Cov txheej txheem epitaxial pab cov khoom siv semiconductor li cas?

Lub hauv paus chiv keeb ntawm lub npe epitaxial wafer

Ua ntej, cia peb nrov lub tswv yim me me: kev npaj wafer suav nrog ob qhov txuas loj: kev npaj substrate thiab txheej txheem epitaxial. Lub substrate yog wafer ua los ntawm semiconductor ib qho khoom siv lead ua. Lub substrate tuaj yeem ncaj qha nkag mus rau cov txheej txheem tsim khoom wafer los tsim cov khoom siv semiconductor, lossis nws tuaj yeem ua tiav los ntawm cov txheej txheem epitaxial los tsim cov wafers epitaxial. Epitaxy yog hais txog cov txheej txheem ntawm kev loj hlob ib txheej tshiab ntawm ib qho siv lead ua rau ntawm ib leeg siv lead ua substrate uas tau ua tib zoo ua tiav los ntawm kev txiav, sib tsoo, polishing, thiab lwm yam. Cov siv lead ua tshiab tuaj yeem yog cov khoom siv tib yam li cov substrate, los yog nws tuaj yeem ua ib qho cov khoom sib txawv (homogeneous) epitaxy lossis heteroepitaxy). Vim tias cov txheej txheem siv lead ua tshiab txuas ntxiv thiab loj hlob raws li theem siv lead ua ntawm cov substrate, nws yog hu ua txheej txheej epitaxial (lub thickness feem ntau yog ob peb microns, siv silicon ua piv txwv: lub ntsiab lus ntawm silicon epitaxial kev loj hlob yog nyob rau ntawm silicon ib leeg. siv lead ua substrate nrog ib tug tej yam siv lead ua orientation Ib txheej ntawm siv lead ua nrog zoo lattice qauv kev ncaj ncees thiab txawv resistivity thiab thickness nrog tib siv lead ua orientation raws li lub substrate yog zus), thiab cov substrate nrog txheej epitaxial hu ua epitaxial wafer (epitaxial wafer = epitaxial txheej + substrate). Thaum cov cuab yeej ua rau ntawm txheej epitaxial, nws yog hu ua zoo epitaxy. Yog tias lub cuab yeej ua rau ntawm lub substrate, nws yog hu ua rov qab epitaxy. Lub sijhawm no, txheej txheej epitaxial tsuas yog ua lub luag haujlwm txhawb nqa.

Polished wafer

Txoj kev loj hlob epitaxial

Molecular beam epitaxy (MBE): Nws yog semiconductor epitaxial kev loj hlob technology ua nyob rau hauv ultra-high lub tshuab nqus tsev. Nyob rau hauv cov txheej txheem no, cov khoom siv yog evaporated nyob rau hauv daim ntawv ntawm ib tug beam ntawm atoms los yog molecules thiab ces tso rau ntawm ib tug crystalline substrate. MBE yog ib qho yooj yim heev thiab tswj tau semiconductor nyias zaj duab xis loj hlob tshuab uas tuaj yeem tswj cov tuab ntawm cov khoom tso rau ntawm qib atomic.
Hlau organic CVD (MOCVD): Nyob rau hauv cov txheej txheem MOCVD, cov organic hlau thiab hydride gas N gas uas muaj cov ntsiab lus yuav tsum tau muab nkag rau hauv lub substrate ntawm qhov kub thiab txias, tau txais cov tshuaj tiv thaiv los tsim cov khoom siv semiconductor, thiab muab tso rau hauv substrate. ntawm, thaum cov khoom sib txuas ntxiv thiab cov khoom siv tshuaj tiv thaiv raug tso tawm.
Vapor theem epitaxy (VPE): Vapor theem epitaxy yog ib qho tseem ceeb technology uas feem ntau siv nyob rau hauv zus tau tej cov semiconductor li. Lub hauv paus ntsiab lus tseem ceeb yog thauj cov vapor ntawm cov khoom siv hluav taws xob lossis cov khoom sib txuas hauv cov pa roj carbon monoxide, thiab tso cov khoom siv lead ua rau ntawm cov substrate los ntawm cov tshuaj tiv thaiv.

Cov txheej txheem epitaxy daws teeb meem dab tsi?

Tsuas yog cov ntaub ntawv siv lead ua ntau tuaj yeem ua tsis tau raws li qhov xav tau ntawm kev tsim ntau yam khoom siv semiconductor. Yog li ntawd, txoj kev loj hlob ntawm epitaxial, ib txheej nyias nyias siv lead ua cov khoom siv kev loj hlob, tau tsim nyob rau thaum xaus ntawm xyoo 1959. Yog li dab tsi tshwj xeeb ntawm kev siv tshuab epitaxy muaj rau kev nce qib ntawm cov ntaub ntawv?

