiP. A multi-chip module (MCM), is created by combining multiple dies on a small substrate often made of ceramic. The distinction between a large MCM and a small printed circuit board is sometimes fuzzy.

Packaged integrated circuits are usually large enough to include identifying information. Four common sections are the manufacturer's name or logo, the part number, a part production batch number and serial number, and a four-digit date-code to identify when the chip was manufactured. Extremely small surface-mount technology parts often bear only a number used in a manufacturer's lookup table to find the integrated circuit's characteristics.

The manufacturing date is commonly represented as a two-digit year followed by a two-digit week code, such that a part bearing the code 8341 was manufactured in week 41 of 1983, or approximately in October 1983.

Intellectual property

The possibility of copying by photographing each layer of an integrated circuit and preparing photomasks for its production on the basis of the photographs obtained is a reason for the introduction of legislation for the protection of layout-designs. The Semiconductor Chip Protection Act of 1984 established intellectual property protection for photomasks used to produce integrated circuits. [46]

A diplomatic conference was held at Washington, D.C., in 1989, which adopted a Treaty on Intellectual Property in Respect of Integrated Circuits (IPIC Treaty).

The Treaty on Intellectual Property in respect of Integrated Circuits, also called Washington Treaty or IPIC Treaty (signed at Washington on 26 May 1989) is currently not in force, but was partially integrated into the TRIPS agreement. [47]

National laws protecting IC layout designs have been adopted in a number of countries, including Japan, [48] the EC, [49] the UK, Australia, and Korea. [50]

Other developments

Future developments seem to follow the multi-core multi-microprocessor paradigm, already used by Intel and AMD multi-core processors. Rapport Inc. and IBM started shipping the KC256 in 2006, a 256-core microprocessor. Intel, as recently as February–August 2011, unveiled a prototype, "not for commercial sale" chip that bears 80 cores. Each core is capable of handling its own task independently of the others. This is in response to heat-versus-speed limit, that is about to be reached[ when? ] using existing transistor technology (see: thermal design power). This design provides a new challenge to chip programming. Parallel programming languages such as the open-source X10 programming language are designed to assist with this task. [51]

Generations

In the early days of simple integrated circuits, the technology's large scale limited each chip to only a few transistors, and the low degree of integration meant the design process was relatively simple. Manufacturing yields were also quite low by today's standards. As the technology progressed, millions, then billions [52] of transistors could be placed on one chip, and good designs required thorough planning, giving rise to the field of electronic design automation, or EDA.

NameSignificationYear Transistors number [53] Logic gates number [54]
SSIsmall-scale integration19641 to 101 to 12
MSImedium-scale integration196810 to 50013 to 99
LSIlarge-scale integration1971500 to 20 000100 to 9999
VLSIvery large-scale integration198020 000 to 1 000 00010 000 to 99 999
ULSIultra-large-scale integration19841 000 000 and more100 000 and more

SSI, MSI and LSI

The first integrated circuits contained only a few transistors. Early digital circuits containing tens of transistors provided a few logic gates, and early linear ICs such as the Plessey SL201 or the Philips TAA320 had as few as two transistors. The number of transistors in an integrated circuit has increased dramatically since then. The term "large scale integration" (LSI) was first used by IBM scientist Rolf Landauer when describing the theoretical concept; [55] that term gave rise to the terms "small-scale integration" (SSI), "medium-scale integration" (MSI), "very-large-scale integration" (VLSI), and "ultra-large-scale integration" (ULSI). The early integrated circuits were SSI.

SSI circuits were crucial to early aerospace projects, and aerospace projects helped inspire development of the technology. Both the Minuteman missile and Apollo program needed lightweight digital computers for their inertial guidance systems. Although the Apollo guidance computer led and motivated integrated-circuit technology, [56] it was the Minuteman missile that forced it into mass-production. The Minuteman missile program and various other United States Navy programs accounted for the total $4 million integrated circuit market in 1962, and by 1968, U.S. Government spending on space and defense still accounted for 37% of the $312 million total production.

