Sassan Semiconductor - Tushen graphite mai rufi na SiC

Ana amfani da sansanonin graphite masu rufi na SiC don tallafawa da kuma dumama abubuwan da ke cikin kristal guda ɗaya a cikin kayan aikin adana tururin ƙarfe-organic (MOCVD). Kwanciyar hankali na zafi, daidaiton zafi da sauran sigogin aiki na tushen graphite mai rufi na SiC suna taka muhimmiyar rawa a cikin ingancin haɓakar kayan epitaxial, don haka shine babban ɓangaren kayan aikin MOCVD.

A cikin tsarin ƙera wafer, an ƙara gina layukan epitaxial akan wasu ƙananan wafer don sauƙaƙe ƙera na'urori. Na'urorin da ke fitar da haske na LED na yau da kullun suna buƙatar shirya layukan epitaxial na GaAs akan ƙananan silicon; Ana shuka Layer ɗin epitaxial na SiC akan ƙaramin SiC don gina na'urori kamar SBD, MOSFET, da sauransu, don babban ƙarfin lantarki, babban wutar lantarki da sauran aikace-aikacen wutar lantarki; Layer ɗin epitaxial na GaN an gina shi akan ƙaramin SiC don ƙara gina HEMT da sauran na'urori don aikace-aikacen RF kamar sadarwa. Wannan tsari ba zai iya rabuwa da kayan aikin CVD ba.

A cikin kayan aikin CVD, ba za a iya sanya substrate kai tsaye a kan ƙarfe ba ko kuma kawai a sanya shi a kan tushe don ajiyar epitaxial, saboda yana ɗauke da kwararar iskar gas (kwance, a tsaye), zafin jiki, matsin lamba, gyarawa, zubar da gurɓatattun abubuwa da sauran fannoni na abubuwan da ke tasiri. Saboda haka, ana buƙatar tushe, sannan a sanya substrate a kan faifai, sannan a yi aikin ajiyar epitaxial akan substrate ta amfani da fasahar CVD, kuma wannan tushe shine tushen graphite mai rufi na SiC (wanda kuma aka sani da tire).

Ana amfani da sansanonin graphite masu rufi na SiC don tallafawa da kuma dumama abubuwan da ke cikin kristal guda ɗaya a cikin kayan aikin adana tururin ƙarfe-organic (MOCVD). Kwanciyar hankali na zafi, daidaiton zafi da sauran sigogin aiki na tushen graphite mai rufi na SiC suna taka muhimmiyar rawa a cikin ingancin haɓakar kayan epitaxial, don haka shine babban ɓangaren kayan aikin MOCVD.

Tacewar tururin sinadarai na ƙarfe (MOCVD) ita ce babbar fasahar da ake amfani da ita wajen haɓaka fina-finan GaN a cikin shuɗin LED. Tana da fa'idodin aiki mai sauƙi, saurin girma mai sarrafawa da kuma tsaftar fina-finan GaN. A matsayin muhimmin sashi a cikin ɗakin amsawa na kayan aikin MOCVD, tushen ɗaukar nauyi da ake amfani da shi don haɓakar epitaxial na fim ɗin GaN yana buƙatar samun fa'idodin juriyar zafi mai yawa, daidaitaccen yanayin zafi, kwanciyar hankali na sinadarai, juriyar girgiza mai ƙarfi, da sauransu. Kayan Graphite na iya cika sharuɗɗan da ke sama.

A matsayin ɗaya daga cikin muhimman abubuwan da ke cikin kayan aikin MOCVD, tushen graphite shine mai ɗaukar kaya da kuma jikin dumama na substrate, wanda ke ƙayyade daidaito da tsarkin kayan fim ɗin kai tsaye, don haka ingancinsa yana shafar shirye-shiryen takardar epitaxial kai tsaye, kuma a lokaci guda, tare da ƙaruwar yawan amfani da canjin yanayin aiki, yana da sauƙin sawa, mallakar abubuwan da ake amfani da su.

Duk da cewa graphite yana da kyakkyawan yanayin zafi da kwanciyar hankali, yana da fa'ida mai kyau a matsayin tushen kayan aikin MOCVD, amma a cikin tsarin samarwa, graphite zai lalata foda saboda ragowar iskar gas mai lalata da sinadarai masu ƙarfe, kuma tsawon rayuwar tushen graphite zai ragu sosai. A lokaci guda, faɗuwar foda mai graphite zai haifar da gurɓatawa ga guntu.

