Plaub, Txoj kev hloov lub cev vapor
Lub cev vapor thauj (PVT) txoj kev pib los ntawm vapor theem sublimation thev naus laus zis tsim los ntawm Lely hauv xyoo 1955. SiC hmoov tau muab tso rau hauv ib lub raj graphite thiab rhaub kom kub kub kom decompose thiab sublimate SiC hmoov, thiab tom qab ntawd lub graphite raj txias.Tom qab lub decomposition ntawm SiC hmoov, lub vapor theem Cheebtsam yog tso thiab crystallized rau hauv SiC muaju nyob ib ncig ntawm lub graphite raj.Txawm hais tias txoj kev no nyuaj kom tau txais qhov loj me SiC ib leeg muaju, thiab cov txheej txheem tso rau hauv lub raj graphite yog qhov nyuaj los tswj, nws muab cov tswv yim rau cov kws tshawb fawb tom qab.
Ym Terairov et al.Nyob rau hauv Russia qhia lub tswv yim ntawm noob muaju nyob rau hauv lub hauv paus no, thiab daws teeb meem ntawm uncontrolled siv lead ua duab thiab nucleation txoj hauj lwm ntawm SiC muaju.Cov kws tshawb fawb tom qab txuas ntxiv txhim kho thiab nws thiaj li tsim lub cev roj theem thauj (PVT) txoj hauv kev siv niaj hnub no.
Raws li qhov ntxov tshaj SiC siv lead ua txoj kev loj hlob, lub cev vapor hloov txoj kev yog txoj kev loj hlob tshaj plaws rau SiC siv lead ua kev loj hlob.Piv nrog rau lwm txoj kev, txoj kev muaj cov khoom siv tsis zoo rau kev loj hlob, cov txheej txheem kev loj hlob yooj yim, kev tswj kom muaj zog, kev txhim kho thiab kev tshawb fawb, thiab tau paub txog kev lag luam.Cov qauv ntawm cov siv lead ua loj hlob los ntawm cov qauv tseem ceeb PVT tam sim no tau qhia hauv daim duab.
Lub axial thiab radial kub teb tuaj yeem tswj tau los ntawm kev tswj cov thermal rwb thaiv tsev sab nraud ntawm graphite crucible.SiC hmoov yog muab tso rau hauv qab ntawm graphite crucible nrog kub siab dua, thiab SiC noob siv lead ua yog tsau rau sab saum toj ntawm graphite crucible nrog qhov kub thiab txias.Qhov kev ncua deb ntawm cov hmoov thiab cov noob yog feem ntau tswj kom muaj kaum tawm millimeters kom tsis txhob muaj kev sib cuag ntawm ib leeg siv lead ua thiab cov hmoov.Qhov kub gradient feem ntau yog nyob rau hauv thaj tsam ntawm 15-35 ℃ / cm.Ib qho roj inert ntawm 50-5000 Pa yog khaws cia rau hauv lub qhov cub kom nce convection.Nyob rau hauv txoj kev no, tom qab SiC hmoov yog rhuab mus rau 2000-2500 ℃ los ntawm induction cua sov, SiC hmoov yuav sublimate thiab decompose rau Si, Si2C, SiC2 thiab lwm yam vapor Cheebtsam, thiab thauj mus rau cov noob kawg nrog roj convection, thiab cov SiC siv lead ua yog crystallized ntawm cov noob siv lead ua kom ua tiav ib qho kev loj hlob siv lead ua.Nws tus nqi loj hlob yog 0.1-2mm / h.
PVT txheej txheem tsom rau kev tswj kev loj hlob ntawm qhov kub thiab txias, qhov kub thiab txias gradient, kev loj hlob ntawm qhov chaw, cov khoom siv qhov sib txawv thiab kev loj hlob siab, nws qhov zoo dua yog tias nws cov txheej txheem kuj paub tab, cov khoom siv raw khoom yooj yim tsim, tus nqi qis, tab sis cov txheej txheem kev loj hlob ntawm kev loj hlob. PVT txoj kev tsis yooj yim rau kev soj ntsuam, siv lead ua kev loj hlob ntawm 0.2-0.4mm / h, nws nyuaj rau loj hlob muaju nrog loj thickness (> 50mm).Tom qab ntau xyoo ntawm kev siv zog tas mus li, kev ua lag luam tam sim no rau SiC substrate wafers zus los ntawm PVT txoj kev tau loj heev, thiab cov khoom txhua xyoo ntawm SiC substrate wafers tuaj yeem ncav cuag ntau pua txhiab tus wafers, thiab nws qhov loj me yog maj mam hloov ntawm 4 ntiv mus rau 6 ntiv tes. , thiab tau tsim 8 nti ntawm SiC substrate qauv.
