(1) Kev tswj cov nyhuv ntawm vGS ntawm ID thiab channel
① Case of vGS=0
Nws tuaj yeem pom tau tias muaj ob qhov rov qab-rau-rov qab PN junctions ntawm lub qhov dej d thiab qhov chaw s ntawm kev txhim kho-homMOSFET.
Thaum lub rooj vag-qhov hluav taws xob vGS = 0, txawm tias qhov ntws-qhov hluav taws xob vDS ntxiv, thiab tsis hais qhov polarity ntawm vDS, yeej ib txwm muaj PN hlws ris hauv lub xeev tsis ncaj ncees lawm. Tsis muaj cov kab hluav taws xob txuas nruab nrab ntawm qhov ntws thiab qhov chaw, yog li qhov ntws tam sim no ID≈0 nyob rau lub sijhawm no.
② Cov ntaub ntawv ntawm vGS> 0
Yog tias vGS> 0, ib qho hluav taws xob yog tsim nyob rau hauv SiO2 insulating txheej ntawm lub rooj vag thiab substrate. Cov kev taw qhia ntawm hluav taws xob teb yog perpendicular mus rau hluav taws xob teb qhia los ntawm lub rooj vag mus rau lub substrate ntawm lub semiconductor nto. Qhov hluav taws xob teb no ua rau lub qhov thiab nyiam cov electrons. Repelling qhov: Lub qhov nyob rau hauv P-hom substrate nyob ze ntawm lub rooj vag yog repelled, tawm immovable txais ions (tsis zoo ions) los tsim ib tug depletion txheej. Txaus nyiam electrons: Cov electrons (cov neeg nqa khoom tsawg) nyob rau hauv P-hom substrate yog attracted rau substrate nto.
(2) Tsim cov conductive channel:
Thaum tus nqi vGS me me thiab muaj peev xwm nyiam cov khoom siv hluav taws xob tsis muaj zog, tseem tsis muaj qhov cuam tshuam ntawm cov dej ntws thiab qhov chaw. Raws li vGS nce, ntau electrons yog attracted rau saum npoo ntawm P substrate. Thaum vGS nce mus txog ib qho nqi, cov khoom siv hluav taws xob no tsim N-hom nyias txheej ntawm P substrate ze ntawm lub rooj vag thiab txuas rau ob thaj tsam N +, tsim N-hom conductive channel ntawm qhov ntws thiab qhov chaw. Nws hom conductivity yog opposite rau ntawm P substrate, yog li nws kuj yog hu ua ib tug inversion txheej. Qhov loj vGS yog, lub zog hluav taws xob ua yeeb yam ntawm lub semiconductor nto yog, ntau electrons yog attracted rau saum npoo ntawm P substrate, lub thicker lub conductive channel yog, thiab qhov me dua cov channel kuj yog. Lub rooj vag-qhov hluav taws xob thaum lub channel pib tsim yog hu ua tig-on voltage, sawv cev los ntawm VT.
CovN-channel MOSFETtham saum toj no tsis tuaj yeem tsim cov channel conductive thaum vGS < VT, thiab lub raj nyob rau hauv lub xeev txiav. Tsuas yog thaum vGS≥VT tuaj yeem tsim cov channel. Hom noMOSFETuas yuav tsum tsim ib tug conductive channel thaum vGS≥VT hu ua kev txhim kho-homMOSFET. Tom qab tsim cov channel, cov dej ntws tawm yog tsim thaum lub zog pem hauv ntej vDS tau siv ntawm qhov ntws thiab qhov chaw. Kev cuam tshuam ntawm vDS ntawm ID, thaum vGS> VT thiab yog ib qho txiaj ntsig, qhov cuam tshuam ntawm qhov hluav taws xob qhov hluav taws xob vDS ntawm cov khoom siv hluav taws xob thiab tus ID tam sim no zoo ib yam li cov hluav taws xob hluav taws xob sib txuas. Qhov hluav taws xob poob tsim los ntawm qhov ntws tam sim no ID raws cov channel ua rau qhov voltages ntawm txhua qhov taw tes hauv cov channel thiab lub rooj vag tsis sib npaug. Qhov voltage ntawm qhov kawg ze ntawm qhov chaw yog qhov loj tshaj plaws, qhov twg cov channel yog thickest. Qhov hluav taws xob ntawm qhov dej ntws kawg yog qhov tsawg tshaj plaws, thiab nws tus nqi yog VGD = vGS-vDS, yog li cov channel yog thinnest ntawm no. Tab sis thaum vDS me me (vDS
Post lub sij hawm: Nov-12-2023
