1.1 Taw qhia rau semiconductors
Cov cuab yeej ua kom zoo nkauj yog cov khoom siv hluav taws xob ntawm hluav taws xob, thiab lawv tau tsim los ntawm cov ntaub ntawv semiconductor. Cov ntaub ntawv semiconductor yog txhais tau tias cov tshuaj nrog hluav taws xob conduction ntawm tus cwj pwm thiab cov insulators. Ntxiv nrog rau qhov muaj kev cuam tshuam nrog cov neeg ntawm cov neeg thiab cov insulators, semiconductors kuj muaj cov khoom nram qab no:
1, Qhov nce siab nyob hauv qhov kub tuaj yeem txhim kho qhov kev coj ua ntawm cov semiconductors. Piv txwv li, kev tiv taus ntshiab ntawm silicon (Si) ob npaug thaum qhov kub nce siab los ntawm 30℃mus rau 20 degree.
2, Lw cov nqi ntawm cov impurities (lawv muaj thiab concentration) tuaj yeem hloov kho qhov kev coj ua ntawm cov semiconductors. Piv txwv li, yog tias ib tug impurity atom (xws li +3 t {}? 216,000 leej / ω ω ω ω ω ω ω ω ω.
3, Lub teeb ci tau tuaj yeem txhim kho qhov kev coj ua ntawm cov semiconductors. Piv txwv li, ib qho Cadmium Sulfide (CDs) Zaj duab xis tso rau ntawm MEAMOHMS (Mω) tsis kam lees ntawm lub teeb,
4, ntxiv ntxiv, sib nqus thiab hluav taws xob thiab cov hluav taws xob tuaj yeem tseem hloov kho qhov kev ua haujlwm ntawm cov semiconductors.
Yog li, semiconductors yog cov khoom siv nrog kev coj ua ntawm cov kev hloov pauv ntawm sab nraud xws li lub teeb sib txawv, thiab cov hluav taws xob kub, thiab taug kev txawv ncauj tsis huv.
Muab cov khoom zoo no, semiconductors tuaj yeem siv tau zoo siv. In particular, the subsequent discussions on diodes, transistors, and field-effect transistors will demonstrate how the property of trace impurities significantly altering semiconductor conductivity is harnessed.
1.2 intrinsic soob ntaiv
Yuav ua li cas peb qhia cov kab tsis huv rau cov semiconductors? Peb puas tuaj yeem cuam tshuam ncaj qha rau kev tsis txaus siab rau ntuj Quartz (uas nws qhov tseem ceeb yog si)? Peb tsis tuaj yeem siv cov silicon ncaj qha vim tias nws muaj ntau yam tsis txaus siab, uas ua rau nws tus cwj pwm tsis sib haum xeeb. Txhawm rau ua cov ntaub ntawv tseem ceeb rau txhua lub semiconductors, lub hom phiaj tseem ceeb yog kom ua tiav cov tswj tau kev coj ua.
Yog li ntawd, peb yuav tsum ua kom huv si silicon rau hauv lub ntshiab silicon crystal qauv. Qhov no ntshiab synemonductor Crystal qauv Crystal yog xa mus ua ib tug intrinsic sinsonductor.
Cov yam ntxwv ntawm intrinsic semiconductors: (intrinsic semiconductors yog cov ntshiab siv lead ua qauv)
1, purity, lub ntsiab tsis muaj impurities.
2, cov qauv siv lead ua, sawv cev kom ruaj khov. Cov atoms yog khi rau ib leeg, tiv thaiv kev txav dim dawb, uas ua rau muaj qis dua piv rau ntuj silicon.
1.2.1 Crystal qauv ntawm intrinsic semiconductors
Hauv Chemistry, peb tau kawm tias cov tshuab hluav taws xob outermost ntawm ob seem silicon (si) atoms hauv ib lub crystal ua cov ntawv sib koom ua ke, ua cov ntawv sib dhos. Txawm li cas los xij, tsis yog txhua yam roj hluav taws xob roj rau txhua qhov Si atom tseem nruj me ntsis nyob hauv lawv txoj kev sib tsooalent. Qhov laj thawj rau qhov no yog tias cov khoom siv nyob hauv ib puag ncig nrog kub. Ntxiv rau kev txiav txim cov lus tsa suab, cov tshuab hluav taws xob sab nraud kuj tseem tab tom cov lus qhia thermal {3} {random exterch {}} Vim hais tias kub. Qee zaum, ib lub tshuab hluav taws xob yuav muaj lub zog siab dua li lwm cov atoms, tso cai rau nws kom tawg ntawm kev sib khi sib khi thiab ua kom muaj hluav taws xob pub dawb. Txawm hais tias muaj me me ntawm lub zog, cov tshuab hluav taws xob sab nraud ntawm tus neeg xyuas pib tuaj yeem tsim cov lus tsa suab.
