Hona jwale,khabide ea silicon (SiC)ke thepa ea letsopa e tsamaisang mocheso e ithutoang ka mafolofolo lapeng le linaheng tse ling. Khokahano ea mocheso ea khopolo-taba ea SiC e phahame haholo, 'me mefuta e meng ea kristale e ka fihla ho 270W/mK, e seng e le moetapele har'a thepa e seng tsamaisang motlakase. Mohlala, ts'ebeliso ea khokahano ea mocheso ea SiC e ka bonoa linthong tsa substrate tsa lisebelisoa tsa semiconductor, thepa ea letsopa e tsamaisang mocheso e phahameng, li-heater le lipoleiti tsa ho futhumatsa bakeng sa ts'ebetso ea semiconductor, thepa ea capsule bakeng sa mafura a nyutlelie, le masale a ho tiisa khase bakeng sa lipompo tsa compressor.
Tšebeliso eakhabide ea silicontšimong ea semiconductor
Di-disc le disebediswa tsa ho sila ke disebediswa tsa bohlokwa tsa tshebetso bakeng sa tlhahiso ya wafer ya silicon indastering ya semiconductor. Haeba diski ya ho sila e entswe ka tshepe e lahlilweng kapa tshepe ya carbon, nako ya yona ya tshebeletso e kgutshwane mme coefficient ya yona ya katoloso ya mocheso e kgolo. Nakong ya ho sebetsana le di-wafer tsa silicon, haholoholo nakong ya ho sila kapa ho polisha ka lebelo le phahameng, ka lebaka la ho tsofala le ho fetoha ha mocheso ha diski ya ho sila, ho ba bataletse le ho bapa ha wafer ya silicon ho thata ho netefatsa. Diski ya ho sila e entsweng kali-ceramic tsa silicon carbideHa e na le ho tsofala ho hoholo ka lebaka la ho thatafala ha eona ho hoholo, 'me coefficient ea eona ea katoloso ea mocheso e tšoana hantle le ea li-wafer tsa silicon, kahoo e ka siloa le ho bentšoa ka lebelo le phahameng.
Ho phaella moo, ha di-wafer tsa silicon di hlahiswa, di hloka ho futhumatswa ka mocheso o phahameng mme hangata di tsamaiswa ka ho sebedisa disebediswa tsa silicon carbide. Di hanela mocheso mme ha di senyehe. Khabone e kang taemane (DLC) le dikobo tse ding di ka sebediswa hodima bokahodimo ho ntlafatsa tshebetso, ho fokotsa tshenyo ya di-wafer, le ho thibela tshilafatso ho ata.
Ho feta moo, jwalo ka moemeli wa thepa ya semiconductor ya moloko wa boraro ya bandgap e pharaletseng, thepa ya kristale ya silicon carbide e le nngwe e na le thepa e kang bophara bo boholo ba bandgap (makgetlo a ka bang 3 ho feta a Si), conductivity e phahameng ya mocheso (makgetlo a ka bang 3.3 ho feta a Si kapa makgetlo a 10 ho feta a GaAs), sekgahla se phahameng sa ho falla ha dielektrone (makgetlo a ka bang 2.5 ho feta a Si) le tshimo ya motlakase e senyehang haholo (makgetlo a ka bang 10 ho feta a Si kapa makgetlo a 5 ho feta a GaAs). Disebediswa tsa SiC di lokisa diphoso tsa disebediswa tsa setso tsa thepa ya semiconductor ditshebedisong tse sebetsang mme butle-butle di fetoha karolo e ka sehloohong ya di-semiconductor tsa matla.
Tlhoko ea li-ceramics tsa silicon carbide tse nang le conductivity e phahameng ea mocheso e eketsehile haholo.