The demand by the U.S. Government supported the nascent integrated circuit market until costs fell enough to allow IC firms to penetrate the industrial market and eventually the consumer market. The average price per integrated circuit dropped from $50.00 in 1962 to $2.33 in 1968. [57] Integrated circuits began to appear in consumer products by the turn of the 1970s decade. A typical application was FM inter-carrier sound processing in television receivers.

The first MOS chips were small-scale integration chips for NASA satellites. [58]

The next step in the development of integrated circuits, taken in the late 1960s, introduced devices which contained hundreds of transistors on each chip, called "medium-scale integration" (MSI).

In 1964, Frank Wanlass demonstrated a single-chip 16-bit shift register he designed, with a then-incredible 120 transistors on a single chip. [58] [59]

MSI devices were attractive economically because while they cost a little more to produce than SSI devices, they allowed more complex systems to be produced using smaller circuit boards, less assembly work because of fewer separate components, and a number of other advantages.

Further development, driven by the same economic factors, led to "large-scale integration" (LSI) in the mid-1970s, with tens of thousands of transistors per chip.

The masks used to process and manufacture SSI, MSI and early LSI and VLSI devices (such as the microprocessors of the early 1970s) were mostly created by hand, often using Rubylith-tape or similar. [60] For large or complex ICs (such as memories or processors), this was often done by specially hired professionals in charge of circuit layout, placed under the supervision of a team of engineers, who would also, along with the circuit designers, inspect and verify the correctness and completeness of each mask.

Integrated circuits such as 1K-bit RAMs, calculator chips, and the first microprocessors, that began to be manufactured in moderate quantities in the early 1970s, had under 4,000 transistors. True LSI circuits, approaching 10,000 transistors, began to be produced around 1974, for computer main memories and second-generation microprocessors.

Some SSI and MSI chips, like discrete transistors, are still mass-produced, both to maintain old equipment and build new devices that require only a few gates. The 7400 series of TTL chips, for example, has become a de facto standard and remains in production.

VLSI

Upper interconnect layers on an Intel 80486DX2 microprocessor die 80486DX2 200x.png
Upper interconnect layers on an Intel 80486DX2 microprocessor die

The final step in the development process, starting in the 1980s and continuing through the present, was "very-large-scale integration" (VLSI). The development started with hundreds of thousands of transistors in the early 1980s, As of 2016, transistor counts continue to grow beyond ten billion transistors per chip.

Multiple developments were required to achieve this increased density. Manufacturers moved to smaller design rules and cleaner fabrication facilities so that they could make chips with more transistors and maintain adequate yield. The path of process improvements was summarized by the International Technology Roadmap for Semiconductors (ITRS), which has since been succeeded by the International Roadmap for Devices and Systems (IRDS). Electronic design tools improved enough to make it practical to finish these designs in a reasonable time. The more energy-efficient CMOS replaced NMOS and PMOS, avoiding a prohibitive increase in power consumption. Modern VLSI devices contain so many transistors, layers, interconnections, and other features that it is no longer feasible to check the masks or do the original design by hand. Instead, engineers use EDA tools to perform most functional verification work. [61]

In 1986 the first one-megabit random-access memory (RAM) chips were introduced, containing more than one million transistors. Microprocessor chips passed the million-transistor mark in 1989 and the billion-transistor mark in 2005. [62] The trend continues largely unabated, with chips introduced in 2007 containing tens of billions of memory transistors. [63]

ULSI, WSI, SoC and 3D-IC

To reflect further growth of the complexity, the term ULSI that stands for "ultra-large-scale integration" was proposed for chips of more than 1 million transistors. [64]

Wafer-scale integration (WSI) is a means of building very large integrated circuits that uses an entire silicon wafer to produce a single "super-chip". Through a combination of large size and reduced packaging, WSI could lead to dramatically reduced costs for some systems, notably massively parallel supercomputers. The name is taken from the term Very-Large-Scale Integration, the current state of the art when WSI was being developed. [65]

