ʻO ke kūkulu ʻana a me ka ʻenehana ulu o ka silikon carbide (Ⅰ)

ʻO ka mea mua, ke ʻano a me nā waiwai o ka kristal SiC.

ʻO SiC kahi pūhui binary i hoʻokumu ʻia e Si element a me C element ma 1:1 ratio, ʻo ia hoʻi, 50% silicon (Si) a me 50% carbon (C), a ʻo kāna ʻāpana kumu kumu ʻo SI-C tetrahedron.

Kiʻi kiʻi kiʻi kiʻi ʻoniʻoni o ke ʻano hana tetrahedron silicon carbide

 No ka laʻana, nui nā ʻātoma Si i ke anawaena, e like me ka ʻāpala, a ʻo nā ʻātoma C he liʻiliʻi ke anawaena, e like me ka ʻalani, a ua hōʻuluʻulu ʻia ka helu like o nā ʻalani a me nā ʻōlaʻi e hana i kahi aniani SiC.

ʻO SiC He pūhui binary, i loko o ka Si-Si bond atom spacing he 3.89 A, pehea e maopopo ai i kēia kaawale? I kēia manawa, ʻo ka mīkini lithography maikaʻi loa ma ka mākeke he 3nm ka pololei o ka lithography, ʻo ia ka mamao o 30A, a ʻo ka pololei lithography he 8 mau manawa o ka mamao atomic.

ʻO ka ikehu hoʻopaʻa Si-Si he 310 kJ/mol, no laila hiki iā ʻoe ke hoʻomaopopo ʻo ka ikehu pili ka ikaika e huki ai i kēia mau ʻātoma ʻelua, a ʻoi aku ka nui o ka ikehu paʻa, ʻoi aku ka nui o ka ikaika e pono ai ʻoe e huki.

 No ka laʻana, nui nā ʻātoma Si i ke anawaena, e like me ka ʻāpala, a ʻo nā ʻātoma C he liʻiliʻi ke anawaena, e like me ka ʻalani, a ua hōʻuluʻulu ʻia ka helu like o nā ʻalani a me nā ʻōlaʻi e hana i kahi aniani SiC.

ʻO SiC He pūhui binary, i loko o ka Si-Si bond atom spacing he 3.89 A, pehea e maopopo ai i kēia kaawale? I kēia manawa, ʻo ka mīkini lithography maikaʻi loa ma ka mākeke he 3nm ka pololei o ka lithography, ʻo ia ka mamao o 30A, a ʻo ka pololei lithography he 8 mau manawa o ka mamao atomic.

ʻO ka ikehu hoʻopaʻa Si-Si he 310 kJ/mol, no laila hiki iā ʻoe ke hoʻomaopopo ʻo ka ikehu pili ka ikaika e huki ai i kēia mau ʻātoma ʻelua, a ʻoi aku ka nui o ka ikehu paʻa, ʻoi aku ka nui o ka ikaika e pono ai ʻoe e huki.

Kiʻi kiʻi kiʻi kiʻi ʻoniʻoni o ke ʻano hana tetrahedron silicon carbide

 No ka laʻana, nui nā ʻātoma Si i ke anawaena, e like me ka ʻāpala, a ʻo nā ʻātoma C he liʻiliʻi ke anawaena, e like me ka ʻalani, a ua hōʻuluʻulu ʻia ka helu like o nā ʻalani a me nā ʻōlaʻi e hana i kahi aniani SiC.

ʻO SiC He pūhui binary, i loko o ka Si-Si bond atom spacing he 3.89 A, pehea e maopopo ai i kēia kaawale? I kēia manawa, ʻo ka mīkini lithography maikaʻi loa ma ka mākeke he 3nm ka pololei o ka lithography, ʻo ia ka mamao o 30A, a ʻo ka pololei lithography he 8 mau manawa o ka mamao atomic.

ʻO ka ikehu hoʻopaʻa Si-Si he 310 kJ/mol, no laila hiki iā ʻoe ke hoʻomaopopo ʻo ka ikehu pili ka ikaika e huki ai i kēia mau ʻātoma ʻelua, a ʻoi aku ka nui o ka ikehu paʻa, ʻoi aku ka nui o ka ikaika e pono ai ʻoe e huki.

 No ka laʻana, nui nā ʻātoma Si i ke anawaena, e like me ka ʻāpala, a ʻo nā ʻātoma C he liʻiliʻi ke anawaena, e like me ka ʻalani, a ua hōʻuluʻulu ʻia ka helu like o nā ʻalani a me nā ʻōlaʻi e hana i kahi aniani SiC.

ʻO SiC He pūhui binary, i loko o ka Si-Si bond atom spacing he 3.89 A, pehea e maopopo ai i kēia kaawale? I kēia manawa, ʻo ka mīkini lithography maikaʻi loa ma ka mākeke he 3nm ka pololei o ka lithography, ʻo ia ka mamao o 30A, a ʻo ka pololei lithography he 8 mau manawa o ka mamao atomic.

