Kungani i-High-Purity Graphite Ibaluleke Kakhulu Ekulawuleni Amaphutha e-SiC Epitaxy

Ikhwalithi ye-silicon carbide (SiC) wafer ekhiqizwayo ithonywa ngisho nayizinguquko ezincane endaweni yokukhula. Indawo abaningi abangayicabangi yi-graphite emboze i-reactor. Imela ukuhlolwa kokushisa okukhulu okutholakala ngaphakathi kwe-reactor ngenkathi isekela futhi ibeka i-wafer ngesikhathi se-epitaxy. Uma i-graphite ingcolile noma ihlelwe ngendlela engajwayelekile, izingcezu ezincane zezinto noma ukusabela okungafuneki kungabekwa kuyo yonke inqubo yokukhula. Izinkinga ezincane ebusweni be-graphite zingaqhakaza zibe amaphutha amakhulu e-wafer, okuholela emsebenzini owengeziwe kanye nesivuno esiphansi kubakhiqizi be-chip. Ngakho-ke isimo nokuhlanzeka kwe- I-Graphite susceptor kuyindaba ebaluleke kakhulu kunalokho abaningi abangakucabanga.

Ukuhlanzeka Kwe-Graphite Kuthinta Kanjani Izinkinga Zezinhlayiya Emakamelweni E-Epitaxy?

Izinhlayiya ziyisici esivamile se-wafer emakamelweni e-SiC epitaxy, futhi zivame ukufaka i-graphite kule nqubo. Izingxenye ze-graphite zihlala endaweni eshisayo ye-reactor ye-SiC, zithwala i-wafer futhi zithonya imingcele yokushisa. Ngokusebenzisa i-graphite engahlanzekile kangako, ukungcola okumbalwa, njengokungcola kwensimbi, umlotha, noma ukucubungula izinsalela ezisele, kungaphuma igesi ku-graphite kancane kancane ngokuhamba kwesikhathi ngesikhathi sokukhula kwezinga lokushisa eliphezulu. Ukungcola okukhishwe yigesi kuvame ukungabonakali ekamelweni, kodwa ekugcineni kuwela ebusweni be-wafer, noma kube yingxenye yesigaba segesi. Isibonelo, kwesinye isicelo, i-fab yakhetha i-graphite yezinga eliphansi ukuze kongiwe izindleko. Nakuba kungekho zinkinga ezabonakala ngesikhathi esifushane ekuqaleni, ngemva kwemijikelezo eminingana ye Sic epitaxy , kwabonakala ama-pinholes angahleliwe kanye namabala amabi ebusweni be-wafer. Umthombo walezi ziphambeko wawulandelwa ezinhlayiyeni ezincane eziphuma kumnikazi we-graphite noma i-susceptor. Izinhlayiya zazingena ekamelweni lokukhula futhi zisebenze njengembewu ngendlela engathandeki. Ubuningi obungalingani bengxenye ye-graphite bungafaka isandla ekuqhekekeni okuncane ebusweni bengxenye lapho kushisa, okuholela ekuchithekeni kwezinhlayiya ezincane ekamelweni ngokuhamba kwesikhathi, noma ngabe ingxenye ingase ibonakale ihlanzekile. Ngakho-ke, ukuqapha umthombo we-graphite nomlando wayo kuwumsebenzi ojwayelekile ezintweni eziqanjiwe ukuze kugwenywe iziphambeko ezihlobene nezinhlayiya. I-graphite ehlanzekile kakhulu enomthamo womlotha olawulwayo ngokuvamile iyafiseleka, ikakhulukazi emikhiqizweni yesikhathi eside. Inani lemijikelezo yokushisa yezingxenye nalo liyaqashwa njengoba izinto zizokhipha izinhlayiya ngisho nangemva kokucubungula okuhle kokuqala. Futhi, indlela yokulungisa izingxenye ze-graphite ithonya iziphambeko. Isibonelo, izinqubo zokuhlanza ezinolaka zingalimaza ubuso be-graphite futhi ziholele ekuqhekekeni okuncane. Indlela ekhethwayo inqubo yokuhlanza emnene, elawulwayo enokuxhumana okuncane ngokomzimba nezingxenye ze-graphite. Ngenxa yezizathu zomnotho, ukufaka izingxenye esikhundleni sazo ngokushesha kunalokho obekulindelwe kungaba ngcono kunokubhekana nokulahlekelwa kwesivuno ezigabeni zakamuva. Ngamafuphi, ukulawulwa kokukhiqizwa kwezinhlayiya enkambisweni ejwayelekile ye-SiC epitaxy kugxile emininingwaneni emincane ngekhwalithi yezinto ezibonakalayo kanye nemikhuba yokuphatha. Indaba yekhwalithi ye-graphite iyinhloko yendaba.

