Ua ntej, cov qauv thiab cov khoom ntawm SiC siv lead ua.
SiC yog ib qho binary compound tsim los ntawm Si element thiab C keeb hauv 1: 1 piv, uas yog, 50% silicon (Si) thiab 50% carbon (C), thiab nws cov qauv tsim qauv yog SI-C tetrahedron.
Schematic daim duab ntawm silicon carbide tetrahedron qauv
Piv txwv li, Si atoms yog loj nyob rau hauv txoj kab uas hla, sib npaug rau cov kua, thiab C atoms yog me me nyob rau hauv txoj kab uas hla, sib npaug rau ib tug txiv kab ntxwv, thiab ib tug sib npaug ntawm txiv kab ntxwv thiab txiv apples yog piled ua ke los ua ib tug SiC siv lead ua.
SiC yog A binary compound, uas Si-Si daim ntawv cog lus atom sib nrug yog 3.89 A, yuav ua li cas nkag siab qhov sib nrug no?Tam sim no, lub tshuab lithography zoo tshaj plaws ntawm kev ua lag luam muaj qhov tseeb lithography ntawm 3nm, uas yog qhov deb ntawm 30A, thiab qhov tseeb lithography yog 8 npaug ntawm qhov kev ncua deb ntawm atomic.
Si-Si daim ntawv cog lus lub zog yog 310 kJ / mol, yog li koj tuaj yeem nkag siab tias lub zog ntawm daim ntawv cog lus yog lub zog uas rub ob lub atoms sib nrug, thiab lub zog ntawm daim ntawv cog lus ntau dua, lub zog ntau dua uas koj xav tau rub tawm.
Piv txwv li, Si atoms yog loj nyob rau hauv txoj kab uas hla, sib npaug rau cov kua, thiab C atoms yog me me nyob rau hauv txoj kab uas hla, sib npaug rau ib tug txiv kab ntxwv, thiab ib tug sib npaug ntawm txiv kab ntxwv thiab txiv apples yog piled ua ke los ua ib tug SiC siv lead ua.
SiC yog A binary compound, uas Si-Si daim ntawv cog lus atom sib nrug yog 3.89 A, yuav ua li cas nkag siab qhov sib nrug no?Tam sim no, lub tshuab lithography zoo tshaj plaws ntawm kev ua lag luam muaj qhov tseeb lithography ntawm 3nm, uas yog qhov deb ntawm 30A, thiab qhov tseeb lithography yog 8 npaug ntawm qhov kev ncua deb ntawm atomic.
Si-Si daim ntawv cog lus lub zog yog 310 kJ / mol, yog li koj tuaj yeem nkag siab tias lub zog ntawm daim ntawv cog lus yog lub zog uas rub ob lub atoms sib nrug, thiab lub zog ntawm daim ntawv cog lus ntau dua, lub zog ntau dua uas koj xav tau rub tawm.
Schematic daim duab ntawm silicon carbide tetrahedron qauv
Piv txwv li, Si atoms yog loj nyob rau hauv txoj kab uas hla, sib npaug rau cov kua, thiab C atoms yog me me nyob rau hauv txoj kab uas hla, sib npaug rau ib tug txiv kab ntxwv, thiab ib tug sib npaug ntawm txiv kab ntxwv thiab txiv apples yog piled ua ke los ua ib tug SiC siv lead ua.
SiC yog A binary compound, uas Si-Si daim ntawv cog lus atom sib nrug yog 3.89 A, yuav ua li cas nkag siab qhov sib nrug no?Tam sim no, lub tshuab lithography zoo tshaj plaws ntawm kev ua lag luam muaj qhov tseeb lithography ntawm 3nm, uas yog qhov deb ntawm 30A, thiab qhov tseeb lithography yog 8 npaug ntawm qhov kev ncua deb ntawm atomic.
Si-Si daim ntawv cog lus lub zog yog 310 kJ / mol, yog li koj tuaj yeem nkag siab tias lub zog ntawm daim ntawv cog lus yog lub zog uas rub ob lub atoms sib nrug, thiab lub zog ntawm daim ntawv cog lus ntau dua, lub zog ntau dua uas koj xav tau rub tawm.
Piv txwv li, Si atoms yog loj nyob rau hauv txoj kab uas hla, sib npaug rau cov kua, thiab C atoms yog me me nyob rau hauv txoj kab uas hla, sib npaug rau ib tug txiv kab ntxwv, thiab ib tug sib npaug ntawm txiv kab ntxwv thiab txiv apples yog piled ua ke los ua ib tug SiC siv lead ua.
SiC yog A binary compound, uas Si-Si daim ntawv cog lus atom sib nrug yog 3.89 A, yuav ua li cas nkag siab qhov sib nrug no?Tam sim no, lub tshuab lithography zoo tshaj plaws ntawm kev ua lag luam muaj qhov tseeb lithography ntawm 3nm, uas yog qhov deb ntawm 30A, thiab qhov tseeb lithography yog 8 npaug ntawm qhov kev ncua deb ntawm atomic.
