Ukugeleza kwenqubo ye-semiconductor

Ungakuqonda noma ungakaze ufunde i-physics noma izibalo, kodwa kulula kakhulu futhi kufanelekile kwabaqalayo. Uma ufuna ukwazi okwengeziwe nge-CMOS, kufanele ufunde okuqukethwe kwalolu daba, ngoba kuphela ngemva kokuqonda ukugeleza kwenqubo (okungukuthi, inqubo yokukhiqiza ye-diode) lapho ungaqhubeka nokuqonda okuqukethwe okulandelayo. Ake sifunde ukuthi le CMOS ikhiqizwa kanjani enkampanini ye-foundry kulolu daba (uma sibheka inqubo engathuthukisiwe njengesibonelo, i-CMOS yenqubo ethuthukisiwe ihlukile ngesakhiwo kanye nesimiso sokukhiqiza).

Okokuqala, kufanele wazi ukuthi ama-wafer atholwa yifektri kumhlinzeki (i-silicon waferumhlinzeki) ngamunye ngamunye, enobubanzi obungu-200mm (Amasentimitha angu-8ifektri) noma 300mm (Amasentimitha angu-12ifektri). Njengoba kuboniswe esithombeni esingezansi, empeleni kufana nekhekhe elikhulu, esilibiza ngokuthi i-substrate.

Kodwa-ke, akulula ngathi ukukubheka ngale ndlela. Sibheka kusukela phansi kuya phezulu bese sibheka umbono onqamulayo, ozoba yisibalo esilandelayo.

Okulandelayo, ake sibone ukuthi imodeli ye-CMOS ivela kanjani. Njengoba inqubo yangempela idinga izinkulungwane zezinyathelo, ngizokhuluma ngezinyathelo eziyinhloko ze-wafer elula kakhulu engamasentimitha angu-8 lapha.

 

 

Ukwenza Umthombo kanye Nesendlalelo Sokuguqulwa:

Okusho ukuthi, umthombo ufakwa ku-substrate ngokufakelwa kwe-ion (Ion Implantation, okuzobizwa ngokuthi imp lapha). Uma ufuna ukwenza i-NMOS, udinga ukufaka imigodi yohlobo lwe-P. Uma ufuna ukwenza i-PMOS, udinga ukufaka imigodi yohlobo lwe-N. Ukuze kube lula kuwe, ake sithathe i-NMOS njengesibonelo. Umshini wokufakelwa kwe-ion ufaka izakhi zohlobo lwe-P ezizofakwa ku-substrate ngokujula okuthile, bese uzifudumeza ekushiseni okuphezulu epayipini lesithando ukuze kusebenze lawa ma-ion futhi awasakaze. Lokhu kuqedela ukukhiqizwa komthombo. Yilokhu okubukeka ngakho ngemva kokuqedwa kokukhiqiza.

Ngemva kokwenza umthombo, kunezinye izinyathelo zokufakelwa kwama-ion, inhloso yazo ukulawula usayizi wamanje wesiteshi kanye ne-voltage yomkhawulo. Wonke umuntu angakubiza ngokuthi ungqimba lokuguqulwa. Uma ufuna ukwenza i-NMOS, ungqimba lokuguqulwa lufakwa ngama-ion ohlobo lwe-P, futhi uma ufuna ukwenza i-PMOS, ungqimba lokuguqulwa lufakwa ngama-ion ohlobo lwe-N. Ngemva kokufakelwa, kuyimodeli elandelayo.

Kunezinto eziningi lapha, njengamandla, i-engeli, ukuhlushwa kwama-ion ngesikhathi sokufakelwa kwama-ion, njll., okungafakwanga kulolu daba, futhi ngikholwa ukuthi uma uzazi lezo zinto, kumele ube ngumuntu ongaphakathi, futhi kumele ube nendlela yokuzifunda.

