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What do these terms mean? |
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A good site for examples, definitions and terminology is www.wikipedia.org. However, I’ll provide some explanation of the terms here. Semiconductors—elements and compounds which range from somewhat metallic to electronically insulating. These materials can be doped with other elements to change their resistance by about ten orders of magnitude! Because of this extremely wide range of “tunability”, the elements are extremely useful as switching elements. Materials Science—the study of materials properties and how processing the materials affects the physical and chemical characteristics. This is often state as looking for “structure-property correlations”. Semiconductor materials science—Because semiconductors are so useful in electronics, the techniques of processing these materials has become extremely important for extracting every “once” of potential from the devices made of these materials. This applied to elemental semiconductors as well as compound semiconductors and organic semiconductors. Surface science—semiconductors are typically single crystals, that is the atoms are neatly arranged in a periodic fashion, giving the material special properties that can be calculated. Because a surface involves a break in the periodic nature of the crystal, the surface behaves differently from the rest of the semiconductor. Studying the effects of the surface becomes more important as thin films are used since the film eventually turns into two surfaces. Wafer bonding—semiconductors are typically made into single crystal “wafers” which are polished to be almost atomically flat. The surfaces are so flat that contacting two of these surfaces together can result in them sticking together. This is a relatively new way of creating a structure that will have “new” properties. Energy conversion technologies—A good example of this is a solar cell. It converts sunlight to electricity. Other examples include thermoelectric devices which can convert heat to electricity. Methods to improve the efficiency of conversion are in high demand. MEMS— An acronym that stands for MicroElectroMechanical Systems.These are small, electrostatically actuated devices like small mirrors and gears that can make microscale machines. Quantum Information Science—A broad field of study that involves such things as teleportation, inherently unbreakable encryption, quantum computation, and single photon detection. This is basically communications and computation but using quantum mechanical based rules instead of the classical rules that we are all used to seeing. Silicon—a semiconducting element that is one of the more abundant elements available to us. Because of this, it is cheap, and due to that, it is used often and well studied. This makes it available as one of the purest chemicals that we can refine. It is the mostly commonly used element in integrated circuits due to its low cost, strong (for high yield), and forms a very good passivating oxide that other semiconductors can’t come close to matching. InGaAs—Indium Gallium Arsenide. Basically gallium arsenide that has a large amount of indium alloyed into it. The indium replaces the gallium and the stoichiometry of the alloy affects it’s physical as well as electronic properties. Often used as an electrical contact layer and/or optical absorbing layer in the infrared part of the optical spectrum. Fused heterojunctions—Basically a wafer bonded junction that does not have an insulating layer between the semiconductors so that electrons and holes can cross the interface. This has tremendous implications for devices made using these since the interfacial properties are not well understood yet. Photodetector—typically a device that absorbs photons and creates electrons and holes. These electrons and holes are then detected using special circuity. These can be constructed of semiconductors and designed to only detect specific light colors.
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Visiting Research Scientist in the Department of Electrical and Computer Engineering |