Rau silicon, thaum silicon epitaxial txoj kev loj hlob tshuab pib, nws yog ib lub sij hawm nyuaj rau zus tau tej cov silicon high-frequency thiab high-power transistors. Los ntawm qhov kev xav ntawm transistor cov hauv paus ntsiab lus, kom tau txais cov zaus siab thiab lub zog siab, qhov tawg ntawm qhov chaw sib sau yuav tsum siab thiab cov kev ua haujlwm yuav tsum yog me me, uas yog, qhov saturation voltage poob yuav tsum me me. Cov yav tas yuav tsum tau hais tias lub resistivity ntawm cov khoom nyob rau hauv lub collecting cheeb tsam yuav tsum siab, thaum lub tom kawg yuav tsum tau hais tias lub resistivity ntawm cov khoom nyob rau hauv lub collecting cheeb tsam yuav tsum tsawg. Ob lub xeev muaj kev sib cav sib ceg. Yog hais tias lub thickness ntawm cov khoom nyob rau hauv lub collector cheeb tsam yog txo kom txo tau lub series kuj, lub silicon wafer yuav nyias nyias thiab tsis yooj yim rau ua. Yog hais tias qhov resistivity ntawm cov khoom raug txo, nws yuav tawm tsam thawj qhov yuav tsum tau ua. Txawm li cas los xij, txoj kev loj hlob ntawm epitaxial technology tau ua tiav. daws qhov nyuaj no.

Kev daws: Loj hlob ib txheej txheej epitaxial siab rau ntawm qhov tsis tshua muaj siab tsis kam substrate, thiab ua rau cov cuab yeej ntawm txheej epitaxial. Qhov no high-resistivity epitaxial txheej xyuas kom meej tias lub raj muaj lub siab tawg voltage, thaum lub substrate uas tsis muaj-resistance Nws kuj txo qhov tsis kam ntawm substrate, yog li txo qhov saturation voltage poob, yog li daws qhov tsis sib haum xeeb ntawm ob.

Tsis tas li ntawd, epitaxy thev naus laus zis xws li vapor theem epitaxy thiab kua theem epitaxy ntawm GaAs thiab lwm yam III-V, II-VI thiab lwm yam khoom siv molecular compound semiconductor kuj tau tsim zoo heev thiab tau dhau los ua lub hauv paus rau feem ntau cov khoom siv microwave, optoelectronic li, lub zog. Nws yog ib tug indispensable txheej txheem technology rau zus tau tej cov pab kiag li lawm, tshwj xeeb tshaj yog ua tau zoo daim ntawv thov ntawm molecular beam thiab hlau organic vapor theem epitaxy tshuab nyob rau hauv nyias txheej, superlattices, quantum wells, strained superlattices, thiab atomic-theem nyias-txheej epitaxy, uas yog ib kauj ruam tshiab hauv kev tshawb fawb semiconductor. Txoj kev loj hlob ntawm "kev siv zog siv hluav taws xob" hauv kev ua haujlwm tau tsim lub hauv paus ruaj khov.

Nyob rau hauv kev siv tswv yim, dav bandgap semiconductor pab kiag li lawm yuav luag ib txwm ua nyob rau hauv lub epitaxial txheej, thiab silicon carbide wafer nws tus kheej tsuas yog ua lub substrate. Yog li ntawd, kev tswj cov txheej txheem epitaxial yog ib feem tseem ceeb ntawm kev lag luam dav bandgap semiconductor.

7 cov txuj ci tseem ceeb hauv kev siv tshuab epitaxy

1. High (qis) tsis kam epitaxial txheej tuaj yeem ua rau epitaxially loj hlob ntawm qis (siab) tsis kam substrates.
2. N (P) hom epitaxial txheej tuaj yeem ua rau epitaxially loj hlob ntawm P (N) hom substrate los tsim PN hlws ris ncaj qha. Tsis muaj teeb meem them nyiaj thaum siv txoj kev diffusion los ua PN kev sib tshuam ntawm ib qho siv lead ua substrate.
3. Ua ke nrog cov cuab yeej siv lub ntsej muag, xaiv qhov kev loj hlob ntawm epitaxial yog ua nyob rau hauv cov cheeb tsam uas tau xaiv, tsim cov xwm txheej rau kev tsim cov kev sib xyaw ua ke thiab cov khoom siv nrog cov qauv tshwj xeeb.
4. Hom thiab concentration ntawm doping tuaj yeem hloov tau raws li kev xav tau thaum lub sijhawm kev loj hlob ntawm epitaxial. Qhov kev hloov ntawm qhov concentration tuaj yeem yog qhov hloov pauv sai lossis hloov qeeb.
5. Nws tuaj yeem loj hlob heterogeneous, multi-layered, multi-component compounds thiab ultra-nyias txheej nrog cov khoom sib txawv.
6. Epitaxial kev loj hlob tuaj yeem ua tau ntawm qhov kub qis dua qhov melting point ntawm cov khoom, qhov kev loj hlob yog tswj tau, thiab kev loj hlob ntawm epitaxial ntawm atomic-level thickness tuaj yeem ua tiav.
7. Nws tuaj yeem loj hlob ib qho khoom siv lead ua uas tsis tuaj yeem rub tau, xws li GaN, ib txheej siv lead ua ntawm tertiary thiab quaternary compounds, thiab lwm yam.