Fitowar fasahar rufewa na iya samar da gyara foda a saman, haɓaka kwararar zafi, da daidaita rarraba zafi, wanda ya zama babban fasahar magance wannan matsala. Tushen graphite a cikin kayan aiki na MOCVD yana amfani da muhalli, murfin saman graphite ya kamata ya cika waɗannan halaye:

(1) Ana iya naɗe tushen graphite gaba ɗaya, kuma yawansa yana da kyau, in ba haka ba tushen graphite yana da sauƙin lalacewa a cikin iskar gas mai lalata.

(2) Ƙarfin haɗin gwiwa tare da tushen graphite yana da girma don tabbatar da cewa murfin ba shi da sauƙin faɗuwa bayan zagayowar zafin jiki mai yawa da ƙarancin zafin jiki da yawa.

(3) Yana da kyakkyawan daidaiton sinadarai don guje wa lalacewar shafi a cikin yanayin zafi mai yawa da kuma yanayin lalata.

SiC yana da fa'idodin juriyar tsatsa, yawan watsa zafi, juriyar girgizar zafi da kuma kwanciyar hankali mai yawa na sinadarai, kuma yana iya aiki da kyau a cikin yanayin epitaxial na GaN. Bugu da ƙari, ƙimar faɗaɗa zafi na SiC ba ta bambanta sosai da na graphite ba, don haka SiC shine kayan da aka fi so don rufin saman tushen graphite.

A halin yanzu, SiC da aka fi amfani da shi galibi nau'in 3C, 4H da 6H ne, kuma amfani da SiC na nau'ikan lu'ulu'u daban-daban ya bambanta. Misali, 4H-SiC na iya ƙera na'urori masu ƙarfi; 6H-SiC shine mafi karko kuma yana iya ƙera na'urorin lantarki na lantarki; Saboda tsarinsa iri ɗaya da GaN, ana iya amfani da 3C-SiC don samar da layin epitaxial na GaN da kuma ƙera na'urorin SiC-GaN RF. 3C-SiC kuma ana kiransa β-SiC, kuma muhimmin amfani da β-SiC shine kayan fim da rufi, don haka β-SiC a halin yanzu shine babban kayan da ake amfani da shi don rufewa.

Hanyar shirya murfin silicon carbide

A halin yanzu, hanyoyin shiryawa na shafa SiC sun haɗa da hanyar gel-sol, hanyar sakawa, hanyar shafa goga, hanyar fesawa ta plasma, hanyar amsawar iskar gas (CVR) da hanyar adana tururin sinadarai (CVD).

Hanyar sakawa:

Hanyar wani nau'i ne na sintering mai ƙarfi na yanayin zafi mai zafi, wanda galibi yana amfani da cakuda foda na Si da foda na C azaman foda mai haɗawa, ana sanya matrix na graphite a cikin foda mai haɗawa, kuma ana yin sintering mai zafi mai zafi a cikin iskar gas mara aiki, kuma a ƙarshe ana samun murfin SiC akan saman matrix na graphite. Tsarin yana da sauƙi kuma haɗin da ke tsakanin murfin da substrate yana da kyau, amma daidaiton murfin a gefen kauri ba shi da kyau, wanda ke da sauƙin samar da ƙarin ramuka kuma yana haifar da rashin juriya ga iskar shaka.

Hanyar shafa goga:

Hanyar shafa goga ita ce a shafa ruwan da aka yi amfani da shi a saman matrix na graphite, sannan a shafa ruwan da aka yi amfani da shi a wani zafin jiki don shirya murfin. Tsarin yana da sauƙi kuma farashinsa bai yi ƙasa ba, amma shafa da aka yi ta hanyar shafa goga yana da rauni idan aka haɗa shi da substrate, daidaiton shafa ba shi da kyau, shafa yana da siriri kuma juriyar iskar shaka ba ta da yawa, kuma ana buƙatar wasu hanyoyi don taimakawa.