Ka nts'etsopele e tsoelang pele ea mahlale le theknoloji, tlhoko ea ts'ebeliso ea li-ceramic tsa silicon carbide tšimong ea semiconductor e eketsehile haholo, 'me ho khanna ha mocheso o phahameng ke sesupo sa bohlokoa bakeng sa ts'ebeliso ea eona likarolong tsa lisebelisoa tsa tlhahiso ea semiconductor. Ka hona, ho bohlokoa ho matlafatsa lipatlisiso mabapi le ho khanna ha mocheso o phahameng li-ceramic tsa silicon carbide. Ho fokotsa oksijene ea lattice, ho ntlafatsa bongata, le ho laola kabo ea mohato oa bobeli ka har'a lattice ka nepo ke mekhoa e meholo ea ho ntlafatsa ho khanna ha mocheso oa li-ceramic tsa silicon carbide.
Hona jwale, ho na le diphuputso tse mmalwa mabapi le diseramike tsa silicon carbide tse tsamaisang mocheso o phahameng naheng ya heso, mme ho ntse ho na le lekhalo le leholo ha le bapiswa le boemo ba lefatshe. Ditaelo tsa dipatlisiso tsa nakong e tlang di kenyeletsa:
●Matlafatsa lipatlisiso tsa ts'ebetso ea ho lokisa phofo ea ceramic ea silicon carbide. Ho lokisa phofo ea silicon carbide e hloekileng haholo, e nang le oksijene e tlase ke motheo oa ho lokisa li-ceramic tsa silicon carbide tse nang le mocheso o phahameng;
● Matlafatsa khetho ea lithuso tsa ho sinter le lipatlisiso tse amanang le tsona tsa khopolo-taba;
●Matlafatsa lipatlisiso le nts'etsopele ea lisebelisoa tsa ho sila tsa maemo a holimo. Ka ho laola ts'ebetso ea ho sila ho fumana sebopeho se loketseng sa microstructure, ke boemo bo hlokahalang ho fumana liserami tsa silicon carbide tse nang le conductivity e phahameng ea mocheso.
Mehato ea ho ntlafatsa conductivity ea mocheso oa li-ceramics tsa silicon carbide
Senotlolo sa ho ntlafatsa tsamaiso ya mocheso wa diserami tsa SiC ke ho fokotsa maqhubu a ho hasana ha diserami tsa SiC le ho eketsa tsela e mahareng ya phonon e lokolohileng. Tsamaiso ya mocheso wa SiC e tla ntlafatswa ka katleho ka ho fokotsa masoba le bongata ba moedi wa diserami tsa SiC, ho ntlafatsa bohlweki ba meedi ya diserami tsa SiC, ho fokotsa ditshila tsa lattice kapa diphoso tsa lattice, le ho eketsa mojari wa phetisetso ya phallo ya mocheso ho SiC. Hona jwale, ho ntlafatsa mofuta le dikahare tsa dithuso tsa ho sinter le kalafo ya mocheso o phahameng ke mehato e ka sehloohong ya ho ntlafatsa tsamaiso ya mocheso wa diserami tsa SiC.
① Ho ntlafatsa mofuta le dikahare tsa dithuso tsa ho sintering
Hangata ho eketsoa lithuso tse fapaneng tsa ho sinta ha ho lokisetsoa liseramike tsa SiC tse nang le motlakase o phahameng. Har'a tsona, mofuta le dikahare tsa lithuso tsa ho sinta li na le tšusumetso e kholo ho tsamaiso ea mocheso ea liseramike tsa SiC. Mohlala, likarolo tsa Al kapa O tsamaisong ea lisebelisoa tsa ho sinta tsa Al2O3 li qhibiliha habonolo ka har'a lattice ea SiC, e leng se fellang ka likheo le likoli, e leng se lebisang keketsehong ea maqhubu a ho hasana ha li-phonon. Ho phaella moo, haeba dikahare tsa lithuso tsa ho sinta li le tlase, thepa e thata ho sinta le ho teteana, ha dikahare tse phahameng tsa lithuso tsa ho sinta li tla lebisa keketsehong ea litšila le likoli. Lisebelisoa tse feteletseng tsa ho sinta tsa mokelikeli li ka boela tsa thibela kholo ea lithollo tsa SiC le ho fokotsa tsela e mahareng ea mahala ea li-phonon. Ka hona, e le ho lokisa liseramike tsa SiC tse nang le motlakase o phahameng, ho hlokahala ho fokotsa dikahare tsa lithuso tsa ho sinta ka hohle kamoo ho ka khonehang ha ho ntse ho fihlelloa litlhoko tsa bongata ba ho sinta, 'me u leke ho khetha lithuso tsa ho sinta tse thata ho qhibilihisa ka har'a lattice ea SiC.