A system-on-a-chip (SoC or SOC) is an integrated circuit in which all the components needed for a computer or other system are included on a single chip. The design of such a device can be complex and costly, and building disparate components on a single piece of silicon may compromise the efficiency of some elements.[ needs update? ] However, these drawbacks are offset by lower manufacturing and assembly costs and by a greatly reduced power budget: because signals among the components are kept on-die, much less power is required (see Packaging). [66] Further, signal sources and destinations are physically closer on die, reducing the length of wiring and therefore latency, transmission power costs and waste heat from communication between modules on the same chip. This has led to an exploration of so-called Network-on-Chip (NoC) devices, which apply system-on-chip design methodologies to digital communication networks as opposed to traditional bus architectures.

A three-dimensional integrated circuit (3D-IC) has two or more layers of active electronic components that are integrated both vertically and horizontally into a single circuit. Communication between layers uses on-die signaling, so power consumption is much lower than in equivalent separate circuits. Judicious use of short vertical wires can substantially reduce overall wire length for faster operation. [67]

Silicon labelling and graffiti

To allow identification during production most silicon chips will have a serial number in one corner. It is also common to add the manufacturer's logo. Ever since ICs were created, some chip designers have used the silicon surface area for surreptitious, non-functional images or words. These are sometimes referred to as chip art, silicon art, silicon graffiti or silicon doodling.

ICs and IC families

See also

Related Research Articles

Microprocessor computer processor contained on an integrated-circuit chip

A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC), or at most a few integrated circuits. The microprocessor is a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output. Microprocessors contain both combinational logic and sequential digital logic. Microprocessors operate on numbers and symbols represented in the binary number system.

Motorola 6800

The 6800 is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips. A significant design feature was that the M6800 family of ICs required only a single five-volt power supply at a time when most other microprocessors required three voltages. The M6800 Microcomputer System was announced in March 1974 and was in full production by the end of that year.

Very Large Scale Integration process of creating an integrated circuit by combining thousands of transistors into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed

Very-large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining hundreds of thousands of transistors or devices into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed. The microprocessor is a VLSI device. Before the introduction of VLSI technology most ICs had a limited set of functions they could perform. An electronic circuit might consist of a CPU, ROM, RAM and other glue logic. VLSI lets IC designers add all of these into one chip.

Dual in-line package

In microelectronics, a dual in-line package, or dual in-line pin package (DIPP) is an electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board (PCB) or inserted in a socket. The dual-inline format was invented by Don Forbes, Rex Rice and Bryant Rogers at Fairchild R&D in 1964, when the restricted number of leads available on circular transistor-style packages became a limitation in the use of integrated circuits. Increasingly complex circuits required more signal and power supply leads ; eventually microprocessors and similar complex devices required more leads than could be put on a DIP package, leading to development of higher-density packages. Furthermore, square and rectangular packages made it easier to route printed-circuit traces beneath the packages.

CMOS technology for constructing integrated circuits

Complementary metal–oxide–semiconductor (CMOS) is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits. CMOS technology is also used for several analog circuits such as image sensors, data converters, and highly integrated transceivers for many types of communication. Frank Wanlass patented CMOS in 1963 while working for Fairchild Semiconductor.

The history of computing hardware starting at 1960 is marked by the conversion from vacuum tube to solid-state devices such as the transistor and later the integrated circuit. By 1959 discrete transistors were considered sufficiently reliable and economical that they made further vacuum tube computers uncompetitive. Computer main memory slowly moved away from magnetic core memory devices to solid-state static and dynamic semiconductor memory, which greatly reduced the cost, size and power consumption of computers.