ʻO ka ikehu hoʻopaʻa Si-Si he 310 kJ/mol, no laila hiki iā ʻoe ke hoʻomaopopo ʻo ka ikehu pili ka ikaika e huki ai i kēia mau ʻātoma ʻelua, a ʻoi aku ka nui o ka ikehu paʻa, ʻoi aku ka nui o ka ikaika e pono ai ʻoe e huki.

Ua ʻike mākou ua hana ʻia kēlā me kēia mea i nā ʻātoma, a ʻo ke ʻano o ke aniani he hoʻonohonoho maʻamau o nā ʻātoma, i kapa ʻia ʻo ka papa lōʻihi, e like me kēia. Kapa ʻia ka ʻāpana aniani liʻiliʻi ʻo ke kelepona, inā he ʻano cubic ke kelepona, ua kapa ʻia ʻo ia he cubic paʻa paʻa, a ʻo ke kelepona he ʻano hexagonal, ua kapa ʻia ʻo ia he hexagonal pili kokoke.

ʻO nā ʻano kristal SiC maʻamau ka 3C-SiC, 4H-SiC, 6H-SiC, 15R-SiC, a pēlā aku. Hōʻike ʻia kā lākou kaʻina hoʻopaʻa ʻana i ke kuhikuhi axis c ma ke kiʻi.

 

Ma waena o lākou, ʻo ke kaʻina hoʻonohonoho kumu o 4H-SiC ʻo ABCB ...; ʻO ke kaʻina hoʻonohonoho kumu o 6H-SiC ʻo ABCACB ... ; ʻO ke kaʻina hoʻonohonoho kumu o 15R-SiC ʻo ABCACBCABACABCB... .

 

Hiki ke ʻike ʻia kēia ma ke ʻano he pōhaku lepo no ke kūkulu hale, ʻekolu ala o ke kau ʻana o kekahi o ka hale, ʻehā mau ala o kekahi, ʻeono ala o kekahi.
Hōʻike ʻia nā ʻāpana kelepona kumu o kēia mau ʻano kristal SiC maʻamau i ka papa:

He aha ke ʻano o ka a, b, c a me nā kihi? Ua wehewehe ʻia ke ʻano o ka cell unit liʻiliʻi loa i loko o kahi semiconductor SiC penei:

I ka hihia o ke kelepona hoʻokahi, e ʻokoʻa nō hoʻi ke ʻano aniani, e like me kā mākou kūʻai ʻana i ka loteri, ʻo ka helu lanakila ʻo 1, 2, 3, kūʻai ʻoe i 1, 2, 3 ʻekolu mau helu, akā inā e hoʻokaʻawale ʻia ka helu. ʻokoʻa, ʻokoʻa ka nui o ka lanakila, no laila hiki ke kapa ʻia ka helu a me ke kauoha o ke aniani like.
Hōʻike ke kiʻi ma lalo nei i nā ʻano hoʻopaʻa ʻana maʻamau ʻelua, ʻo ka ʻokoʻa wale nō i ke ʻano hoʻopaʻa ʻana o nā ʻātoma luna, ʻokoʻa ke ʻano aniani.

ʻO ka hana aniani i hoʻokumu ʻia e SiC pili ikaika i ka mahana. Ma lalo o ka hana o ke kiʻekiʻe wela o 1900 ~ 2000 ℃, 3C-SiC e lohi e hoʻololi i ka hexagonal SiC polyform e like me 6H-SiC no ka maikaʻi ʻole o ka paʻa. Ma muli o ka pilina ikaika ma waena o ka hiki ke hoʻokumu ʻia o SiC polymorphs a me ka mahana, a me ka instability o 3C-SiC ponoʻī, paʻakikī ka ulu ʻana o 3C-SiC, a paʻakikī ka hoʻomākaukau. ʻO ka ʻōnaehana hexagonal o 4H-SiC a me 6H-SiC ka mea maʻamau a maʻalahi hoʻi e hoʻomākaukau, a ua aʻo nui ʻia ma muli o ko lākou ʻano ponoʻī.

 ʻO 1.89A wale nō ka lōʻihi o ka paʻa o ka paʻa SI-C i ka kristal SiC, akā ʻoi aku ka kiʻekiʻe o ka ikehu paʻa me 4.53eV. No laila, nui loa ka ʻokoʻa o ka ikehu ma waena o ka mokuʻāina hoʻopaʻa a me ka mokuʻāina anti-bonding, a hiki ke hoʻokumu ʻia kahi ʻāpana ākea ākea, ʻo ia ka nui o nā manawa o Si a me GaAs. ʻO ka laula o ka pūnaʻi kiʻekiʻe, ʻo ia ke ʻano o ka paʻa ʻana o ka hale aniani kiʻekiʻe. Hiki i nā uila uila pili ke hoʻomaopopo i nā hiʻohiʻona o ka hana paʻa i nā wela kiʻekiʻe a me ka hoʻoheheʻe ʻana o ka wela maʻalahi.

