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Semiconductor Device Modeling
Semiconductor device modeling creates models for the behavior of the electrical devices based on fundamental physics, such as the doping profiles of the devices. It may also include the creation of compact models (such as the well known SPICE transistor models), which try to capture the electrical behavior of such devices but do not generally derive them from the underlying physics. Normally it starts from the output of a semiconductor process simulation. Introduction The figure to the right provides a simplified conceptual view of “the big picture.” This figure shows two inverter stages and the resulting input-output voltage-time plot of the circuit. From the digital systems point of view the key parameters of interest are: timing delays, switching power, leakage current and cross-coupling (''crosstalk'') with other blocks. The voltage levels and transition speed are also of concern. The figure also shows schematically the importance of Ion versus Ioff, which in tur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bipolar Junction Transistor
A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor, uses only one kind of charge carrier. A bipolar transistor allows a small current injected at one of its terminals to control a much larger current flowing between the terminals, making the device capable of amplification or switching. BJTs use two p–n junctions between two semiconductor types, n-type and p-type, which are regions in a single crystal of material. The junctions can be made in several different ways, such as changing the doping of the semiconductor material as it is grown, by depositing metal pellets to form alloy junctions, or by such methods as diffusion of n-type and p-type doping substances into the crystal. The superior predictability and performance of junction transistors quickly displaced the original point-contact transistor. Diffused transistors, alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Design Automation
Electronic design automation (EDA), also referred to as electronic computer-aided design (ECAD), is a category of software tools for designing electronic systems such as integrated circuits and printed circuit boards. The tools work together in a design flow that chip designers use to design and analyze entire semiconductor chips. Since a modern semiconductor chip can have billions of components, EDA tools are essential for their design; this article in particular describes EDA specifically with respect to integrated circuits (ICs). History Early days Prior to the development of EDA, integrated circuits were designed by hand and manually laid out. Some advanced shops used geometric software to generate tapes for a Gerber photoplotter, responsible for generating a monochromatic exposure image, but even those copied digital recordings of mechanically drawn components. The process was fundamentally graphic, with the translation from electronics to graphics done manually; t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compact Model Coalition
The Compact Model Coalition (formerly the Compact Model Council) is a working group in the Electronic Design Automation industry formed to choose, maintain and promote the use of standard semiconductor device models. Commercial and industrial analog simulators (such as SPICE) need to add device models as technology advances (see Moore's law) and earlier models become inaccurate. Before this group was formed, new transistor models were largely proprietary, which severely limited the choice of simulators that could be used. It was formed in August, 1996, for the purpose developing and standardizing the use and implementation of SPICE models and the model interfaces. In May 2013, the Silicon Integration Initiative (Si2) and TechAmerica announced the transfer of the Compact Model Council to Si2 and a renaming to Compact Model Coalition. New models are submitted to the Coalition, where their technical merits are discussed, and then potential standard models are voted on. Some of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diode Modelling
In electronics, diode modelling refers to the mathematical models used to approximate the actual behaviour of real diodes to enable calculations and circuit analysis. A diode's I- V curve is nonlinear. A very accurate, but complicated, physical model composes the I-V curve from three exponentials with a slightly different steepness (i.e. ideality factor), which correspond to different recombination mechanisms in the device; at very large and very tiny currents the curve can be continued by linear segments (i.e. resistive behaviour). In a relatively good approximation a diode is modelled by the single-exponential Shockley diode law. This nonlinearity still complicates calculations in circuits involving diodes so even simpler models are often used. This article discusses the modelling of p-n junction diodes, but the techniques may be generalized to other solid state diodes. Large-signal modelling Shockley diode model The Shockley diode equation relates the diode current ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latchup
A latch-up is a type of short circuit which can occur in an integrated circuit (IC). More specifically it is the inadvertent creation of a low- impedance path between the power supply rails of a MOSFET circuit, triggering a parasitic structure which disrupts proper functioning of the part, possibly even leading to its destruction due to overcurrent. A power cycle is required to correct this situation. The parasitic structure is usually equivalent to a thyristor (or SCR), a PNPN structure which acts as a PNP and an NPN transistor stacked next to each other. During a latch-up when one of the transistors is conducting, the other one begins conducting too. They both keep each other in saturation for as long as the structure is forward-biased and some current flows through it - which usually means until a power-down. The SCR parasitic structure is formed as a part of the totem-pole PMOS and NMOS transistor pair on the output drivers of the gates. The latch-up does not have to happe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CMOS
