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LOCOS
LOCOS, short for LOCal Oxidation of Silicon, is a microfabrication process where silicon dioxide is formed in selected areas on a silicon wafer having the Si-SiO2 interface at a lower point than the rest of the silicon surface. As of 2008 it was largely superseded by shallow trench isolation. This technology was developed to insulate MOS transistors from each other and limit transistor cross-talk. The main goal is to create a silicon oxide insulating structure that penetrates under the surface of the wafer, so that the Si-SiO2 interface occurs at a lower point than the rest of the silicon surface. This cannot be easily achieved by etching field oxide. Thermal oxidation of selected regions surrounding transistors is used instead. The oxygen penetrates in depth of the wafer, reacts with silicon and transforms it into silicon oxide. In this way, an immersed structure is formed. For process design and analysis purposes, the oxidation of silicon surfaces can be modeled effectively us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shallow Trench Isolation
Shallow trench isolation (STI), also known as box isolation technique, is an integrated circuit feature which prevents electric current leakage between adjacent semiconductor device components. STI is generally used on CMOS process technology nodes of 250 nanometers and smaller. Older CMOS technologies and non-MOS technologies commonly 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 (such as silicon dioxide) to fill the trenches, and removing the excess dielectric using a technique such as chemical-mechanical planarizationbr> Certain semiconductor fabrication technologies also include deep trench isolation, a related feature often found in analog integrated circuits. The effect of the trench edge has given rise to what has recently been termed the "reverse narro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Oxide Semiconductor
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 V_in_the_''off''_state,_and_can_conduct_a_continuous_current_of_30 surface-mount_packages._Operating_as_switches,_each_of_these_components_can_su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shallow Trench Isolation
Shallow trench isolation (STI), also known as box isolation technique, is an integrated circuit feature which prevents electric current leakage between adjacent semiconductor device components. STI is generally used on CMOS process technology nodes of 250 nanometers and smaller. Older CMOS technologies and non-MOS technologies commonly 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 (such as silicon dioxide) to fill the trenches, and removing the excess dielectric using a technique such as chemical-mechanical planarizationbr> Certain semiconductor fabrication technologies also include deep trench isolation, a related feature often found in analog integrated circuits. The effect of the trench edge has given rise to what has recently been termed the "reverse narro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfabrication
Microfabrication is the process of fabricating miniature structures of micrometre scales and smaller. Historically, the earliest microfabrication processes were used for integrated circuit fabrication, also known as "semiconductor manufacturing" or "semiconductor device fabrication". In the last two decades microelectromechanical systems (MEMS), microsystems (European usage), micromachines (Japanese terminology) and their subfields, microfluidics/lab-on-a-chip, optical MEMS (also called MOEMS), RF MEMS, PowerMEMS, BioMEMS and their extension into nanoscale (for example NEMS, for nano electro mechanical systems) have re-used, adapted or extended microfabrication methods. Flat-panel displays and solar cells are also using similar techniques. Miniaturization of various devices presents challenges in many areas of science and engineering: physics, chemistry, materials science, computer science, ultra-precision engineering, fabrication processes, and equipment design. It is also giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Oxidation
In microfabrication, thermal oxidation is a way to produce a thin layer of oxide (usually silicon dioxide) on the surface of a wafer. The technique forces an oxidizing agent to diffuse into the wafer at high temperature and react with it. The rate of oxide growth is often predicted by the Deal–Grove model. Thermal oxidation may be applied to different materials, but most commonly involves the oxidation of silicon substrates to produce silicon dioxide. The chemical reaction Thermal oxidation of silicon is usually performed at a temperature between 800 and 1200 °C, resulting in so called High Temperature Oxide layer (HTO). It may use either water vapor (usually UHP steam) or molecular oxygen as the oxidant; it is consequently called either ''wet'' or ''dry'' oxidation. The reaction is one of the following: :\rm Si + 2H_2O \rightarrow SiO_2 + 2H_ :\rm Si + O_2 \rightarrow SiO_2 \, The oxidizing ambient may also contain several percent of hydrochloric acid (HCl). The chlori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locos (microtechnology)
''Locos: A Comedy of Gestures'' is the first novel of Spanish-born American writer Felipe Alfau (1902–1999), written in 1928 and published in 1936. The metafictional novel remained out of print until 1988 when it was reprinted by Dalkey Archive Press; its positive reception then led to the publication of Alfau's second novel '' Chromos'' in 1990, which he had written in 1948. Synopsis The book consists of eight independent but interrelated short stories that the author states can be read in any order. In the introduction, Alfau thanks his characters "for their anarchic collaboration"—in the stories the characters and narrator often interact. Contents # "Identity" # "A Character" # "The Beggar" # "Fingerprints" # "The Wallet" # "Chinelato" #: I "The Ogre" #: II "The Black Mandarin" #: III "Tia Mariquita" # "The Necrophil" # "A Romance of Dogs" #: I "Students" #: II "Spring" Background Felipe Alfau was born and grew up in Spain. In 1916, the 14-year-old Alfau moved wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Dioxide
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound of several minerals and as a synthetic product. Notable examples include fused quartz, fumed silica, silica gel, opal and aerogels. It is used in structural materials, microelectronics (as an electrical insulator), and as components in the food and pharmaceutical industries. Structure In the majority of silicates, the silicon atom shows tetrahedral coordination, with four oxygen atoms surrounding a central Si atomsee 3-D Unit Cell. Thus, SiO2 forms 3-dimensional network solids in which each silicon atom is covalently bonded in a tetrahedral manner to 4 oxygen atoms. In contrast, CO2 is a linear molecule. The starkly different structures of the dioxid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Oxide
Silicon oxide may refer to either of the following: *Silicon dioxide or quartz, SiO2, very well characterized *Silicon monoxide Silicon monoxide is the chemical compound with the formula SiO where silicon is present in the oxidation state +2. In the vapour phase, it is a diatomic molecule. It has been detected in stellar objects and has been described as the most common o ..., SiO, not very well characterized {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deal–Grove Model
The Deal–Grove model mathematically describes the growth of an oxide layer on the surface of a material. In particular, it is used to predict and interpret thermal oxidation of silicon in semiconductor device fabrication. The model was first published in 1965 by Bruce Deal and Andrew Grove of Fairchild Semiconductor, building on Mohamed M. Atalla's work on silicon surface passivation by thermal oxidation at Bell Labs in the late 1950s. This served as a step in the development of CMOS devices and the fabrication of integrated circuits. Physical assumptions The model assumes that the oxidation reaction occurs at the interface between the oxide layer and the substrate material, rather than between the oxide and the ambient gas. Thus, it considers three phenomena that the oxidizing species undergoes, in this order: # It diffuses from the bulk of the ambient gas to the surface. # It diffuses through the existing oxide layer to the oxide-substrate interface. # It reacts with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtechnology
Microtechnology deals with technology whose features have dimensions of the order of one micrometre (one millionth of a metre, or 10−6 metre, or 1μm). It focuses on physical and chemical processes as well as the production or manipulation of structures with one-micrometre magnitude. Development Around 1970, scientists learned that by arraying large numbers of microscopic transistors on a single chip, microelectronic circuits could be built that dramatically improved performance, functionality, and reliability, all while reducing cost and increasing volume. This development led to the Information Revolution. More recently, scientists have learned that not only electrical devices, but also mechanical devices, may be miniaturized and batch-fabricated, promising the same benefits to the mechanical world as integrated circuit technology has given to the electrical world. While electronics now provide the ‘brains’ for today's advanced systems and products, micro-mechanical devic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
