Keeb kwm ntawm lub npe "Epitaxial Wafer"
Kev npaj wafer muaj ob kauj ruam tseem ceeb: kev npaj substrate thiab txheej txheem epitaxial. Lub substrate yog ua los ntawm semiconductor ib qho khoom siv lead ua thiab feem ntau ua tiav los tsim cov khoom siv semiconductor. Nws kuj tseem tuaj yeem ua cov txheej txheem epitaxial los tsim ib qho epitaxial wafer. Epitaxy hais txog cov txheej txheem ntawm kev loj hlob ib txheej tshiab siv lead ua rau ntawm ib qho ua tib zoo ua tib zoo siv lead ua substrate. Cov siv lead ua tshiab tuaj yeem yog cov khoom siv tib yam li cov substrate (homogeneous epitaxy) lossis lwm yam khoom (heterogeneous epitaxy). Txij li cov txheej txheem siv lead ua tshiab loj hlob nyob rau hauv kev sib raug zoo nrog lub substrate lub crystal orientation, nws yog hu ua epitaxial txheej. Lub wafer nrog txheej epitaxial yog hu ua epitaxial wafer (epitaxial wafer = epitaxial txheej + substrate). Cov cuab yeej tsim los ntawm cov txheej txheem epitaxial hu ua "rau pem hauv ntej epitaxy," thaum cov cuab yeej tsim tawm ntawm lub substrate raug xa mus rau "rov qab epitaxy," qhov chaw epitaxial txheej tsuas yog kev txhawb nqa.
Homogeneous thiab Heterogeneous Epitaxy
▪Homogeneous Epitaxy:Lub epitaxial txheej thiab substrate yog ua los ntawm tib yam khoom: xws li Si/Si, GaAs/GaAs, GaP/GaP.
▪Heterogeneous Epitaxy:Cov txheej txheem epitaxial thiab substrate yog ua los ntawm cov khoom sib txawv: xws li Si / Al₂O₃, GaS / Si, GaAlAs / GaAs, GaN / SiC, thiab lwm yam.
Polished Wafers
Epitaxy daws teeb meem dab tsi?
Cov ntaub ntawv siv lead ua ib leeg ib leeg tsis txaus los ua kom tau raws li qhov xav tau ntawm cov khoom siv semiconductor fabrication. Yog li ntawd, nyob rau xyoo 1959, cov txheej txheem nyias nyias siv lead ua cov khoom loj hlob hu ua epitaxy tau tsim. Tab sis li cas cov tshuab epitaxial tshwj xeeb pab kev nce qib ntawm cov ntaub ntawv? Rau silicon, txoj kev loj hlob ntawm silicon epitaxy tshwm sim thaum lub sij hawm tseem ceeb thaum fabrication ntawm high-frequency, high-power silicon transistors ntsib teeb meem loj. Los ntawm qhov kev xav ntawm transistor cov hauv paus ntsiab lus, kev ua tiav siab zaus thiab lub hwj chim yuav tsum tau hais tias lub cheeb tsam ntawm lub collector breakdown voltage siab, thiab series kuj tsis tshua muaj, lub ntsiab lus saturation voltage yuav tsum me me. Cov yav tas yuav tsum muaj siab resistivity nyob rau hauv cov khoom collector, thaum lub tom kawg yuav tsum tau tsawg resistivity, uas tsim ib tug contradiction. Txo lub thickness ntawm lub collector cheeb tsam kom txo tau series kuj yuav ua rau cov silicon wafer nyias nyias thiab tsis yooj yim rau kev ua, thiab txo cov resistivity yuav tsis sib haum nrog cov thawj yuav tsum tau. Txoj kev loj hlob ntawm kev siv tshuab epitaxial ntse daws qhov teeb meem no. Qhov kev daws teeb meem yog kom loj hlob ib qho kev tiv thaiv siab epitaxial txheej rau ntawm qhov qis-resistivity substrate. Cov cuab yeej yog tsim los ntawm cov txheej epitaxial, kom ntseeg tau tias qhov siab tawg voltage ntawm lub transistor, thaum lub substrate low-resistivity txo lub hauv paus kuj thiab txo qhov saturation voltage, daws qhov tsis sib xws ntawm ob qhov yuav tsum tau ua.
