Litaba - Sebopeho le theknoloji ea kholo ea silicon carbide (Ⅱ)

Ea bone, mokhoa oa ho fetisa mouoane 'meleng

Thesepalangoang sa mouoane (PVT)mokhoa o simolohile ho theknoloji ea sublimation ea mouoane e qapiloeng ke Lely ka 1955. Phofo ea SiC e kenngoa ka har'a tube ea graphite 'me e futhumetse ho mocheso o phahameng ho senya le ho fokotsa phofo ea SiC, ebe tube ea graphite e pholile. Ka mor'a ho senyeha ha phofo ea SiC, likarolo tsa mouoane oa mouoane li kenngoa 'me li kenngoe ka har'a likristale tsa SiC ho pota-potile tube ea graphite. Le hoja mokhoa ona o etsa hore ho be thata ho fumana likristale tse le 'ngoe tsa SiC tsa boholo bo boholo,' me mokhoa oa ho bea ka har'a tube ea graphite o thata ho o laola, o fana ka maikutlo ho bafuputsi ba latelang.
Ym Terairov et al. Russia e hlahisitse khopolo ea likristale tsa peo motheong ona 'me ea rarolla bothata ba sebopeho sa kristale se sa laoleheng le boemo ba nucleation ea likristale tsa SiC. Bafuputsi ba latelang ba ile ba tsoela pele ho ntlafatsa mme qetellong ba hlahisa mokhoa oa ho tsamaisa khase ea 'mele (PVT) ts'ebelisong ea indasteri kajeno.

Joalo ka mokhoa oa khale oa ho hola oa kristale oa SiC, mokhoa oa phetisetso ea mouoane oa 'mele ke mokhoa o ka sehloohong oa kholo ea kholo ea kristale ea SiC. Ha ho bapisoa le mekhoa e meng, mokhoa ona o na le litlhoko tse tlase tsa lisebelisoa tsa kholo, ts'ebetso e bonolo ea kholo, taolo e matla, nts'etsopele e phethahetseng, le lipatlisiso, 'me o hlokometse ts'ebeliso ea indasteri. Sebopeho sa kristale e hōlileng ka mokhoa o tloaelehileng oa PVT o bontšoa setšoantšong.

Libaka tsa mocheso oa axial le radial li ka laoloa ka ho laola maemo a ka ntle a mocheso oa mocheso oa graphite crucible. Phofo ea SiC e behoa ka tlaase ho graphite crucible e nang le mocheso o phahameng, 'me kristale ea peo ea SiC e tsitsitsoe ka holimo ho graphite crucible ka mocheso o tlaase. Sebaka se pakeng tsa phofo le peo ka kakaretso se laoloa ho ba limilimithara tse mashome ho qoba ho kopana pakeng tsa kristale e le 'ngoe e ntseng e hōla le phofo. Thempereichara ea mocheso hangata e maemong a 15-35 ℃/cm. Khase ea inert ea 50-5000 Pa e bolokiloe ka sebōping ho eketsa convection. Ka tsela ena, ka mor'a hore phofshoana ea SiC e futhumatsoe ho 2000-2500 ℃ ka ho futhumatsa ka induction, phofshoana ea SiC e tla theoha 'me e bola e be Si, Si2C, SiC2 le likarolo tse ling tsa mouoane, ebe e isoa qetellong ea peo ka convection ea khase, le SiC kristale e khabisitsoe holim'a kristale ea peo ho fihlela kholo e le 'ngoe ea kristale. Sekhahla sa eona se tloaelehileng sa kholo ke 0.1-2mm / h.

Ts'ebetso ea PVT e tsepamisitse maikutlo taolong ea mocheso oa kholo, sekhahla sa mocheso, bokaholimo ba kholo, sebaka sa sebaka sa marang-rang, le khatello ea kholo, molemo oa eona ke hore ts'ebetso ea eona e se e hōlile, lisebelisoa tse tala li bonolo ho li hlahisa, litšenyehelo li tlase, empa ts'ebetso ea kholo. mokhoa oa PVT o thata ho o hlokomela, sekhahla sa kholo ea kristale ea 0.2-0.4mm / h, ho thata ho hōlisa likristale tse nang le botenya bo boholo (> 50mm). Ka mor'a mashome a lilemo a boiteko bo tsoelang pele, 'maraka oa hona joale oa li-wafers tsa SiC substrate tse hōlileng ka mokhoa oa PVT o bile moholo haholo,' me tlhahiso ea selemo le selemo ea li-wafers tsa SiC substrate e ka fihla makholo a likete tsa liphaephe, 'me boholo ba eona bo ntse bo fetoha butle-butle ho tloha ho 4 inches ho ea ho 6. lisenthimithara tse 8, 'me e hlahisitse lisampole tsa SiC substrate tse 8.