SiGe, or silicon-germanium, is an alloy with any molar ratio of silicon and germanium, i.e. with a molecular formula of the form Si1−xGex. It is commonly used as a semiconductor material in integrated circuits (ICs) for heterojunction bipolar transistors or as a strain-inducing layer for CMOS transistors. IBM introduced the technology into mainstream manufacturing in 1989. This relatively new technology offers opportunities in mixed-signal circuit and analog circuit IC design and manufacture. SiGe is also used as a thermoelectric material for high temperature applications.

Front end of line

The front-end-of-line (FEOL) is the first portion of IC fabrication where the individual devices are patterned in the semiconductor. FEOL generally covers everything up to the deposition of metal interconnect layers.

Back end of line

The back end of line (BEOL) is the second portion of IC fabrication where the individual devices get interconnected with wiring on the wafer, the metalization layer. Common metals are copper and aluminum. BEOL generally begins when the first layer of metal is deposited on the wafer. BEOL includes contacts, insulating layers (dielectrics), metal levels, and bonding sites for chip-to-package connections.

An analog chip is a set of miniature electronic analog circuits formed on a single piece of semiconductor material.

Die (integrated circuit) an unpackaged integrated circuit

A die, in the context of integrated circuits, is a small block of semiconducting material on which a given functional circuit is fabricated. Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon (EGS) or other semiconductor through processes such as photolithography. The wafer is cut (diced) into many pieces, each containing one copy of the circuit. Each of these pieces is called a die.

Multigate device

A multigate device or multiple-gate field-effect transistor (MuGFET) refers to a MOSFET that incorporates more than one gate into a single device. The multiple gates may be controlled by a single gate electrode, wherein the multiple gate surfaces act electrically as a single gate, or by independent gate electrodes. A multigate device employing independent gate electrodes is sometimes called a multiple-independent-gate field-effect transistor (MIGFET).

The term die shrink refers to a simple semiconductor scaling of semiconductor devices, mainly transistors. The act of shrinking a die is to create a somewhat identical circuit using a more advanced fabrication process, usually involving an advance of lithographic node. This reduces overall costs for a chip company, as the absence of major architectural changes to the processor lowers research and development costs, while at the same time allowing more processor dies to be manufactured on the same piece of silicon wafer, resulting in less cost per product sold.

Through-silicon via

In electronic engineering, a through-silicon via (TSV) or through-chip via is a vertical electrical connection (via) that passes completely through a silicon wafer or die. TSVs are high performance interconnect techniques used as an alternative to wire-bond and flip chips to create 3D packages and 3D integrated circuits. Compared to alternatives such as package-on-package, the interconnect and device density is substantially higher, and the length of the connections becomes shorter.

In microelectronics, a three-dimensional integrated circuit is an integrated circuit manufactured by stacking silicon wafers or dies and interconnecting them vertically using, for instance, through-silicon vias (TSVs) or Cu-Cu connections, so that they behave as a single device to achieve performance improvements at reduced power and smaller footprint than conventional two dimensional processes. 3D IC is just one of a host of 3D integration schemes that exploit the z-direction to achieve electrical performance benefits.

In integrated circuits, optical interconnects refers to any system of transmitting signals from one part of an integrated circuit to another using light. Optical interconnects have been the topic of study due to the high latency and power consumption incurred by conventional metal interconnects in transmitting electrical signals over long distances, such as in interconnects classed as global interconnects. The International Technology Roadmap for Semiconductors (ITRS) has highlighted interconnect scaling as a problem for the semiconductor industry.

The idea of integrating electronic circuits into a single device was born when the German physicist and engineer Werner Jacobi developed and patented the first known integrated transistor amplifier in 1949 and the British radio engineer Geoffrey Dummer proposed to integrate a variety of standard electronic components in a monolithic semiconductor crystal in 1952. A year later, Harwick Johnson filed a patent for a prototype integrated circuit (IC).