Thib tsib,High kub tshuaj vapor deposition txoj kev
High Temperature Chemical Vapor Deposition (HTCVD) yog ib txoj hauv kev txhim kho raws li Chemical Vapor Deposition (CVD).Cov txheej txheem yog thawj zaug tau thov nyob rau hauv 1995 los ntawm Kordina li al., Linkoping University, Sweden.
Daim duab loj hlob tau pom hauv daim duab:
Lub axial thiab radial kub teb tuaj yeem tswj tau los ntawm kev tswj cov thermal rwb thaiv tsev sab nraud ntawm graphite crucible.SiC hmoov yog muab tso rau hauv qab ntawm graphite crucible nrog kub siab dua, thiab SiC noob siv lead ua yog tsau rau sab saum toj ntawm graphite crucible nrog qhov kub thiab txias.Qhov kev ncua deb ntawm cov hmoov thiab cov noob yog feem ntau tswj kom muaj kaum tawm millimeters kom tsis txhob muaj kev sib cuag ntawm ib leeg siv lead ua thiab cov hmoov.Qhov kub gradient feem ntau yog nyob rau hauv thaj tsam ntawm 15-35 ℃ / cm.Ib qho roj inert ntawm 50-5000 Pa yog khaws cia rau hauv lub qhov cub kom nce convection.Nyob rau hauv txoj kev no, tom qab SiC hmoov yog rhuab mus rau 2000-2500 ℃ los ntawm induction cua sov, SiC hmoov yuav sublimate thiab decompose rau Si, Si2C, SiC2 thiab lwm yam vapor Cheebtsam, thiab thauj mus rau cov noob kawg nrog roj convection, thiab cov SiC siv lead ua yog crystallized ntawm cov noob siv lead ua kom ua tiav ib qho kev loj hlob siv lead ua.Nws tus nqi loj hlob yog 0.1-2mm / h.
PVT txheej txheem tsom rau kev tswj kev loj hlob ntawm qhov kub thiab txias, qhov kub thiab txias gradient, kev loj hlob ntawm qhov chaw, cov khoom siv qhov sib txawv thiab kev loj hlob siab, nws qhov zoo dua yog tias nws cov txheej txheem kuj paub tab, cov khoom siv raw khoom yooj yim tsim, tus nqi qis, tab sis cov txheej txheem kev loj hlob ntawm kev loj hlob. PVT txoj kev tsis yooj yim rau kev soj ntsuam, siv lead ua kev loj hlob ntawm 0.2-0.4mm / h, nws nyuaj rau loj hlob muaju nrog loj thickness (> 50mm).Tom qab ntau xyoo ntawm kev siv zog tas mus li, kev ua lag luam tam sim no rau SiC substrate wafers zus los ntawm PVT txoj kev tau loj heev, thiab cov khoom txhua xyoo ntawm SiC substrate wafers tuaj yeem ncav cuag ntau pua txhiab tus wafers, thiab nws qhov loj me yog maj mam hloov ntawm 4 ntiv mus rau 6 ntiv tes. , thiab tau tsim 8 nti ntawm SiC substrate qauv.
Thib tsib,High kub tshuaj vapor deposition txoj kev
High Temperature Chemical Vapor Deposition (HTCVD) yog ib txoj hauv kev txhim kho raws li Chemical Vapor Deposition (CVD).Cov txheej txheem yog thawj zaug tau thov nyob rau hauv 1995 los ntawm Kordina li al., Linkoping University, Sweden.