Ea bohlano, Mokhoa oa ho beha mouoane oa lik'hemik'hale oa mocheso o phahameng

High-Temperature Chemical Vapor Deposition (HTCVD) ke mokhoa o ntlafetseng o thehiloeng ho Chemical Vapor Deposition (CVD). Mokhoa ona o ile oa hlahisoa ka lekhetlo la pele ka 1995 ke Kordina et al., Univesithi ea Linkoping, Sweden.
Setšoantšo sa sebopeho sa kholo se bontšoa setšoantšong:

Ha kristale ea SiC e holisoa ka mokhoa oa mokelikeli, mocheso le phepelo ea convection ka har'a tharollo e thusang li bonts'oa setšoantšong:

Ho ka bonoa hore mocheso o haufi le lerako la crucible ka tharollo e thusang e phahame, ha mocheso oa kristale ea peo o tlaase. Nakong ea ts'ebetso ea ho hōla, graphite crucible e fana ka mohloli oa C bakeng sa khōlo ea kristale. Hobane mocheso leboteng la crucible o phahame, ho qhibiliha ha C ho kholo, 'me lebelo la ho qhibiliha le potlakile, palo e kholo ea C e tla qhibiliha leboteng la crucible ho theha tharollo e tletseng ea C. Litharollo tsena tse nang le chelete e ngata haholo. ea C e qhibilihisitsoeng e tla isoa karolong e ka tlaase ea likristale tsa peo ka convection ka har'a tharollo e thusang. Ka lebaka la mocheso o tlase oa pheletso ea kristale ea peo, ho qhibiliha ha C e tsamaisanang ho fokotseha ka tsela e ts'oanang, 'me tharollo ea pele ea C-saturated e fetoha tharollo ea supersaturated ea C ka mor'a hore e fetisetsoe qetellong ea mocheso o tlaase tlas'a boemo bona. Supersaturated C ka tharollo e kopantsoeng le Si ka tharollo e thusang e ka hōla SiC crystal epitaxial holim'a kristale ea peo. Ha karolo e phunyeletsoeng ea C e tsoa, tharollo e khutlela qetellong ea mocheso o phahameng oa lebota la crucible le convection le ho qhaqha C hape ho etsa tharollo e tletseng.

Ts'ebetso eohle e pheta-pheta, 'me kristale ea SiC ea hōla. Ts'ebetsong ea kholo ea mohato oa mokelikeli, ho qhibiliha le pula ea C ka tharollo ke index ea bohlokoa haholo ea tsoelo-pele ea kholo. E le ho etsa bonnete ba hore khōlo e tsitsitseng ea kristale, hoa hlokahala ho boloka ho leka-lekana pakeng tsa ho qhibiliha ha C leboteng la crucible le pula qetellong ea peo. Haeba ho qhibiliha ha C ho feta pula ea C, joale C ka kristale e ntlafatsoa butle-butle, 'me nucleation e ikemetseng ea SiC e tla etsahala. Haeba ho qhibiliha ha C ho le tlase ho pula ea C, kholo ea kristale e tla ba thata ho e phetha ka lebaka la khaello ea solute.
Ka nako e ts'oanang, ho tsamaisoa ha C ka convection ho boetse ho ama phepelo ea C nakong ea kholo. E le ho hōlisa likristale tsa SiC tse nang le boleng bo lekaneng ba kristale le botenya bo lekaneng, hoa hlokahala ho netefatsa ho leka-lekana ha likarolo tse tharo tse ka holimo, e leng ho eketsang haholo bothata ba kholo ea mohato oa mokelikeli oa SiC. Leha ho le joalo, ka ntlafatso le ntlafatso ea butle-butle ea likhopolo le mahlale a amanang, melemo ea kholo ea mokelikeli oa likristale tsa SiC e tla bonts'a butle-butle.
Hajoale, kholo ea karolo ea mokelikeli ea likristale tsa 2-inch SiC e ka fihlelleha Japane, mme kholo ea karolo ea mokelikeli ea likristale tsa 4-inch le eona e ntse e ntlafatsoa. Hajoale, lipatlisiso tsa lehae tse amehang ha li so bone litholoana tse ntle, 'me hoa hlokahala ho sala morao mosebetsi o nepahetseng oa lipatlisiso.

