A semiconductor material has an electrical conductivity value falling between that of a metal, like copper, etc. and an insulator, such as glass. Their resistance decreases as their temperature increases, behaviour opposite to that of a metal, their conducting properties may be altered in useful ways by the deliberate, controlled introduction of impurities 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 and electron holes at these junctions is the basis of diodes and all modern electronics. Some examples of semiconductors are silicon and gallium arsenide. After silicon, gallium arsenide is the second most common semiconductor used in laser diodes, solar cells, microwave frequency integrated circuits, others. Silicon is a critical element for fabricating most electronic circuits. Semiconductor devices can display a range of useful properties such as passing current more in one direction than the other, showing variable resistance, sensitivity to light or heat.
Because the electrical properties of a semiconductor material can be modified by doping, or by the application of electrical fields or light, devices made from semiconductors can be used for amplification and energy conversion. The conductivity of silicon is increased by adding a small amount of trivalent atoms; this process is known as doping and 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 behaviour of a metal in which conductivity decreases with 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 increases the number of charge carriers within the crystal; when a doped semiconductor contains free holes it is called "p-type", when it contains free electrons it is known as "n-type". 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 crystal can have many p- and n-type regions. Although some pure elements and many compounds display semiconductor properties, silicon and compounds of gallium are the most used in electronic devices. Elements near the so-called "metalloid staircase", where the metalloids are located on the periodic table, are used as semiconductors; some 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. Developments in quantum physics in turn allowed the development of the transistor in 1947 and the integrated circuit in 1958. Variable electrical conductivity Semiconductors in their natural state are poor conductors because a current requires the flow of electrons, semiconductors have their valence bands filled, preventing the entry flow of new electrons.
There are several developed techniques that allow semiconducting materials to behave like conducting materials, such as doping or gating. These modifications have two outcomes: p-type; these refer to the shortage of electrons, respectively. An unbalanced number of electrons would cause a current to flow through the material. Heterojunctions Heterojunctions occur when two differently doped semiconducting materials are joined together. For example, a configuration could consist of n-doped germanium; this results in an exchange of electrons and holes between the differently doped semiconducting materials. The n-doped germanium would have an excess of electrons, the p-doped germanium would have an excess of holes; the transfer occurs until equilibrium is reached by a process called recombination, which causes the migrating electrons from the n-type to come in contact with the migrating holes from the p-type. A product of this process is charged ions. Excited electrons A difference in electric potential on a semiconducting material would cause it to leave thermal equilibrium and create a non-equilibrium situation.
This introduces electrons and holes to the system, which interact via a process called ambipolar diffusion. Whenever thermal equilibrium is disturbed in a semiconducting material, the number of holes and electrons changes; such disruptions can occur as a result of a temperature difference or photons, which can enter the system and create electrons and holes. The process that creates and annihilates electrons and holes are called generation and recombination. Light emission In certain semiconductors, excited electrons can relax by emitting light instead of producing heat; these semiconductors are used in the construction of light-emitting diodes and fluorescent quantum dots. High thermal conductivitySemiconductors with high thermal conductivity can be used for heat dissipation and improving thermal management of electronics. Thermal energy conversion Semiconductors have large thermoelectric power factors making them useful in thermoelectric generators, as well as high thermoelectric figures of merit making them useful in thermoelectric coolers.
A large number of elements and compounds have semiconducting properties, including: Certain pure elements are found in Group 14 of the p
Computer hardware includes the physical, tangible parts or components of a computer, such as the cabinet, central processing unit, keyboard, computer data storage, graphics card, sound card and motherboard. By contrast, software is instructions that can be run by hardware. Hardware is so-termed because it rigid with respect to changes or modifications. Intermediate between software and hardware is "firmware", software, coupled to the particular hardware of a computer system and thus the most difficult to change but among the most stable with respect to consistency of interface; the progression from levels of "hardness" to "softness" in computer systems parallels a progression of layers of abstraction in computing. Hardware is directed by the software to execute any command or instruction. A combination of hardware and software forms a usable computing system, although other systems exist with only hardware components; the template for all modern computers is the Von Neumann architecture, detailed in a 1945 paper by Hungarian mathematician John von Neumann.
