Izindlela eziyinhloko zokutshala amakristalu e-silicon carbide single zifaka phakathi i-Physical Vapor Transport (PVT), i-Top-Seeded Solution Growth (TSSG), kanye ne-High-Temperature Chemical Vapor Deposition (HT-CVD).

Phakathi kwalokhu, indlela ye-PVT isibe yindlela eyinhloko yokukhiqiza izimboni ngenxa yokusethwa kwayo kwemishini okulula, ukulula kokusebenza nokulawula, kanye nezindleko zemishini nezokusebenza eziphansi.

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Amaphuzu Obuchwepheshe Abalulekile Okukhula Kwekristalu Le-SiC Ukusebenzisa Indlela Ye-PVT

Ukuze kukhuliswe amakristalu e-silicon carbide kusetshenziswa indlela ye-PVT, izici eziningana zobuchwepheshe kumele zilawulwe ngokucophelela:

1. Ukuhlanzeka Kwezinto Ze-Graphite Ensimini Yokushisa
   Izinto ze-graphite ezisetshenziswa ensimini yokushisa yokukhula kwekristalu kumele zihlangabezane nezidingo eziqinile zobumsulwa. Okuqukethwe kokungcola ezingxenyeni ze-graphite kufanele kube ngaphansi kuka-5×10⁻⁶, kanye nama-felt okushisa kufanele kube ngaphansi kuka-10×10⁻⁶. Ngokukhethekile, okuqukethwe yi-boron (B) kanye ne-aluminium (Al) ngayinye kumele kube ngaphansi kuka-0.1×10⁻⁶.

2. I-Polarity Efanele ye-Seed Crystal
   Idatha engokomlando ikhombisa ukuthi i-C-face (0001) ifanelekela ukukhulisa amakristalu angu-4H-SiC, kuyilapho i-Si-face (0001) ifanelekela ukukhula kwe-6H-SiC.

3. Ukusetshenziswa Kwamakristalu Embewu Engaxhumekile Ku-Axis
   Imbewu engaxhumekile ku-axis ingashintsha ukulingana kokukhula, inciphise amaphutha ekristalu, futhi ikhuthaze ikhwalithi engcono yekristalu.

4. Indlela Ethembekile Yokubopha I-Crystal Yembewu
   Ukubopha okufanele phakathi kwekristalu yembewu kanye nesiphathi kubalulekile ukuze kuqine ngesikhathi sokukhula.

5. Ukugcina Ukuqina Kwe-Growth Interface
   Phakathi nomjikelezo wonke wokukhula kwekristalu, isikhombikubona sokukhula kumele sihlale sizinzile ukuqinisekisa ukuthuthukiswa kwekristalu esezingeni eliphezulu.

 

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Ubuchwepheshe Obuyinhloko Ekukhuleni Kwekristalu le-SiC

1. Ubuchwepheshe bokusebenzisa i-Doping ye-SiC Powder

Ukufaka i-doping ye-SiC powder nge-cerium (Ce) kungazinzisa ukukhula kwe-polytype eyodwa njenge-4H-SiC. Umkhuba ukhombisile ukuthi ukufaka i-Ce doping kungenza okulandelayo:

• Khulisa izinga lokukhula kwamakristalu e-SiC;

• Thuthukisa ukuqondiswa kwekristalu ukuze kukhule ngendlela efanayo futhi ngendlela eqondile;

• Nciphisa ukungcola kanye nokukhubazeka;

• Cindezela ukugqwala kwekristalu ngemuva;

• Thuthukisa izinga lokukhiqiza i-single crystal.

2. Ukulawulwa kwe-Axial kanye ne-Radial Thermal Gradients

Ama-gradients okushisa kwe-Axial athinta i-polytype yekristalu kanye nesilinganiso sokukhula. I-gradient encane kakhulu ingaholela ekufakweni kwe-polytype kanye nokuncipha kokuthuthwa kwezinto ezisetshenziswayo esigabeni somusi. Ukwenza ngcono ama-gradients e-axial kanye ne-radial kubalulekile ekukhuleni kwekristalu okusheshayo nokuzinzile ngekhwalithi ehambisanayo.

3. Ubuchwepheshe Bokulawula Ukuhlukaniswa Kwendiza Eyisisekelo (BPD)

Ama-BPD akheka kakhulu ngenxa yokucindezeleka okuncishisiwe okungaphezu komkhawulo obalulekile kumakristalu e-SiC, okusebenzisa izinhlelo zokushelela. Njengoba ama-BPD eqonde ngqo endleleni yokukhula, avame ukuvela ngesikhathi sokukhula kwekristalu kanye nokupholisa. Ukunciphisa ukucindezeleka kwangaphakathi kunganciphisa kakhulu ukuminyana kwe-BPD.

