A cikin tsarin girma na lu'ulu'u guda ɗaya na silicon carbide, jigilar tururi ta zahiri ita ce babbar hanyar masana'antu ta yanzu. Don hanyar girma ta PVT,foda mai siliki carbideyana da babban tasiri akan tsarin girma. Duk sigogi nafoda mai siliki carbidekai tsaye yana shafar ingancin girma na lu'ulu'u ɗaya da halayen lantarki. A aikace-aikacen masana'antu na yanzu, ana amfani da shi akai-akaifoda mai siliki carbideTsarin hadawa shine hanyar hadawa mai zafi mai zafi da kanta.
Hanyar haɗa kai mai zafi mai yawa tana amfani da zafin jiki mai yawa don ba wa masu amsawa zafi na farko don fara halayen sinadarai, sannan ta yi amfani da zafin amsawar sinadarai nata don ba da damar abubuwan da ba su amsawa su ci gaba da kammala halayen sinadarai. Duk da haka, tunda amsawar sinadarai na Si da C suna fitar da ƙarancin zafi, dole ne a ƙara wasu masu amsawa don ci gaba da amsawar. Saboda haka, masana da yawa sun ba da shawarar ingantacciyar hanyar haɗa kai ta hanyar haɓaka amsawar kai bisa wannan tushen, suna gabatar da mai kunnawa. Hanyar yaɗa kai tana da sauƙin aiwatarwa, kuma sigogin haɗa kai daban-daban suna da sauƙin sarrafawa. Babban haɗa kai yana biyan buƙatun masana'antu.
Tun a shekarar 1999, Bridgeport ta yi amfani da hanyar hadawa mai zafi mai zafi da kanta don hadawa.Foda SiC, amma ta yi amfani da ethoxysilane da phenol resin a matsayin kayan da aka samar, wanda hakan ya yi tsada. Gao Pan da sauransu sun yi amfani da foda Si mai tsarki da foda C a matsayin kayan da aka samar don hadawa.Foda SiCta hanyar yanayin zafi mai yawa a cikin yanayin argon. Ning Lina ta shirya babban barbashiFoda SiCta hanyar haɗakarwa ta biyu.
Tanderun dumama mai matsakaicin mitar induction wanda Cibiyar Bincike ta Biyu ta China Electronics Technology Group Corporation ta ƙirƙiro yana haɗa foda silicon da foda carbon daidai gwargwado a cikin wani rabo na stoichiometric kuma yana sanya su a cikin graphite crucible.graphite CrucibleAna sanya shi a cikin tanda mai dumama matsakaici-mita don dumama, kuma ana amfani da canjin zafin jiki don haɗawa da canza yanayin ƙarancin zafin jiki da kuma babban zafin jiki na silicon carbide bi da bi. Tunda zafin amsawar haɗakar β-SiC a cikin yanayin ƙarancin zafin jiki ya yi ƙasa da zafin canzawa na Si, haɗakar β-SiC a ƙarƙashin babban injin zai iya tabbatar da yaduwar kansa. Hanyar shigar da iskar argon, hydrogen da HCl a cikin haɗakar α-SiC yana hana ruɓewarFoda SiCa matakin zafi mai yawa, kuma yana iya rage yawan sinadarin nitrogen a cikin foda α-SiC yadda ya kamata.
Shandong Tianyue ta ƙera tanderu mai haɗaka, ta amfani da iskar silane a matsayin kayan silicon da kuma foda na carbon a matsayin kayan carbon. An daidaita adadin iskar gas da aka gabatar ta hanyar haɗa matakai biyu, kuma girman barbashi na ƙarshe da aka haɗa ya kasance tsakanin 50 zuwa 5,000 um.
