Na farko, tsari da kaddarorin SiC crystal.
SiC wani fili ne na binaryar da Si element da C element suka yi a cikin rabo 1:1, wato, 50% silicon (Si) da 50% carbon (C), kuma ainihin tsarin sa shine SI-C tetrahedron.
Tsarin tsari na tsarin tetrahedron silicon carbide
Misali, Si atoms suna da girma a diamita, daidai da apple, da kuma atom ɗin C suna kanana a diamita, daidai da orange, kuma ana tattara adadin adadin lemu da apples daidai gwargwado don samar da SiC crystal.
SiC wani fili ne na binary, wanda Si-Si bond atom tazarar 3.89 A, ta yaya za a fahimci wannan tazara? A halin yanzu, mafi kyawun injin lithography a kasuwa yana da daidaiton lithography na 3nm, wanda shine nisa na 30A, kuma daidaiton lithography shine sau 8 na nisan atomic.
Ƙarfin haɗin Si-Si shine 310 kJ/mol, don haka za ku iya fahimtar cewa makamashin haɗin gwiwa shine ƙarfin da ke janye waɗannan kwayoyin halitta guda biyu, kuma mafi girma ƙarfin haɗin gwiwa, mafi girma ƙarfin da kuke buƙatar cirewa.
Misali, Si atoms suna da girma a diamita, daidai da apple, da kuma atom ɗin C suna kanana a diamita, daidai da orange, kuma ana tattara adadin adadin lemu da apples daidai gwargwado don samar da SiC crystal.
SiC wani fili ne na binary, wanda Si-Si bond atom tazarar 3.89 A, ta yaya za a fahimci wannan tazara? A halin yanzu, mafi kyawun injin lithography a kasuwa yana da daidaiton lithography na 3nm, wanda shine nisa na 30A, kuma daidaiton lithography shine sau 8 na nisan atomic.
Ƙarfin haɗin Si-Si shine 310 kJ/mol, don haka za ku iya fahimtar cewa makamashin haɗin gwiwa shine ƙarfin da ke janye waɗannan kwayoyin halitta guda biyu, kuma mafi girma ƙarfin haɗin gwiwa, mafi girma ƙarfin da kuke buƙatar cirewa.
Tsarin tsari na tsarin tetrahedron silicon carbide
Misali, Si atoms suna da girma a diamita, daidai da apple, da kuma atom ɗin C suna kanana a diamita, daidai da orange, kuma ana tattara adadin adadin lemu da apples daidai gwargwado don samar da SiC crystal.
SiC wani fili ne na binary, wanda Si-Si bond atom tazarar 3.89 A, ta yaya za a fahimci wannan tazara? A halin yanzu, mafi kyawun injin lithography a kasuwa yana da daidaiton lithography na 3nm, wanda shine nisa na 30A, kuma daidaiton lithography shine sau 8 na nisan atomic.
Ƙarfin haɗin Si-Si shine 310 kJ/mol, don haka za ku iya fahimtar cewa makamashin haɗin gwiwa shine ƙarfin da ke janye waɗannan kwayoyin halitta guda biyu, kuma mafi girma ƙarfin haɗin gwiwa, mafi girma ƙarfin da kuke buƙatar cirewa.
Misali, Si atoms suna da girma a diamita, daidai da apple, da kuma atom ɗin C suna kanana a diamita, daidai da orange, kuma ana tattara adadin adadin lemu da apples daidai gwargwado don samar da SiC crystal.
SiC wani fili ne na binary, wanda Si-Si bond atom tazarar 3.89 A, ta yaya za a fahimci wannan tazara? A halin yanzu, mafi kyawun injin lithography a kasuwa yana da daidaiton lithography na 3nm, wanda shine nisa na 30A, kuma daidaiton lithography shine sau 8 na nisan atomic.
Ƙarfin haɗin Si-Si shine 310 kJ/mol, don haka za ku iya fahimtar cewa makamashin haɗin gwiwa shine ƙarfin da ke janye waɗannan kwayoyin halitta guda biyu, kuma mafi girma ƙarfin haɗin gwiwa, mafi girma ƙarfin da kuke buƙatar cirewa.
