Layin epitaxial wani takamaiman fim ne mai sirara guda ɗaya da aka girma a kan wafer substrate ta hanyar tsarin epitaxial; an haɗa wafer ɗin substrate da fim ɗin epitaxial a matsayin wafer epitaxial. Daga cikin waɗannan, haɓaka layin epitaxial na silicon carbide akan substrate silicon carbide mai sarrafawa yana samar da wafer epitaxial na silicon carbide mai kama da juna, wanda za'a iya ƙara ƙera shi zuwa na'urorin wutar lantarki kamar Schottky diodes, MOSFETs, da IGBTs. Nau'in substrate da aka fi amfani da shi shine substrate 4H-SiC.
Tunda kusan dukkan na'urori ana ƙera su ne a kan layukan epitaxial, ingancin layin epitaxial yana da tasiri sosai kan aikin na'urar. Duk da haka, ingancin layin epitaxial yana da tasiri ta hanyar sarrafa lu'ulu'u da substrate, wanda hakan ke sanya shi a wani muhimmin matsayi a masana'antar kuma yana taka muhimmiyar rawa a ci gabansa.
Manyan hanyoyin shirya layukan epitaxial na silicon carbide sun haɗa da: ajiyar tururi; epitaxy na lokaci-lokaci na ruwa (LPE); epitaxy na kwayoyin halitta (MBE); da kuma ajiyar tururi na sinadarai (CVD). Daga cikin waɗannan, ajiyar tururi na sinadarai (CVD) ita ce hanyar da aka fi amfani da ita don epitaxy mai kama da 4H-SiC. Epitaxy na 4H-SiC CVD yawanci yana amfani da kayan aikin CVD, wanda ke tabbatar da ci gaba da tsarin lu'ulu'u na 4H-SiC a ƙarƙashin yanayin zafi mai girma.
A cikin kayan aikin CVD, ba za a iya sanya substrate kai tsaye a kan saman ƙarfe ba ko kuma kawai a sanya shi a kan tushe don ajiyar epitaxial, saboda wannan ya ƙunshi abubuwa daban-daban masu tasiri kamar alkiblar kwararar iskar gas (kwance, a tsaye), zafin jiki, matsin lamba, gyarawa, da gurɓatawa daga zubar da ƙwayoyin cuta. Saboda haka, ana buƙatar tushen tallafi; ana sanya substrate a kan tire, sannan ana yin ajiyar epitaxial akan substrate ta amfani da fasahar CVD. Wannan tushen tallafi tushe ne mai rufi da SiC graphite.
A matsayin babban sashi, ɓangaren graphite yana da ƙarfi mai ƙarfi da takamaiman modulus, da kuma kyakkyawan girgizar zafi da juriyar tsatsa. Duk da haka, yayin samarwa, graphite yana fuskantar tsatsa da zubar da foda saboda iskar gas mai lalata da sauran mahaɗan organometallic, wanda hakan ke rage tsawon rayuwar substrate ɗin sosai. A lokaci guda, foda graphite na shed na iya gurɓata guntu. A cikin samar da wafers na silicon carbide na epitaxial, ya zama da wahala a cika buƙatun kayan graphite da ke ƙara tsauri, wanda ke iyakance ci gaban su da aikace-aikacen su. Saboda haka,fasahar rufewaya fito a matsayin mafita.
Fa'idodin Rufin SiC a Masana'antar Semiconductor
Sifofin jiki da sinadarai na rufin dole ne su cika ƙa'idodi masu tsauri don juriya ga zafi mai yawa da tsatsa, domin waɗannan suna shafar yawan amfanin samfur da tsawon rayuwarsa kai tsaye. Kayan SiC yana da ƙarfi mai yawa, tauri mai yawa, ƙarancin yawan faɗaɗa zafi, da kuma kyakkyawan yanayin zafi, wanda hakan ya sa ya zama muhimmin abu na tsarin da semiconductor mai zafi mai yawa. Idan aka yi amfani da shi ga substrates na graphite, fa'idodinsa sun haɗa da:
1) SiC yana da juriya ga tsatsa kuma yana iya rufe saman graphite gaba ɗaya. Yawansa yana hana lalacewa daga iskar gas mai lalata.