1 Abubuwan sarrafawa na tsarin haɗa foda
1.1 Tasirin girman barbashi na foda akan girman lu'ulu'u
Girman barbashi na foda carbide na silicon yana da tasiri mai mahimmanci akan ci gaban kristal guda ɗaya na gaba. Girman lu'ulu'u guda ɗaya na SiC ta hanyar hanyar PVT galibi ana samunsa ne ta hanyar canza rabon molar na silicon da carbon a cikin ɓangaren iskar gas, kuma rabon molar na silicon da carbon a cikin ɓangaren iskar gas yana da alaƙa da girman barbashi na foda carbide na silicon. Jimlar matsin lamba da rabon silicon-carbon na tsarin girma yana ƙaruwa tare da raguwar girman barbashi. Lokacin da girman barbashi ya ragu daga 2-3 mm zuwa 0.06 mm, rabon silicon-carbon yana ƙaruwa daga 1.3 zuwa 4.0. Lokacin da barbashi suka yi ƙanana zuwa wani matsayi, matsin lamba na Si yana ƙaruwa, kuma an samar da wani Layer na fim ɗin Si a saman lu'ulu'u mai girma, wanda ke haifar da ci gaban gas-ruwa-mai ƙarfi, wanda ke shafar polymorphism, lahani na maki da lahani na layi a cikin lu'ulu'u. Saboda haka, dole ne a sarrafa girman barbashi na foda carbide mai tsabta sosai.
Bugu da ƙari, idan girman ƙwayoyin SiC foda sun yi ƙanƙanta, foda yana ruɓewa da sauri, wanda ke haifar da ƙaruwar lu'ulu'u guda ɗaya na SiC. A gefe guda, a cikin yanayin zafi mai yawa na girma lu'ulu'u guda ɗaya na SiC, ana aiwatar da hanyoyin haɗa abubuwa guda biyu da ruɓewa a lokaci guda. Foda na silicon carbide zai ruɓe ya samar da carbon a cikin yanayin iskar gas da yanayin ƙarfi kamar Si, Si2C, SiC2, wanda ke haifar da carbonization mai tsanani na foda polycrystalline da samuwar haɗakar carbon a cikin lu'ulu'u; a gefe guda kuma, lokacin da yawan ruɓewar foda ya yi sauri, tsarin lu'ulu'u na lu'ulu'u guda ɗaya na SiC da aka girma yana da saurin canzawa, wanda hakan ke sa ya yi wuya a sarrafa ingancin lu'ulu'u guda ɗaya na SiC da aka girma.
1.2 Tasirin siffar lu'ulu'u ta foda akan girman lu'ulu'u
Girman lu'ulu'u guda ɗaya na SiC ta hanyar hanyar PVT tsari ne na sake yin amfani da su a yanayin zafi mai yawa. Siffar lu'ulu'u ta kayan albarkatun ƙasa na SiC tana da tasiri mai mahimmanci akan haɓakar lu'ulu'u. A cikin tsarin haɗa foda, matakin haɗa ƙananan zafin jiki (β-SiC) tare da tsarin cubic na ƙwayar naúrar da kuma matakin haɗa zafi mai yawa (α-SiC) tare da tsarin hexagonal na ƙwayar naúrar za a samar da shi galibi. Akwai nau'ikan lu'ulu'u da yawa na silicon carbide da kuma kewayon sarrafa zafin jiki mai kunkuntar. Misali, 3C-SiC zai canza zuwa polymorph na silicon carbide na hexagonal, watau 4H/6H-SiC, a yanayin zafi sama da 1900°C.
A lokacin tsarin girma na lu'ulu'u ɗaya, lokacin da ake amfani da foda β-SiC don noman lu'ulu'u, rabon molar silicon-carbon ya fi 5.5 girma, yayin da lokacin da ake amfani da foda α-SiC don noman lu'ulu'u, rabon molar silicon-carbon shine 1.2. Lokacin da zafin jiki ya tashi, canjin lokaci yana faruwa a cikin bututun. A wannan lokacin, rabon molar a cikin lokacin iskar gas ya zama mafi girma, wanda ba ya taimakawa ga haɓakar lu'ulu'u. Bugu da ƙari, sauran ƙazanta na lokacin iskar gas, gami da carbon, silicon, da silicon dioxide, ana samun su cikin sauƙi a lokacin tsarin sauyawar lokaci. Kasancewar waɗannan ƙazanta yana sa lu'ulu'u ya haifar da ƙananan tubes da voids. Saboda haka, dole ne a sarrafa siffar lu'ulu'u na foda daidai.