Izidingo Zezinto Ezibalulekile Zezingxenye Nezisusa Ze-SiC Epitaxial Ezisezingeni Eliphezulu

Kwi-SiC epitaxy, izingxenye eziku-reactor azigcini nje ngokubamba i-wafer. Ama-susceptors, abathwali be-graphite kanye nezingxenye ze-hotzone ku-reactor zithinta ngqo ukukhula kwekristalu. Yingakho izinto zidinga kakhulu futhi iphutha elincane lizogcina libonakala njengephutha ku-wafer. Ukuqina okuphezulu kokushisa kuyimfuneko eyisisekelo. Izingxenye zishiswa emazingeni okushisa aphezulu kakhulu isikhathi eside (ngezinye izikhathi imijikelezo yokushisa/yokupholisa ephindaphindayo). Izinto ezingakwazi ukugcina ukuzinza kulezi zimo zokushisa zizophambuka futhi ekugcineni zingaqhekeka. Izinguquko ezincane ku-geometry zingashintsha kakhulu ukugeleza kwegesi kanye nokusatshalaliswa kokushisa okuholela ekukhuleni kwekristalu okungafani ebusweni be-wafer. Ubumsulwa bungenye into ebalulekile. Izinqubo ze-SiC eziphezulu zidinga okuqukethwe kwensimbi okuphansi kakhulu kanye nezinga eliphansi kakhulu lomlotha ezingxenyeni ezisekelwe ku-graphite. Ngesikhathi sokusebenza izinsimbi zokulandelela zizophuma kancane ezingxenyeni, ukungcola kungasakazeka ekamelweni futhi kuholele ekungcoleni kwezinhlayiya noma emaphutheni ekristalu endawo. Kwezinye izinto ezithambile, iphutha lokufaka ngokungahleliwe lilandelwe yiqembu elilodwa le-susceptor engcolile. Isakhiwo somphezulu siyimfuneko ebalulekile. Ubuso obubushelelezi nobulinganayo buzosiza ekunciphiseni ukuchitheka kwezinhlayiya ngesikhathi somjikelezo wokushisa/wokupholisa. Ubuso obungalingani, noma ama-pores ngaphakathi kwesakhiwo sobuso, buzoqhubeka nokuqhekeka ngesikhathi sokusebenza futhi ngaleyo ndlela bukhiqize umthombo ozinzile wezinhlayiya egumbini. Ikhwalithi yokugqoka nayo ingenye imfuneko ebalulekile. Ama-susceptor amaningi aphezulu asebenzisa i-SiC coating njengesendlalelo sokuvikela. Ingubo kumele inamathele kahle ezintweni eziyisisekelo futhi kumele imelane nokusebenza isikhathi eside. Ukubopha okungekuhle kanye nokuhlukanisa kuzoveza ngqo i-base graphite endaweni yokusabela enzima. Sivame ukubona lokhu ekusetshenzisweni kwangempela: isibonelo, i-wafer fab esebenza isikhathi eside yokukhiqiza izobona izinga lokukhubazeka likhuphuka kancane ngemva kwemijikelezo engamakhulu. Ukuhlola i-susceptor kuzoveza ukuguguleka okuncane kokugqoka kanye nokuguguleka komphetho. Ukushintsha noma ukufaka esikhundleni ingxenye kuzobuyisela izinga lokukhubazeka ezingeni elamukelekayo. Ukukhetha izinto ezifanele akukhona nje ngokusebenza kokuqala kwezingxenye, kodwa nokuzinza kwezinto emijikelezweni ephindaphindwayo.