Mun san cewa kowane sinadari an yi shi ne da atom, kuma tsarin kristal tsari ne na yau da kullun na atom, wanda ake kira tsari mai tsayi, kamar haka. Mafi ƙanƙanta naúrar crystal ana kiranta da tantanin halitta, idan tantanin halitta tsarin cubic ne, ana kiransa da cubic cubic kusa, kuma tantanin halitta tsari ne mai siffar ɗari huɗu, ana kiransa da madaidaicin cubic cubic.
Nau'in kristal na SiC na yau da kullun sun haɗa da 3C-SiC, 4H-SiC, 6H-SiC, 15R-SiC, da sauransu. An nuna jerin gwanon su a cikin jagorar c axis a cikin adadi.
Daga cikin su, ainihin jerin abubuwan 4H-SiC shine ABCB ... ; Ainihin jerin abubuwan tarawa na 6H-SiC shine ABCACB... ; Mahimmin tsarin tarawa na 15R-SiC shine ABCACBCABACABCB... .
Ana iya kallon wannan a matsayin tubali na ginin gida, wasu tubalin gidan suna da hanyoyi uku na sanya su, wasu suna da hanyoyi guda hudu, wasu kuma hanyoyi shida.
Ana nuna ainihin sigogin tantanin halitta na waɗannan nau'ikan kristal na SiC gama-gari a cikin tebur:
Menene ma'anar a, b, c da kusurwoyi? An kwatanta tsarin mafi ƙanƙanta tantanin halitta a cikin semiconductor na SiC kamar haka:
Dangane da tantanin halitta guda, tsarin crystal shima zai bambanta, wannan shine kamar yadda muke siyan caca, lambar nasara shine 1, 2, 3, kun sayi lambobi uku 1, 2, 3, amma idan an jera lambar. daban, adadin nasara ya bambanta, don haka lamba da tsari na crystal iri ɗaya, ana iya kiran shi crystal iri ɗaya.
Alkali mai zuwa tana nuna hanyoyin daidaitawa guda biyu, kawai bambanci a cikin yanayin ɗigon atoms na manyan atoms, tsarin kristal ya bambanta.
Tsarin lu'ulu'u da SiC ya kafa yana da alaƙa da zafi sosai. A karkashin aikin high zafin jiki na 1900 ~ 2000 ℃, 3C-SiC za a sannu a hankali canza zuwa hexagonal SiC polyform kamar 6H-SiC saboda ta matalauta tsarin kwanciyar hankali. Daidai ne saboda ƙaƙƙarfan alaƙa tsakanin yuwuwar samuwar SiC polymorphs da zafin jiki, da rashin kwanciyar hankali na 3C-SiC kanta, haɓakar haɓakar 3C-SiC yana da wahalar haɓakawa, kuma shiri yana da wahala. Tsarin hexagonal na 4H-SiC da 6H-SiC sune aka fi sani da sauƙin shiryawa, kuma ana yin nazari sosai saboda halayensu.
Tsawon haɗin haɗin SI-C a cikin SiC crystal shine kawai 1.89A, amma ƙarfin ɗaurin ya kai 4.53eV. Saboda haka, tazarar matakin makamashi tsakanin yanayin haɗin gwiwa da jihar anti-bonding yana da girma sosai, kuma ana iya samun tazara mai faɗi, wanda sau da yawa na Si da GaAs. Nisa mafi girma na band yana nufin cewa babban yanayin kristal yana da ƙarfi. Na'urorin lantarki masu alaƙa na iya gane halayen barga aiki a yanayin zafi da sauƙaƙan tsarin kawar da zafi.