 

Ukwenza i-SiO2:

I-Silicon dioxide (i-SiO2, ebizwa ngokuthi i-oxide) izokwenziwa kamuva. Enqubweni yokukhiqiza i-CMOS, kunezindlela eziningi zokwenza i-oxide. Lapha, i-SiO2 isetshenziswa ngaphansi kwesango, futhi ubukhulu bayo buthinta ngqo usayizi we-threshold voltage kanye nosayizi wamanje wesiteshi. Ngakho-ke, iningi lama-foundries likhetha indlela ye-oxidation ye-furnace tube enekhwalithi ephezulu kakhulu, ukulawula ukujiya okunembile kakhulu, kanye nokufana okuhle kakhulu kulesi sinyathelo. Eqinisweni, kulula kakhulu, okungukuthi, epayipini lesithando elinomoya-mpilo, izinga lokushisa eliphezulu lisetshenziswa ukuvumela umoya-mpilo ne-silicon ukuthi zisabele ngamakhemikhali ukuze kukhiqizwe i-SiO2. Ngale ndlela, kukhiqizwa ungqimba oluncane lwe-SiO2 ebusweni be-Si, njengoba kuboniswe esithombeni esingezansi.

Vele, kukhona nolwazi oluningi oluqondile lapha, njengokuthi mangaki amadigri adingekayo, ukuthi kudingeka ukuhlushwa okungakanani komoya-mpilo, ukuthi kudingeka isikhathi esingakanani izinga lokushisa eliphezulu, njll. Lokhu akusikho esikucabangayo manje, lokho kuqondile kakhulu.

Ukwakheka kwe-Gate End Poly:

Kodwa akukapheli. I-SiO2 ifana nje nentambo, futhi isango langempela (i-Poly) alikaqali. Ngakho isinyathelo sethu esilandelayo ukubeka ungqimba lwe-polysilicon ku-SiO2 (i-polysilicon nayo yakhiwe ngesici esisodwa se-silicon, kodwa ukuhlelwa kwe-lattice kuhlukile. Ungangibuzi ukuthi kungani i-substrate isebenzisa i-silicon eyodwa yekristalu kanti isango lisebenzisa i-polysilicon. Kukhona incwadi ebizwa ngokuthi i-Semiconductor Physics. Ungafunda ngakho. Kuyahlazisa ~). I-Poly nayo iyisixhumanisi esibaluleke kakhulu ku-CMOS, kodwa ingxenye ye-poly yi-Si, futhi ayikwazi ukukhiqizwa ngokuphendula okuqondile ne-substrate ye-Si njenge-SiO2 ekhulayo. Lokhu kudinga i-CVD edumile (i-Chemical Vapor Deposition), okuwukusabela ngamakhemikhali ku-vacuum bese kunciphisa into ekhiqizwe ku-wafer. Kulesi sibonelo, into ekhiqizwe yi-polysilicon, bese incipha ku-wafer (lapha kufanele ngithi i-poly ikhiqizwa kushubhu lesithando yi-CVD, ngakho-ke ukukhiqizwa kwe-poly akwenziwa umshini we-CVD omsulwa).

Kodwa i-polysilicon eyakhiwe yile ndlela izohlala phezu kwe-wafer yonke, futhi ibukeka kanje ngemva kwemvula.

 

Ukuvezwa kwe-Poly kanye ne-SiO2:

Kulesi sinyathelo, isakhiwo esiqondile esisifunayo sesakhiwe, sine-poly phezulu, i-SiO2 phansi, kanye ne-substrate phansi. Kodwa manje lonke i-wafer linje, futhi sidinga kuphela indawo ethile ukuze sibe yisakhiwo "se-faucet". Ngakho-ke kukhona isinyathelo esibaluleke kakhulu kuyo yonke inqubo - ukuvezwa.
Siqala ngokusabalala ungqimba lwe-photoresist ebusweni be-wafer, bese kuba kanje.

Bese ubeka imaski echaziwe (iphethini yesekethe ichazwe kumaski) kuyo, bese ekugcineni uyikhanyisela ngokukhanya kobude besikhathi obuthile. I-photoresist izosebenza endaweni ekhanyiswe. Njengoba indawo evinjiwe yimaski ingakhanyiswa ngumthombo wokukhanya, le ngxenye ye-photoresist ayisebenzi.

Njengoba i-photoresist esebenzayo kulula kakhulu ukuyihlanza ngoketshezi oluthile lwamakhemikhali, kuyilapho i-photoresist engasebenzanga ingenakuhlanzwa, ngemva kokushiswa ngemisebe, uketshezi oluthile lusetshenziswa ukuhlanza i-photoresist esebenzayo, futhi ekugcineni kuba kanje, kushiye i-photoresist lapho i-Poly ne-SiO2 kudingeka zigcinwe khona, bese kususwa i-photoresist lapho kungadingeki igcinwe khona.