Kamar yadda aka nuna a cikin siffa 3, akwai manyan fasahohin da suka fi dacewa da nufin samar da SiC guda kristal tare da inganci da inganci: ruwa lokaci epitaxy (LPE), jigilar tururi ta jiki (PVT), da kuma yawan zafin jiki na tururi (HTCVD). PVT shine ingantaccen tsari don samar da SiC guda kristal, wanda ake amfani dashi sosai a cikin manyan masana'antun wafer.
Koyaya, duk matakai guda uku suna haɓaka da sauri da haɓakawa. Har yanzu ba a iya yin watsi da tsarin da za a yi amfani da shi sosai a nan gaba ba. Musamman ma, babban ingancin SiC guda kristal da aka samar ta hanyar haɓakar bayani a cikin adadi mai yawa an bayar da rahoton a cikin 'yan shekarun nan, SiC girma girma a cikin ruwa lokaci yana buƙatar ƙananan zafin jiki fiye da na tsarin ƙaddamarwa ko ƙaddamarwa, kuma yana nuna fifiko a cikin samar da P -nau'in SiC substrates (Table 3) [33, 34].
Hoto na 3: Tsarin dabarun ci gaban SiC guda uku masu rinjaye: (a) epitaxy lokaci na ruwa; (b) jigilar tururi ta jiki; (c) Matsakaicin tururin sinadarai masu zafi
Table 3: Kwatanta LPE, PVT da HTCVD don haɓaka lu'ulu'u ɗaya na SiC [33, 34]
Ci gaban Magani shine daidaitaccen fasaha don shirya mahaɗan semiconductor [36]. Tun daga 1960s, masu bincike sun yi ƙoƙarin haɓaka crystal a cikin bayani [37]. Da zarar an haɓaka fasahar, za a iya sarrafa supersaturation na farfajiyar girma da kyau, wanda ya sa hanyar mafita ta zama fasaha mai ban sha'awa don samun ingots guda ɗaya mai inganci.
Don haɓakar haɓakar kristal guda ɗaya na SiC, tushen Si ya fito ne daga tsantsar Si narke yayin da graphite crucible yayi amfani da dalilai guda biyu: hita da tushen C solute. SiC guda lu'ulu'u suna iya girma a ƙarƙashin madaidaicin ma'auni na stoichiometric lokacin da rabon C da Si yana kusa da 1, yana nuna ƙarancin ƙarancin lahani [28]. Koyaya, a matsa lamba na yanayi, SiC ba ta nuna alamar narkewa kuma tana rubewa kai tsaye ta yanayin yanayin tururi wanda ya wuce 2,000 ° C. SiC ya narke, bisa ga tsammanin hasashen, za a iya samuwa ne kawai a ƙarƙashin mai tsanani za a iya gani daga Si-C tsarin tsarin binary (Fig. 4) wanda ta hanyar zafin jiki da kuma tsarin bayani. Mafi girman C a cikin Si narke ya bambanta daga 1at.% zuwa 13at.%. Tuki C supersaturation, da saurin haɓakar girma, yayin da ƙarancin C na haɓaka shine C supersaturation wanda ke mamaye matsin lamba na 109 Pa da yanayin zafi sama da 3,200 °C. Yana iya supersaturation samar da m surface [22, 36-38].zazzabi tsakanin 1,400 da 2,800 °C, da solubility na C a cikin Si narkewa dabam daga 1at.% zuwa 13at.%. Ƙarfin haɓakar haɓaka shine C supersaturation wanda ke mamaye yanayin zafin jiki da tsarin mafita. Mafi girman girman C, saurin haɓakar haɓaka, yayin da ƙarancin C supersaturation yana samar da ƙasa mai santsi [22, 36-38].
Hoto na 4: Si-C tsarin tsarin binary [40]
Doping abubuwan ƙarfe na canzawa ko abubuwan da ba kasafai ba na duniya ba kawai rage yawan zafin jiki yadda ya kamata ba amma da alama ita ce hanya ɗaya tilo da za a inganta haɓakar carbon solubility a cikin Si narke. Ƙarin ƙarafa na rukuni na canji, kamar Ti [8, 14-16, 19, 40-52], Cr [29, 30, 43, 50, 53-75], Co [63, 76], Fe [77- 80], da sauransu. 50at.% a cikin jihar kusa da ma'aunin ma'aunin zafi da sanyio. Bugu da ƙari, fasahar LPE tana da kyau ga nau'in nau'in P-doping na SiC, wanda za'a iya samu ta hanyar haɗa Al a cikin
sauran ƙarfi [50, 53, 56, 59, 64, 71-73, 82, 83]. Duk da haka, haɗawar Al yana haifar da karuwa a cikin juriya na nau'in P-type SiC single lu'ulu'u [49, 56].Baya ga nau'in nau'in N-girma a ƙarƙashin nitrogen doping,
Ci gaban maganin gabaɗaya yana gudana a cikin yanayin iskar gas mara ƙarfi. Duk da cewa helium (He) ya fi argon tsada, malamai da yawa sun fi son sa saboda ƙananan danko da mafi girman yanayin zafi (lokaci 8 na argon) [85]. Yawan ƙaura da abun ciki na Cr a cikin 4H-SiC sun yi kama da yanayin He da Ar, an tabbatar da cewa girma a ƙarƙashin Heresults a cikin ƙimar girma mafi girma fiye da girma a ƙarƙashinAr saboda tsananin zafi na mai riƙe iri [68]. Yana hana samuwar ɓoyayyiyar kristal da aka girma da ƙwayar cuta ta kwatsam a cikin maganin, sa'an nan, za'a iya samun santsin yanayin halitta [86].
Wannan takarda ta gabatar da ci gaba, aikace-aikace, da kaddarorin na'urorin SiC, da manyan hanyoyi guda uku don haɓaka SiC guda crystal. A cikin ɓangarorin da ke gaba, an sake duba dabarun haɓaka mafita na yanzu da madaidaitan maɓalli masu mahimmanci. A ƙarshe, an gabatar da hangen nesa wanda ya tattauna ƙalubalen da ayyuka na gaba game da girma mai girma na lu'ulu'u ɗaya na SiC ta hanyar mafita.
Lokacin aikawa: Jul-01-2024