Daim duab loj hlob tau pom hauv daim duab:
Thaum SiC siv lead ua tau loj hlob los ntawm cov txheej txheem ua kua theem, qhov kub thiab txias ntawm cov khoom siv sib xyaw ua ke hauv cov tshuaj pab tau pom hauv daim duab:
Nws tuaj yeem pom tau tias qhov kub nyob ze ntawm phab ntsa crucible nyob rau hauv lub auxiliary tov yog siab dua, thaum qhov kub ntawm cov noob siv lead ua yog qis dua.Thaum lub sij hawm txoj kev loj hlob, graphite crucible muab C qhov chaw rau kev loj hlob siv lead ua.Vim tias qhov kub ntawm cov phab ntsa crucible yog siab, qhov solubility ntawm C yog loj, thiab cov dissolution tus nqi yog ceev, ib tug loj npaum li cas ntawm C yuav yaj nyob rau hauv lub crucible phab ntsa los tsim ib tug saturated tov ntawm C. Cov kev daws teeb meem nrog ib tug loj npaum li cas. ntawm C yaj yuav raug thauj mus rau hauv qab ntawm cov noob muaju los ntawm convection nyob rau hauv lub auxiliary tov.Vim yog qhov kub ntawm cov noob siv lead ua kawg, qhov solubility ntawm C sib raug zoo txo qis, thiab cov tshuaj C-saturated qub dhau los ua cov tshuaj supersaturated C tom qab hloov mus rau qhov kub qis kawg hauv qhov xwm txheej no.Suprataturated C hauv kev daws nrog Si hauv cov tshuaj pabcuam tuaj yeem loj hlob SiC siv lead ua epitaxial ntawm cov noob siv lead ua.Thaum lub superforated ib feem ntawm C precipitates tawm, cov tshuaj rov qab mus rau high-kub kawg ntawm lub crucible phab ntsa nrog convection, thiab dissolves C dua los tsim ib tug saturated tov.
Tag nrho cov txheej txheem rov ua dua, thiab SiC siv lead ua loj hlob.Nyob rau hauv tus txheej txheem ntawm cov kua theem kev loj hlob, lub dissolution thiab nag lossis daus ntawm C nyob rau hauv kev daws yog ib tug tseem ceeb heev Performance index ntawm kev loj hlob kev loj hlob.Txhawm rau kom ruaj khov siv lead ua kev loj hlob, nws yog ib qho tsim nyog yuav tsum muaj qhov sib npaug ntawm qhov sib luag ntawm C ntawm phab ntsa crucible thiab nag lossis daus ntawm cov noob kawg.Yog tias qhov tawg ntawm C ntau dua li nag lossis daus ntawm C, ces cov C hauv cov siv lead ua yog maj mam ntxiv, thiab cov nucleation ntawm SiC yuav tshwm sim.Yog tias qhov tawg ntawm C tsawg dua cov nag lossis daus ntawm C, qhov kev loj hlob siv lead ua yuav nyuaj rau kev ua tiav vim tsis muaj cov kuab tshuaj.
Nyob rau tib lub sijhawm, kev thauj mus los ntawm C los ntawm convection kuj cuam tshuam rau cov khoom ntawm C thaum lub sij hawm loj hlob.Yuav kom loj hlob SiC crystals nrog zoo txaus siv lead ua zoo thiab txaus tuab, nws yog ib qho tsim nyog los xyuas kom meej qhov sib npaug ntawm peb lub ntsiab lus saum toj no, uas ua rau muaj kev nyuaj siab ntawm SiC kua theem kev loj hlob.Txawm li cas los xij, nrog kev txhim kho me ntsis thiab kev txhim kho ntawm cov kev xav thiab cov thev naus laus zis, qhov zoo ntawm cov kua theem kev loj hlob ntawm SiC crystals yuav maj mam qhia.
Tam sim no, cov kua theem kev loj hlob ntawm 2-nti SiC crystals tuaj yeem ua tiav hauv Nyij Pooj, thiab cov kua theem kev loj hlob ntawm 4-inch crystals kuj tau tsim.Tam sim no, cov kev tshawb fawb tseem ceeb hauv tsev tseem tsis tau pom cov txiaj ntsig zoo, thiab nws yuav tsum tau ua raws li cov kev tshawb fawb cuam tshuam.
Xya, Lub cev thiab tshuaj muaj zog ntawm SiC crystals
(1) Mechanical zog: SiC crystals muaj siab hardness thiab zoo hnav tsis kam.Nws Mohs hardness yog nyob nruab nrab ntawm 9.2 thiab 9.3, thiab nws Krit hardness yog nyob nruab nrab ntawm 2900 thiab 3100Kg / mm2, uas yog thib ob tsuas yog pob zeb diamond muaju ntawm cov ntaub ntawv uas tau pom.Vim yog cov khoom siv zoo heev ntawm SiC, hmoov SiC feem ntau siv hauv kev txiav lossis kev sib tsoo, nrog rau kev thov txhua xyoo txog li lab tons.Cov txheej hnav-tiv taus ntawm qee qhov haujlwm yuav siv SiC txheej, Piv txwv li, cov txheej hnav-tiv taus ntawm qee lub nkoj ua rog yog tsim los ntawm SiC txheej.