This describes a design architecture for an electronic digital computer with subdivisions of a processing unit consisting of an arithmetic logic unit and processor registers, a control unit containing an instruction register and program counter, a memory to store both data and instructions, external mass storage, input and output mechanisms. The meaning of the term has evolved to mean a stored-program computer in which an instruction fetch and a data operation cannot occur at the same time because they share a common bus; this is referred to as the Von Neumann bottleneck and limits the performance of the system. The personal computer known as the PC, is one of the most common types of computer due to its versatility and low price. Laptops are very similar, although they may use lower-power or reduced size components, thus lower performance; the computer case encloses most of the components of the system. It provides mechanical support and protection for internal elements such as the motherboard, disk drives, power supplies, controls and directs the flow of cooling air over internal components.
The case is part of the system to control electromagnetic interference radiated by the computer, protects internal parts from electrostatic discharge. Large tower cases provide extra internal space for multiple disk drives or other peripherals and stand on the floor, while desktop cases provide less expansion room. All-in-one style designs include a video display built into the same case. Portable and laptop computers require cases. A current development in laptop computers is a detachable keyboard, which allows the system to be configured as a touch-screen tablet. Hobbyists may decorate the cases with colored lights, paint, or other features, in an activity called case modding. A power supply unit converts alternating current electric power to low-voltage DC power for the internal components of the computer. Laptops are capable of running from a built-in battery for a period of hours; the motherboard is the main component of a computer. It is a board with integrated circuitry that connects the other parts of the computer including the CPU, the RAM, the disk drives as well as any peripherals connected via the ports or the expansion slots.
Components directly attached to or to part of the motherboard include: The CPU, which performs most of the calculations which enable a computer to function, is sometimes referred to as the brain of the computer. It is cooled by a heatsink and fan, or water-cooling system. Most newer CPUs include an on-die graphics processing unit; the clock speed of CPUs governs how fast it executes instructions, is measured in GHz. Many modern computers have the option to overclock the CPU which enhances performance at the expense of greater thermal output and thus a need for improved cooling; the chipset, which includes the north bridge, mediates communication between the CPU and the other components of the system, including main memory. Random-access memory, which stores the code and data that are being accessed by the CPU. For example, when a web browser is opened on the computer it takes up memory. RAM comes on DIMMs in the sizes 2GB, 4GB, 8GB, but can be much larger. Read-only memory, which stores the BIOS that runs when the computer is powered on or otherwise begins execution, a process known as Bootstrapping, or "booting" or "booting up".
The BIOS includes power management firmware. Newer motherboards use Unified Extensible Firmware Interface instead of BIOS. Buses that connect the CPU to various internal components and to expand cards for graphics and sound; the CMOS battery, which powers the memory for date and time in the BIOS chip. This battery is a watch battery; the video card, which processes computer graphics. More powerful graphics cards are better suited to handle strenuous tasks, such as playing intensive video games. An expansion card in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements, or as sensing devices for heat, humidity, force, or chemical activity. Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various forms. Resistors are implemented within integrated circuits; the electrical function of a resistor is specified by its resistance: common commercial resistors are manufactured over a range of more than nine orders of magnitude.
The nominal value of the resistance falls within the manufacturing tolerance, indicated on the component. Two typical schematic diagram symbols are as follows: The notation to state a resistor's value in a circuit diagram varies. One common scheme is the RKM code following IEC 60062, it avoids using a decimal separator and replaces the decimal separator with a letter loosely associated with SI prefixes corresponding with the part's resistance. For example, 8K2 as part marking code, in a circuit diagram or in a bill of materials indicates a resistor value of 8.2 kΩ. Additional zeros imply a tighter tolerance, for example 15M0 for three significant digits; when the value can be expressed without the need for a prefix, an "R" is used instead of the decimal separator. For example, 1R2 indicates 1.2 Ω, 18R indicates 18 Ω. The behaviour of an ideal resistor is dictated by the relationship specified by Ohm's law: V = I ⋅ R. Ohm's law states that the voltage across a resistor is proportional to the current, where the constant of proportionality is the resistance.
For example, if a 300 ohm resistor is attached across the terminals of a 12 volt battery a current of 12 / 300 = 0.04 amperes flows through that resistor. Practical resistors have some inductance and capacitance which affect the relation between voltage and current in alternating current circuits; the ohm is the SI unit of electrical resistance, named after Georg Simon Ohm. An ohm is equivalent to a volt per ampere. Since resistors are specified and manufactured over a large range of values, the derived units of milliohm and megohm are in common usage; the total resistance of resistors connected in series is the sum of their individual resistance values. R e q = R 1 + R 2 + ⋯ + R n; the total resistance of resistors connected in parallel is the reciprocal of the sum of the reciprocals of the individual resistors. 1 R e q = 1 R 1 + 1 R 2 + ⋯ + 1 R n. For example, a 10 ohm resistor connected in parallel with a 5 ohm resistor and a 15 ohm resistor produces 1/1/10 + 1/5 + 1/15 ohms of resistance, or 30/11 = 2.727 ohms.
