THE WHATIS.COM WORD-OF-THE-DAY September 3, 2002 semiconductor ______________ TODAY'S SPONSOR: VeriSign - The Value of Trust
Secure all your Web servers now - with a proven 5-part strategy. The FREE Server Security Guide shows you how to deploy the latest encryption and authentication techniques, deliver transparent protection with the strongest security without disrupting users, and more. Get your FREE Guide now: http://WhatIs.com/r/0,,5309,00.htm?FreeGuide ______________ TODAY'S WORD: semiconductor See our definition with hyperlinks at http://whatis.techtarget.com/definition/0,,sid9_gci212960,00.html A semiconductor is a substance, usually a solid chemical element or compound, that can conduct electricity under some conditions but not others, making it a good medium for the control of electrical current. Its conductance varies depending on the current or voltage applied to a control electrode, or on the intensity of irradiation by infrared (IR), visible light, ultraviolet (UV), or X rays. The specific properties of a semiconductor depend on the impurities, or dopants, added to it. An N-type semiconductor carries current mainly in the form of negatively-charged electrons, in a manner similar to the conduction of current in a wire. A P-type semiconductor carries current predominantly as electron deficiencies called holes. A hole has a positive electric charge, equal and opposite to the charge on an electron. In a semiconductor material, the flow of holes occurs in a direction opposite to the flow of electrons. Elemental semiconductors include antimony, arsenic, boron, carbon, germanium, selenium, silicon, sulfur, and tellurium. Silicon is the best-known of these, forming the basis of most integrated circuits (ICs). Common semiconductor compounds include gallium arsenide, indium antimonide, and the oxides of most metals. Of these, gallium arsenide (GaAs) is widely used in low-noise, high-gain, weak-signal amplifying devices. A semiconductor device can perform the function of a vacuum tube having hundreds of times its volume. A single integrated circuit (IC), such as a microprocessor chip, can do the work of a set of vacuum tubes that would fill a large building and require its own electric generating plant. RELATED TERMS: conductance http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci213702,00.html voltage http://whatis.techtarget.com/definition/0,,sid9_gci213320,00.html silicon http://whatis.techtarget.com/definition/0,,sid9_gci214633,00.html integrated circuit http://whatis.techtarget.com/definition/0,,sid9_gci213503,00.html vacuum tube http://whatis.techtarget.com/definition/0,,sid9_gci213686,00.html chip http://whatis.techtarget.com/definition/0,,sid9_gci211780,00.html ______________________ WHATIS DISCUSSION FORUM | Challenge #13: Choosing an HTML editor Les is at the point where he needs to invest some money in a good HTML editor. He's confused about whether to invest in a high-end product that has features he's not yet ready to use, or go with something less expensive that he might outgrow. THE CHALLENGE: What is your favorite HTML editor? Recommend an HTML editor for Les to consider purchasing. http://whatis.discussions.techtarget.com/WebX?[EMAIL PROTECTED]@.1dcfae0e/113!viewtype= ______________________ QUIZ #7 | Protocols How much do you know about IT protocols? Take our quiz and find out! http://searchsystemsmanagement.techtarget.com/sDefinition/0,,sid20_gci558485,00.html ______________________________ RECENT ADDITIONS AND UPDATES [1] Hierarchical Mobile IPv6 http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci847453,00.html [2] Group Policy Object http://searchwindowsmanageability.techtarget.com/sDefinition/0,,sid33_gci847626,00.html [3] ACK http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci847659,00.html [4] NAK http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci847658,00.html [5] HDMI http://whatis.techtarget.com/definition/0,,sid9_gci847398,00.html ____________________________________________________________________ ::::::::::::::::::: WHATIS.COM CONTACTS ::::::::::::::::::: LOWELL THING, Site Editor ([EMAIL PROTECTED]) ____________________________________________________________________ MARGARET ROUSE, Assistant Editor ([EMAIL PROTECTED]) ___________________________________________________________________ :::::::::::::::::::: ABOUT THIS NEWSLETTER ::::::::::::::::::::: Published by TechTarget (http://www.techtarget.com) TechTarget - The Most Targeted IT Media Copyright 2002, All Rights Reserved. If you would like to sponsor this or any TechTarget newsletter, please contact Gabrielle DeRussy at [EMAIL PROTECTED] Unsubscribe from 'Word of the Day' - Simply Reply to this Email with REMOVE within the Body or Subject > or - Go to: http://WhatIs.techtarget.com/register - Log in to edit your profile. - Click on the link to Edit email subscriptions. - Uncheck the box next to the newsletter you wish to unsubscribe from. - When finished, click "Save Changes to My Profile."
