Umaleko we-epitaxial yifilimu ethile ebhityileyo yekristale enye ekhuliswe kwi-substrate ye-wafer ngenkqubo ye-epitaxial; i-substrate wafer kunye nefilimu ye-epitaxial zibizwa ngokuba yi-epitaxial wafer. Phakathi kwezi, ukukhulisa umaleko we-epitaxial we-silicon carbide kwi-substrate ye-silicon carbide eqhubayo kuvelisa i-epitaxial wafer ye-silicon carbide epitaxial ehambelanayo, enokwenziwa ngakumbi kwizixhobo zamandla ezifana nee-diode ze-Schottky, ii-MOSFET, kunye nee-IGBTs. Uhlobo lwe-substrate olusetyenziswa kakhulu yi-4H-SiC substrate.
Ekubeni phantse zonke izixhobo zenziwe kwiileya ze-epitaxial, umgangatho womaleko we-epitaxial unempembelelo enkulu ekusebenzeni kwesixhobo. Nangona kunjalo, umgangatho womaleko we-epitaxial uchatshazelwa yi-crystal kunye ne-substrate processing, nto leyo eyibeka kwindawo ebalulekileyo kushishino kwaye idlala indima ebalulekileyo ekuphuhlisweni kwayo.
Iindlela eziphambili zokulungiselela iileya ze-epitaxial ze-silicon carbide ziquka: ukubekwa komphunga; i-epitaxy yesigaba solwelo (LPE); i-epitaxy ye-molecular beam (MBE); kunye nokubekwa komphunga wekhemikhali (CVD). Phakathi kwezi, ukubekwa komphunga wekhemikhali (CVD) yeyona ndlela isetyenziswa kakhulu kwi-epitaxy ehambelanayo ye-4H-SiC. I-epitaxy ye-4H-SiC CVD idla ngokusebenzisa izixhobo ze-CVD, eziqinisekisa ukuqhubeka kwesakhiwo sekristale ye-4H-SiC phantsi kwamaqondo obushushu aphezulu okukhula.
Kwizixhobo ze-CVD, i-substrate ayinakubekwa ngqo kumphezulu wesinyithi okanye ibekwe nje kwisiseko sokufakwa kwe-epitaxial, njengoko oku kubandakanya izinto ezahlukeneyo ezinefuthe ezifana nolwalathiso lokuhamba kwegesi (ethe tye, ethe nkqo), ubushushu, uxinzelelo, ukuqina, kunye nongcoliseko oluvela kumasuntswana aphumayo. Ke ngoko, kufuneka isiseko senkxaso; i-substrate ibekwa kwitreyi, kwaye ukufakwa kwe-epitaxial emva koko kwenziwa kwi-substrate kusetyenziswa itekhnoloji ye-CVD. Esi siseko senkxaso sisiseko se-graphite esigqunywe yi-SiC.
Njengenxalenye ephambili, i-graphite substrate inamandla aphezulu athile kunye ne-modulus ethile, kunye noxinzelelo oluhle lobushushu kunye nokumelana nokugqwala. Nangona kunjalo, ngexesha lokuveliswa, i-graphite ichaphazeleka kukugqwala kunye nokuchitheka komgubo ngenxa yeegesi ezigqwalisayo kunye nee-organometallic compounds eziseleyo, nto leyo enciphisa kakhulu ubomi benkonzo ye-substrate. Kwangaxeshanye, i-graphite powder eshed ingcolisa ii-chips. Kwimveliso yee-wafers ze-silicon carbide epitaxial, kuye kwaba nzima ngakumbi ukuhlangabezana neemfuno ezingqongqo zezinto ze-graphite, nto leyo ethintela kakhulu uphuhliso lwazo kunye nokusetyenziswa kwazo. Ngenxa yoko,iteknoloji yokwalekaiye yavela njengesisombululo.
Iingenelo zeSiC Coatings kwiShishini leSemiconductor
Iimpawu zomzimba nezekhemikhali zemigqumo kufuneka zihlangabezane neemfuno ezingqongqo zokumelana nobushushu obuphezulu kunye nokugqwala, njengoko ezi zinto zichaphazela ngokuthe ngqo isivuno semveliso kunye nobomi bayo. Izinto zeSiC zinamandla aphezulu, ubulukhuni obuphezulu, i-coefficient ephantsi yokwandiswa kobushushu, kunye nokuqhuba kakuhle kobushushu, okwenza ukuba zibe zizinto ezibalulekileyo zokwakha kunye ne-semiconductor ezikumgangatho ophezulu. Xa zisetyenziswa kwi-graphite substrates, izibonelelo zazo ziquka:
1) I-SiC ayimelani nokugqwala kwaye ingayigquma ngokupheleleyo i-graphite substrate. Uxinano lwayo oluphezulu luthintela umonakalo ovela kwiigesi ezigqwalayo.
