Ukusetshenziswa Kwezinsimbi Ekukhiqizweni Kwamadivayisi E-Semiconductor
Amadivayisi e-semiconductor—njenge-transistors, ama-diode, ama-sensor, ama-integrated circuits (ama-IC), kanye nama-processor—angumgogodla wobuchwepheshe besimanje. Ngemuva kokusebenza kwawo okuphezulu kanye nobukhulu obuncane kakhulu kukhona inqubo yokukhiqiza eyinkimbinkimbi, enembile, futhi encike kakhulu ezintweni ezibonakalayo. Iqembu elilodwa lezinto ezibonakalayo elindima yalo engenakuphikwa yinsimbi. Izinsimbi azisetshenziswa nje kuphela njengezintambo eziqhuba ugesi kodwa futhi njengezixhumanisi zikagesi, izithiyo zokusabalalisa, izinto ezixhumanisayo phakathi kwezingxenye, kanye nezinto ezisebenzayo ezinqubweni ze-lithography kanye nokupakisha. Lesi sihloko sixoxa ngendlela izinsimbi ezisetshenziswa ngayo ekukhiqizeni amadivayisi e-semiconductor, izinhlobo zezinsimbi ezivame ukusetshenziswa, kanye nezinselele kanye neziqondiso zentuthuko yazo.
1. Indima yezinsimbi kumadivayisi e-semiconductor
Ngokuvamile, izinsimbi kumadivayisi e-semiconductor zinemisebenzi eminingana eyinhloko:
1. Ukuxhumana (ukuxhumanisa izintambo): Ukuxhumanisa ama-transistor nezinye izingxenye ku-chip ngokusebenzisa izindlela zensimbi eziminyene kakhulu nezinezingqimba eziningi (ukuxhumana okunezingqimba eziningi).
2. Oxhumana nabo be-Ohmic kanye noxhumana nabo be-Schottky: Kwakha isixhumi sikagesi phakathi kwensimbi kanye ne-semiconductor. Oxhumana nabo be-Ohmic bavumela ukuthi ugesi ugeleze kuzo zombili izinhlangothi ngokumelana okuphansi, kuyilapho oxhumana nabo be-Schottky benza i-diode enezici zokulungisa.
3. Isendlalelo sesithintelo kanye nesendlalelo sokunamathela: Kuvimbela ukusabalala kwama-athomu ensimbi ku-semiconductor noma izinto ze-dielectric, futhi kusiza insimbi ukuthi inamathele ngokuqinile kusendlalelo esingezansi.
4. I-electrode yesango ku-transistor: Kweminye imikhakha yobuchwepheshe, insimbi isetshenziselwa ukwakha i-electrode yesango ku-MOSFET ukuze kulawulwe kangcono isiteshi kanye nokumelana okuphansi.
5. Izinto ezisetshenziswa enqubweni yokukhiqiza: Izinsimbi kanye nezinto ezisetshenziswa njengemaski eqinile, izendlalelo ezibonisa ukukhanya, noma izingxenye zamakhemikhali zokufaka nokuqopha.
6. Ukupakishwa nokuxhumeka kwe-chip: I-solder, i-wire bonding, i-bumping, kanye nezinhlobo ezahlukene ze-alloys zensimbi zisetshenziselwa ukuxhuma i-chip ebhodini lesifunda nokuvikela idivayisi emvelweni.
Ngamanye amazwi, ukusebenza kwama-chip esimanje akunqunywa nje kuphela yi-silicon noma ezinye izinto ze-semiconductor, kodwa futhi nangendlela izinsimbi ezikhethwa futhi ezihlanganiswa ngayo.
2. Izinsimbi zokuxhumanisa: kusukela ku-aluminium kuya kuthusi kanye ne-cobalt
Ezizukulwaneni zokuqala zama-IC, i-aluminium (Al) kwakuyiyona ndlela eyinhloko yokuxhumana ngoba kwakulula ukuyibeka, ingabizi kakhulu, futhi ihambisana nezinqubo zokukhiqiza zangaleso sikhathi. Kodwa-ke, njengoba ubuningi be-transistor banda futhi izidingo zamanje zanda, izinkinga ezifana nokufuduka kwe-electro-ukuhamba kwama-athomu ensimbi ngenxa yokugeleza okuphezulu kwama-electron-zabangela ukuphuka kwendlela kanye nokwehla kokuthembeka.