Ƙunƙarar dauri na haɗin Si-C yana sa lattice ya sami mitar girgiza, wato, ƙarar makamashi mai ƙarfi, wanda ke nufin cewa SiC crystal yana da cikakken motsi na lantarki da haɓakar thermal, kuma na'urorin lantarki masu alaƙa suna da mafi girman saurin sauyawa da aminci, wanda ke rage haɗarin gazawar zafin na'urar. Bugu da kari, mafi girman ƙarfin filin fashewar SiC yana ba shi damar cimma mafi girman adadin doping kuma yana da ƙarancin juriya.
Na biyu, tarihin ci gaban SiC crystal
A shekara ta 1905, Dr. Henri Moissan ya gano sic crystal na halitta a cikin ramin, wanda ya same shi yayi kama da lu'u-lu'u kuma ya sa masa suna Mosan diamond.
A gaskiya ma, a farkon 1885, Acheson ya sami SiC ta hanyar hada coke da silica da dumama shi a cikin tanderun lantarki. A lokacin, mutane sun rikitar da shi don cakuda lu'u-lu'u kuma suna kiran shi Emery.
A shekara ta 1892, Acheson ya inganta tsarin haɗin gwiwa, ya haxa yashi quartz, coke, ƙananan guntun itace da NaCl, kuma ya dumama shi a cikin tanderun wutar lantarki zuwa 2700 ℃, kuma ya sami nasarar samun lu'ulu'u na SiC. Wannan hanyar hada lu'ulu'u na SiC ana kiranta da hanyar Acheson kuma har yanzu ita ce babbar hanyar samar da abrasives na SiC a masana'antu. Saboda ƙarancin tsabta na kayan da aka yi da kayan aiki da kuma tsarin haɗin kai, hanyar Acheson yana samar da ƙarin ƙazantattun SiC, rashin mutuncin crystal da ƙananan diamita na crystal, wanda yake da wuyar saduwa da bukatun masana'antar semiconductor don girman girman, high-tsarki da girma. -kyakkyawan lu'ulu'u, kuma ba za a iya amfani da su don kera na'urorin lantarki ba.
Lely na Philips Laboratory ya ba da shawarar sabuwar hanyar don haɓaka lu'ulu'u na SiC guda ɗaya a cikin 1955. A cikin wannan hanyar, ana amfani da graphite crucible azaman jirgin ruwa mai girma, ana amfani da SiC foda crystal azaman albarkatun ƙasa don girma SiC crystal, kuma ana amfani da graphite mai ƙarfi don ware. wuri maras kyau daga tsakiyar albarkatun albarkatun gona. Lokacin girma, da graphite crucible ne mai tsanani zuwa 2500 ℃ a karkashin yanayi na Ar ko H2, da peripheral SiC foda ne sublimed kuma bazu zuwa Si da C tururi lokaci abubuwa, da kuma SiC crystal girma a tsakiyar m yankin bayan gas. kwarara yana daukar kwayar cutar ta graphite mara kyau.
Na uku, fasahar girma ta SiC crystal
Girman kristal guda ɗaya na SiC yana da wahala saboda halayensa. Wannan shi ne yafi saboda gaskiyar cewa babu wani lokaci na ruwa tare da rabon stoichiometric na Si: C = 1: 1 a matsa lamba na yanayi, kuma ba za a iya girma ta hanyar mafi girma balagagge hanyoyin da ake amfani da shi a halin yanzu babban ci gaban tsarin na semiconductor. masana'antu - cZ Hanyar, fadowa crucible hanya da sauran hanyoyin. Bisa ga ka'idar lissafi, kawai a lokacin da matsa lamba ne mafi girma fiye da 10E5atm da zazzabi ne mafi girma fiye da 3200 ℃, da stoichiometric rabo na Si: C = 1: 1 bayani za a iya samu. Domin shawo kan wannan matsala, masana kimiyya sun yi ƙoƙari sosai don ba da shawara daban-daban don samun babban ingancin crystal, girman girman da arha sic lu'ulu'u. A halin yanzu, manyan hanyoyin sune hanyar PVT, hanyar lokacin ruwa da kuma babban zafin tururi na sinadarai.
Lokacin aikawa: Janairu-24-2024