2) SiC yana da ƙarfin jure zafi mai yawa da ƙarfin haɗin gwiwa mai ƙarfi tare da substrate na graphite, yana tabbatar da cewa murfin yana nan lafiya koda bayan sake zagayowar zafin jiki mai yawa.
3) SiC yana da kyakkyawan kwanciyar hankali na sinadarai, yana hana lalacewar shafi a cikin yanayi mai zafi da lalata.
Bugu da ƙari, murhunan epitaxial da aka yi da kayayyaki daban-daban suna buƙatar tiren graphite tare da takamaiman ƙayyadaddun aiki. Dole ne ƙimar faɗaɗa zafi na kayan graphite ya dace da zafin girma na tanderun epitaxial. Misali, tunda zafin girma na silicon carbide epitaxy yana da yawa, ana buƙatar tiren da ke da babban matakin daidaitawa na faɗaɗa zafi. Matsakaicin faɗaɗa zafi na SiC ya bambanta kaɗan da na graphite, wanda hakan ya sa ya zama kayan da aka fi so don shafa saman substrates na graphite.
SiC yana wanzuwa a cikin nau'ikan lu'ulu'u da yawa, inda mafi yawansu a halin yanzu sune nau'ikan 3C, 4H, da 6H, kowannensu yana aiki daban-daban. Misali, ana amfani da 4H-SiC don ƙera na'urori masu ƙarfi; 6H-SiC shine mafi karko kuma ana amfani da shi don ƙera na'urorin optoelectronic; kuma 3C-SiC, saboda kamanceceniya da tsarinsa da GaN, ana amfani da shi don samar da yadudduka na epitaxial na GaN don ƙera na'urorin SiC-GaN RF. Hakanan ana kiran 3C-SiC da β-SiC. Babban aikace-aikacen β-SiC shine kayan sirara da shafi; saboda haka, β-SiC a halin yanzu shine babban kayan da ake amfani da shi don rufewa.
A matsayin abin da ake amfani da shi a fannin samar da semiconductor, ana amfani da rufin SiC a cikin hanyoyin da suka haɗa da shirya substrate, epitaxy, oxidation da diffusion, etching, da kuma dasa ion. Halayen zahiri da na sinadarai na murfin dole ne su cika ƙa'idodi masu tsauri don juriya mai zafi da juriyar tsatsa, domin waɗannan suna shafar yawan amfanin samfur da tsawon rayuwarsa kai tsaye. Saboda haka, shirya rufin SiC yana da matuƙar muhimmanci.
Tsarin Shirya Rufin Silicon Carbide
A halin yanzu, manyan hanyoyin shirya murfin SiC sun haɗa da hanyar sol-gel, hanyar haɗawa, murfin goga, feshi na plasma, amsawar tururin sinadarai (CVR), da kuma adana tururin sinadarai (CVD).
Hanyar Sakawa
Wannan hanya wani nau'i ne na sintering mai ƙarfi mai zafi. Yawanci yana amfani da cakuda foda silicon (Si) da foda carbon (C) a matsayin foda mai haɗawa. Ana sanya wani abu mai siffar graphite a cikin foda mai haɗawa kuma a niƙa shi a yanayin zafi mai yawa a cikin yanayin iskar gas mara aiki, a ƙarshe yana samar da shafi na SiC a saman abin da ke ƙarƙashin graphite. Wannan hanyar tana da tsari mai sauƙi da mannewa mai kyau tsakanin abin rufe fuska da abin da ke ƙarƙashin; duk da haka, murfin yana nuna rashin daidaito a kan alkiblar kauri kuma yana da saurin haifar da ramuka da yawa, wanda ke haifar da rashin juriya ga iskar shaka.
