Izithiyo Zobuchwepheshe kanye Nentuthuko Embonini Ye-Silicon Carbide (SiC)

I-Silicon carbide (SiC), njengezinto ze-semiconductor zesizukulwane sesithathu, ithola ukunakwa okukhulu ngenxa yezakhiwo zayo ezisezingeni eliphezulu kanye nezinhlelo zokusebenza ezithembisayo kuma-elekthronikhi anamandla aphezulu. Ngokungafani nama-semiconductors e-silicon (Si) noma i-germanium (Ge) endabuko, i-SiC ine-bandgap ebanzi, ukuhanjiswa okuphezulu kokushisa, insimu yokuqhekeka okuphezulu, kanye nokuqina kwamakhemikhali okuhle kakhulu. Lezi zici zenza i-SiC ibe yinto efanelekile yamadivayisi kagesi ezimotweni zikagesi, izinhlelo zamandla avuselelekayo, ukuxhumana kwe-5G, kanye nezinye izinhlelo zokusebenza ezisebenza kahle kakhulu nezinokwethenjelwa okuphezulu. Kodwa-ke, naphezu kwamandla ayo, imboni ye-SiC ibhekene nezinselele ezinkulu zobuchwepheshe ezakha izithiyo ezibalulekile zokwamukelwa kabanzi.

1. I-SiC Substrate: Ukukhula Kwekristalu Nokwenziwa Kwe-Wafer

Ukukhiqizwa kwezingxenye ze-SiC kuyisisekelo semboni ye-SiC futhi kumelela isithiyo esikhulu kakhulu sobuchwepheshe. I-SiC ayikwazi ukukhuliswa kusukela esigabeni soketshezi njenge-silicon ngenxa yephuzu layo eliphezulu lokuncibilika kanye ne-crystal chemistry eyinkimbinkimbi. Esikhundleni salokho, indlela eyinhloko ukuthuthwa komhwamuko ongokwenyama (i-PVT), okubandakanya ukufaka i-silicon ehlanzekile kakhulu kanye ne-carbon powders emazingeni okushisa angaphezu kuka-2000°C endaweni elawulwayo. Inqubo yokukhula idinga ukulawulwa okunembile kwama-gradient okushisa, ingcindezi yegesi, kanye ne-flow dynamics ukuze kukhiqizwe amakristalu asezingeni eliphezulu.

I-SiC inama-polytype angaphezu kuka-200, kodwa ambalwa kuphela afanele ukusetshenziswa kwe-semiconductor. Ukuqinisekisa i-polytype efanele ngenkathi kunciphisa amaphutha afana nama-micropipes kanye nokuhlukaniswa kwentambo kubalulekile, njengoba la maphutha ethinta kakhulu ukuthembeka kwedivayisi. Izinga lokukhula elihamba kancane, ngokuvamile elingaphansi kwama-2 mm ngehora, liholela ezikhathini zokukhula kwekristalu ezingafika esontweni ngebhola elilodwa, uma kuqhathaniswa nezinsuku ezimbalwa zamakristalu e-silicon.

Ngemva kokukhula kwekristalu, izinqubo zokusika, ukugaya, ukupholisha, kanye nokuhlanza ziyinselele enkulu ngenxa yobunzima beSiC, obulandela idayimane kuphela. Lezi zinyathelo kumele zilondoloze ubuqotho bomphezulu ngenkathi zigwema ukuqhekeka okuncane, ukuqhekeka komphetho, kanye nomonakalo ongaphansi komhlaba. Njengoba ububanzi be-wafer bukhula kusuka kumasentimitha angu-4 kuya kwangu-6 noma ngisho namasentimitha angu-8, ukulawula ukucindezeleka kokushisa nokufeza ukwanda okungenamaphutha kuba nzima kakhulu.

2. I-SiC Epitaxy: Ukufana Kwezingqimba kanye Nokulawulwa Kokusebenzisa Izidakamizwa

Ukukhula kwe-epitaxial kwezingqimba ze-SiC kuma-substrate kubalulekile ngoba ukusebenza kukagesi kwedivayisi kuncike ngqo kwikhwalithi yalezi zingqimba. Ukufakwa kwe-chemical vapor (CVD) kuyindlela evelele, evumela ukulawula okunembile kohlobo lwe-doping (uhlobo lwe-n noma uhlobo lwe-p) kanye nobukhulu bezingqimba. Njengoba izilinganiso ze-voltage zanda, ubukhulu bezingqimba ze-epitaxial obudingekayo bungakhuphuka kusuka kuma-micrometer ambalwa kuya kumashumi noma ngisho namakhulu ama-micrometer. Ukugcina ubukhulu obufanayo, ukumelana okuqhubekayo, kanye nobuningi obuphansi beziphambeko kuzo zonke izingqimba ezijiyile kunzima kakhulu.

Imishini nezinqubo ze-Epitaxy okwamanje zibuswa abahlinzeki abambalwa bomhlaba wonke, okudala izithiyo zokungena eziphezulu kubakhiqizi abasha. Ngisho noma kunezingqimba zekhwalithi ephezulu, ukulawulwa okungekuhle kwe-epitaxial kungaholela ekukhiqizeni okuphansi, ukwethembeka okunciphile, kanye nokusebenza kwedivayisi okungekuhle.