A resistor network, a combination of parallel and series connections can be broken up into smaller parts that are either one or the other. Some complex networks of resistors cannot be resolved in this manner, requiring more sophisticated circuit analysis; the Y-Δ transform, or matrix methods can be used to solve such problems. At any instant, the power P consumed by a resistor of resistance R is calculated as: P = I 2 R = I V = V 2 R where V is the voltage across the resistor and I is the current flowing through it. Using Ohm's law, the two other forms can be derived; this power is converted into heat which must be dissipated by the resistor's package before its temperature rises excessively. Resistors are rated according to their maximum power dissipation. Discrete resistors in solid-state electronic systems are rated as 1/10, 1/8, or 1/4 watt, they absorb much less than a watt of electrical power and require little attention to their power rating. Resistors required to dissipate substantial amounts of power used in power supplies, power conversion circuits, power amplifiers, are referred to as power resistors.
Power resistors are physically larger and may not use the preferred values, color codes, external packages described below. If the average power dissipated by a resistor is more than its power rating, damage to the resistor may occur, permanently altering its resistance. Excessive power dissip
A capacitor is a passive two-terminal electronic component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit; the capacitor was known as a condenser or condensator. The original name is still used in many languages, but not in English; the physical form and construction of practical capacitors vary and many capacitor types are in common use. Most capacitors contain at least two electrical conductors in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be sintered bead of metal, or an electrolyte; the nonconducting dielectric acts to increase the capacitor's charge capacity. Materials used as dielectrics include glass, plastic film, mica and oxide layers. Capacitors are used as parts of electrical circuits in many common electrical devices. Unlike a resistor, an ideal capacitor does not dissipate energy.
When two conductors experience a potential difference, for example, when a capacitor is attached across a battery, an electric field develops across the dielectric, causing a net positive charge to collect on one plate and net negative charge to collect on the other plate. No current flows through the dielectric. However, there is a flow of charge through the source circuit. If the condition is maintained sufficiently long, the current through the source circuit ceases. If a time-varying voltage is applied across the leads of the capacitor, the source experiences an ongoing current due to the charging and discharging cycles of the capacitor. Capacitance is defined as the ratio of the electric charge on each conductor to the potential difference between them; the unit of capacitance in the International System of Units is the farad, defined as one coulomb per volt. Capacitance values of typical capacitors for use in general electronics range from about 1 picofarad to about 1 millifarad; the capacitance of a capacitor is proportional to the surface area of the plates and inversely related to the gap between them.
In practice, the dielectric between the plates passes a small amount of leakage current. It has an electric field strength limit, known as the breakdown voltage; the conductors and leads introduce an undesired resistance. Capacitors are used in electronic circuits for blocking direct current while allowing alternating current to pass. In analog filter networks, they smooth the output of power supplies. In resonant circuits they tune radios to particular frequencies. In electric power transmission systems, they stabilize power flow; the property of energy storage in capacitors was exploited as dynamic memory in early digital computers. In October 1745, Ewald Georg von Kleist of Pomerania, found that charge could be stored by connecting a high-voltage electrostatic generator by a wire to a volume of water in a hand-held glass jar. Von Kleist's hand and the water acted as conductors, the jar as a dielectric. Von Kleist found that touching the wire resulted in a powerful spark, much more painful than that obtained from an electrostatic machine.
The following year, the Dutch physicist Pieter van Musschenbroek invented a similar capacitor, named the Leyden jar, after the University of Leiden where he worked. He was impressed by the power of the shock he received, writing, "I would not take a second shock for the kingdom of France."Daniel Gralath was the first to combine several jars in parallel to increase the charge storage capacity. Benjamin Franklin investigated the Leyden jar and came to the conclusion that the charge was stored on the glass, not in the water as others had assumed, he adopted the term "battery", subsequently applied to clusters of electrochemical cells. Leyden jars were made by coating the inside and outside of jars with metal foil, leaving a space at the mouth to prevent arcing between the foils; the earliest unit of capacitance was the jar, equivalent to about 1.11 nanofarads. Leyden jars or more powerful devices employing flat glass plates alternating with foil conductors were used up until about 1900, when the invention of wireless created a demand for standard capacitors, the steady move to higher frequencies required capacitors with lower inductance.
