Ka ulu ʻana o ka SiC silicon carbide one crystal

Mai kona loaʻa ʻana mai, ua hoʻokipa nui ʻia ka silicon carbide. Hoʻokumu ʻia ʻo Silicon carbide me nā ʻātoma hapa Si a me nā ʻātoma hapa C, i hoʻopili ʻia e nā paʻa covalent ma o nā pālua electron e kaʻana like ana i nā orbital hybrid sp3. I loko o ka ʻāpana kumu o kona aniani hoʻokahi, ua hoʻonohonoho ʻia nā ʻātoma Si ʻehā i kahi ʻano tetrahedral mau, a aia ka C atom ma ke kikowaena o ka tetrahedron maʻamau. ʻO ka ʻokoʻa, hiki ke manaʻo ʻia ka Si atom ke kikowaena o ka tetrahedron, a laila e hana ʻia ʻo SiC4 a i ʻole CSi4. Hoʻolālā Tetrahedral. ʻO ka paʻa covalent ma SiC he ionic loa, a he kiʻekiʻe loa ka ikehu hoʻopaʻa silicon-carbon, ma kahi o 4.47eV. Ma muli o ka ikehu haʻahaʻa haʻahaʻa haʻahaʻa, hana maʻalahi nā kristal carbide silika i nā polytypes i ka wā o ka ulu ʻana. Aia ma mua o 200 polytypes i ʻike ʻia, hiki ke hoʻokaʻawale ʻia i ʻekolu mau ʻāpana nui: cubic, hexagonal a me trigonal.

I kēia manawa,ʻo nāʻano ulu nui o nā kristal SiC,ʻo ia ka Physical Vapor Transport Method (PVT method), High Temperature Chemical Vapor Deposition (HTCVD method), Liquid Phase Method, a me nā mea'ē aʻe. hana nui. ʻ

ʻO ke ʻano i kapa ʻia ʻo PVT e pili ana i ka waiho ʻana i nā kristal hua SiC ma luna o ke kīʻaha, a me ka waiho ʻana i ka pauka SiC ma ke ʻano he mea maka ma lalo o ka crucible. I loko o kahi wahi paʻa o ka wela kiʻekiʻe a me ka haʻahaʻa haʻahaʻa, hoʻohaʻahaʻa ka pauka SiC a neʻe i luna ma lalo o ka hana o ka gradient wela a me ka ʻokoʻa o ka ʻike. ʻO ke ʻano o ka lawe ʻana iā ia i kahi kokoke i ka ʻano aniani a laila hoʻihoʻi hou iā ia ma hope o ka hiki ʻana i kahi kūlana supersaturated. Hiki i kēia ala ke hoʻokō i ka ulu ʻana o ka nui kristal SiC a me nā ʻano kristal kikoʻī. ʻ
Eia nō naʻe, me ka hoʻohana ʻana i ke ala PVT e ulu ai i nā kristal SiC pono e mālama mau i nā kūlana ulu kūpono i ka wā o ka ulu ʻana o ka wā lōʻihi, inā ʻaʻole ia e alakaʻi i ka maʻi lattice, no laila e hoʻopilikia ai i ka maikaʻi o ke aniani. Eia nō naʻe, hoʻopau ʻia ka ulu ʻana o nā kristal SiC i kahi wahi pani. He liʻiliʻi nā kaʻina nānā pono a me nā ʻano like ʻole, no laila paʻakikī ka hoʻokele kaʻina.

Ma ke kaʻina o ka ulu ʻana i nā kristal SiC ma ke ʻano PVT, ua manaʻo ʻia ke ʻano o ka ulu ʻana o ka step flow growth (Step Flow Growth) ke kumu nui no ka ulu paʻa ʻana o kahi ʻano aniani.
ʻO nā ʻātoma Si a me nā ʻātoma C i vaporized e hoʻopaʻa maikaʻi ʻia me nā ʻāpana ʻili aniani ma ka lae kink, kahi e nucleate ai lākou a ulu, e holo like ai kēlā me kēia ʻanuʻu i mua. Ke ʻoi aku ka laulā o ka ʻanuʻu ma luna o ka ʻili aniani ma mua o ke ala diffusion manuahi o nā adatoms, hiki i ka nui o nā adatoms ke agglomerate, a ʻo ke ʻano ʻano ulu like ʻole o ka mokupuni ʻelua e hoʻopau i ke ʻano o ka ulu ʻana o ka pae, e hopena i ka nalowale o 4H. ʻike ʻike hoʻolālā aniani, ka hopena i nā hemahema lehulehu. No laila, ʻo ka hoʻoponopono ʻana i nā ʻāpana kaʻina e pono e hoʻokō i ka mana o ka pae ʻanuʻu o ka ʻili, no laila ke kāohi nei i ka hana ʻana o nā defects polymorphic, e hoʻokō ai i ke kumu o ka loaʻa ʻana o kahi ʻano kristal hoʻokahi, a me ka hoʻomākaukau ʻana i nā kristal kiʻekiʻe.

E like me ke ʻano o ka ulu ʻana o ka kristal SiC i kūkulu mua ʻia, ʻo ke ʻano o ka lawe ʻana i ka mahu kino i kēia manawa ke ala ulu nui loa no ka ulu ʻana i nā kristal SiC. Ke hoʻohālikelike ʻia me nā ʻano hana ʻē aʻe, ʻoi aku ka haʻahaʻa o kēia ʻano hana no ka ulu ʻana o nā mea ulu, kahi kaʻina ulu maʻalahi, ka mana ikaika, ʻano noiʻi hoʻomohala koʻikoʻi, a ua loaʻa i ka noi ʻoihana. ʻO ka maikaʻi o ke ʻano HTCVD ʻo ia ka mea hiki ke ulu i ka conductive (n, p) a me ka hoʻomaʻemaʻe kiʻekiʻe semi-insulating wafers, a hiki ke hoʻomalu i ka neʻe ʻana o ka doping i hiki ke hoʻololi ʻia ka mea lawe i ka wafer ma waena o 3 × 1013 ~ 5 × 1019. /cm3. ʻO nā hemahema ka paepae ʻenehana kiʻekiʻe a me ka māhele mākeke haʻahaʻa. Ke hoʻomau nei ka ulu ʻana o ka ʻenehana SiC crystal i ka wai, e hōʻike ana i ka mana nui i ka holomua ʻana i ka ʻoihana SiC holoʻokoʻa i ka wā e hiki mai ana a ʻo ia paha kahi wahi holomua hou i ka ulu ʻana o ka kristal SiC.