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Overlay Control
In silicon wafer manufacturing overlay control is the control of pattern-to-pattern alignment necessary in the manufacture of silicon wafers. Silicon wafers are currently manufactured in a sequence of steps, each stage placing a pattern of material on the wafer; in this way transistors, contacts, etc., all made of different materials, are laid down. In order for the final device to function correctly, these separate patterns must be aligned correctly – for example contacts, lines and transistors must all line up. Overlay control has always played an important role in semiconductor manufacturing, helping to monitor layer-to-layer alignment on multi-layer device structures. Misalignment of any kind can cause short circuits and connection failures, which in turn impact fab yield and profit margins. Overlay control has become even more critical now because the combination of increasing pattern density and innovative techniques such as double patterning and 193 nm immersion lith ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Wafer
In electronics, a wafer (also called a slice or substrate) is a thin slice of semiconductor, such as a crystalline silicon (c-Si, silicium), used for the fabrication of integrated circuits and, in photovoltaics, to manufacture solar cells. The wafer serves as the substrate for microelectronic devices built in and upon the wafer. It undergoes many microfabrication processes, such as doping, ion implantation, etching, thin-film deposition of various materials, and photolithographic patterning. Finally, the individual microcircuits are separated by wafer dicing and packaged as an integrated circuit. History In the semiconductor industry, the term wafer appeared in the 1950s to describe a thin round slice of semiconductor material, typically germanium or silicon. The round shape characteristic of these wafers comes from single-crystal ingots usually produced using the Czochralski method. Though, silicon wafers were first introduced in the 1940s. By 1960, silicon wafers were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transistor
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electric power, power. It is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminal (electronics), terminals for connection to an electronic circuit. A voltage or Electric current, 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. Some transistors are packaged individually, but many more in miniature form are found embedded in integrated circuits. Because transistors are the key active components in practically all modern electronics, many people consider them one of the 20th century's greatest inventions. Physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transisto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor Device Fabrication
Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as microprocessors, microcontrollers, and memories (such as Random-access memory, RAM and flash memory). It is a multiple-step Photolithography, photolithographic and physico-chemical process (with steps such as thermal oxidation, thin-film deposition, ion-implantation, etching) during which electronic circuits are gradually created on a wafer (electronics), wafer, typically made of pure single-crystal semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications. This article focuses on the manufacture of integrated circuits, however steps such as etching and photolithography can be used to manufacture other devices such as LCD and OLED displays. The fabrication process is performed in highly specialized semiconductor fabrication plants, also called foundries or "fabs", with the cen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundry (electronics)
In the microelectronics industry, a semiconductor fabrication plant, also called a ''fab'' or a ''foundry'', is a factory where integrated circuits (ICs) are manufactured. The '' cleanroom'' is where all fabrication takes place and contains the machinery for integrated circuit production such as steppers and/or scanners for photolithography, etching, cleaning, and doping. All these devices are extremely precise and thus extremely expensive. Prices for pieces of equipment for the processing of 300 mm wafers range to upwards of $4,000,000 each with a few pieces of equipment reaching as high as $340,000,000 (e.g. EUV scanners). A typical fab will have several hundred equipment items. Semiconductor fabrication requires many expensive devices. Estimates put the cost of building a new fab at over one billion U.S. dollars with values as high as $3–4 billion not being uncommon. For example, TSMC invested $9.3 billion in its ''Fab15'' in Taiwan. The same company estimatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Patterning
Multiple patterning (or multi-patterning) is a class of technologies for manufacturing integrated circuits (ICs), developed for photolithography to enhance the feature density. It is expected to be necessary for the 10 nm and 7 nm node semiconductor processes and beyond. The premise is that a single lithographic exposure may not be enough to provide sufficient resolution. Hence additional exposures would be needed, or else positioning patterns using etched feature sidewalls (using spacers) would be necessary. Even with single exposure having sufficient resolution, extra masks have been implemented for better patterning quality such as by Intel for line-cutting at its 45nm node or TSMC at its 28nm node. Even for electron-beam lithography, single exposure appears insufficient at ~10 nm half-pitch, hence requiring double patterning. Double patterning lithography was first demonstrated in 1983 by D. C. Flanders and N. N. Efremow. Since then several double patterning te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immersion Lithography
Immersion lithography is a technique used in semiconductor manufacturing to enhance the resolution and accuracy of the lithographic process. It involves using a liquid medium, typically water, between the lens and the wafer during exposure. By using a liquid with a higher refractive index than air, immersion lithography allows for smaller features to be created on the wafer. Immersion lithography replaces the usual air gap between the final lens and the wafer surface with a liquid medium that has a refractive index greater than one. The angular resolution is increased by a factor equal to the refractive index of the liquid. Current immersion lithography tools use highly purified water for this liquid, achieving feature sizes below 45 nanometers. Background The ability to resolve features in optical lithography is directly related to the numerical aperture of the imaging equipment, the numerical aperture being the sine of the maximum refraction angle multiplied by the refracti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