Imiphumela Yesakhiwo Sezinhlamvu Ekuzinzeni Kokushisa Kuzinhlelo ze-AIXTRON G10

Isakhiwo sezinhlamvu zezingxenye ze-graphite ngaphakathi kwe-SiC enokushisa okuphezulu Ukukhula kwe-Epitaxy uhlelo, njenge-AIXTRON G10, luthinta kakhulu ukuzinza kokushisa. Lokhu kuhlobene noshintsho lobukhulu, ukugcinwa kwesimo, kanye nokusabela ekujikelezeni kokushisa. I-Graphite akuyona into eqinile ye-monolithic. Yakhiwe ngamakristali amaningi noma okusanhlamvu. Amakristali ngamanye angase abe nokuma okuhlukile. Uma kukhona ukulawulwa okungekuhle kosayizi wokusanhlamvu ngaphakathi kwengxenye ye-graphite, kuvela ukusatshalaliswa kokushisa okungalingani. Izindawo zengxenye ziyashisa futhi ziphole ngamazinga ahlukene. Lokhu kudala ukucindezeleka kwangaphakathi ezingeni elincane. Kancane kancane ngokuhamba kwesikhathi lokhu kucindezeleka kwangaphakathi kubangela ukugoba noma ukuphambuka ezingxenyeni ezifana ne-susceptor noma i-wafer carrier. Le nqubo ibonakala kalula ngesikhathi sokukhiqizwa. Ngokuvamile ivela lapho umugqa we-wafer usebenza emazingeni okushisa aphezulu. Ikhwalithi ye-wafer iqala ukukhukhuleka ngemva kwamakhulu emijikelezo yokushisa. Ukwehluka kobukhulu kuyakhula, futhi amaphutha onqenqemeni aqala ukuvela njalo. Uma lezi zingxenye sezihloliwe zivame ukuba nezimpawu zokugoba noma ukukhathala kwezinto. Izakhiwo zokusanhlamvu ezinhle ezinokusatshalaliswa kwe-crystallite okulawulwayo zizoba nokuzinza kokushisa okungcono kakhulu kunezinhlamvu eziqinile noma izakhiwo ezingahleliwe. Lokhu kuzoholela ekudlulisweni kokushisa okulinganayo kanye nokunciphisa amaphuzu okucindezeleka endawo. Ngesakhiwo sokusanhlamvu esifanele, izingxenye zizomelana nokugoba ngisho nangaphezu kwamakhulu emijikelezo yokushisa. Izakhiwo ezimangelengele noma izakhiwo zokusanhlamvu ezingasabalaliswanga kahle zibangela izindawo ezibuthakathaka ngaphakathi kwengxenye, okuvumela ukuqhekeka okuncane nokukhululwa kwezinhlayiya ekamelweni. Enye inkinga ebalulekile okufanele icatshangelwe ukumelana nokushaqeka kokushisa. Kunezindawo lapho ingxenye ibhekana noshintsho olukhulu lokushisa njengokulayisha ku-reactor noma lapho isuswa. Uma kunemingcele ebuthakathaka phakathi kokusanhlamvu khona-ke ukuqhekeka okuncane kungakheka emigqeni yokusanhlamvu. Nakuba lokhu ngokuvamile kungabangela ukwehluleka kwengxenye, kuvumela lobu buthakathaka ukuba bakheke ezintweni, okuholela ezinkingeni zokuthembeka zesikhathi esizayo. Iningi lezinto ezithambile lilandelela isikhathi sokuphila kwengxenye kokubili ngamahora asetshenzisiwe, kanye nenani lemijikelezo yokushisa kanye nokwelashwa kokushisa okuphelele. Izingxenye ezinesakhiwo sokusanhlamvu esiklanywe kahle zinokuphila isikhathi eside, imiphumela ehambisanayo ngokuhamba kwesikhathi.