2) I-SiC inomoya ophezulu wokushisa kunye namandla aqinileyo okunamathelana ne-graphite substrate, iqinisekisa ukuba ulwelo luhlala luqinile nangona emva kwemijikelo yobushushu obuphantsi obuphindaphindwayo.
3) I-SiC inozinzo oluhle kakhulu lweekhemikhali, ithintela ukungaphumeleli kokwaleka kwiindawo ezinobushushu obuphezulu nezinobuthi.
Ngaphezu koko, ii-epitaxial furnaces ezenziwe ngezinto ezahlukeneyo zifuna iitreyi zegrafiti ezineenkcazo ezithile zokusebenza. I-thermal expansion coefficient yezinto zegrafiti kufuneka ihambelane nobushushu bokukhula kwe-epitaxial furnace. Umzekelo, ekubeni ubushushu bokukhula kwe-silicon carbide epitaxy buphezulu, iitreyi ezinezinga eliphezulu lokuhambelana kwe-thermal expansion coefficient ziyafuneka. I-thermal expansion coefficient yeSiC yahlukile kancinci kweyegrafiti, nto leyo eyenza ukuba ibe yeyona nto ikhethwayo yokugquma umphezulu we-graphite substrates.
I-SiC ikhona kwiintlobo ezininzi zekristale, kwaye ezona zixhaphakileyo ngoku ziintlobo ze-3C, 4H, kunye ne-6H, nganye inika usetyenziso olwahlukileyo. Umzekelo, i-4H-SiC isetyenziselwa ukuvelisa izixhobo ezinamandla aphezulu; i-6H-SiC yeyona izinzileyo kwaye isetyenziselwa ukuvelisa izixhobo ze-optoelectronic; kwaye i-3C-SiC, ngenxa yokufana kwayo nesakhiwo seGaN, isetyenziselwa ukuvelisa iileya ze-epitaxial zeGaN zokwenza izixhobo ze-SiC-GaN RF. I-3C-SiC ikwabizwa ngokuba yi-β-SiC. Ukusetyenziswa okuphambili kwe-β-SiC kukusetyenziswa kwefilimu encinci kunye nezinto zokugquma; ngenxa yoko, i-β-SiC okwangoku sesona sixhobo siphambili esisetyenziselwa ukugquma.
Njengento eqhelekileyo esetyenziswa kwimveliso ye-semiconductor, ii-SiC coatings zisetyenziswa kakhulu kwiinkqubo ezifana nokulungiselela i-substrate, i-epitaxy, i-oxidation kunye ne-diffusion, i-etching, kunye nokufakelwa kwe-ion. Iimpawu zomzimba nezekhemikhali ze-coatings kufuneka zihlangabezane neemfuno ezingqongqo zokumelana nobushushu obuphezulu kunye nokumelana nokugqwala, njengoko ezi zinto zichaphazela ngokuthe ngqo isivuno semveliso kunye nobomi bayo. Ngenxa yoko, ukulungiswa kwee-SiC coatings kubalulekile.
Inkqubo yokulungiselela iiSilicon Carbide Coatings
Okwangoku, iindlela eziphambili zokulungiselela ii-SiC coating ziquka indlela ye-sol-gel, indlela yokufaka, i-brush coating, i-plasma spray, i-chemical vapor reaction (CVR), kunye ne-chemical vapor deposition (CVD).
Indlela yokuFakela
Le ndlela luhlobo lokusinta okuqinileyo okushushu kakhulu. Ngokuyintloko isebenzisa umxube we-silicon (Si) powder kunye ne-carbon (C) powder njengomgubo wokusinta. I-graphite substrate ifakwa ngaphakathi kwi-embedding powder kwaye itshiswe kumaqondo obushushu aphezulu kwindawo enegesi engasebenziyo, ekugqibeleni yenze i-SiC coating kumphezulu we-graphite substrate. Le ndlela inenkqubo elula kunye nokunamathela okuhle phakathi kwe-coating kunye ne-substrate; nangona kunjalo, i-coating ibonisa ukufana okungahambi kakuhle kwicala lobukhulu kwaye ithambekele ekuphuhliseni ii-pores ezininzi, nto leyo ebangela ukunganyamezeli kakuhle kwe-oxidation.