1.3 Tasirin ƙazanta na foda akan girman lu'ulu'u
Rashin tsafta a cikin foda SiC yana shafar nucleation na bazata yayin girma na lu'ulu'u. Mafi girman rashin tsaftar, haka nan rashin yuwuwar lu'ulu'u ya yi ba zato ba tsammani. Ga SiC, manyan ƙazanta na ƙarfe sun haɗa da B, Al, V, da Ni, waɗanda za a iya shigar da su ta hanyar kayan aiki yayin sarrafa foda na silicon da foda na carbon. Daga cikinsu, B da Al sune manyan ƙazanta masu karɓar matakin makamashi mara zurfi a cikin SiC, wanda ke haifar da raguwar juriyar SiC. Sauran ƙazanta na ƙarfe za su gabatar da matakan makamashi da yawa, wanda ke haifar da rashin daidaituwar halayen lantarki na lu'ulu'u guda ɗaya na SiC a yanayin zafi mai yawa, kuma suna da tasiri mafi girma akan halayen lantarki na manyan abubuwan da ke cikin lu'ulu'u guda ɗaya masu rufi, musamman juriya. Saboda haka, dole ne a haɗa foda mai silicon carbide mai tsabta gwargwadon iko.
1.4 Tasirin sinadarin nitrogen a cikin foda akan girman lu'ulu'u
Matsayin sinadarin nitrogen yana ƙayyade juriyar sinadarin kristal guda ɗaya. Manyan masana'antun suna buƙatar daidaita yawan sinadarin nitrogen a cikin kayan roba bisa ga tsarin girma na kristal mai girma yayin haɗa foda. Abubuwan silicon carbide guda ɗaya masu tsafta mai tsafta mai tsafta su ne mafi kyawun kayan aiki ga kayan lantarki na tsakiya na soja. Don haɓaka abubuwan silicon carbide guda ɗaya masu tsafta mai tsafta mai ƙarfi tare da juriya mai ƙarfi da kyawawan halayen lantarki, dole ne a sarrafa abubuwan da ke cikin babban sinadarin nitrogen mara tsabta a cikin substrate a ƙaramin matakin. Abubuwan kristal guda ɗaya masu sarrafawa suna buƙatar a sarrafa abubuwan nitrogen a babban taro.
2 Fasahar sarrafa maɓalli don haɗa foda
Saboda yanayin amfani da sinadarai daban-daban na silicon carbide, fasahar hadawa don foda mai girma tana da matakai daban-daban. Ga foda mai girma na kristal mai guda ɗaya mai sarrafa nau'in N, ana buƙatar tsarkin tsabta mai yawa da kuma mataki ɗaya; yayin da ga foda mai girma na kristal mai rabin-rufi, ana buƙatar cikakken iko akan abun da ke cikin nitrogen.
2.1 Kula da girman barbashi na foda
2.1.1 Zafin jiki na haɗaka
A yayin da ake kiyaye wasu yanayin aiki ba a canza su ba, an ɗauki samfurin foda na SiC da aka samar a yanayin zafi na 1900 ℃, 2000 ℃, 2100 ℃, da 2200 ℃. Kamar yadda aka nuna a Hoto na 1, za a iya ganin cewa girman barbashi shine 250 ~ 600 μm a 1900 ℃, kuma girman barbashi yana ƙaruwa zuwa 600 ~ 850 μm a 2000 ℃, kuma girman barbashi yana canzawa sosai. Lokacin da zafin jiki ya ci gaba da tashi zuwa 2100 ℃, girman barbashi na foda na SiC shine 850 ~ 2360 μm, kuma ƙaruwar tana da laushi. Girman barbashi na SiC a 2200 ℃ yana da tabbas a kusan 2360 μm. Ƙara yawan zafin jiki na haɗakarwa daga 1900 ℃ yana da tasiri mai kyau akan girman barbashi na SiC. Lokacin da zafin jiki na haɗakarwa ya ci gaba da ƙaruwa daga 2100 ℃, girman barbashi ba ya canzawa sosai. Saboda haka, idan aka saita zafin haɗakar zuwa 2100 ℃, ana iya haɗa babban girman barbashi a ƙaramin amfani da makamashi.