ʻO ka hoʻopaʻa paʻa ʻana o ka paʻa Si-C e loaʻa i ka lattice ke alapine vibration kiʻekiʻe, ʻo ia hoʻi, he phonon ikehu kiʻekiʻe, ʻo ia hoʻi he kiʻekiʻe ka mobility electron saturated a me ka conductivity thermal i ka kristal SiC. ʻoi aku ka wikiwiki o ka hoʻololi ʻana a me ka hilinaʻi, e hōʻemi ana i ka hopena o ka hāʻule ʻana o ka overtemperature. Eia kekahi, ʻo ka ʻoi aku ka ikaika o ke kahua haʻihaʻi kiʻekiʻe o SiC hiki iā ia ke hoʻokō i nā manaʻo doping kiʻekiʻe a loaʻa ka haʻahaʻa haʻahaʻa.

 ʻO ka lua, ka mōʻaukala o ka hoʻomohala ʻana o ka kristal SiC

 I ka makahiki 1905, ua ʻike ʻo Kauka Henri Moissan i kahi aniani SiC maoli i loko o ka lua, a ua ʻike ʻo ia ua like me ke daimana a kapa ʻia ʻo ia ka daimana Mosan.

 ʻO ka ʻoiaʻiʻo, i ka makahiki 1885, ua loaʻa iā Acheson ʻo SiC ma ka hui ʻana i ka coke me ka silica a hoʻomehana iā ia i loko o ka umu uila. I kēlā manawa, kuhi ka poʻe he hui daimana a kapa ʻia ʻo emery.

 I ka makahiki 1892, ua hoʻomaikaʻi ʻo Acheson i ke kaʻina hana synthesis, ua hui ʻo ia i ke one quartz, coke, kahi wahi liʻiliʻi o nā ʻāpana lāʻau a me NaCl, a hoʻomehana iā ia i loko o ka umu uila a 2700 ℃, a loaʻa maikaʻi nā kristal SiC scaly. ʻO kēia ʻano hana o ka synthesizing crystals SiC i ʻike ʻia ʻo ke ʻano Acheson a ʻo ia ke ʻano kumu nui o ka hana ʻana i nā abrasives SiC i ka ʻoihana. Ma muli o ka hoʻomaʻemaʻe haʻahaʻa o nā mea waiwai synthetic a me ke kaʻina hana synthesis, hana ʻo Acheson i nā mea haumia SiC, maikaʻi ʻole ke aniani a me ke anawaena aniani liʻiliʻi, he paʻakikī ke hoʻokō i nā koi o ka ʻoihana semiconductor no ka nui-nui, kiʻekiʻe-maʻemaʻe a kiʻekiʻe. - nā kristal maikaʻi, a ʻaʻole hiki ke hoʻohana ʻia e hana i nā mea uila.

 Hoʻolālā ʻo Lely o Philips Laboratory i kahi ala hou no ka ulu ʻana i nā kristal SiC hoʻokahi i ka makahiki 1955. Ma kēia ʻano, hoʻohana ʻia ka graphite crucible ma ke ʻano he moku ulu, hoʻohana ʻia ʻo SiC pauda kristal i mea maka no ka ulu ʻana i ka kristal SiC, a hoʻohana ʻia ka graphite porous e hoʻokaʻawale. he wahi hakahaka mai ke kikowaena o ka mea ulu. I ka wā e ulu ana, hoʻomehana ʻia ka graphite crucible i 2500 ℃ ma lalo o ka lewa o Ar a i ʻole H2, a hoʻoheheʻe ʻia ka pauka SiC peripheral a hoʻoheheʻe ʻia i loko o Si a me C vapor phase substances, a ua ulu ka SiC crystal i ka waena o ka lua ma hope o ke kinoea. lawe ʻia ke kahe ma o ka graphite porous.

ʻO ke kolu, ʻenehana ulu ʻana o ka kristal SiC

He paʻakikī ka ulu kristal hoʻokahi o SiC ma muli o kona mau hiʻohiʻona. ʻO kēia ma muli o ka loaʻa ʻole o ka pae wai me ka ratio stoichiometric o Si: C = 1: 1 ma ke kaomi ʻana i ka lewa, a ʻaʻole hiki ke ulu ʻia e nā ʻano ulu ulu ʻoi aʻe i hoʻohana ʻia e ke kaʻina ulu ulu nui o ka semiconductor. ʻoihana - cZ ala, hāʻule crucible ala a me nā ʻano hana ʻē aʻe. E like me ka helu theoretical, aia wale nō ke kiʻekiʻe o ke kaomi ma mua o 10E5atm a ʻoi aku ka kiʻekiʻe o ka mahana ma mua o 3200 ℃, hiki ke loaʻa ka lākiō stoichiometric o Si: C = 1: 1. I mea e pale aku ai i kēia pilikia, ua hoʻoikaika ʻole nā ​​​​mea ʻepekema e noi i nā ʻano hana like ʻole e loaʻa ai ka maikaʻi kristal kiʻekiʻe, ka nui a me nā kristal SiC haʻahaʻa. I kēia manawa, ʻo nā ʻano kumu nui ke ʻano PVT, ke kaʻina hana wai a me ke ʻano deposition kemika wela wela.