Lub hauv paus ntsiab lus ua haujlwm ntawm N-channel txhim kho hom MOSFET

(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.