References

  1. "Integrated circuit (IC)". JEDEC.
  2. Andrew Wylie (2009). "The first monolithic integrated circuits" . Retrieved 14 March 2011. Nowadays when people say 'integrated circuit' they usually mean a monolithic IC, where the entire circuit is constructed in a single piece of silicon.
  3. Horowitz, Paul; Hill, Winfield (1989). The Art of Electronics (2nd ed.). Cambridge University Press. p. 61. ISBN   978-0-521-37095-0. Integrated circuits, which have largely replaced circuits constructed from discrete transistors, are themselves merely arrays of transistors and other components built from a single chip of semiconductor material.
  4. "3NF". RadioMuseum.
  5. "Integrated circuits help Invention". Integratedcircuithelp.com. Retrieved 2012-08-13.
  6. DE 833366 W. Jacobi/SIEMENS AG: "Halbleiterverstärker" priority filing on 14 April 1949, published on 15 May 1952.
  7. "The Hapless Tale of Geoffrey Dummer" Archived 11 May 2013 at the Wayback Machine , (n.d.), (HTML), Electronic Product News, accessed 8 July 2008.
  8. Rostky, George. "Micromodules: the ultimate package". EE Times. Archived from the original on 2010-01-07. Retrieved 2018-04-23.
  9. "The RCA Micromodule". Vintage Computer Chip Collectibles, Memorabilia & Jewelry. Retrieved 2018-04-23.
  10. Dummer, G.W.A.; Robertson, J. Mackenzie (2014-05-16). American Microelectronics Data Annual 1964–65. Elsevier. pp. 392–397, 405–406. ISBN   978-1-4831-8549-1.
  11. The Chip that Jack Built, (c. 2008), (HTML), Texas Instruments, Retrieved 29 May 2008.
  12. Jack S. Kilby, Miniaturized Electronic Circuits, United States Patent Office, US Patent 3,138,743, filed 6 February 1959, issued 23 June 1964.
  13. Winston, Brian (1998). Media Technology and Society: A History: From the Telegraph to the Internet. Routledge. p. 221. ISBN   978-0-415-14230-4.
  14. "Texas Instruments – 1961 First IC-based computer". Ti.com. Retrieved 2012-08-13.
  15. Nobel Web AB, (10 October 2000),The Nobel Prize in Physics 2000, Retrieved 29 May 2008
  16. "Milestones:First Semiconductor Integrated Circuit (IC), 1958". IEEE Global History Network. IEEE. Retrieved 3 August 2011.
  17. Kurt Lehovec's patent on the isolation p–n junction: U.S. Patent 3,029,366 granted on 10 April 1962, filed 22 April 1959. Robert Noyce credits Lehovec in his article – "Microelectronics", Scientific American , September 1977, Volume 23, Number 3, pp. 63–69.
  18. Federico Faggin, The Making of the First Microprocessor, IEEE Solid-State Circuits Magazine, Winter 2009, IEEE Xplore
  19. Davari, Bijan, Robert H. Dennard, and Ghavam G. Shahidi (1995). "CMOS scaling for high performance and low power-the next ten years" (PDF). Proceedings of the IEEE. 83 (4). pp. 595–606.CS1 maint: Multiple names: authors list (link)
  20. "Qualcomm and Samsung Collaborate on 10nm Process Technology for the Latest Snapdragon 835 Mobile Processor". news.samsung.com. Retrieved 2017-02-11.
  21. 1 2 "Inside Pascal: NVIDIA's Newest Computing Platform". 2016-04-05.. 15,300,000,000 transistors in 610 mm2.
  22. "International Roadmap for Devices and Systems" (PDF). IEEE. 2016.
  23. H. Fujita (1997). A decade of MEMS and its future. Tenth Annual International Workshop on Micro Electro Mechanical Systems.