2.1.2 Lokacin haɗawa
Sauran yanayin aiki ba su canza ba, kuma an saita lokacin haɗawa zuwa awanni 4, awanni 8, da awanni 12 bi da bi. An nuna nazarin samfurin foda na SiC da aka samar a Hoto na 2. An gano cewa lokacin haɗawa yana da tasiri mai mahimmanci akan girman barbashi na SiC. Lokacin da lokacin haɗawa ya kasance awanni 4, girman barbashi galibi yana rarrabawa a 200 μm; lokacin haɗawa shine awanni 8, girman barbashi na roba yana ƙaruwa sosai, galibi yana rarrabawa a kusan 1 000 μm; yayin da lokacin haɗawa ya ci gaba da ƙaruwa, girman barbashi yana ƙaruwa, galibi yana rarrabawa a kusan 2 000 μm.
2.1.3 Tasirin girman barbashi na kayan abu
Yayin da ake inganta sarkar samar da kayan silicon a cikin gida a hankali, tsarkin kayan silicon kuma yana ƙara inganta. A halin yanzu, kayan silicon da ake amfani da su wajen haɗa su galibi an raba su zuwa silikon granular da silikon foda, kamar yadda aka nuna a Hoto na 3.
An yi amfani da kayan silicon daban-daban don gudanar da gwaje-gwajen haɗa silicon carbide. Kwatanta kayayyakin roba an nuna su a Hoto na 4. Bincike ya nuna cewa lokacin amfani da kayan silicon na toshe, akwai adadi mai yawa na abubuwan Si a cikin samfurin. Bayan an niƙa toshe silicon a karo na biyu, sinadarin Si a cikin samfurin roba yana raguwa sosai, amma har yanzu yana wanzuwa. A ƙarshe, ana amfani da foda na silicon don haɗawa, kuma SiC ne kawai ke cikin samfurin. Wannan saboda a cikin tsarin samarwa, babban silicon granular yana buƙatar yin amsawar haɗa saman farko, kuma ana haɗa silicon carbide a saman, wanda ke hana foda na ciki na Si ya ƙara haɗuwa da foda na C. Saboda haka, idan ana amfani da silicon na toshe azaman kayan ƙasa, yana buƙatar a niƙa shi sannan a yi masa aikin haɗa na biyu don samun foda na silicon carbide don haɓaka lu'ulu'u.
2.2 Kula da siffar lu'ulu'u na foda
2.2.1 Tasirin zafin jiki na haɗaka
A kiyaye wasu yanayin aiki ba tare da an canza su ba, zafin haɗakarwa shine 1500℃, 1700℃, 1900℃, da 2100℃, kuma ana yin samfurin foda na SiC da aka samar kuma ana yin nazari a kai. Kamar yadda aka nuna a Hoto na 5, β-SiC rawaya ce ta ƙasa, kuma α-SiC launinta ya fi haske. Ta hanyar lura da launi da yanayin foda da aka haɗa, za a iya tantance cewa samfurin da aka haɗa shine β-SiC a zafin jiki na 1500℃ da 1700℃. A 1900℃, launin yana zama mai haske, kuma ƙwayoyin hexagonal sun bayyana, wanda ke nuna cewa bayan zafin jiki ya tashi zuwa 1900℃, canjin lokaci yana faruwa, kuma wani ɓangare na β-SiC yana canzawa zuwa α-SiC; lokacin da zafin jiki ya ci gaba da tashi zuwa 2100℃, an gano cewa ƙwayoyin da aka haɗa suna da haske, kuma α-SiC an canza su da sauƙi.
2.2.2 Tasirin lokacin haɗaka
Sauran yanayin aiki ba su canza ba, kuma an saita lokacin haɗawa zuwa awanni 4, awanni 8, da awanni 12, bi da bi. Ana ɗaukar samfurin foda na SiC da aka samar kuma ana nazarin shi ta hanyar diffractometer (XRD). Sakamakon an nuna shi a Hoto na 6. Lokacin haɗawa yana da wani tasiri ga samfurin da foda SiC ya haɗa. Lokacin haɗawa shine awanni 4 da awanni 8, samfurin da aka haɗa galibi shine 6H-SiC; lokacin haɗawa shine awanni 12, 15R-SiC ya bayyana a cikin samfurin.