Ea bosupa, Thepa ea 'mele le ea lik'hemik'hale ea likristale tsa SiC

(1) Lisebelisoa tsa mochini: Likristale tsa SiC li na le bothata bo phahameng haholo le ho hanyetsa ho apara hantle. Boima ba eona ba Mohs bo pakeng tsa 9.2 le 9.3, 'me boima ba eona ba Krit bo pakeng tsa 2900 le 3100Kg / mm2, e leng ea bobeli ho likristale tsa daemane har'a lisebelisoa tse fumanoeng. Ka lebaka la thepa e babatsehang ea SiC, phofo ea SiC e atisa ho sebelisoa indastering ea ho itšeha kapa ea ho sila, ka tlhokahalo ea selemo le selemo ea ho fihlela ho lithane tse limilione. Seaparo se sa sebetseng holim'a lisebelisoa tse ling tsa mosebetsi le sona se tla sebelisa seaparo sa SiC, mohlala, seaparo se thibelang ho roala likepeng tse ling tsa ntoa se entsoe ka seaparo sa SiC.

(2) Thermal properties: Thermal conductivity ea SiC e ka fihla 3-5 W / cm·K, e leng makhetlo a 3 a semiconductor ea setso Si le makhetlo a 8 a GaAs. Tlhahiso ea mocheso ea sesebelisoa e lokiselitsoeng ke SiC e ka etsoa ka potlako, kahoo litlhoko tsa maemo a mocheso a mocheso oa sesebelisoa sa SiC li batla li hlephile, 'me li loketse ho lokisoa ha lisebelisoa tse matla haholo. SiC e na le thepa e tsitsitseng ea thermodynamic. Tlas'a maemo a tloaelehileng a khatello, SiC e tla senyeha ka ho toba hore e be mouoane o nang le Si le C holimo.

(3) Lintho tsa lik'hemik'hale: SiC e na le metsoako e tsitsitseng ea lik'hemik'hale, e thibelang kutu e ntle, 'me ha e sebetsane le acid leha e le efe e tsejoang mocheso oa kamore. SiC e behiloeng moeeng nako e telele e tla theha sekhahla se tšesaane sa SiO2 butle-butle, e thibele karabelo e eketsehileng ea oxidation. Ha mocheso o nyolohela ho feta 1700 ℃, lesela le tšesaane la SiO2 lea qhibiliha ebe le oxidize kapele. SiC e ka kenella butle ha oxidation e sebelisa li-oxidants kapa li-bases tse qhibilihisitsoeng, 'me li-wafers tsa SiC hangata li holisoa ka har'a KOH e qhibilihisitsoeng le Na2O2 ho bontša ho kheloha ha likristale tsa SiC.

(4) Thepa ea motlakase: SiC e le thepa e emelang li-semiconductors tse pharaletseng, 6H-SiC, le 4H-SiC bophara ba li-bandgap ke 3.0 eV le 3.2 eV ka ho latellana, e leng makhetlo a 3 a Si le makhetlo a 2 a GaAs. Lisebelisoa tsa semiconductor tse entsoeng ka SiC li na le maqhubu a manyane a ho lutla le masimo a maholo a ho senyeha ha motlakase, kahoo SiC e nkuoa e le thepa e loketseng lisebelisoa tse matla a phahameng. The saturated electron motsamao oa SiC e boetse e ka makhetlo a 2 ho feta ea Si, hape e na le melemo e totobetseng ha ho lokisoa lisebelisoa tse phahameng tsa maqhubu. Likristale tsa SiC tsa mofuta oa P kapa likristale tsa SiC tsa mofuta oa N li ka fumanoa ka ho theola liathomo tse sa hloekang ka har'a likristale. Hajoale, likristale tsa SiC tsa mofuta oa P li entsoe haholo ke Al, B, Be, O, Ga, Sc, le liathomo tse ling, 'me likristale tsa sic tsa mofuta oa N li entsoe haholo ke liathomo tsa N. Phapang ea mahloriso le mofuta oa doping e tla ba le tšusumetso e kholo ho thepa ea 'mele le ea lik'hemik'hale ea SiC. Ka nako e ts'oanang, sesebelisoa sa mahala se ka khokhotheloa ka li-doping tse tebileng tse kang V, ho hanyetsa ho ka eketsoa, 'me kristale ea SiC ea semi-insulating e ka fumanoa.