Tsis tas li ntawd, cov thev naus laus zis epitaxial rau III-V thiab II-VI compound semiconductors xws li GaAs, GaN, thiab lwm yam, suav nrog theem vapor thiab kua theem epitaxy, tau pom kev nce qib tseem ceeb. Cov thev naus laus zis no tau dhau los ua qhov tseem ceeb rau kev tsim ntau lub microwave, optoelectronic, thiab cov khoom siv fais fab. Tshwj xeeb, cov tswv yim zoo li molecular beam epitaxy (MBE) thiab hlau-organic chemical vapor deposition (MOCVD) tau ua tiav rau cov txheej nyias nyias, superlattices, quantum qhov dej, strained superlattices, thiab atomic-scale nyias epitaxial txheej, tso lub hauv paus ruaj khov rau. txoj kev loj hlob ntawm tshiab semiconductor teb xws li "band engineering."
Hauv kev siv cov tswv yim, cov khoom siv dav dav feem ntau yog tsim los ntawm cov txheej txheem epitaxial, nrog cov ntaub ntawv zoo li silicon carbide (SiC) tsuas yog siv los ua cov substrates. Yog li, tswj cov txheej txheem epitaxial yog qhov tseem ceeb hauv kev lag luam dav-bandgap semiconductor.
Epitaxy Technology: Xya qhov tseem ceeb
1. Epitaxy tuaj yeem loj hlob txheej txheej siab (lossis qis) ntawm qhov qis (lossis siab) resistivity substrate.
2. Epitaxy tso cai rau kev loj hlob ntawm N (los yog P) hom epitaxial txheej ntawm P (los yog N) hom substrates, ncaj qha tsim PN junction yam tsis muaj cov teeb meem them nyiaj uas tshwm sim thaum siv diffusion los tsim PN junction ntawm ib lub pob zeb siv lead ua.
3. Thaum ua ke nrog cov cuab yeej siv lub ntsej muag, xaiv qhov kev loj hlob ntawm epitaxial tuaj yeem ua tau nyob rau hauv cov cheeb tsam tshwj xeeb, ua rau kev tsim cov khoom siv sib xyaw ua ke thiab cov khoom siv nrog cov qauv tshwj xeeb.
4. Epitaxial kev loj hlob tso cai rau kev tswj ntawm doping hom thiab concentrations, nrog rau kev muaj peev xwm ua kom tiav sai lossis maj mam hloov hauv concentration.
5. Epitaxy tuaj yeem loj hlob heterogeneous, multi-layered, multi-component compounds nrog sib txawv sib txawv, nrog rau ultra-nyias txheej.
6. Epitaxial kev loj hlob tuaj yeem tshwm sim ntawm qhov kub thiab txias hauv qab lub melting point ntawm cov khoom, nrog rau kev loj hlob tus nqi, tso cai rau atomic-theem precision nyob rau hauv txheej thickness.
7. Epitaxy ua rau muaj kev loj hlob ntawm ib txheej siv lead ua ntawm cov ntaub ntawv uas tsis tuaj yeem rub mus rau hauv cov muaju, xws li GaN thiab ternary/quaternary compound semiconductors.
Ntau cov txheej txheem epitaxial thiab cov txheej txheem epitaxial
Hauv cov ntsiab lus, cov txheej txheem epitaxial muab cov txheej txheem tswj tau yooj yim dua thiab zoo meej siv lead ua ntau dua li cov substrates, uas muaj txiaj ntsig zoo rau kev tsim cov khoom siv siab heev.
Post lub sij hawm: Dec-24-2024