2.2.3 Tasirin rabon kayan abu
Sauran hanyoyin ba su canza ba, an yi nazarin adadin abubuwan silicon-carbon, kuma rabon su ne 1.00, 1.05, 1.10 da 1.15 bi da bi don gwaje-gwajen hadawa. Sakamakon an nuna shi a Hoto na 7.
Daga bakan XRD, za a iya gani cewa lokacin da rabon silicon-carbon ya fi 1.05, yawan Si ya bayyana a cikin samfurin, kuma lokacin da rabon silicon-carbon ya ƙasa da 1.05, yawan C ya bayyana. Lokacin da rabon silicon-carbon ya kasance 1.05, ana kawar da carbon kyauta a cikin samfurin roba, kuma babu silicon kyauta da ya bayyana. Saboda haka, rabon adadin rabon silicon-carbon ya kamata ya zama 1.05 don haɗa SiC mai tsabta.
2.3 Kula da ƙarancin sinadarin nitrogen a cikin foda
2.3.1 Kayan da aka yi da roba
Kayan da aka yi amfani da su a cikin wannan gwajin sune foda mai yawan tsarkin carbon da foda mai yawan tsarkin silicon tare da matsakaicin diamita na 20 μm. Saboda ƙaramin girman barbashi da babban yankin saman su, suna da sauƙin sha N2 a cikin iska. Lokacin haɗa foda, za a kawo shi cikin siffar lu'ulu'u na foda. Don haɓaka lu'ulu'u na nau'in N, rashin daidaituwa na N2 a cikin foda yana haifar da juriya mara daidaito na lu'ulu'u har ma da canje-canje a cikin siffar lu'ulu'u. Yawan nitrogen na foda da aka haɗa bayan an shigar da hydrogen yana da ƙasa sosai. Wannan saboda yawan ƙwayoyin hydrogen ƙarami ne. Lokacin da N2 da aka sha a cikin foda mai yawan carbon da foda mai yawan silicon suka yi zafi suka ruɓe daga saman, H2 ya bazu gaba ɗaya zuwa cikin rata tsakanin foda tare da ƙaramin girmansa, yana maye gurbin matsayin N2, kuma N2 yana tserewa daga bututun yayin aikin injin, yana cimma manufar cire sinadarin nitrogen.
2.3.2 Tsarin haɗawa
A lokacin hada sinadarin silicon carbide foda, tunda radius na atoms na carbon da nitrogen atoms iri daya ne, nitrogen zai maye gurbin guraben carbon a cikin silicon carbide, ta haka ne zai kara yawan sinadarin nitrogen. Wannan tsarin gwaji ya rungumi hanyar shigar da H2, kuma H2 yana amsawa da abubuwan carbon da silicon a cikin hadadden crucible don samar da iskar gas ta C2H2, C2H, da SiH. Yawan sinadarin carbon yana karuwa ta hanyar watsa iskar gas, ta haka ne rage guraben carbon. An cimma manufar cire nitrogen.
2.3.3 Tsarin sarrafa abun ciki na nitrogen na baya
Ana iya amfani da graphite crucibles masu babban porosity a matsayin ƙarin tushen C don shanye tururin Si a cikin sassan yanayin iskar gas, rage Si a cikin sassan yanayin iskar gas, don haka ƙara C/Si. A lokaci guda, graphite crucibles kuma za su iya amsawa tare da yanayin Si don samar da Si2C, SiC2 da SiC, wanda yayi daidai da yanayin Si wanda ke kawo tushen C daga graphite crucible zuwa yanayin girma, yana ƙara rabon C, da kuma ƙara rabon carbon-silicon. Saboda haka, ana iya ƙara rabon carbon-silicon ta hanyar amfani da graphite crucibles tare da babban porosity, rage gurɓataccen carbon, da kuma cimma manufar cire nitrogen.