  24. A. Narasimha; et al. (2008). "A 40-Gb/s QSFP optoelectronic transceiver in a 0.13 µm CMOS silicon-on-insulator technology". Proceedings of the Optical Fiber Communication Conference (OFC): OMK7.
  25. M. Birkholz; A. Mai; C. Wenger; C. Meliani; R. Scholz (2016). "Technology modules from micro- and nano-electronics for the life sciences". WIREs Nanomed. Nanobiotech. 8 (3): 355–377. doi:10.1002/wnan.1367. PMID   26391194.
  26. A.H.D. Graham; J. Robbins; C.R. Bowen; J. Taylor (2011). "Commercialisation of CMOS Integrated Circuit Technology in Multi-Electrode Arrays for Neuroscience and Cell-Based Biosensors". Sensors. 11 (5): 4943–4971. doi:10.3390/s110504943. PMC   3231360 . PMID   22163884.
  27. Zvi Or-Bach. "Why SOI is the Future Technology of Semiconductors". 2013.
  28. "Samsung’s Eight-Stack Flash Shows up in Apple’s iPhone 4". 2010.
  29. "Spherical semiconductor radio temperature sensor". NatureInterface. 2002.
  30. Takeda, Nobuo, MEMS applications of Ball Semiconductor Technology (PDF), archived from the original (PDF) on 2015-01-01
  31. Mark LaPedus (16 April 2015). "FinFET Rollout Slower Than Expected". Semiconductor Engineering.
  32. "About the EDA Industry". Electronic Design Automation Consortium. Archived from the original on 2 August 2015. Retrieved 29 July 2015.
  33. Paul R. Gray; Paul J. Hurst; Stephen H. Lewis; Robert G. Meyer (2009). Analysis and Design of Analog Integrated Circuits. Wiley. ISBN   978-0-470-24599-6.
  34. Jan M. Rabaey; Anantha Chandrakasan; Borivoje Nikolic (2003). Digital Integrated Circuits (2nd Edition). Pearson. ISBN   978-0-13-090996-1.
  35. Jacob Baker (2008). CMOS: Mixed-Signal Circuit Design. Wiley. ISBN   978-0-470-29026-2.
  36. "CD4068 data sheet" (PDF). Intersil.
  37. "Stratix 10 Device Overview" (PDF). Altera . 12 December 2015. Retrieved 18 Nov 2016.
  38. Nathawad, L.; Zargari, M.; Samavati, H.; Mehta, S.; Kheirkhaki, A.; Chen, P.; Gong, K.; Vakili-Amini, B.; Hwang, J.; Chen, M.; Terrovitis, M.; Kaczynski, B.; Limotyrakis, S.; Mack, M.; Gan, H.; Lee, M.; Abdollahi-Alibeik, B.; Baytekin, B.; Onodera, K.; Mendis, S.; Chang, A.; Jen, S.; Su, D.; Wooley, B. "20.2: A Dual-band CMOS MIMO Radio SoC for IEEE 802.11n Wireless LAN" (PDF). IEEE Entity Web Hosting. IEEE. Retrieved 22 October 2016.
  39. Coucoulas, A., http://commons.wikimedia.org/wiki/File:Hot_Work_Ultrasonic_(Thermosonic)_Bonding_549-556.pdf "Hot Work Ultrasonic Bonding – A Method Of Facilitating Metal Flow By Restoration Processes", Proc. 20th IEEE Electronic Components Conf. Washington, D.C., May 1970, pp. 549–556. https://sites.google.com/site/hotworkultrasonicbonding/
  40. Max Chafkin; Ian King (June 9, 2016). "How Intel Makes a Chip". Bloomburg Businessweek.
  41. Mark Lapedus (May 21, 2015). "10 nm Fab Watch". Semiconductor Engineering.
  42. "145 series ICs (in Russian)" . Retrieved 22 April 2012.
  43. Moammer, Khalid (2016-09-16). "AMD Zen CPU & AM4 Socket Pictured, Launching February 2017 – PGA Design With 1331 Pins Confirmed". Wccftech. Retrieved 2018-05-20.
  44. "Ryzen 5 2500U – AMD – WikiChip" . Retrieved 2018-05-20.
  45. "AMD's 'TR4' Threadripper CPU socket is gigantic". PCWorld. Retrieved 2018-05-20.
  46. "Federal Statutory Protection for Mask Works" (PDF). United States Copyright Office. United States Copyright Office. Retrieved 22 October 2016.