Imboni yabe isiphendukela ethusini (Cu) ngoba inokumelana okuphansi kune-aluminium, okunciphisa ukulahleka kwamandla nokwandisa isivinini sesiginali. Kodwa-ke, ithusi liletha inselele: I-Cu isakazeka kalula ibe yi-dielectrics (isb., i-SiO₂ noma i-low-k dielectrics) futhi ingalimaza izakhiwo zikagesi. Ngakho-ke, i-Cu cishe isetshenziswa njalo ngesendlalelo sokuvimbela njenge-tantalum (Ta) noma i-tantalum nitride (TaN).
Kubuchwepheshe obuncane kakhulu (ama-node athuthukile), ingxenye yokuxhumana iyancipha, ukumelana kwanda kakhulu, futhi imiphumela yemingcele (ukusabalala kobuso) iba namandla kakhulu. Kwezingqimba ezithile, ukusetshenziswa kwe-cobalt (Co) noma i-ruthenium (Ru) njengendlela ehlukile/ehambisana ne-Cu sekuqalile ukuvela ngoba kunganikeza ukusebenza okuzinzile kakhulu ngobukhulu obuncane kakhulu futhi kunciphisa isidingo sezithiyo ezijiyile.
3. Oxhumana nabo be-Metal-semiconductor: ohmic kanye ne-Schottky
Ukuxhumana phakathi kwensimbi ne-semiconductor kungenye yezici ezibaluleke kakhulu. Uma ukuxhumana kunamandla kakhulu, i-transistor ishisa kakhulu futhi ilahlekelwe ukusebenza. Kumadivayisi e-CMOS anamuhla, oxhumana nabo bomthombo/bokukhipha kanye nama-contact plugs aklanyelwe ukuba nokumelana okuphansi kakhulu.
Ezinye izinsimbi kanye namakhemikhali avame ukusetshenziswa kokuxhumana zifaka:
– I-Titanium (Ti): ivame ukusetshenziswa njenge-glue kanye nesendlalelo esisebenzayo ukwakha ama-silicides.
– I-Nickel (Ni) kanye ne-cobalt (Co): kuvame kakhulu ezinqubweni ze-silicide (isb. i-NiSi, i-CoSi₂) ukunciphisa ukumelana kokuthintana ku-silicon.
– I-Tungsten (W): isetshenziswa kabanzi njenge-“plug” yokugcwalisa imigodi yokuxhumana (contact/via fill) ngoba izinzile futhi ifanelekela ukufakwa kwe-CVD (chemical vapor deposition).
– Iplatinum (Pt) noma i-palladium (Pd): ingasetshenziswa ukwakha oxhumana nabo be-Schottky noma kwezinye izinhlelo zokusebenza ezidinga ukuqina okuphezulu kwamakhemikhali.
Kumadivayisi enziwe ngama-semiconductor ngaphandle kwe-silicon—njenge-GaN (gallium nitride) noma i-SiC (i-silicon carbide)—ukukhetha insimbi yokuxhumana kuba yinto ebaluleke kakhulu ngenxa yokwehluka kwesakhiwo sebhendi yamandla, izidingo zokushisa okuphezulu, kanye nezimo zokusebenza ezimbi kakhulu (isb., amandla kagesi).
4. Isendlalelo sesithintelo, i-liner, kanye nesendlalelo sokunamathela
Ngenxa yokuthi ama-chip anamuhla mancane kakhulu, ama-athomu ensimbi angasabalala futhi abangele ukuvuza, ama-short, noma izinguquko kumapharamitha e-transistor. Ngakho-ke, kusetshenziswa izendlalelo ezincane, ezifeza imisebenzi elandelayo:
– Isithiyo sokusabalalisa: sivimbela ukusabalala kwe-Cu noma ezinye izinsimbi.
– I-Liner: isiza ukugcwalisa izici ezincane (umsele/ngokusebenzisa) ngokulinganayo.