More compact construction methods began to be used, such as a flexible dielectric sheet sandwiched between sheets of metal foil, rolled or folded into a small package. Early capacitors were known as condensers, a term, still used today in high power applications, such as automotive systems; the term was first used for this purpose by Alessandro Volta in 1782, with reference to the device's ability to store a higher density of electric charge than was possible with an isolated conductor. The term became deprecated because of the ambiguous meaning of steam condenser, with capacitor becoming the recommended term from 1926. Since the beginning of the study of electricity non conductive materials like glass, porcelain and mica have been used as insulators; these materials some decades were well-suited for further use as the dielectric for the first capacitors. Paper capacitors made by sandwiching a strip of impregnated paper between strips of metal, rolling the result into a cylinder were used in the late 19th century.
An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material, silicon. The integration of large numbers of tiny transistors into a small chip results in circuits that are orders of magnitude smaller and faster than those constructed of discrete electronic components; the IC's mass production capability 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 all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, 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. Integrated circuits were made practical by mid-20th-century technology advancements in semiconductor device fabrication. Since their origins in the 1960s, the size 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 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. ICs have two main advantages over discrete circuits: 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 and consume comparatively little power because of their small size and close proximity; the main disadvantage of ICs is the high cost to fabricate the required photomasks. This high initial cost means. An integrated circuit is 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. 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 known as a monolithic integrated circuit. Arguably, the first examples of integrated circuits would include the Loewe 3NF. Although far from a monolithic construction, it meets the definition given above. Early developments of the integrated circuit go back to 1949, when German engineer Werner Jacobi filed a patent for an integrated-circuit-like semiconductor amplifying device showing five transistors on a common substrate in a 3-stage amplifier arrangement. Jacobi disclosed cheap hearing aids as typical industrial applications of his patent. An immediate commercial use of his patent has not been reported; the idea of the integrated circuit was conceived by Geoffrey Dummer, 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.
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, each containing a single miniaturized component. Components could be integrated and wired into a bidimensional or tridimensional compact grid; this idea, which seemed promising in 1957, was proposed to the US Army by Jack Kilby and led to the short-lived Micromodule Program. However, as the project was gaining momentum, Kilby came up with a new, revolutionary design: the IC. Newly employed by Texas Instruments, Kilby recorded his initial ideas concerning the integrated circuit in July 1958 demonstrating the first working integrated example 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 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.
His work was named an IEEE Milestone in 2009. 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. Noyce credited Kurt Lehovec of Sprague Electric for the principle of p–n junction isolation, a key concept behind the IC; this isolation allows each transistor to operate independently despite being part of the same piece of silicon. Fairchild Semiconductor was 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 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.
Advances in IC technology smaller features and la
Shallow trench isolation
Shallow trench isolation known as box isolation technique, is an integrated circuit feature which prevents electric current leakage between adjacent semiconductor device components. STI is used on CMOS process technology nodes of 250 nanometers and smaller. Older CMOS technologies and non-MOS technologies use isolation based on LOCOS. STI is created early during the semiconductor device fabrication process, before transistors are formed; the key steps of the STI process involve etching a pattern of trenches in the silicon, depositing one or more dielectric materials to fill the trenches, removing the excess dielectric using a technique such as chemical-mechanical planarization. Certain semiconductor fabrication technologies include deep trench isolation, a related feature found in analog integrated circuits; the effect of the trench edge has given rise to what has been termed the "reverse narrow channel effect" or "inverse narrow width effect". Due to the electric field enhancement at the edge, it is easier to form a conducting channel at a lower voltage.