(2) Cov khoom siv hluav taws xob: thermal conductivity ntawm SiC tuaj yeem ncav cuag 3-5 W / cm·K, uas yog 3 npaug ntawm cov khoom siv semiconductor Si thiab 8 npaug ntawm GaAs.Kev tsim cov cua sov ntawm cov cuab yeej npaj los ntawm SiC tuaj yeem ua sai sai, yog li cov kev xav tau ntawm cov cua kub dissipation ntawm SiC cov cuab yeej yog qhov xoob, thiab nws yog qhov tsim nyog rau kev npaj cov khoom siv hluav taws xob siab.SiC muaj cov khoom siv thermodynamic ruaj khov.Nyob rau hauv ib txwm muaj kev kub ntxhov, SiC yuav ncaj qha decomposed rau hauv vapor uas muaj Si thiab C ntawm siab dua.
(3) Cov khoom siv tshuaj lom neeg: SiC muaj cov tshuaj lom neeg ruaj khov, zoo corrosion kuj, thiab tsis hnov mob nrog cov kua qaub nyob hauv chav sov.SiC tso rau hauv huab cua ntev ntev yuav maj mam tsim ib txheej nyias ntawm SiO2, tiv thaiv cov tshuaj tiv thaiv oxidation ntxiv.Thaum qhov kub nce mus rau ntau tshaj 1700 ℃, SiO2 nyias txheej melts thiab oxidizes sai.SiC tuaj yeem ua rau qeeb oxidation cov tshuaj tiv thaiv nrog molten oxidants los yog hauv paus, thiab SiC wafers feem ntau corroded nyob rau hauv molten KOH thiab Na2O2 yam ntxwv qhov dislocation hauv SiC muaju..
(4) Cov khoom siv hluav taws xob: SiC ua cov khoom sawv cev ntawm dav bandgap semiconductors, 6H-SiC thiab 4H-SiC bandgap widths yog 3.0 eV thiab 3.2 eV feem, uas yog 3 npaug ntawm Si thiab 2 npaug ntawm GaAs.Cov khoom siv semi-conductor ua los ntawm SiC muaj qhov me me tam sim no thiab cov hluav taws xob tawg loj dua, yog li SiC suav tias yog cov khoom siv zoo tshaj plaws rau cov khoom siv hluav taws xob siab.Lub saturated electron txav ntawm SiC kuj yog 2 lub sij hawm siab dua ntawm Si, thiab nws kuj muaj qhov zoo tshaj plaws hauv kev npaj cov khoom siv ntau zaus.P-type SiC crystals lossis N-type SiC crystals tuaj yeem tau los ntawm doping cov impurity atoms hauv cov muaju.Tam sim no, P-type SiC crystals feem ntau doped los ntawm Al, B, Be, O, Ga, Sc thiab lwm yam atoms, thiab N-type sic crystals yog doped los ntawm N atoms.Qhov sib txawv ntawm doping concentration thiab hom yuav muaj kev cuam tshuam zoo rau lub cev thiab tshuaj lom neeg ntawm SiC.Nyob rau tib lub sijhawm, tus neeg nqa khoom pub dawb tuaj yeem ntsia tau los ntawm qib sib sib zog nqus doping xws li V, qhov kev tiv thaiv tuaj yeem nce ntxiv, thiab cov khoom siv hluav taws xob semi-insulating SiC tuaj yeem tau txais.
(5) Cov khoom siv kho qhov muag: Vim muaj qhov sib txawv ntawm qhov sib txawv, cov siv lead ua SiC tsis muaj xim tsis muaj xim thiab pob tshab.Cov doped SiC crystals qhia cov xim sib txawv vim lawv cov khoom sib txawv, piv txwv li, 6H-SiC yog ntsuab tom qab doping N;4H-SiC yog xim av.15R-SiC yog daj.Doped nrog Al, 4H-SiC tshwm xiav.Nws yog ib txoj hauv kev yooj yim kom paub qhov txawv ntawm SiC siv lead ua los ntawm kev soj ntsuam qhov sib txawv ntawm cov xim.Nrog rau kev tshawb fawb txuas ntxiv ntawm SiC ntsig txog kev ua haujlwm hauv 20 xyoo dhau los, kev ua tiav zoo tau ua tiav hauv cov thev naus laus zis ntsig txog.