Si-Si daim ntawv cog lus lub zog yog 310 kJ / mol, yog li koj tuaj yeem nkag siab tias lub zog ntawm daim ntawv cog lus yog lub zog uas rub ob lub atoms sib nrug, thiab lub zog ntawm daim ntawv cog lus ntau dua, lub zog ntau dua uas koj xav tau rub tawm.
Peb paub tias txhua yam khoom yog tsim los ntawm cov atoms, thiab cov qauv ntawm cov khoom siv lead ua yog ib qho kev ua haujlwm tsis tu ncua ntawm atoms, uas yog hu ua kev txiav txim ntev ntev, zoo li hauv qab no.Lub tsev siv lead ua me tshaj plaws yog hu ua cell, yog tias lub xov tooj ntawm tes yog lub cubic qauv, nws yog hu ua lub cubic kaw, thiab lub xov tooj ntawm tes yog cov qauv hexagonal, nws yog hu ua lub kaw ntom nti hexagonal.
Feem ntau SiC siv lead ua muaj xws li 3C-SiC, 4H-SiC, 6H-SiC, 15R-SiC, thiab lwm yam. Lawv cov txheej txheem stacking nyob rau hauv c axis kev taw qhia yog qhia nyob rau hauv daim duab.
Ntawm lawv, qhov yooj yim stacking sequence ntawm 4H-SiC yog ABCB ... ;Qhov yooj yim stacking ib ntus ntawm 6H-SiC yog ABCACB... ;Qhov yooj yim stacking sequence ntawm 15R-SiC yog ABCACBCABACABCB....
Qhov no tuaj yeem pom tias yog cib rau kev tsim tsev, qee lub tsev cib muaj peb txoj kev tso lawv, qee qhov muaj plaub txoj kev tso lawv, qee qhov muaj rau txoj kev.
Cov txheej txheem ntawm tes tsis zoo ntawm cov hom SiC siv lead ua no muaj nyob hauv cov lus:
A, b, c thiab kaum txhais li cas?Cov qauv ntawm cov chav tsev me me tshaj plaws hauv SiC semiconductor tau piav qhia hauv qab no:
Nyob rau hauv cov ntaub ntawv ntawm tib lub xovtooj, cov qauv siv lead ua kuj yuav txawv, qhov no zoo li peb yuav rho npe, tus lej yeej yog 1, 2, 3, koj yuav 1, 2, 3 peb tus lej, tab sis yog tias tus lej raug txheeb sib txawv, tus nqi yeej sib txawv, yog li tus lej thiab qhov kev txiav txim ntawm tib lub siv lead ua, tuaj yeem hu ua tib lub siv lead ua.
Cov duab hauv qab no qhia tau hais tias ob hom stacking raug, tsuas yog qhov sib txawv ntawm hom stacking ntawm cov atoms sab saud, cov qauv siv lead ua txawv.
Cov qauv siv lead ua tsim los ntawm SiC muaj feem cuam tshuam rau qhov kub thiab txias.Nyob rau hauv qhov kev txiav txim siab kub ntawm 1900 ~ 2000 ℃, 3C-SiC yuav maj mam hloov mus rau hexagonal SiC polyform xws li 6H-SiC vim nws cov qauv tsis zoo.Nws yog qhov tseeb vim tias muaj kev sib raug zoo ntawm qhov tshwm sim ntawm kev tsim ntawm SiC polymorphs thiab qhov kub thiab txias, thiab qhov tsis ruaj khov ntawm 3C-SiC nws tus kheej, qhov kev loj hlob ntawm 3C-SiC yog qhov nyuaj rau kev txhim kho, thiab kev npaj nyuaj.Lub hexagonal system ntawm 4H-SiC thiab 6H-SiC yog qhov ntau tshaj plaws thiab yooj yim rau kev npaj, thiab tau kawm dav vim lawv tus yam ntxwv.
Daim ntawv cog lus ntev ntawm SI-C daim ntawv cog lus hauv SiC siv lead ua tsuas yog 1.89A, tab sis lub zog sib txuas yog siab li 4.53eV.Yog li ntawd, qhov sib txawv ntawm lub zog ntawm lub xeev kev sib raug zoo thiab lub xeev kev tiv thaiv yog qhov loj heev, thiab qhov sib txawv ntawm qhov dav tuaj yeem tsim tau, uas yog ntau zaus ntawm Si thiab GaAs.Qhov siab dua qhov sib txawv ntawm qhov dav txhais tau hais tias cov qauv siv lead ua kub kub yog qhov ruaj khov.Cov khoom siv hluav taws xob sib txuas tuaj yeem paub txog cov yam ntxwv ntawm kev ua haujlwm ruaj khov ntawm qhov kub thiab txias thiab yooj yim thermal dissipation qauv.
