Ke Kumumanaʻo o ke ʻAno PVT Silicon Carbide (SiC) Crystal Growth

ʻO ke ʻano PVT, nona ka inoa piha ʻo Physical Vapor Transportation, he ʻano maʻamau no ka ulu ʻana i ka silicon carbide (SiC)nā kristal ma lalo o ke ana wela a me ke kaomi kiʻekiʻe. ʻO kona kumu nui ka hoʻomehana ʻana i ka pauka silicon carbide i ka sublimation ma kahi mahana ma luna o 2300 ℃ a ma kahi haʻahaʻa haʻahaʻa kokoke i ka vacuum, e hana ana i kahi kinoea hopena e loaʻa ana nā ʻāpana kinoea e like me Si, Si2C, a me SiC2. Ma muli o nā kaomi hapa kinoea ʻokoʻa o nā ʻāpana Si a me C i hoʻokumu ʻia e ka hopena sublimation paʻa, ʻokoʻa ka lakio Si/C stoichiometric me ka hoʻolaha ʻana o ke kahua wela. No laila, pono e kāohi i ka hoʻolaha ʻana a me ka lawe ʻana o nā ʻāpana kinoea e hōʻoia i ko lākou hiki ʻana i nā kūlana crystallization kikoʻī i loko o ke keʻena ulu.

I mea e pale aku ai i ka hoʻokumu ʻana o ka crystallization gas-phase i hoʻoponopono ʻole ʻia mai ka hana ʻana i ka polycrystalline silicon carbide, ua hoʻonoho ʻia nā kristal hua silicon carbide ma luna o ke keʻena ulu. Ma lalo o ke alakaʻi ʻana o ka supersaturation gas-phase, e waiho nā ʻāpana gas-phase ma luna o ka ʻili o ka kristal hua e hana i nā kristal hoʻokahi silicon carbide. Hana ʻia ke kaʻina hana holoʻokoʻa i loko o kahi keʻena ulu pani ʻia, kahi e hoʻopili ʻia ai nā palena āpau o ka ʻōnaehana hana me kekahi. ʻO kēlā me kēia loli i nā kūlana ulu e hoʻopilikia i ke kūpaʻa o ka ulu ʻana o ka kristal hoʻokahi.

Eia kekahi, ʻo nā ʻano like ʻole o nā kristal silicon carbide hoʻokahi e pili ana i ko lākou kuhikuhi kristal e alakaʻi i nā ʻano pilina atomika like ʻole a me nā ʻano hoʻopili, no laila e hana ana ma mua o 200 mau ʻano kristal o nā isomers silicon carbide. He haʻahaʻa loa ka pale hoʻololi ikehu ma waena o nā ʻano kristal like ʻole, no laila he mea hiki ke hana ʻia ka hoʻololi ʻana o ke ʻano kristal i loko o ka ʻōnaehana ulu kristal hoʻokahi PVT, e hopena ana i nā ʻano kristal pahuhopu i hoʻopilikia ʻole ʻia a me nā hemahema crystallization like ʻole. No laila, pono e hoʻohana i nā lako nānā i hoʻolaʻa ʻia e ʻike i ke ʻano kristal a me nā hemahema like ʻole o ka ingot kristal.

He kiʻekiʻe loa nā koi o ke kaʻina hana hoʻomākaukau o ka silicon carbide, i hōʻike nui ʻia ma nā ʻano penei:

• Nui nā haumia o ke kaiapuni i ke kaʻina hana synthesis o ka pauka silicon carbide, e paʻakikī ai ka loaʻa ʻana o ka pauka maʻemaʻe kiʻekiʻe. ʻO ka hopena piha ʻole ma waena o ka pauka silicon a me ka pauka kalapona ma ke ʻano he kumu hopena e hiki ke hana i kahi kaulike ʻole i ka lakio Si/C. He paʻakikī ke kaohi i ke ʻano kristal a me ka nui o ka ʻāpana o ka pauka silicon carbide ma hope o ka synthesis.
• Ma lalo o nā kūlana o ke kiʻekiʻe o ka mahana ma luna o 2300 ℃ a kokoke i ka vacuum, ke hana nei ka silicon carbide i kahi hoʻololi "paʻa-gas-paʻa" a me ke kaʻina hana recrystallization i loko o kahi keʻena graphite pani. He lōʻihi ka pōʻaiapuni ulu o kēia kaʻina hana, he paʻakikī ke kaohi, a he maʻalahi i nā hemahema e like me nā microtubules a me nā inclusions.
• Loaʻa i ka Silicon carbide ma mua o 200 mau ʻano kristal like ʻole, akā ʻo ka hana ʻana maʻamau e pono ai hoʻokahi ʻano kristal. I ka wā o ke kaʻina hana ulu, hiki ke hoʻololi ʻia ke ʻano kristal, e hopena ana i nā hemahema hoʻokomo multitype. I ka wā o ke kaʻina hana hoʻomākaukau, he paʻakikī ke kāohi paʻa i kahi ʻano kristal hoʻokahi, a he haʻahaʻa loa ka pale hoʻololi ikehu ma waena o nā ʻano kristal like ʻole, kahi e hoʻonui ai i ka paʻakikī o ka kaohi. ʻO ka kaohi parameter a me ka noiʻi pili i kēia wā e koi ai i nā kumukūʻai R&D nui, ʻo ia kekahi o nā kumu no ke kumukūʻai kiʻekiʻe o ka silicon carbide kūpono.