– Isendlalelo sokunamathela: kwandisa ukunamathela.
Izinto ezivamile zifaka phakathi i-Ta/TaN, i-Ti/TiN, i-W, kanye nocwaningo lwakamuva, izithiyo ezisekelwe ku-Ru, i-Mn, noma izendlalelo ezincane kakhulu ezisekelwe ezintweni ze-2D njengezithiyo zokusabalalisa. Njengoba ama-node ethuthuka, inselele iwukwenza isithiyo sibe sincane ngangokunokwenzeka ngenkathi siqhubeka sisebenza, njengoba isithiyo esikhulu kakhulu "sidla" isikhala sendlela futhi sandisa ukumelana.
5. Insimbi esakhiweni se-transistor: isango lensimbi kanye ne-high-k
Kuma-transistors e-MOSFET anamuhla, ikakhulukazi selokhu kwethulwa amasango e-high-k/metal, insimbi iphinde yadlala indima enkulu esakhiweni samasango. Ngaphambilini, amasango e-polysilicon ayevame ukusetshenziswa, kodwa ayebhekene nezinkinga ezifana nomphumela wokuncipha kanye nokuhambisana nama-dielectric e-high-k. Ngamasango ensimbi, ukulawulwa kwe-electrostatic kuyathuthukiswa futhi ukuvuza kungacindezelwa.
Izinto ezisetshenziswayo ziyahlukahluka, njenge-titanium nitride (TiN), i-tantalum nitride, noma inhlanganisela yezinsimbi ezenzelwe ukufeza umsebenzi ofanele (ukuze i-threshold voltage ihlangabezane nomklamo). Lapha, insimbi akuyona nje i-conductor; izakhiwo zayo ze-elekthronikhi ezingaphezulu zinquma ukuziphatha kwe-transistor.
6. Ukusetshenziswa kwensimbi ezinqubweni zokubeka kanye nokwenza amaphethini
Ukukhiqizwa kwama-chip kuhilela ukufakwa kwezingqimba ezincane zensimbi ngamasu ahlukahlukene, okuhlanganisa:
– I-PVD (Ukususwa Komusi Ongokwenyama): njengokukhafula, okuvamile ku-Al, Ti, Ta, nabanye.
– I-CVD (Ukususwa Komusi Wekhemikhali): ivame ukusetshenziswa kuma-plug e-W (tungsten) kanye nezendlalelo ezithile zensimbi.
– I-ALD (Ukubekwa Kwezingqimba Ze-Atomic): ibaluleke kakhulu ezingqimbeni ezincane kakhulu nezifanayo ezakhiweni ze-3D, isibonelo izithiyo/ama-liners, amasango ensimbi, kanye nezinye izinto zokuxhumana.
Ngemva kokufakwa, insimbi kumele idwetshwe ngephethini kusetshenziswa i-lithography kanye nokuqopha noma inqubo ye-damascene (ikakhulukazi ye-Cu), ehilela ukudala imisele ku-dielectric, ukuyigcwalisa ngensimbi, bese uyipholisha kusetshenziswa i-Chemical Mechanical Planarization (CMP). Le nqubo idinga i-slurry kanye ne-chemistry efanele ukudala indawo eyisicaba ngaphandle kokulimaza izendlalelo ezingaphansi.
7. Insimbi ekupakishweni: i-solder, i-bump, kanye ne-wire bond
Uma i-wafer isiqediwe, i-chip iyasikwa (inqunywe) bese ipakishwa. Kulesi sigaba, insimbi nayo iyabusa:
– Ukubopha ngentambo kusebenzisa insimbi yegolide (Au), i-aluminium (Al), noma ithusi (Cu).
– Ukugoqa kanye nokugoqa i-chip kusebenzisa izinsika/amaqhubu ensimbi kanye ne-solder ukuze kuxhunywe ngesivinini esikhulu kanye nokubalwa kwamaphini amakhulu.
– Ama-solder anamuhla ngokuvamile asetshenziswa nge-tin (Sn) asekelwe kuma-alloy (isb. i-Sn-Ag-Cu) ukuze athathe indawo ye-lead (Pb) solder ngenxa yezizathu zemvelo.