  47. On Jan. 1, 1995, the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPs) (Annex 1C to the World Trade Organization (WTO) Agreement), went into force. Part II, section 6 of TRIPs protects semiconductor chip products and was the basis for Presidential Proclamation No. 6780, March 23, 1995, under SCPA § 902(a)(2), extending protection to all present and future WTO members.
  48. Japan was the first country to enact its own version of the SCPA, the Japanese "Act Concerning the Circuit Layout of a Semiconductor Integrated Circuit" of 1985.
  49. In 1986 the EC promulgated a directive requiring its members to adopt national legislation for the protection of semiconductor topographies. Council Directive 1987/54/EEC of 16 Dec. 1986 on the Legal Protection of Topographies of Semiconductor Products, art. 1(1)(b), 1987 O.J. (L 24) 36.
  50. The UK enacted the Copyright, Designs and Patents Act, 1988, c. 48, § 213, after it initially took the position that its copyright law fully protected chip topographies. See British Leyland Motor Corp. v. Armstrong Patents Co. Criticisms of inadequacy of the UK copyright approach as perceived by the US chip industry are summarized in Further chip rights developments, Micro Law, IEEE Micro, Aug. 1985, pp. 91–92. Australia passed the Circuit Layouts Act of 1989 as a sui generis form of chip protection. Korea passed the Act Concerning the Layout-Design of Semiconductor Integrated Circuits
  51. Biever, C. "Chip revolution poses problems for programmers", New Scientist (Vol 193, Number 2594)
  52. Peter Clarke, Intel enters billion-transistor processor era, EE Times, 14 October 2005
  53. http://www.iutbayonne.univ-pau.fr/~dalmau/documents/cours/archi/MICROPancien.pdf
  54. Bulletin de la Societe fribourgeoise des sciences naturelles, Volumes 62 à 63 (in French). 1973.
  55. Safir, Ruben (March 2015). "System On Chip - Integrated Circuits". NYLXS Journal.
  56. Mindell, David A. (2008). Digital Apollo: Human and Machine in Spaceflight. The MIT Press. ISBN   978-0-262-13497-2.
  57. Ginzberg, Eli (1976). Economic impact of large public programs: the NASA Experience. Olympus Publishing Company. p. 57. ISBN   978-0-913420-68-3.
  58. 1 2 Bob Johnstone (1999). We were burning: Japanese entrepreneurs and the forging of the electronic age. Basic Books. pp. 47–48. ISBN   978-0-465-09118-8.
  59. Lee Boysel (2007-10-12). "Making Your First Million (and other tips for aspiring entrepreneurs)". U. Mich. EECS Presentation / ECE Recordings.
  60. "Intel's Accidental Revolution". CNET.
  61. C.F. O'Donnell. "Engineering for systems using large scale integration". p. 870.
  62. Peter Clarke, EE Times: Intel enters billion-transistor processor era, 14 November 2005
  63. Antone Gonsalves, EE Times, "Samsung begins production of 16-Gb flash", 30 April 2007
  64. Meindl, J.D. (1984). "Ultra-large scale integration". IEEE Transactions on Electron Devices. 31 (11): 1555–1561. doi:10.1109/T-ED.1984.21752 . Retrieved 21 September 2014.
  65. Shanefield, Daniel. "Wafer scale integration". google.com/patents. Retrieved 21 September 2014.
  66. Klaas, Jeff. "System-on-a-chip". google.com/patents. Retrieved 21 September 2014.
  67. Topol, A.W.; Tulipe, D.C.La; Shi, L; et., al (2006). "Three-dimensional integrated circuits". IBM Journal of Research and Development. 50 (4.5): 491–506. doi:10.1147/rd.504.0491.

Further reading

General

Patents

Integrated circuit die manufacturing