Complementary metal–oxide–semiconductor (CMOS, pronounced "sea-moss", ) is a type of metal–oxide–semiconductor field-effect transistor (MOSFET) fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions. CMOS technology is used for constructing integrated circuit (IC) chips, including microprocessors, microcontrollers, memory chips (including CMOS BIOS), and other digital logic circuits. CMOS technology is also used for analog circuits such as image sensors ( CMOS sensors), data converters, RF circuits ( RF CMOS), and highly integrated transceivers for many types of communication. The CMOS process was originally conceived by Frank Wanlass at Fairchild Semiconductor and presented by Wanlass and Chih-Tang Sah at the International Solid-State Circuits Conference in 1963. Wanlass later filed US patent 3,356,858 for CMOS circuitry and it was granted in 1967. commercialized the technology with the trademar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOSFET
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, the voltage of which determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. A metal-insulator-semiconductor field-effect transistor (MISFET) is a term almost synonymous with MOSFET. Another synonym is IGFET for insulated-gate field-effect transistor. The basic principle of the field-effect transistor was first patented by Julius Edgar Lilienfeld in 1925.Lilienfeld, Julius Edgar (1926-10-08) "Method and apparatus for controlling electric currents" upright=1.6, Two power MOSFETs in watt.html" ;"title="amperes">A in the ''on'' state, dissipating up to about 100 watt">W and controlling a load of over 2000 W. A matchstick is pictured ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siegfried Selberherr
Siegfried Selberherr (* 3. August 1955 in Klosterneuburg) is an Austrian scientist in the field of microelectronics. He is a professor at the Institute for Microelectronics of the Technische Universität Wien (TU Wien). His primary research interest is in modeling and simulation of physical phenomena in the field of microelectronics. Biography Since 1988 Siegfried Selberherr is a chair professor for software technology of microelectronic systems at the TU Wien. He studied electrical engineering at the TU Wien, where he received the degree of Diplom-Ingenieur and the doctoral degree in technical sciences in 1978 and 1981, respectively, and the Habilitation in 1984. Afterwards he was a visiting researcher with the Bell-Labs for some time. Between 1996 and 2020 Prof. Selberherr was a Distinguished Lecturer of the IEEE Electron Devices Society. For many years, Prof. Selberherr was a leader of the Institute for Microelectronics at the TU Wien (now this Institute is headed by his yo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Circuit
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, usually silicon. Transistor count, Large numbers of tiny MOSFETs (metal–oxide–semiconductor field-effect transistors) integrate into a small chip. This results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The IC's mass production capability, reliability, and building-block approach to integrated 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 home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs such as mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Circuit Design
Integrated circuit design, or IC design, is a sub-field 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. IC design can be divided into the broad categories of digital and analog IC design. Digital IC design is to produce components such as microprocessors, FPGAs, memories ( RAM, ROM, and flash) and digital ASICs. Digital design focuses on logical correctness, maximizing circuit density, and placing circuits so that clock and timing signals are routed efficiently. Analog IC design also has specializations in power IC design and RF IC design. Analog IC design is used in the design of op-amps, linear regulators, phase locked loops, oscillators and active filters. Analog design is more concerned with the physics of the semiconductor devices ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffusion Transistor
A diffused junction transistor is a transistor formed by diffusing dopants into a semiconductor substrate. The diffusion process was developed later than the alloy junction and grown junction processes for making bipolar junction transistors (BJTs). Bell Labs developed the first prototype diffused junction bipolar transistors in 1954. Diffused-base transistor The earliest diffused junction transistors were diffused-base transistors. These transistors still had alloy emitters and sometimes alloy collectors like the earlier alloy-junction transistors. Only the base was diffused into the substrate. Sometimes the substrate formed the collector, but in transistors like Philco's micro-alloy diffused transistors the substrate was the bulk of the base. Double diffusion At Bell Labs Calvin Souther Fuller produced basic physical understanding of a means of directly forming the emitter, base, and collector by double diffusion. The method was summarized in a history of science at Bell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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