Kutheni le nto kufuneka senze i-epitaxy kwi-silicon wafer substrates?

Kwikhonkco leshishini le-semiconductor, ngakumbi kwi-semiconductor yesizukulwana sesithathu (i-wide bandgap semiconductor) ikhonkco leshishini, kukho ii-substrates kunyeepitaxialiileya. Yintoni intsingiselo yeepitaxialumaleko? Uthini umahluko phakathi kwe-substrate kunye ne-substrate?

Isubstrate yi aiqhekeza lesonkayenziwe nge-semiconductor enye yezinto zekristale. I-substrate ingangena ngokuthe ngqo kwiiqhekeza lesonkaikhonkco lokuvelisa ukuvelisa izixhobo ze-semiconductor, okanye inokuqhutyelwa phambiliepitaxialinkqubo yokuvelisa ii-wafers ze-epitaxial. I-substrate isezantsi kweiqhekeza lesonka(Sika i-wafer, unokufumana enye ifa emva kwenye, kwaye uyipakishe ukuze ibe yintsomi ye-chip) (enyanisweni, umzantsi wetshiphu uhlala utyatyekwe ngomqolo wegolide ongasemva, osetyenziswa njengonxibelelwano "lomhlaba", kodwa yenziwe kwinkqubo yangasemva), kunye nesiseko esithwala wonke umsebenzi wenkxaso (i-skyscraper kwi-chip yakhiwe kwi-substrate).

I-Epitaxy ibhekisela kwinkqubo yokukhulisa i-crystal entsha kwi-crystal substrate enye ecutshungulwe ngokucokisekileyo ngokusika, ukugaya, ukupolisha, njl njl. I-crystal entsha ingaba yinto efanayo ne-substrate, okanye ingaba yinto eyahlukileyo (i-homoepitaxial okanye i-heteroepitaxial).
Ukusukela ukuba umaleko wekristale osandula ukubunjwa ukhula ecaleni kwesigaba sekristale, ubizwa ngokuba ngumaleko we-epitaxial (ngokuqhelekileyo ii-microns ezininzi ezityebileyo. Thatha isilicon njengomzekelo: intsingiselo ye-silicon epitaxial ukukhula kukukhulisa umaleko wekristale kunye nentembeko yesakhiwo selathisi elungileyo. kwi-silicon enye ye-crystal substrate ene-crystal orientation kunye ne-resistiveivity eyahlukileyo kunye nobukhulu njenge-substrate), kwaye i-substrate ene-epitaxial layer ibizwa ngokuba yi-epitaxial wafer (i-epitaxial wafer = i-epitaxial layer + substrate). Ukwenziwa kwesixhobo kuqhutyelwa kwi-epitaxial layer.