Hanyar fesawa ta plasma:

Hanyar fesawa ta plasma galibi ita ce fesa kayan da aka narke ko waɗanda aka narke a saman matrix ɗin graphite da bindigar plasma, sannan a ƙarfafa su kuma a haɗa su don samar da shafi. Hanyar tana da sauƙin aiki kuma tana iya shirya shafi mai kauri na silicon carbide, amma murfin silicon carbide da aka shirya ta hanyar sau da yawa yana da rauni sosai kuma yana haifar da raunin juriya ga iskar shaka, don haka galibi ana amfani da shi don shirya shafi mai haɗa SiC don inganta ingancin shafi.

Hanyar Gel-sol:

Hanyar gel-sol galibi ita ce shirya wani maganin sol mai kama da juna wanda ke rufe saman matrix, yana bushewa ya zama gel sannan a yi sintering don samun shafi. Wannan hanyar tana da sauƙin aiki kuma tana da ƙarancin farashi, amma murfin da aka samar yana da wasu gazawa kamar ƙarancin juriya ga girgizar zafi da sauƙin fashewa, don haka ba za a iya amfani da shi sosai ba.

Haɗakar Iskar Gas (CVR):

CVR galibi yana samar da rufin SiC ta hanyar amfani da foda Si da SiO2 don samar da tururin SiO a zafin jiki mai yawa, kuma jerin halayen sinadarai suna faruwa a saman substrate na kayan C. Rufin SiC da aka shirya ta wannan hanyar yana da alaƙa da substrate, amma zafin amsawar ya fi girma kuma farashin ya fi girma.

Tsarin Tururin Sinadarai (CVD):

A halin yanzu, CVD ita ce babbar fasahar shirya murfin SiC a saman substrate. Babban tsari shine jerin halayen jiki da sinadarai na kayan aikin gas a saman substrate, kuma a ƙarshe ana shirya murfin SiC ta hanyar ajiyewa a saman substrate. Rufin SiC da fasahar CVD ta shirya yana da alaƙa da saman substrate, wanda zai iya inganta juriyar oxidation da juriyar ablative na kayan substrate yadda ya kamata, amma lokacin ajiyewa na wannan hanyar ya fi tsayi, kuma iskar gas ɗin yana da wani iskar gas mai guba.

Yanayin kasuwa na tushen graphite mai rufi na SiC

Lokacin da masana'antun ƙasashen waje suka fara aiki da wuri, suna da jagora mai kyau da kuma babban hannun jari a kasuwa. A duniya, manyan masu samar da tushen graphite mai rufi na SiC sune Dutch Xycard, Jamus SGL Carbon (SGL), Japan Toyo Carbon, Amurka MEMC da sauran kamfanoni, waɗanda galibi ke mamaye kasuwar duniya. Duk da cewa China ta karya babbar fasahar ci gaban shafi ɗaya na SiC a saman matrix na graphite, matrix mai inganci har yanzu yana dogara ne akan Jamus SGL, Japan Toyo Carbon da sauran kamfanoni, matrix na graphite da kamfanonin cikin gida ke bayarwa yana shafar rayuwar sabis saboda yanayin zafi, modulus na roba, modulus masu ƙarfi, lahani na lattice da sauran matsalolin inganci. Kayan aikin MOCVD ba za su iya biyan buƙatun amfani da tushen graphite mai rufi na SiC ba.

Masana'antar semiconductor ta kasar Sin tana ci gaba da bunkasa cikin sauri, tare da karuwar saurin gano kayan aikin epitaxial na MOCVD a hankali, da kuma fadada sauran aikace-aikacen tsari, ana sa ran kasuwar kayayyakin tushe na SiC mai rufi da graphite za ta bunkasa cikin sauri. A cewar kididdigar farko ta masana'antu, kasuwar tushe ta graphite ta cikin gida za ta wuce Yuan miliyan 500 a cikin shekaru masu zuwa.

Tushen graphite mai rufi na SiC shine babban ɓangaren kayan aikin masana'antar semiconductor mai haɗawa, ƙwarewa a cikin babbar fasahar samarwa da kerawa, da kuma fahimtar inda aka samo dukkan sarkar masana'antar kayan aiki-tsari-kayan aiki yana da matuƙar mahimmanci don tabbatar da ci gaban masana'antar semiconductor ta China. Fannin tushen graphite mai rufi na SiC na cikin gida yana bunƙasa, kuma ingancin samfurin zai iya kaiwa ga matakin ci gaba na duniya nan ba da jimawa ba.