Intrinsic semiconductors yog pub dawb ntawm impurities. Thaum twg ib lub tshuab hluav taws xob so los ntawm kev sib khi sib khi, nws yoojyim rau tom qab lub suab hu ua vacancy hu ua ib lub qhov. Hauv intrinsic semiconductors, tus naj npawb ntawm cov hluav taws xob dawb yog sib npaug nrog cov qhov, thiab lawv tau tsim ua khub. Tus qauv siv lead ua, lub qhov, thiab cov hluav taws xob dawb yog ua piv txwv hauv daim duab hauv qab no:
1.2.1 Crystal qauv ntawm intrinsic semiconductors (txuas ntxiv)
Yog tias ib daim teb sab nraud yog thov rau ntawm cov intrinsic sinsonductor:
1, cov hluav taws xob hluav taws xob dawb txav sab nraud, ua ib qhoHluav Taws Xob Tam Sim No.
2, vim lub xub ntiag, Valence electrons nyob rau hauv ib qho kev taw qhia txav cov kev taw qhia tshwj xeeb, ua rau lub qhov, txij li lub tshuab hluav taws xob tsis zoo thiab cov qhov tau tsim ua khub). Qhov kev txav ntawm qhov ua iblub qhov tam sim noCov. Raws li cov hluav taws xob hluav taws xob dawb thiab cov qhov tsis sib xws them thiab txav mus rau hauv cov lus qhia rov qab, tag nrho tam sim no nyob rau hauv ib tug intrinsic syniconductor yog qhov tawm ntawm ob tus diav.
Cov xwm txheej saum toj no qhia tau hais tias ob lub qhov thiab dawb hluav taws xob ua raws li cov lus nqa cov hluav taws xob (xws li cov lus yog hu uaCov neeg nqa khoom ntawm). Yog li, ob leeg yog cov neeg nqa khoom them. Qhov no txiav txim siab qhov sib txawv ntawm cov neeg saib xyuas: Hauv kev saib xyuas, muaj ib hom ntawm cov neeg nqa khoom, muaj ob yam ntawm cov neeg nqa khoom.
1.2.2 Tus Cwj Pwm Concentration hauv Intrinsic soob Lasnonductors
Qhov tshwm sim nyob qhov twg semiconductor tsis pub dawb hauv hluav taws xob - lub qhov khub nyob rau hauv thermal excitation yog huintrinsic aititation.
Thaum lub sij hawm cov lus tsa suab dawb ntawm cov tshuab hluav taws xob dawb, thaum lawv ntsib qhov, cov hluav taws xob hluav taws xob dawb thiab cov qhov ib txhij ploj mus. Qhov tshwm sim no hu uakev tsis sib haumCov. Tus naj npawb ntawm cov hluav taws xob dawb - lub qhov sib luag tau tsim los ntawm intrinsic excities tus lej dawb Qhov no txhais tau hais tias nyob rau ntawm ib qho kub thiab txias, qhov ntau ntawm cov tshuab hluav taws xob dawb thiab qhov zoo ib yam.
Thaum lub caij nyoog kub nce, thermal suab ua kom muaj zog, thiab ntau lub tshuab hluav taws xob ntxiv dawb los ntawm cov kev txwv ntawm cov hluav taws xob hluav taws xob, ua rau muaj kev nce ntxiv hauv qhov. Thiaj li, tus cab kuj nce, txhim kho kev coj ua. Hloov siab, thaum ntsuas kub, cov cab kuj kev txiav txim siab txo qis, txo kev ua haujlwm. Thaum lub tee qhov kub kom tsis muaj lub zog hluav taws xob tsis muaj lub zog tawg tawm dawb los ntawm kev sib cav sib ceg, ua rau tsis muaj kev ua haujlwm.
Hauv intrinsic semiconductors, conductivity cuam tshuam nrog kev txav ntawm ob hom kev them nqi. Txawm hais tias qhov kev coj ua ntawm intrinsic semiconductors nyob ntawm seb qhov kub thiab txias, nws tseem muaj kev tsis zoo rau lawv cov qauv crystalline. Txawm hais tias lawv tsis zoo, intrinsic semiconderors nthuav qhia cov kev muaj zog hauv lawv cov khoom ua tau zoo.
1.3 doped semiconductors
Seem no yuav piav qhia yog vim li cas intrinsic semiconductors ua piv txwv xws li cov kev tswj hwm muaj zog hauv kev ua haujlwm zoo. Ntawm no, peb yuav tau siv cov khoom ntiag tug nram qab no ntawm cov semiconductors:Cov nqi tsheb ntawm cov impurities tuaj yeem hloov kho lawv qhov kev coj ua tau zoo.
