Tun bayan gano shi, silicon carbide ya jawo hankalin jama'a. Silicon carbide ya ƙunshi rabin atoms na Si da rabin atoms na C, waɗanda aka haɗa ta hanyar haɗin covalent ta hanyar haɗin electron da ke raba sp3 hybrid orbitals. A cikin tsarin asali na lu'ulu'u ɗaya, an shirya atoms na Si guda huɗu a cikin tsarin tetrahedral na yau da kullun, kuma atom ɗin C yana tsakiyar tetrahedral na yau da kullun. Akasin haka, ana iya ɗaukar atom ɗin Si a matsayin tsakiyar tetrahedron, ta haka ne ke samar da SiC4 ko CSi4. Tsarin tetrahedral. Haɗin covalent a cikin SiC yana da ionic sosai, kuma kuzarin haɗin silicon-carbon yana da yawa, kusan 4.47eV. Saboda ƙarancin kuzarin kuskure na tara, lu'ulu'u na silicon carbide suna samar da nau'ikan polytypes daban-daban cikin sauƙi yayin tsarin girma. Akwai nau'ikan polytypes sama da 200 da aka sani, waɗanda za a iya raba su zuwa manyan rukuni uku: cubic, hexagonal da trigonal.
A halin yanzu, manyan hanyoyin girma na lu'ulu'u na SiC sun haɗa da Hanyar Sufuri na Tururi na Jiki (hanyar PVT), Tsarin Tsabtace Tururi na Zafi Mai Zafi (hanyar HTCVD), Hanyar Matakin Ruwa, da sauransu. Daga cikinsu, hanyar PVT ta fi girma kuma ta fi dacewa da samar da kayan masana'antu.
Hanyar da ake kira PVT tana nufin sanya lu'ulu'u iri na SiC a saman bututun, da kuma sanya foda na SiC a matsayin kayan da aka samo a ƙasan bututun. A cikin yanayin rufewa mai zafi da ƙarancin matsin lamba, foda na SiC yana raguwa kuma yana motsawa sama ƙarƙashin tasirin canjin yanayin zafi da bambancin taro. Hanya ce ta jigilar shi zuwa kusa da gilashin iri sannan a sake sanya shi bayan ya kai matsayin da ya cika. Wannan hanyar na iya cimma girman lu'ulu'u na SiC da takamaiman siffofin kristal.
Duk da haka, amfani da hanyar PVT don shuka lu'ulu'u na SiC yana buƙatar ci gaba da kiyaye yanayin girma mai dacewa a lokacin girma na dogon lokaci, in ba haka ba zai haifar da rashin daidaituwa, don haka yana shafar ingancin lu'ulu'u. Duk da haka, girman lu'ulu'u na SiC yana kammala a cikin sarari a rufe. Akwai ƙananan hanyoyin sa ido masu inganci da kuma masu canji da yawa, don haka sarrafa tsari yana da wahala.
A cikin tsarin girma lu'ulu'u na SiC ta hanyar hanyar PVT, ana ɗaukar yanayin girma na kwararar matakai (Mataki na Gudun Mataki) a matsayin babban hanyar da ke tabbatar da dorewar girma na siffar lu'ulu'u guda ɗaya.
Atom ɗin Si da aka yi tururi da kuma atom ɗin C za su fi son haɗawa da atom ɗin saman lu'ulu'u a wurin kink, inda za su nucleate su girma, wanda hakan zai sa kowane mataki ya gudana gaba a layi ɗaya. Lokacin da faɗin matakin da ke kan lu'ulu'u ya fi hanyar da ba ta yaɗuwa ta adatoms, adadi mai yawa na adatoms na iya taruwa, kuma yanayin girma mai kama da tsibiri mai girma biyu da aka samar zai lalata yanayin haɓakar kwararar matakai, wanda ke haifar da asarar bayanan tsarin lu'ulu'u na 4H, wanda ke haifar da lahani da yawa. Saboda haka, daidaita sigogin tsari dole ne ya cimma ikon sarrafa tsarin matakin saman, ta haka ne zai danne samar da lahani na polymorphic, cimma manufar samun siffar lu'ulu'u ɗaya, da kuma a ƙarshe shirya lu'ulu'u masu inganci.
A matsayin hanyar girma ta lu'ulu'u ta SiC ta farko da aka ƙirƙiro, hanyar jigilar tururi ta zahiri a halin yanzu ita ce hanya mafi girma ta girma don girma lu'ulu'u na SiC. Idan aka kwatanta da sauran hanyoyi, wannan hanyar tana da ƙarancin buƙatu don kayan aikin girma, tsarin girma mai sauƙi, ikon sarrafawa mai ƙarfi, bincike mai zurfi game da ci gaba, kuma ta riga ta cimma aikace-aikacen masana'antu. Amfanin hanyar HTCVD shine cewa tana iya haɓaka wafers masu amfani da wutar lantarki (n, p) da kuma wafers masu tsafta, kuma tana iya sarrafa yawan doping don haka yawan mai ɗaukar kaya a cikin wafer ɗin zai iya daidaitawa tsakanin 3 × 1013 ~ 5 × 1019/cm3. Rashin amfani shine babban matakin fasaha da ƙarancin rabon kasuwa. Yayin da fasahar girma ta lu'ulu'u ta SiC ta ruwa-mataki ke ci gaba da girma, zai nuna babban damar ci gaba da masana'antar SiC gaba ɗaya a nan gaba kuma yana iya zama sabon ci gaba a cikin ci gaban lu'ulu'u na SiC.
Lokacin Saƙo: Afrilu-16-2024