Indlela Yokugquma Ibhrashi
Indlela yokugquma ngebrashi ibandakanya ikakhulu ukufaka izinto eziluhlaza ezingamanzi kumphezulu we-graphite substrate, kulandele ukucocwa kwezinto kubushushu obuthile ukuze kwenziwe i-coating. Le ndlela ilula kwaye ayibizi kakhulu; nangona kunjalo, i-coating ephumayo ibonisa ukunamathela okubuthathaka kwi-substrate, ukungalingani kakuhle, kwaye incinci kakhulu kwaye ayinamandla okuxilisa, nto leyo ebangela ukuba kufuneke iindlela ezongezelelweyo.
Indlela yokutshiza ngePlasma
Indlela yokutshiza ngeplasma ibandakanya ukusebenzisa isibhamu seplasma ukutshiza izinto eziluhlaza ezinyibilikisiweyo okanye ezinyibilikisiweyo kancinci kumphezulu we-graphite substrate, ezithi emva koko ziqine kwaye zibopheleleke ukuze zenze i-coating. Le ndlela ilula ukuyisebenzisa kwaye inokuvelisa i-silicon carbide coating exineneyo; nangona kunjalo, i-coating evelayo idla ngokuba yincinci kakhulu, nto leyo ekhokelela ekuchaseni i-oxidation. Ke ngoko, isetyenziswa ngokubanzi ekulungiseleleni i-SiC composite coating ukuphucula umgangatho we-coating.
Indlela yeGel-Sol
Indlela ye-gel-sol ibandakanya kakhulu ukulungiselela isisombululo se-sol esifanayo nesibonakalayo ukuze sigqume umphezulu we-substrate. Emva kokuba yomile ibe yi-gel, izinto ziyatshizwa ukuze zenze i-coating. Le ndlela ilula ukuyisebenzisa kwaye ixabisa kancinci; nangona kunjalo, i-coating ephumayo ineengxaki ezifana nokumelana nobushushu obuphantsi kunye nokuthambekela kokuqhekeka, okuthintela ukusetyenziswa kwayo ngokubanzi.
Indlela yeChemical Vapor Reaction (CVR)
I-CVR isebenzisa ikakhulu iipowder ze-Si kunye ne-SiO₂ ukuvelisa umphunga we-SiO₂ kumaqondo obushushu aphezulu, okubangela uthotho lweempendulo zeekhemikhali kumphezulu we-substrate ye-Si ukwenza i-SiC coating. I-SiC coating eveliswa yile ndlela ibopha ngokuqinileyo kwi-substrate; nangona kunjalo, ubushushu be-reaction buphezulu, kwaye nexabiso liphezulu kakhulu.
Ukususwa koMphunga weKhemikhali (i-CVD)
I-CVD okwangoku bubuchwepheshe obuphambili bokulungiselela ii-SiC coatings kwiindawo ze-substrate. Inkqubo ephambili ibandakanya uthotho lwee-physicochemical reactions phakathi kwee-reactants zegesi kunye nomphezulu we-substrate, ekugqibeleni okubangela ukuba i-SiC coating ibe yi-SiC coating. Ii-SiC coatings eziveliswa yi-CVD technology zibophana ngokuqinileyo kumphezulu we-substrate kwaye zinokuphucula ngempumelelo ukumelana ne-oxidation kunye nokumelana ne-ablation yezinto ze-substrate; nangona kunjalo, le ndlela ifuna ixesha elide lokufaka, kwaye ii-reaction gases ziqulathe izinto ezithile ezinobuthi.
Iindlela zokugquma zeSiC
Iingubo zeSiC zisetyenziswa kakhulu njengezinto ezisetyenziswayo kwimveliso ye-semiconductor, kunye neemilinganiselo eziphambili zokusebenza eziquka ukufana kweengubo, i-coefficient of thermal expansion, kunye ne-thermal conductivity. Nangona kukho imfuno enkulu yasekhaya yeengubo zeSiC eTshayina, ubuchwepheshe abukavuthwa. Ngaphesheya kweelwandle, yinkampani enye kuphela yase-US esebenza kweli candelo, kwaye iimveliso zayo zibiza kakhulu.
Iinqanawa zekristalezizinto ezisetyenziswayo kwimveliso ye-epitaxial ezinokuthatha indawo ye-graphite egqunywe yi-SiC, nangona umthamo wemarike umncinci. Okulandelayo yi-graphite egqunywe yi-TaC, enika ukumelana okungcono kokugqwala kweekhemikhali kune-graphite engenanto okanye i-graphite egqunywe yi-SiC, kodwa ibiza kakhulu kwaye isekwinqanaba lokuqala lophuhliso. Okwangoku, iinkampani zasekhaya ezifanaLiufang semiconductor, I-SemicerakunyeI-Vetek Semiconductorbabandakanyeka kwi-R&D kule ndawo.
Ixesha leposi: Meyi-20-2026