"Doping" yog hais txog cov txheej txheem ntawm kev qhia txog kev tsim txom cov khoom tawg hauv cov intrinsic semiconductor. Nyob ntawm seb hom kev tawg nkoj ntxiv, doped semiconductors tuaj yeem faib rau hauvN - Hom semiconductorsthiabP - Hom semiconductorsCov. Los ntawm kev tswj lub concentration ntawm lub impurity element, qhov kev coj ua ntawm doped sliconduct tuaj yeem yog tswj hwm meej.
1.3.1 n - hom semiconductor
"N" sawv rauTsis zoo, raws li hluav taws xob nqa tus nqi tsis zoo thiab yog lub teeb yuag. Txhawm rau qhia cov tshuab hluav taws xob ntxiv rau hauv cov qauv crystav, Pentavalent ntsiab (piv txwv li, phosphorus, p) feem ntau yog doped rau hauv lub semiconductor. Txij li thaum phosphorus atom muaj tsib lub peev hluav taws xob, tom qab tsim kev sib txuas lus nrog ib puag ncig silicon atoms, ib qho hluav taws xob ntxiv nyob. Cov tshuab hluav taws xob no tuaj yeem ua tau yooj yim hluav taws xob nrog kev siv hluav taws xob tsawg. Tus neeg ifurity atom, tam sim no tsau nyob rau hauv lub crystal lattice thiab tsis muaj hluav taws xob, ua ib qho kev tsis sib haum xeeb ion. Qhov no yog qhia hauv daim duab hauv qab no:
1.3.1 n {- Hom semiconductor (txuas ntxiv)
Hauv ib qho n - Hom semiconductor, cov concentration ntawm dawb hluav taws xob yog ntau dua li ntawm lub qhov. Yog li ntawd, cov hluav taws xob dawb tau hu uaCov neeg nqa khoom loj(Ntau tus), thaum lub qhov yog hu uaCov Neeg Muaj Tsawg(Cov Menyuam Yaus). Yog li, qhov kev tshaj tawm ntawm n - Hom Snemiconductor feem ntau yog cov tshuab hluav taws xob dawb. Qhov siab dua ntawm cov kev xav ntawm doped impurities, ntau dua cov concentration ntawm cov khoom lag luam loj, thiab qhov muaj zog tshaj plaws.
Cia peb tshuaj xyuas li cas cov concentration ntawm cov neeg muaj feem tsawg hloov pauv thaum cov cab kuj tseem ceeb nce ntxiv. Cov neeg tsawg dua cov nqi kuj txo qis vim tias cov hluav taws xob tau nce ntxiv kom muaj qhov tshwm sim ntawm lub qhov.
Thaum qhov kub nce, tus naj npawb ntawm cov cab kuj nce, thiab kev nce hauv cov neeg nqa khoom loj yog sib npaug nrog cov neeg muaj peev xwm tsawg. Txawm li cas los xij, qhov kev hloov pauv feem pua ntawm cov neeg muaj peev xwm ntau dua yog siab dua ntawm cov neeg muaj hnub nyoog ntau dua ntawm cov neeg muaj hnub nyoog sib txawv (txawm hais tias cov lej nce yog tib yam). Yog li ntawd, txawm hais tias cov neeg nqa khoom tsawg yog tsawg, lawv yuav tsum tsis txhob tawm tsam. Cov neeg nqa khoom tsawg yog qhov tseem ceeb tshaj plaws cuam tshuam rau qhov kub thiab txias ntawm semiconductor ntawm cov cuab yeej siv, thiab yog li lawv lub siab xav tau.
1.3.2 P - Hom Semiconductor
"P" sawv rauYam zoo, muaj npe tom qab lub qhov zoo. Txhawm rau qhia cov qhov qauv ntxiv rau hauv cov qauv crystal, xws li boron, b) yog feem ntau doped rau hauv semiconductor. Thaum ib tug boron atom ua daim ntawv cog lus sib khi nrog ib puag ncig silicon atoms, nws tsim kom muaj kev cuam tshuam hluav taws xob (uas yog hluav taws xob nruab nrab). Thaum lub laj valence electron los ntawm cov neeg nyob sib ze nyob ib leeg Lub tshuab nyom atom ces dhau los ua ib qho immobile tsis zoo ion. Qhov no yog qhia hauv daim duab hauv qab no:
1.3.2 P {- hom semiconductor (txuas ntxiv)
Piv rau n - Hom semiconductors, hauv p - Hom semiconductors:
Qhov yog cov cab kuj tseem ceeb, thaum lub tshuab hluav taws xob dawb yog cov nqa khoom tsawg.
Kev cog lus feem ntau nyob rau ntawm lub qhov. Qhov siab dua cov kev xav ntawm doped impurities, ntau dua cov kev xav ntawm lub qhov, raws li cov chaw seem hauv kev txhim kho atomith unrathb electron). Cov neeg tsawg dua cov nqi kuj txo qis.
Thaum qhov kub nce, qhov feem pua hloov nyob rau hauv dawb hluav taws xob kev pom zoo yog siab dua li ntawm lub qhov cub.