Hanyar Shafa Goro
Hanyar shafa goga ta ƙunshi shafa ruwa mai yawa a saman abin da aka yi wa graphite substrate, sannan a shafa kayan a wani zafin jiki na musamman don samar da murfin. Wannan hanyar tana da sauƙi kuma mai araha; duk da haka, murfin da aka samu yana nuna raunin mannewa ga abin da aka yi wa substrate, rashin daidaito, kuma siriri ne tare da ƙarancin juriya ga iskar shaka, wanda ke buƙatar ƙarin hanyoyin.
Hanyar Fesawa ta Plasma
Hanyar fesawa ta plasma ta ƙunshi amfani da bindigar plasma don fesa kayan da aka narke ko na ɗan narke a saman abin da aka yi wa graphite, wanda daga nan zai taurare ya kuma ɗaure don samar da shafi. Wannan hanyar tana da sauƙin aiki kuma tana iya samar da murfin silicon carbide mai yawa; duk da haka, murfin da aka samu sau da yawa ya yi siriri sosai, wanda ke haifar da rashin juriya ga iskar shaka. Saboda haka, galibi ana amfani da shi wajen shirya murfin hadadden SiC don inganta ingancin shafi.
Hanyar Gel-Sol
Hanyar gel-sol ta ƙunshi shirya wani maganin sol mai haske iri ɗaya don shafa saman substrate. Bayan bushewa ya zama gel, ana yin sintiri a cikin kayan don samar da murfin. Wannan hanyar tana da sauƙin aiki kuma tana da araha; duk da haka, rufin da ke haifar da shi yana fama da rashin amfani kamar ƙarancin juriya ga girgizar zafi da kuma yanayin fashewa, wanda ke iyakance amfani da su a ko'ina.
Hanyar Sinadarin Tururi (CVR)
CVR galibi yana amfani da foda na Si da SiO₂ don samar da tururin SiO₂ a yanayin zafi mai yawa, wanda ke haifar da jerin halayen sinadarai a saman substrate na Si don samar da murfin SiC. Rufin SiC da wannan hanyar ke samarwa yana manne da substrate sosai; duk da haka, zafin amsawar yana da yawa, kuma farashin ma yana da yawa.
Tsaftace Tururin Sinadarai (CVD)
A halin yanzu CVD ita ce babbar fasahar shirya murfin SiC a saman substrate. Babban tsari ya ƙunshi jerin halayen sinadarai tsakanin masu amsawar iskar gas da saman substrate, wanda a ƙarshe ke haifar da ajiye murfin SiC. Rufin SiC da fasahar CVD ke samarwa yana ɗaure sosai zuwa saman substrate kuma yana iya inganta juriyar iskar shaka da juriyar ablation na kayan substrate yadda ya kamata; duk da haka, wannan hanyar tana buƙatar lokaci mai tsawo na ajiya, kuma iskar gas ɗin amsawa suna ɗauke da wasu sinadarai masu guba.
Sauye-sauye a cikin Rufin SiC
Ana amfani da murfin SiC a matsayin abubuwan da ake amfani da su a masana'antar semiconductor, tare da mahimman ma'aunin aiki waɗanda suka haɗa da daidaiton shafi, yawan faɗaɗa zafi, da kuma ikon sarrafa zafi. Duk da cewa akwai buƙatar murfin SiC mai yawa a cikin gida a China, fasahar ba ta cika ba. A ƙasashen waje, kamfani ɗaya ne kawai na Amurka ke aiki a wannan fanni, kuma kayayyakinsa suna da tsada sosai.
Jiragen ruwa na lu'ulu'uAna amfani da su wajen samar da sinadarai masu amfani da su a cikin samar da sinadarai masu amfani da za su iya maye gurbin graphite mai rufi da SiC, kodayake yawan kasuwa ya yi ƙasa. Na gaba kuma shine graphite mai rufi da TaC, wanda ke ba da juriya ga lalata sinadarai fiye da graphite mara launi ko graphite mai rufi da SiC, amma yana da tsada sosai kuma har yanzu yana cikin matakan farko na ci gaba. A halin yanzu, kamfanonin cikin gida kamar suLiufang semiconductor, Semicera, kumaVetek Semiconductorsuna cikin bincike da haɓaka fasaha a wannan fanni.
Lokacin Saƙo: Mayu-20-2026