The threshold voltage is reduced for a narrower transistor width. The main concern for electronic devices is the resulting subthreshold leakage current, larger after the threshold voltage reduction. Stack deposition Lithography print Dry etch Trench fill with oxide Chemical-mechanical polishing of the oxide Removal of the protective nitride Adjusting the oxide height to Si FEOL Clarycon: Shallow trench isolation N and K Technologies: Shallow trench isolation Dow Corning: Spin on Dielectrics - Spin-on Shallow Trench Isolation
In electronics, a wafer is a thin slice of semiconductor, such as a crystalline silicon, used for the fabrication of integrated circuits and, in photovoltaics, to manufacture solar cells. The wafer serves as the substrate for microelectronic devices built upon the wafer, it and undergoes many microfabrication processes, such as doping, ion implantation, thin-film deposition of various materials, photolithographic patterning. The individual microcircuits are separated by wafer dicing and packaged as an integrated circuit. By 1960, silicon wafers were being manufactured in the U. S. by companies such as MEMC/SunEdison. In 1965, American engineers Eric O. Ernst, Donald J. Hurd, Gerard Seeley, while working under IBM, filed Patent US3423629A for the first high-capacity epitaxial apparatus. Wafers are formed of pure, nearly defect-free single crystalline material. One process for forming crystalline wafers is known as Czochralski growth invented by the Polish chemist Jan Czochralski. In this process, a cylindrical ingot of high purity monocrystalline semiconductor, such as silicon or germanium, called a boule, is formed by pulling a seed crystal from a'melt'.
Donor impurity atoms, such as boron or phosphorus in the case of silicon, can be added to the molten intrinsic material in precise amounts in order to dope the crystal, thus changing it into n-type or p-type extrinsic semiconductor. The boule is sliced with a wafer saw and polished to form wafers; the size of wafers for photovoltaics is 100–200 mm square and the thickness is 200–300 μm. In the future, 160 μm will be the standard. Electronics use wafer sizes from 100–450 mm diameter; the largest wafers made are not yet in general use. Wafers are cleaned with weak acids to remove unwanted particles, or repair damage caused during the sawing process; when used for solar cells, the wafers are textured to create a rough surface to increase their efficiency. The generated PSG is removed from the edge of the wafer in the etching. Silicon wafers are available in a variety of diameters from 25.4 mm to 300 mm. Semiconductor fabrication plants, colloquially known as fabs, are defined by the diameter of wafers that they are tooled to produce.
The diameter has increased to improve throughput and reduce cost with the current state-of-the-art fab using 300 mm, with a proposal to adopt 450 mm. Intel, TSMC and Samsung are separately conducting research to the advent of 450 mm "prototype" fabs, though serious hurdles remain. 1-inch 2-inch with thickness 275 µm. 3-inch with thickness 375 µm. 4-inch with thickness 525 µm. Or 4.9 inch with thickness 625 µm. 150 mm with thickness 675 µm. 200 mm with thickness 725 µm. 300 mm with thickness 775 µm. 450 mm with thickness 925 µm. 675-millimetre Unknown thickness.. Wafers grown using materials other than silicon will have different thicknesses than a silicon wafer of the same diameter. Wafer thickness is determined by the mechanical strength of the material used. A unit wafer fabrication step, such as an etch step, can produce more chips proportional to the increase in wafer area, while the cost of the unit fabrication step goes up more than the wafer area; this was the cost basis for increasing wafer size.
Conversion to 300 mm wafers from 200 mm wafers began in earnest in 2000, reduced the price per die about 30-40%. There is considerable resistance to the 450 mm transition despite the possible productivity improvement, because of concern about insufficient return on investment. Higher cost semiconductor fabrication equipment for larger wafers increases the cost of 450 mm fabs. Lithographer Chris Mack claimed in 2012 that the overall price per die for 450 mm wafers would be reduced by only 10–20% compared to 300 mm wafers, because over 50% of total wafer processing costs are lithography-related. Converting to larger 450 mm wafers would reduce price per die only for process operations such as etch where cost is related to wafer count, not wafer area. Cost for processes such as lithography is proportional to wafer area, larger wafers would not reduce the lithography contribution to die cost. Nikon planned to deliver 450-mm lithography equipment in 2015, with volume production in 2017. In November 2013 ASML paused development of 450-mm lithography equipment, citing uncertain timing of chipmaker demand.
The timeline for 450 mm has not been fixed. Mark Durcan CEO of Micron Technology, said in February 2014 that he expects 450 mm adoption to be delayed indefinitely or discontinued. “I am not convinced that 450mm will happen but, to the extent that it does, it’s a long way out in the future. There is not a lot of necessity for Micron, at least over the next five years, to be spending a lot of money on 450mm. There is a lot of investment, and the value at the end of the day – so that customers would buy that equipment – I think is dubious.” As of March 2014, Intel Corporation expected 450 mm deployment by 2020. Mark LaPedus of semiengineering.com reported in mid-2014 that chipmakers had delayed adoption of 450 mm “for the foreseeable future.” According to this report some observers expected 2018 to 2020, while G. Dan Hutcheson, chief executive of VLSI Research, didn’t see 450mm fabs moving into production until 2020 to 2025. Th