I-Epitaxiality ihlukaniswe ibe yi-homoepitaxiality kunye ne-heteroepitaxiality. I-Homoepitaxiality kukukhulisa i-epitaxial layer yezinto ezifanayo njenge-substrate kwi-substrate. Yintoni intsingiselo ye-homoepitaxiality? – Ukuphucula ukuzinza nokuthembeka kwemveliso. Nangona i-homoepitaxiality ikhula i-epitaxial layer yezinto ezifanayo njenge-substrate, nangona izinto eziphathekayo zifana, zinokuphucula ukucoceka kwezinto kunye nokufana kwe-wafer surface. Xa kuthelekiswa neewafers ezikhazimlisiweyo ezicutshungulwa ngokugudiswa ngoomatshini, i-substrate ecutshungulwa yi-epitaxiality inomgangatho ophezulu womphezulu othe tyaba, ucoceko oluphezulu, iziphene ezincinci ezincinci, kunye nokungcola okumbalwa komhlaba. Ke ngoko, ukuxhathisa kufana ngakumbi, kwaye kulula ukulawula iziphene zomhlaba ezinje ngamasuntswana omphezulu, iimpazamo zokupakisha, kunye nokuhanjiswa. I-Epitaxy ayiphuculi kuphela ukusebenza kwemveliso, kodwa iqinisekisa ukuzinza kwemveliso kunye nokuthembeka.
Ziziphi izibonelelo zokwenza omnye umaleko we-athomu ye-silicon epitaxial kwi-silicon wafer substrate? Kwinkqubo ye-silicon ye-CMOS, ukukhula kwe-epitaxial (EPI, epitaxial) kwi-wafer substrate yinkqubo ebaluleke kakhulu.
1. Ukuphucula umgangatho wekristale
Iziphene zokuqala zesubstrate kunye nokungcola: I-wafer substrate ingaba neziphene ezithile kunye nokungcola ngexesha lenkqubo yokuvelisa. Ukukhula kwe-epitaxial layer kunokuvelisa umgangatho ophezulu, ophantsi-isiphene kunye nokungcola-concentration single-crystalline silicon layer kwi-substrate, ebaluleke kakhulu kwimveliso yesixhobo esilandelayo. Isakhiwo sekristal esifanayo: Ukukhula kwe-Epitaxial kunokuqinisekisa isakhiwo se-crystal esifanayo, ukunciphisa impembelelo yemida yengqolowa kunye neziphene kwi-substrate material, kwaye ngaloo ndlela kuphuculwe umgangatho we-crystal we-wafer yonke.
2. Ukuphucula ukusebenza kombane
Lungiselela iimpawu zesixhobo: Ngokukhulisa i-epitaxial layer kwi-substrate, i-doping concentration kunye nohlobo lwe-silicon inokulawulwa ngokuchanekileyo ukuze kulungiswe ukusebenza kombane kwesixhobo. Ngokomzekelo, i-doping ye-epitaxial layer inokulungelelanisa ngokuchanekileyo i-voltage ye-threshold kunye nezinye iiparamitha zombane ze-MOSFET. Ukunciphisa ukuvuza kwangoku: Iingqimba eziphezulu ze-epitaxial zineziphene ezisezantsi, ezinceda ukunciphisa ukuvuza kwangoku kwisixhobo, ngaloo ndlela kuphuculwe ukusebenza kunye nokuthembeka kwesixhobo.
3. Ukuxhasa iindawo eziphambili zenkqubo
Ukunciphisa ubungakanani beempawu: Kwiindawo ezincinci zenkqubo (ezinje nge-7nm, 5nm), ubungakanani besixhobo sesixhobo siyaqhubeka nokuncipha, sifuna izinto ezisulungekileyo nezikumgangatho ophezulu. Itekhnoloji yokukhula kwe-Epitaxial inokuhlangabezana nezi mfuno kwaye ixhase ukusebenza okuphezulu kunye noxinzelelo oluphezulu lwesekethe edibeneyo yokwenziwa kwesekethe. Phucula i-voltage yokuqhekeka: Umaleko we-epitaxial unokuyilwa ukuba ube ne-voltage ephezulu yokuphuka, ebaluleke kakhulu ekwenzeni izixhobo zamandla aphezulu kunye ne-high-voltage. Ngokomzekelo, kwizixhobo zamandla, i-epitaxial layer inokunyusa i-voltage yokuphuka kwesixhobo kunye nokwandisa uluhlu olukhuselekileyo lokusebenza.
4. Ukuhambelana kwenkqubo kunye nesakhiwo se-multi-layer
Isakhiwo se-Multi-layer: I-teknoloji yokukhula kwe-Epitaxial ivumela ukuba izakhiwo ezininzi zikhule kwi-substrate, kwaye iileyile ezahlukeneyo zinokuba neentlobo ezahlukeneyo ze-doping kunye neentlobo. Oku kuluncedo kakhulu ekwenzeni izixhobo ze-CMOS ezintsonkothileyo kunye nokuphumeza ukudityaniswa kwamacala amathathu. Ukuhambelana: Inkqubo yokukhula kwe-epitaxial ihambelana kakhulu neenkqubo ezikhoyo zokuvelisa i-CMOS kwaye inokuhlanganiswa ngokulula kwiinkqubo ezikhoyo zokuvelisa ngaphandle kokuguqula kakhulu imigca yenkqubo.