3. Ukwakhiwa Kwedivayisi: Izinqubo Ezinembile Nokuhambisana Kwezinto Ezibonakalayo

Ukwenziwa kwamadivayisi e-SiC kuletha ezinye izinselele. Izindlela zendabuko zokusabalalisa i-silicon aziphumeleli ngenxa yezinga eliphezulu lokuncibilika kwe-SiC; kusetshenziswa ukufakelwa kwama-ion esikhundleni salokho. Ukufakwa kwama-annealing okushisa okuphezulu kuyadingeka ukuze kusebenze ama-dopants, okuyingozi ekulimaleni kwe-crystal lattice noma ukuwohloka kwendawo.

Ukwakheka kokuxhumana kwensimbi okuseqophelweni eliphezulu kungenye inkinga ebalulekile. Ukumelana okuphansi kokuxhumana (<10⁻⁵ Ω·cm²) kubalulekile ekusebenzeni kahle kwedivayisi yamandla, kodwa izinsimbi ezijwayelekile ezifana ne-Ni noma i-Al zinokuzinza okulinganiselwe kokushisa. Izinhlelo zokuhlanganisa insimbi zithuthukisa ukuzinza kodwa zandisa ukumelana kokuxhumana, okwenza ukwenza ngcono kube nzima kakhulu.

Ama-SiC MOSFET nawo ahlushwa izinkinga zesikhombikubona; isikhombikubona se-SiC/SiO₂ sivame ukuba nobunzima obukhulu bezithiyo, okunciphisa ukuhamba kwesiteshi kanye nokuqina kwe-threshold voltage. Isivinini sokushintsha okusheshayo senza kube nzima nakakhulu nge-parasitic capacitance kanye ne-inductance, okufuna ukuklanywa ngokucophelela kwamasekethe okushayela isango kanye nezixazululo zokupakisha.

4. Ukuhlanganiswa Kokupakisha Nohlelo

Amadivayisi kagesi e-SiC asebenza ngama-voltage aphezulu kanye namazinga okushisa kunalawo ahambisana ne-silicon, okudinga amasu amasha okupakisha. Amamojula avamile ane-wire-bond awanele ngenxa yemikhawulo yokusebenza kokushisa kanye nogesi. Izindlela zokupakisha ezithuthukisiwe, njengezixhumanisi ezingenantambo, ukupholisa okunezinhlangothi ezimbili, kanye nokuhlanganiswa kwama-capacitor ahlukanisayo, izinzwa, kanye ne-drive circuitry, kuyadingeka ukuze kusetshenziswe ngokugcwele amakhono e-SiC. Amadivayisi e-SiC ohlobo lwe-Trench ane-unit density ephezulu ayaba yinto evamile ngenxa yokumelana kwawo okuphansi kokuhambisa, ukuncipha kwamandla e-parasitic, kanye nokusebenza kahle kokushintsha okuthuthukisiwe.

5. Ukwakheka Kwezindleko kanye Nemiphumela Yemboni

Izindleko eziphezulu zamadivayisi e-SiC zibangelwa kakhulu ukukhiqizwa kwezinto ezingaphansi komhlaba kanye ne-epitaxial, okubalwa cishe u-70% wezindleko zokukhiqiza eziphelele. Naphezu kwezindleko eziphakeme, amadivayisi e-SiC anikeza izinzuzo zokusebenza ngaphezu kwe-silicon, ikakhulukazi ezinhlelweni ezisebenza kahle kakhulu. Njengoba izikali zokukhiqiza ezingaphansi komhlaba kanye namadivayisi kanye nemikhiqizo kuthuthuka, kulindeleke ukuthi izindleko zehle, okwenza amadivayisi e-SiC ancintisane kakhulu ezimotweni, emandleni avuselelekayo, kanye nasezisetshenzisweni zezimboni.

Isiphetho

Imboni ye-SiC imele intuthuko enkulu kwezobuchwepheshe ezintweni ze-semiconductor, kodwa ukwamukelwa kwayo kuvinjelwe ukukhula kwekristalu okuyinkimbinkimbi, ukulawulwa kwezingqimba ze-epitaxial, ukwenziwa kwamadivayisi, kanye nezinselele zokupakisha. Ukunqoba lezi zithiyo kudinga ukulawulwa kokushisa okunembile, ukucubungula izinto ezithuthukisiwe, izakhiwo zamadivayisi ezintsha, kanye nezixazululo ezintsha zokupakisha. Ukuthuthukiswa okuqhubekayo kulezi zindawo ngeke kunciphise izindleko kuphela futhi kuthuthukise isivuno kodwa futhi kuzovula amandla aphelele e-SiC kuma-electronics kagesi esizukulwane esilandelayo, izimoto zikagesi, izinhlelo zamandla avuselelekayo, kanye nezinhlelo zokusebenza zokuxhumana ezivame kakhulu.

Ikusasa lomkhakha we-SiC lilele ekuhlanganisweni kokusungula izinto ezintsha, ukukhiqizwa okunembile, kanye nokwakhiwa kwamadivayisi, okuqhuba ushintsho oluvela ezixazululweni ezisekelwe ku-silicon luye kuma-semiconductors asebenza kahle kakhulu futhi athembekile kakhulu.