Yim yim,Taw qhia ntawm SiC txoj kev txhim kho
Tam sim no, SiC kev lag luam tau dhau los ua qhov zoo tshaj plaws, los ntawm substrate wafers, epitaxial wafers mus rau cov cuab yeej tsim khoom, ntim, tag nrho cov saw hlau tau loj hlob tuaj, thiab nws tuaj yeem muab SiC cuam tshuam rau kev lag luam.
Cree yog tus thawj coj hauv SiC siv lead ua kev loj hlob kev lag luam nrog txoj haujlwm tseem ceeb hauv ob qho tib si loj thiab zoo ntawm SiC substrate wafers.Cree tam sim no tsim 300,000 SiC substrate chips hauv ib xyoos, suav txog ntau dua 80% ntawm kev xa khoom thoob ntiaj teb.
Thaum lub Cuaj Hlis 2019, Cree tshaj tawm tias nws yuav tsim qhov chaw tshiab hauv New York State, Tebchaws Asmeskas, uas yuav siv cov thev naus laus zis tshaj plaws kom loj hlob 200 hli txoj kab uas hla lub zog thiab RF SiC substrate wafers, qhia tias nws 200 hli SiC substrate khoom npaj siv tshuab muaj. ua kom paub tab.
Tam sim no, cov khoom tseem ceeb ntawm SiC substrate chips ntawm kev ua lag luam feem ntau yog 4H-SiC thiab 6H-SiC conductive thiab semi-insulated hom 2-6 ntiv tes.
Thaum Lub Kaum Hli 2015, Cree yog thawj zaug tshaj tawm 200 mm SiC substrate wafers rau N-hom thiab LED, cim qhov pib ntawm 8-nti SiC substrate wafers rau kev ua lag luam.
Xyoo 2016, Romm pib txhawb pab pawg Venturi thiab yog thawj tus siv IGBT + SiC SBD ua ke hauv lub tsheb los hloov IGBT + Si FRD tov hauv cov tsoos 200 kW inverter.Tom qab kev txhim kho, qhov hnyav ntawm lub inverter yog txo los ntawm 2 kg thiab qhov loj me yog txo los ntawm 19% thaum tuav tib lub zog.
Nyob rau hauv 2017, tom qab kev saws me nyuam ntxiv ntawm SiC MOS + SiC SBD, tsis tsuas yog qhov hnyav txo los ntawm 6 kg, qhov loj yog txo los ntawm 43%, thiab lub zog inverter kuj nce los ntawm 200 kW mus rau 220 kW.
Tom qab Tesla tau txais SIC-raws li cov khoom siv hauv cov tsav tsheb tseem ceeb ntawm nws cov qauv 3 cov khoom lag luam hauv xyoo 2018, qhov kev ua yeeb yam tau nthuav dav sai, ua rau xEV tsheb ua lag luam sai sai yog qhov zoo siab rau SiC kev ua lag luam.Nrog rau kev ua tiav ntawm SiC, nws cov txiaj ntsig kev lag luam muaj feem cuam tshuam kuj tau nce sai.
cuaj,Xaus:
Nrog rau kev txhim kho txuas ntxiv ntawm SiC ntsig txog kev lag luam thev naus laus zis, nws cov txiaj ntsig thiab kev ntseeg siab yuav raug txhim kho ntxiv, tus nqi ntawm SiC cov cuab yeej kuj yuav raug txo, thiab kev lag luam kev sib tw ntawm SiC yuav pom tseeb dua.Nyob rau hauv lub neej yav tom ntej, SiC cov cuab yeej yuav siv dav hauv ntau qhov chaw xws li tsheb, kev sib txuas lus, daim phiaj hluav taws xob, thiab kev thauj mus los, thiab cov khoom lag luam yuav dav dua, thiab kev lag luam loj yuav nthuav dav ntxiv, dhau los ua kev txhawb nqa tseem ceeb rau lub teb chaws. kev lag luam.
Post lub sij hawm: Jan-25-2024