3 Bincike da ƙira tsarin haɗa foda mai lu'ulu'u ɗaya
3.1 Ka'ida da tsarin hadawa
Ta hanyar cikakken bincike da aka ambata a sama kan sarrafa girman barbashi, siffar lu'ulu'u da kuma sinadarin nitrogen na hada foda, an gabatar da tsarin hadawa. An zabi foda mai tsafta na C da foda Si, kuma an hade su daidai gwargwado sannan a zuba su a cikin graphite crucible bisa ga rabon silicon-carbon na 1.05. Matakan aikin galibi an raba su zuwa matakai hudu:
1) Tsarin rage zafi mai ƙarancin zafi, a yi amfani da injin tsabtace iska zuwa 5×10-4 Pa, sannan a shigar da sinadarin hydrogen, a sanya matsin lamba a ɗakin ya kai kimanin 80 kPa, a ci gaba da riƙe shi na tsawon mintuna 15, sannan a maimaita shi sau huɗu. Wannan tsari zai iya cire abubuwan nitrogen a saman foda na carbon da foda na silicon.
2) Tsarin rage zafin jiki mai zafi, a yi amfani da injin tsabtace iska zuwa 5 × 10-4 Pa, sannan a dumama zuwa 950 ℃, sannan a shigar da sinadarin hydrogen, a sanya matsin lamba a ɗakin ya kai kimanin 80 kPa, a ci gaba da aiki na tsawon mintuna 15, sannan a maimaita sau huɗu. Wannan tsari zai iya cire sinadarin nitrogen a saman foda da foda na silicon, sannan a fitar da nitrogen a filin zafi.
3) Tsarin tsarin yanayin zafi mai ƙarancin zafi, a kwashe zuwa 5 × 10-4 Pa, sannan a dumama zuwa 1350℃, a ajiye na tsawon awanni 12, sannan a shigar da hydrogen don sanya matsin lamba na ɗakin ya kai kimanin 80 kPa, a ajiye na tsawon awa 1. Wannan tsari zai iya cire nitrogen ɗin da ya lalace yayin aikin haɗakarwa.
4) Haɗa tsarin yanayin zafin jiki mai yawa, cika da wani rabo na kwararar iskar gas na hydrogen mai tsarki da iskar argon mai gauraye, sanya matsin lamba a ɗakin ya kai kimanin 80 kPa, ɗaga zafin zuwa 2100℃, ajiye na tsawon awanni 10. Wannan tsari yana kammala canza foda silicon carbide daga β-SiC zuwa α-SiC kuma yana kammala girman ƙwayoyin lu'ulu'u.
A ƙarshe, jira zafin ɗakin ya yi sanyi zuwa zafin ɗaki, ya cika har sai ya yi zafi, sannan a cire foda ɗin.
3.2 Tsarin yin foda bayan an sarrafa shi
Bayan an haɗa foda ta hanyar wannan tsari, dole ne a sarrafa shi bayan an gama sarrafa shi don cire gurɓataccen carbon, silicon da sauran ƙazanta na ƙarfe sannan a tsaftace girman barbashi. Da farko, ana sanya foda ɗin da aka haɗa a cikin injin niƙa don niƙawa, sannan a sanya foda ɗin silicon carbide da aka niƙa a cikin tanda mai murfi sannan a dumama shi zuwa 450°C ta hanyar iskar oxygen. Ana tace carbon ɗin da ke cikin foda ta hanyar zafi don samar da iskar carbon dioxide da ke fita daga ɗakin, don haka ana cimma cire carbon ɗin da ba shi da shi. Bayan haka, ana shirya ruwan tsaftacewa mai acidic kuma ana sanya shi a cikin injin tsabtace barbashi na silicon carbide don tsaftacewa don cire gurɓataccen carbon, silicon da sauran ƙarfe da aka samar yayin aikin haɗawa. Bayan haka, ana wanke ragowar acid ɗin da ruwa mai tsabta sannan a busar da shi. Ana tantance busasshen foda a cikin allon girgiza don zaɓar girman barbashi don haɓakar lu'ulu'u.
Lokacin Saƙo: Agusta-08-2024