*Thepa ea mocheso ea liserami tsa SiC ha ho eketsoa lithuso tse fapaneng tsa ho sintering
Hona jwale, diserame tsa SiC tse hatelletsoeng ka ho tjhesa tse silwang ka BeO e le thuso ya ho silwa di na le bokgoni bo phahameng ba ho tsamaisa mocheso wa kamore (270W·m-1·K-1). Leha ho le jwalo, BeO ke thepa e nang le chefo e ngata mme e baka kankere, mme ha e lokele tshebediso e pharalletseng dilaboratoring kapa masimong a diindasteri. Ntlha e tlase ka ho fetisisa ya eutectic ya sistimi ya Y2O3-Al2O3 ke 1760℃, e leng thuso e tlwaelehileng ya ho silwa ha mokelikeli bakeng sa diserame tsa SiC. Leha ho le jwalo, kaha Al3+ e qhibilihiswa habonolo ka hara lattice ya SiC, ha sistimi ena e sebediswa e le thuso ya ho silwa, bokgoni ba ho tsamaisa mocheso wa kamore ba diserame tsa SiC bo ka tlase ho 200W·m-1·K-1.
Dikarolo tse sa tloaelehang tsa lefatshe tse kang Y, Sm, Sc, Gd le La ha di qhibilihe habonolo ka hara lattice ya SiC mme di na le kamano e phahameng ya oksijene, e leng se ka fokotsang ka katleho dikahare tsa oksijene tsa lattice ya SiC. Ka hona, sistimi ya Y2O3-RE2O3 (RE=Sm, Sc, Gd, La) ke thuso e tlwaelehileng ya ho sinter bakeng sa ho lokisa conductivity e phahameng ya mocheso (>200W·m-1·K-1) SiC ceramics. Ha re nka thuso ya ho sintering ya sistimi ya Y2O3-Sc2O3 e le mohlala, boleng ba ho kheloha ha ion ba Y3+ le Si4+ bo boholo, mme tse pedi ha di fete tharollong e tiileng. Ho qhibiliha ha Sc ka hara SiC e hlwekileng ho 1800~2600℃ ho honyenyane, hoo e ka bang (2~3)×1017atoms·cm-3.
② Kalafo ea mocheso o phahameng
Kalafo ea mocheso o phahameng oa liserami tsa SiC e thusa ho felisa liphoso tsa lattice, ho falla le likhatello tse setseng, e khothalletsa phetoho ea sebopeho sa thepa e 'ngoe e sa fetoheng hore e be likristale, le ho fokolisa phello ea ho hasana ha phonon. Ho phaella moo, kalafo ea mocheso o phahameng e ka khothaletsa kholo ea lithollo tsa SiC ka katleho, 'me qetellong ea ntlafatsa litšobotsi tsa mocheso oa thepa. Mohlala, kamora kalafo ea mocheso o phahameng ka 1950°C, coefficient ea ho hasana ha mocheso oa liserami tsa SiC e eketsehile ho tloha ho 83.03mm2·s-1 ho ea ho 89.50mm2·s-1, 'me conductivity ea mocheso oa kamore e eketsehile ho tloha ho 180.94W·m-1·K-1 ho ea ho 192.17W·m-1·K-1. Kalafo ea mocheso o phahameng e ntlafatsa ka katleho bokhoni ba ho tlosa oxidation ba thuso ea ho sinter holim'a SiC le lattice, 'me e etsa hore kamano pakeng tsa lithollo tsa SiC e tiee. Kamora kalafo ea mocheso o phahameng, conductivity ea mocheso oa kamore ea liserami tsa SiC e ntlafalitsoe haholo.
Nako ea poso: Mphalane-24-2024