Ukunciphisa Ukungcola Kwensimbi Ezingxenyeni Ze-Graphite Ezihlanzekile Kakhulu

Enye yezinkinga "ezingabonakali" kodwa ezibucayi kunoma iyiphi ingxenye ye-graphite, kufaka phakathi inqubo ye-SiC epitaxy, ukungcola kwensimbi. Ngisho neminonjana emincane yensimbi engxenyeni ye-graphite ingangena enkambisweni futhi ibe umthombo wobunzima bokulandelela amaphutha ku-reactor ye-SiC epitaxy njenge-AIXTRON G10. Izinsimbi ezinjalo zivame ukuvela ezintweni zokusetshenziswa noma ezinyathelweni ezahlukahlukene zokucubungula ezihilelekile ekwakhiweni kwengxenye ye-graphite. Izinto ezifana ne-Iron, i-Nickel, i-Calcium ne-Sodium zivame futhi zihlala zibambeke engxenyeni enkulu ye-graphite ekushiseni kwegumbi, nokho, ekushiseni okuphezulu kwenqubo esetshenziswa ku-SiC epitaxy, lezi zinto zingase zihambe. Lezi zinsimbi ezincane zingagcina zikhishwe yigesi noma zithuthele phezu komhlaba ngesikhathi sokujikeleza okuphindaphindiwe kokushisa/ukupholisa endaweni eshisayo, okungukuthi i-susceptor noma i-wafer carrier uqobo. Icala elijwayelekile lingaba kanje: i-fab iqala iqembu lokukhiqiza isebenzisa izingxenye ezintsha ze-graphite. Ama-wafer ambalwa okuqala alungile futhi awabonisi amaphutha, kodwa ngemva kwesikhathi esithile, amaphutha amancane aqala ukuvela. Ngokuvamile kuyimigodi emincane, amaphutha okungahleliwe e-stack, noma izehlakalo zezinhlayiya ezingachazeki. Kulula ukusola ngokungalungile ukugeleza kwegesi okungalungile noma umcimbi wokungcola ngesikhathi sokuhlanza igumbi. Kodwa ukuhlaziywa okuningiliziwe kuvame ukuholela ekukhishweni kancane kwezinsimbi ezilandelanayo ezivela ezingxenyeni ze-graphite. Ukulawula ubumsulwa be-graphite kungenye yezihluthulelo. Ezingxenyeni ezibalulekile, i-graphite ehlanziwe ngokushisa okuphezulu enokuqukethwe komlotha okuphansi ihlala ikhethwa. Lesi sinyathelo sokuhlanza sisusa iningi lensalela yensimbi. I-graphite enjalo ingagcina izinto zivaleleke isikhathi eside ngisho nangaphansi kwemijikelezo yokushisa/yokupholisa ephindaphindwayo. Ukuhlolwa okungenayo kwezingxenye ze-graphite nakho kubaluleke kakhulu kwezinye izinto ezisetshenziswayo. Ukuhlola amaqoqo e-graphite ngamasu afana ne-ICP-OES noma i-XRF kungavimbela ukusebenzisa izingxenye ezingcolile. Kungavimbela futhi ukuxuba izingxenye ezivela emithonjeni ehlukene ngaphakathi kokugeleza kwenqubo efanayo. Izimbozo ezifana ne-SiC noma i-TaC nazo ziyasiza ekuxazululeni inkinga ngokusebenza njengesithiyo phakathi kwengxenye ye-graphite nendawo yenqubo. Uma nje isembozo sibekwe kahle futhi siboshwe ku-substrate engaphansi kwe-graphite kuzonciphisa ukusebenzisana kwengxenye ye-graphite nendawo yenqubo. Okokugcina kodwa okungabalulekile ukuphathwa nokugcinwa kwezingxenye ze-graphite. Izingxenye ze-graphite zingangcoliswa ngesikhathi sokuphathwa ngamagilavu ​​​​angcolile, izinsimbi noma ngokugcinwa eshalofini elingcolile. Lokhu kungcola kobuso kungangena esithandweni ngesikhathi somjikelezo wokushisa. Ukuze kuncishiswe ukungcoliswa kwensimbi kwezingxenye ze-graphite, kuyisamba semizamo eminingi emincane. Kudingeka izinto ezihlanzekile kakhulu ezihlanganiswe nomkhuba omuhle wokuphatha kanye nokulawula inqubo eqinile.

Kungani Izinhlelo ze-Veeco EPIK Zidinga Izinto Ze-Graphite Ezine-Porosity Ephansi Kakhulu?