Kev sib khi nruj ntawm Si-C daim ntawv cog lus ua rau cov lattice muaj kev vibration ntau zaus, uas yog, lub zog phonon, uas txhais tau hais tias SiC siv lead ua muaj lub siab saturated electron txav thiab thermal conductivity, thiab cov khoom siv hluav taws xob muaj feem xyuam nrog cov khoom siv hluav taws xob. kev hloov pauv nrawm dua thiab kev ntseeg siab, uas txo qhov kev pheej hmoo ntawm cov cuab yeej overtemperature tsis ua haujlwm.Tsis tas li ntawd, qhov sib zog ua haujlwm siab dua ntawm SiC tso cai rau nws kom ua tiav cov doping ntau dua thiab muaj kev tiv thaiv qis dua.
Thib ob, keeb kwm ntawm SiC siv lead ua kev loj hlob
Xyoo 1905, Dr. Henri Moissan nrhiav tau lub ntuj SiC siv lead ua nyob rau hauv lub qhov tsua, uas nws pom zoo li lub pob zeb diamond thiab muab nws lub npe hu ua Mosan pob zeb diamond.
Qhov tseeb, thaum ntxov li 1885, Acheson tau txais SiC los ntawm kev sib xyaw coke nrog silica thiab cua sov rau hauv lub cub hluav taws xob.Thaum lub sij hawm, tib neeg mistook nws rau ib tug sib tov ntawm pob zeb diamond thiab hu ua nws emery.
Xyoo 1892, Acheson tau txhim kho cov txheej txheem synthesis, nws sib xyaw quartz xuab zeb, coke, ib qho me me ntawm cov ntoo chips thiab NaCl, thiab muab tso rau hauv hluav taws xob arc rauv rau 2700 ℃, thiab ua tiav tau scaly SiC crystals.Txoj kev no ntawm kev sib xyaw SiC muaju yog hu ua Acheson txoj kev thiab tseem yog txoj hauv kev tseem ceeb ntawm kev tsim SiC abrasives hauv kev lag luam.Vim qhov tsis muaj purity ntawm cov khoom siv hluavtaws thiab cov txheej txheem sib xyaw ntxhib, Acheson txoj kev tsim ntau SiC impurities, tsis zoo siv lead ua kev ncaj ncees thiab me me siv lead ua txoj kab uas hla, uas yog ib qho nyuaj rau ua tau raws li qhov yuav tsum tau ntawm lub semiconductor kev lag luam rau loj-loj, high-purity thiab siab. -zoo crystals, thiab tsis tuaj yeem siv los tsim cov khoom siv hluav taws xob.
Lely ntawm Philips Laboratory tau npaj ib txoj hauv kev tshiab rau kev loj hlob SiC ib leeg siv lead ua hauv xyoo 1955. Nyob rau hauv txoj kev no, graphite crucible yog siv los ua lub nkoj loj hlob, SiC hmoov siv lead ua yog siv los ua cov khoom siv rau kev loj hlob SiC siv lead ua, thiab porous graphite yog siv los cais tawm. ib cheeb tsam hollow los ntawm qhov nruab nrab ntawm cov khoom loj hlob.Thaum loj hlob, graphite crucible yog rhuab mus rau 2500 ℃ nyob rau hauv cov huab cua ntawm Ar los yog H2, thiab peripheral SiC hmoov yog sublimed thiab decomposed rau hauv Si thiab C vapor theem tshuaj, thiab SiC siv lead ua yog zus nyob rau hauv nruab nrab hollow cheeb tsam tom qab cov roj. ntws yog kis los ntawm cov ntxeem tau graphite.
Thib peb, SiC siv lead ua kev loj hlob technology
Ib qho siv lead ua loj hlob ntawm SiC yog qhov nyuaj vim nws tus yam ntxwv.Qhov no yog vim qhov tseeb tias tsis muaj cov theem ua kua nrog qhov sib piv ntawm stoichiometric ntawm Si: C = 1: 1 ntawm atmospheric siab, thiab nws tsis tuaj yeem loj hlob los ntawm txoj kev loj hlob ntau dua uas siv los ntawm cov txheej txheem kev loj hlob tam sim no ntawm semiconductor. kev lag luam - cZ txoj kev, ntog crucible txoj kev thiab lwm txoj kev.Raws li theoretical xam, tsuas yog thaum lub siab siab tshaj 10E5atm thiab qhov kub thiab txias siab tshaj 3200 ℃, qhov stoichiometric piv ntawm Si: C = 1: 1 tov tau.Txhawm rau kom kov yeej qhov teeb meem no, cov kws tshawb fawb tau ua kom tsis muaj zog los tawm tswv yim ntau txoj hauv kev kom tau txais cov khoom siv lead ua zoo, loj loj thiab pheej yig SiC crystals.Tam sim no, cov txheej txheem tseem ceeb yog PVT txoj kev, cov txheej txheem ua kua theem thiab kub vapor tshuaj deposition txoj kev.
Post lub sij hawm: Jan-24-2024