lecture2annotat - 6.012- MicroelectronicDevicesandCircuits-

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 6.012- MicroelectronicDevicesandCircuits- Fall2005Lecture2-1Lecture2- SemiconductorPhysics(I)September13,2005Contents:1.Siliconbondmodel:electronsandholes2.Generationandrecombination3.Thermalequilibrium4.Intrinsicsemiconductor5.Doping;extrinsicsemiconductorReadingassignment:HoweandSodini,Ch.2,2.1-2.36.012- MicroelectronicDevicesandCircuits- Fall2005Lecture2-2KeyquestionsHowdosemiconductorsconductelectricity?Whatisahole?Howmanyelectronsandholesarethereinasemicon-ductorinthermalequilibriumatacertaintempera-ture?Howcanoneengineertheconductivityofsemicon-ductors?6.012- MicroelectronicDevicesandCircuits- Fall2005Lecture2-31.Siliconbondmodel:electronsandholesSiisinColumnIVofperiodictable:IIIA IVA VA VIA 5 6 7 8 B C N O 13 14 15 16 IIB Al Si P S 30 31 32 33 34 Zn Ga Ge As Se 48 49 50 51 52 Cd In Sn Sb Te ElectronicstructureofSiatom:10coreelectrons(tightlybound)4valenceelectrons(looselybound,responsibleformostchemicalproperties)Othersemiconductors:Ge,C(diamondform),SiGeGaAs,InP,InGaAs,InGaAsP,ZnSe,CdTe(onaverage,4valenceelectronsperatom)atomic densit6.012- MicroelectronicDevicesandCircuits- Fall2005Lecture2-4Siliconcrystalstructure:A 3sp tetrahedral bond 2.35 5.43 ASiliconisacrystallinematerial:longrangeatomicarrangementDiamondlattice:atomstetrahedrallybondedbysharingvalenceelec-trons(covalentbonding)Eachatomshares8electrons:lowenergyandstablesituationSiy:51022cm31022cm3Si atomicdensity: 56.012- MicroelectronicDevicesandCircuits- Fall2005Lecture2-5SimpleattenedmodelofSicrystal:4 valence electrons ( 4 q), contributed by each ion silicon ion (+ 4 q) two electrons in bond At0K:allbondssatisfiedallvalenceelectronsengagedinbondingnofreeelectrons6.012 - Microelectronic Devices and Circuits - Fall 2005Lecture 2-6At finite temperature:+incomplete bond (mobile hole)mobile electronfinite thermal energysome bonds are brokenfree electrons (mobile negative charge,1.61019C)freeholes(mobile positive charge, 1...
View Full Document

Page1 / 18

lecture2annotat - 6.012- MicroelectronicDevicesandCircuits-

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online