Izingxenye ze-graphite ngaphakathi kwepulatifomu ye-Veeco EPIK Systems zibhekana nenye yezimo zenqubo ezinzima kakhulu ekukhiqizweni kwe-semiconductor. Lezi zingxenye zibhekana nezimo zokushisa okuphezulu, i-gas chemistry enamandla kanye nemijikelezo yenqubo ende. Ngakho-ke i-graphite ephansi kakhulu ye-porosity ibalulekile ekugcineni ubuqotho be-SiC epitaxy kanye nokuhlanzeka. I-porosity ibhekisela kuma-pores amancane, angaphakathi akhona emzimbeni we-graphite uqobo. Naphezu kobuso obubushelelezi ngokuphelele, ama-pores angaphakathi angaba khona amagesi enqubo yokubamba, izinsalela kanye ne-chemistry yokuhlanza. I-porosity ephezulu isho ivolumu yangaphakathi eyengeziwe yokubamba, lapho ngemva kokuvezwa kokushisa okuphezulu, izinto zingasuswa kancane kancane. Lokhu kususwa kwegesi akuhlali kuqondile futhi kungaholela ekuqhumeni, okwenza inqubo ibe nzima ukuyilawula. Ku-SiC epitaxy, lokhu kuyingozi kakhulu. Lapho amagesi ekhishwa emzimbeni we-graphite angafakwa ekugelezeni kwegesi ngaphakathi kwegumbi le-epitaxy, okufaka isandla ezinhlayiyeni ezingafuneki. Izinhlayiya zizongena ebusweni be-wafer, okuzothinta ukukhula kwekristalu futhi kungaholela ezifweni ezingalindelekile njengemigodi engahleliwe, ukugoba kobuso noma ukuhlukahluka kwendawo kobukhulu be-wafer. Isimo esivamile esihlangatshezwana naso sisezindaweni zokukhiqiza lapho indwangu ehlanzekile ithola izingxenye ezintsha ze-graphite zesistimu ye-EPIK. Imiphumela yokuqala ingase yamukeleke, nokho njengoba imijikelezo yokushisa iphinda, amazinga okukhubazeka angakhuphuka futhi ukuhlolwa kwesitimela senqubo kufaka phakathi imigqa yegesi, ama-valve kanye nezigaba zenqubo yokuhlanza kungase kuveze lutho olusobala. Ngokuvamile kwembulwa ukuthi imbangela yi-graphite ene-porosity ephansi ngaphakathi kwendawo yokushisa ephezulu. Ukukhethwa kwe-graphite ene-porosity ephansi kakhulu kunciphisa ngempumelelo le ngozi ngokunciphisa inani langaphakathi lapho izinhlobo ezivalelekile zingafihlwa khona, kunciphisa amathuba okukhishwa kwegesi ngokuzumayo lapho kushisa. Kuphinde kuhlotshaniswe nobuqotho obuhle bomshini. Isakhiwo esiqinile se-graphite ene-porosity ephansi kakhulu ngokuvamile sinikeza ukumelana okukhulu kokuqhekeka njengoba i-graphite idlula ekujikelezeni okuphindaphindiwe kokushisa. Ngaphezu kwalokho, izindawo ezine-porosity ephansi zikhuthaza ubuqotho bokumboza obuthuthukisiwe. Lapho i-SiC noma ezinye izinto eziphikisayo zimbozwe kulezi zindawo ze-graphite, zinamathela kahle endaweni engena-pority eningi. Lokhu kungenzeka kungenxa yokusondelana okukhulu kokubopha phakathi kwezinto ezimboziwe kanye ne-graphite, okuthuthukisa ukuqina nokuphila isikhathi eside kwezimbozo kanye nekhono lazo lokuqhekeka noma ukuqhekeka. Ekugcineni, ukukhethwa kwe-graphite ephansi kakhulu esimweni sokwenziwa kwansuku zonke, kuyilapho kuyimpahla yezinto ezibonakalayo, kunikeza inzuzo eqondile kakhulu ekufezeni imiphumela ye-wafer ezinzile, ehlanzekile, nebikezelwayo ngaphakathi kwezinqubo ze-SiC epitaxy eziphezulu.