Ukupakisha okuthuthukisiwe okufana nama-chiplets, ukuhlanganiswa kwe-2.5D/3D, kanye ne-TSV (ngokusebenzisa i-silicon) kwandisa isidingo sezinto zensimbi ezinokwethenjelwa kakhulu, njengoba ubuningi bokuxhumana kanye nokushabalaliswa kokushisa kuba kukhulu.
8. Izinselele ezibalulekile: ukufuduka ngogesi, ukugqwala, kanye nokumelana ne-nanoscale
Njengoba ubukhulu buba buncane, ukusetshenziswa kwensimbi kubhekene nezinselele ezinkulu, okuhlanganisa:
– Ukufuduka kwe-Electro: izindlela zensimbi zingonakaliswa yimisinga ephezulu ezindaweni ezincane eziwela phansi.
– Ukwanda kokumelana okusebenzayo: ku-nanoscale, ama-electron ahlangana kaningi nemingcele yokusanhlamvu kanye nobuso, okwandisa ukumelana.
– Ukugqwala kanye nokuhambisana kwamakhemikhali: ikakhulukazi ezigabeni zokukhiqiza ezihilela amakhemikhali amaningi kanye namazinga okushisa aphezulu.
– Imikhawulo yezithiyo: izithiyo kumele zibe zincane futhi zikwazi ukumelana nokusabalala, okuyinto enzima ngokwezobuchwepheshe.
Ngakho-ke, ucwaningo ngezinto zensimbi ze-semiconductor luyaqhubeka nokuthuthuka, okuhlanganisa nokuhlola i-Co, i-Ru, i-Mo, kanye nezindlela ezintsha ezifana nokuxhumana okusekelwe ezintweni ezihlukile kanye namasu okubeka ama-athomu.
9. Iziqondiso zesikhathi esizayo zokusetshenziswa kwensimbi
Izitayela zesikhathi esizayo embonini ye-semiconductor ziqhuba ukusetshenziswa kwezinsimbi "ezithuthukisiwe" kakhulu ezingeni le-athomu. Ama-node athuthukile kanye nezakhiwo ze-3D (i-FinFET, i-GAA nanosheet, njalo njalo) zidinga izendlalelo zensimbi ezifanayo kakhulu, ezincane kakhulu ezine-interface ehlanzekile. Ngaphezu kwalokho, isidingo sokusebenza kahle kwamandla kanye nesivinini senza nokukhethwa kwezinsimbi zokuxhumanisa kanye nokuxhumana kube yisici esibalulekile.
Ngasohlangothini lokupakisha, izidingo ze-bandwidth ephezulu kanye nokuhlanganiswa okungafani kuqhuba ukusungula izinto ezintsha kuma-solder, ama-bump, kanye nama-metal interposer. Insimbi akuyona nje into esekelayo, kodwa iyingxenye eyisisekelo yokuklama uhlelo, ukusebenza, kanye nokuthembeka.
Isiphetho
Izinsimbi zidlala indima ebalulekile ekwakhiweni kwamadivayisi e-semiconductor: njengezixhumanisi, oxhumana nabo, izithiyo, amasango ensimbi, kanye nomgogodla wokupakisha. Ukukhethwa kwensimbi akunqunywa kuphela ngokuqhutshwa komoya, kodwa futhi nangokusabalala, ukunamathela, ukuzinza kokushisa, ukuhambisana kwenqubo, kanye nokuthembeka kwesikhathi eside. Njengoba ukwenziwa okuncane kanye nobunzima kukhula, izinselele ezifana nokufuduka kwe-electro kanye nokumelana ne-nanoscale kuphoqa imboni ukuthi ithuthukise izinto ezintsha nezinqubo. Ngakho-ke, ukuqonda ukusetshenziswa kwezinsimbi kuma-semiconductors kubalulekile hhayi kuphela ezintweni zokwakha kanye nonjiniyela bezinqubo, kodwa nakunoma ubani ofuna ukuqonda ukuthi ubuchwepheshe be-chip besimanje buzoqhubeka kanjani nokukhula.