4. Ukulawulwa Kwesilinganiso Sokwakheka Kwesigaba Somhwamuko

Ukwandisa isilinganiso se-carbon-to-silicon esigabeni somusi kuyindlela eqinisekisiwe yokukhuthaza ukukhula kwe-polytype eyodwa. Isilinganiso se-C/Si esiphezulu sinciphisa ukuhlanganiswa kwe-macrostep futhi sigcina ifa lobuso elivela kukristalu yembewu, ngaleyo ndlela kucindezelwe ukwakheka kwe-polytypes engafuneki.

5. Amasu Okukhula Okucindezeleka Okuphansi

Ukucindezeleka ngesikhathi sokukhula kwekristalu kungaholela ezindizeni ze-lattice ezigobile, imifantu, kanye nobuningi be-BPD obuphezulu. Lokhu kukhubazeka kungadlulela ezingqimbeni ze-epitaxial futhi kuthinte kabi ukusebenza kwedivayisi.

Amasu amaningana okunciphisa ukucindezeleka kwangaphakathi kwekristalu afaka:

• Ukulungisa ukusatshalaliswa kwensimu yokushisa kanye nemingcele yenqubo ukukhuthaza ukukhula okucishe kube ukulingana;

• Ukuthuthukisa ukwakheka kwe-crucible ukuvumela ikristalu ukuthi ikhule ngokukhululeka ngaphandle kwemingcele yomshini;

• Ukuthuthukisa ukwakheka kwesibambi sembewu ukuze kuncishiswe ukungalingani kokukhula kokushisa phakathi kwembewu ne-graphite ngesikhathi sokushisa, ngokuvamile ngokushiya igebe elingu-2 mm phakathi kwembewu nesibambi;

• Ukucubungula izinqubo zokufaka umswakama, ukuvumela ikristalu ukuthi iphole ngesithando somlilo, nokulungisa izinga lokushisa kanye nobude besikhathi ukuze kuncishiswe ngokuphelele ukucindezeleka kwangaphakathi.

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Amathrendi kubuchwepheshe bokukhula kwe-SiC Crystal

1. Osayizi Abakhulu Bekristalu
Ububanzi bekristalu elilodwa le-SiC bukhuphuke kusukela kumamilimitha ambalwa kuya kuma-wafer angu-6-intshi, angu-8-intshi, ngisho nangu-12-intshi. Ama-wafer amakhulu akhulisa ukusebenza kahle kokukhiqiza futhi anciphisa izindleko, ngenkathi ehlangabezana nezidingo zezinhlelo zokusebenza zamadivayisi ezinamandla amakhulu.

2. Ikhwalithi Ephakeme Yekristalu
Amakristalu e-SiC asezingeni eliphezulu abalulekile kumadivayisi asebenza kahle kakhulu. Naphezu kokuthuthuka okukhulu, amakristalu amanje asabonisa amaphutha afana namapayipi amancane, ukuhlukana, kanye nokungcola, konke okungonakalisa ukusebenza kwedivayisi kanye nokuthembeka kwayo.

3. Ukunciphisa Izindleko
Ukukhiqizwa kwekristalu ye-SiC kusabiza kakhulu, kunciphisa ukwamukelwa okubanzi. Ukunciphisa izindleko ngezinqubo zokukhula ezithuthukisiwe, ukwanda kokusebenza kahle kokukhiqiza, kanye nezindleko eziphansi zezinto zokusetshenziswa kubalulekile ekwandiseni izinhlelo zokusebenza zemakethe.

4. Ukukhiqiza Okuhlakaniphile
Ngokuthuthuka kobuhlakani bokwenziwa kanye nobuchwepheshe bedatha enkulu, ukukhula kwekristalu ye-SiC kuya ezinqubweni ezihlakaniphile nezizenzakalelayo. Izinzwa nezinhlelo zokulawula zingaqapha futhi zilungise izimo zokukhula ngesikhathi sangempela, zithuthukise ukuzinza kwenqubo kanye nokubikezela. Ukuhlaziywa kwedatha kungathuthukisa kakhulu amapharamitha enqubo kanye nekhwalithi yekristalu.

Ukuthuthukiswa kobuchwepheshe bokukhula kwekristalu elilodwa le-SiC elisezingeni eliphezulu kugxile kakhulu ocwaningweni lwezinto ze-semiconductor. Njengoba ubuchwepheshe buthuthuka, izindlela zokukhula kwekristalu zizoqhubeka nokukhula futhi zithuthuke, zinikeze isisekelo esiqinile sezinhlelo zokusebenza ze-SiC kumadivayisi kagesi asebenza ngokushisa okuphezulu, imvamisa ephezulu, kanye namandla aphezulu.