(5) Thepa ea Optical: Ka lebaka la lekhalo le pharaletseng la sehlopha, kristale ea SiC e sa koaloang ha e na mebala ebile e pepenene. Likristale tsa SiC tse nang le doped li bontša mebala e fapaneng ka lebaka la thepa ea tsona e fapaneng, mohlala, 6H-SiC e tala ka mor'a doping N; 4H-SiC e sootho. 15R-SiC e mosehla. E entsoe ka Al, 4H-SiC e bonahala e le putsoa. Ke mokhoa o hlakileng oa ho khetholla mofuta oa kristale oa SiC ka ho bona phapang ea 'mala. Ka liphuputso tse tsoelang pele mabapi le masimo a amanang le SiC lilemong tse 20 tse fetileng, ho entsoe katleho e kholo mekhoeng e amanang le eona.

Ea borobeli, Kenyelletso ea boemo ba ntlafatso ea SiC

Hajoale, indasteri ea SiC e se e ntse e tsoela pele ho phethahala, ho tloha ho li-wafers tsa substrate,leepitaxialliphaphathaho hlahisa lisebelisoa, le ho paka, ketane eohle ea indasteri e holile, 'me e ka fana ka lihlahisoa tse amanang le SiC' marakeng.

Cree ke moetapele indastering ea kholo ea kristale ea SiC ea nang le maemo a etelletseng pele ka boholo le boleng ba li-wafers tsa SiC substrate. Hajoale Cree e hlahisa 300,000 SiC substrate chips ka selemo, e ikarabellang ho feta 80% ea thepa e romelloang lefatšeng ka bophara.

Ka Loetse 2019, Cree e phatlalalitse hore e tla aha moaho o mocha New York State, USA, o tla sebelisa theknoloji e tsoetseng pele ho holisa matla a bophara ba 200 mm le liphaephe tsa RF SiC, ho bonts'a hore theknoloji ea eona ea ho lokisa thepa ea 200 mm SiC e na le. ho ba motho ya butsoitseng.

Hajoale, lihlahisoa tsa mantlha tsa SiC substrate chips 'marakeng ke haholo-holo 4H-SiC le 6H-SiC mefuta ea conductive le semi-insulated ea 2-6 inches.
Ka Mphalane 2015, Cree e bile eena oa pele oa ho tsebisa li-wafers tsa 200 mm SiC substrate bakeng sa mofuta oa N le LED, a tšoaea qaleho ea li-wafers tsa 8-inch SiC 'marakeng.
Ka 2016, Romm o ile a qala ho tšehetsa sehlopha sa Venturi 'me ea e-ba eena oa pele oa ho sebelisa motsoako oa IGBT + SiC SBD ka koloing ho nkela tharollo ea IGBT + Si FRD ho inverter e tloaelehileng ea 200 kW. Ka mor'a ntlafatso, boima ba inverter bo fokotsehile ka 2 kg 'me boholo bo fokotsehile ka 19% ha u ntse u boloka matla a tšoanang.

Ka 2017, ka mor'a ho amoheloa ka ho eketsehileng ha SiC MOS + SiC SBD, boima ha bo fokotsehe feela ka lik'hilograma tse 6, empa boholo bo fokotsehile ka 43%, 'me matla a inverter a boetse a eketseha ho tloha ho 200 kW ho ea ho 220 kW.
Kamora hore Tesla e amohele lisebelisoa tse thehiloeng ho SIC ho li-inverters tse kholo tsa lihlahisoa tsa eona tsa Model 3 ka 2018, phello ea lipontšo e ile ea matlafatsoa ka potlako, ea etsa hore 'maraka oa likoloi oa xEV e be mohloli oa thabo bakeng sa mmaraka oa SiC. Ka ts'ebeliso e atlehileng ea SiC, boleng ba eona bo amanang le 'maraka le bona bo nyolohile ka potlako.

Ea borobong, Qetello:

Ka ntlafatso e tsoelang pele ea litheknoloji tse amanang le indasteri ea SiC, lihlahisoa tsa eona le ho tšepahala ho tla ntlafatsoa le ho feta, theko ea lisebelisoa tsa SiC le eona e tla fokotseha, 'me tlhōlisano ea' maraka ea SiC e tla bonahala haholoanyane. Nakong e tlang, lisebelisoa tsa SiC li tla sebelisoa haholo mafapheng a fapaneng a kang likoloi, likhokahano, marang-rang a motlakase le lipalangoang, 'me 'maraka oa lihlahisoa o tla ba o pharaletseng,' me boholo ba 'maraka bo tla atolosoa, e be tšehetso ea bohlokoa bakeng sa naha. moruo.