Ukuhamba kwenkqubo ye-semiconductor

Ungayiqonda nokuba awukaze ufunde ifiziksi okanye izibalo, kodwa ilula kakhulu kwaye ifanelekile kwabaqalayo. Ukuba ufuna ukwazi okungakumbi nge-CMOS, kuya kufuneka ufunde umxholo wale ngxaki, kuba kuphela emva kokuqonda ukuhamba kwenkqubo (oko kukuthi, inkqubo yokuvelisa i-diode) onokuqhubeka nokuqonda umxholo olandelayo. Emva koko makhe sifunde ngendlela le CMOS eveliswa ngayo kwinkampani ye-foundry kule ngxaki (ukuthatha inkqubo engaphucukanga njengomzekelo, i-CMOS yenkqubo ephucukileyo yahlukile kwisakhiwo kunye nomgaqo wemveliso).

Okokuqala, kufuneka wazi ukuba ii-wafers ezifunyanwa yi-foundry kumthengisi (i-silicon waferumthengisi) nganye nganye, kunye nobubanzi obuyi-200mm (Ii-intshi ezi-8umzi-mveliso) okanye i-300mm (Ii-intshi ezili-12Njengoko kubonisiwe kumfanekiso ongezantsi, ifana nekhekhe elikhulu, esilibiza ngokuba yi-substrate.

Nangona kunjalo, akulula kuthi ukuyijonga ngolu hlobo. Sijonga ukusuka ezantsi ukuya phezulu size sijonge umbono onqamlezileyo, oza kuba ngumfanekiso olandelayo.

Okulandelayo, masibone ukuba imodeli yeCMOS ivela njani. Ekubeni inkqubo yokwenyani ifuna amawaka amanyathelo, ndiza kuthetha ngamanyathelo aphambili e-wafer elula ye-intshi ezi-8 apha.

 

 

Ukwenza iWell kunye neInversion Layer:

Oko kukuthi, iqula lifakwa kwi-substrate ngokufaka i-ion (Ion Implantation, emva koko ebizwa ngokuba yi-imp). Ukuba ufuna ukwenza i-NMOS, kufuneka ufake i-P-type wells. Ukuba ufuna ukwenza i-PMOS, kufuneka ufake i-N-type wells. Ukuze kube lula kuwe, makhe sithathe i-NMOS njengomzekelo. Umatshini wokufaka i-ion ufaka izinto ze-P-type eziza kufakwa kwi-substrate kubunzulu obuthile, uze uzifudumeze kubushushu obuphezulu kwi-furnace tube ukuze kusebenze ezi ions kwaye zisasazeke. Oku kugqiba ukuveliswa kwequla. Le yindlela ebonakala ngayo emva kokuba imveliso igqityiwe.

Emva kokwenza umthombo, kukho amanye amanyathelo okufakelwa kwee-ion, injongo yawo kukulawula ubungakanani bombane wetshaneli kunye ne-threshold voltage. Wonke umntu angawubiza ngokuba yi-inversion layer. Ukuba ufuna ukwenza i-NMOS, i-inversion layer ifakwe ii-P-type ions, kwaye ukuba ufuna ukwenza i-PMOS, i-inversion layer ifakwe ii-N-type ions. Emva kokufakelwa, yimodeli elandelayo.

Kukho izinto ezininzi apha, ezifana namandla, i-engile, ukuxinana kwee-ion ngexesha lokufakelwa kwee-ion, njl.njl., ezingafakwanga kule ngxaki, kwaye ndikholelwa ukuba ukuba uyazazi ezo zinto, kufuneka ube ngumntu ongaphakathi, kwaye kufuneka ube nendlela yokuzifunda.

 

Ukwenza i-SiO2:

I-silicon dioxide (i-SiO2, ebizwa ngokuba yi-oxide) iza kwenziwa kamva. Kwinkqubo yokuvelisa i-CMOS, kukho iindlela ezininzi zokwenza i-oxide. Apha, i-SiO2 isetyenziswa phantsi kwesango, kwaye ubukhulu bayo buchaphazela ngokuthe ngqo ubungakanani bomthamo womda kunye nobukhulu bombane wetshaneli. Ke ngoko, uninzi lwee-foundries zikhetha indlela yokuxilisa ityhubhu yesithando somlilo enomgangatho ophezulu, ulawulo lobukhulu oluchanekileyo, kunye nokufana okungcono kweli nyathelo. Enyanisweni, kulula kakhulu, oko kukuthi, kwityhubhu yesithando somlilo ene-oxygen, ubushushu obuphezulu busetyenziswa ukuvumela i-oxygen kunye ne-silicon ukuba zisabele ngokweekhemikhali ukuvelisa i-SiO2. Ngale ndlela, umaleko omncinci we-SiO2 wenziwa phezu kobuso be-Si, njengoko kubonisiwe kumfanekiso ongezantsi.

Kakade ke, kukwakho nolwazi oluninzi olucacileyo apha, njengokuba kufuneka amadigri amangaphi, kufuneka i-oxygen engakanani, kufuneka ubushushu obuphezulu ixesha elingakanani, njl. Ezi asizizo izinto esiziqwalaselayo ngoku, zicacile kakhulu.

Ukwakheka kwesiphelo sesango:

Kodwa ayikapheli. I-SiO2 ilingana nje nomsonto, kwaye isango lokwenyani (iPoly) alikaqali. Ngoko ke inyathelo lethu elilandelayo kukubeka umaleko we-polysilicon kwi-SiO2 (i-polysilicon ikwayilwe yinto enye ye-silicon, kodwa ulungiselelo lwe-lattice lwahlukile. Ungandibuzi ukuba kutheni i-substrate isebenzisa i-silicon enye yekristale kwaye isango lisebenzisa i-polysilicon. Kukho incwadi ebizwa ngokuba yi-Semiconductor Physics. Ungafunda ngayo. Kuyadanisa~). I-Poly ikwalikhonkco elibaluleke kakhulu kwi-CMOS, kodwa icandelo le-poly yi-Si, kwaye ayinakuveliswa yimpendulo ethe ngqo ne-substrate ye-Si njenge-SiO2 ekhulayo. Oku kufuna i-CVD eyintsomi (i-Chemical Vapor Deposition), ekukusabela ngokwekhemikhali kwi-vacuum kwaye kukhawuleze into evelisiweyo kwi-wafer. Kulo mzekelo, into evelisiweyo yi-polysilicon, ize ikhawuleze kwi-wafer (apha kufuneka nditsho ukuba i-poly iveliswa kwityhubhu yesithando somlilo yi-CVD, ngoko ke ukuveliswa kwe-poly akwenziwa ngumatshini we-CVD ococekileyo).

Kodwa i-polysilicon eyenziwe yile ndlela iya kugaleleka kwi-wafer yonke, kwaye ibukeka ngolu hlobo emva kokuna kwemvula.

 

Ukuvezwa kwePoly kunye neSiO2:

Kule nyathelo, isakhiwo esithe nkqo esisifunayo senziwe ngokwenene, sine-poly phezulu, i-SiO2 ezantsi, kunye ne-substrate ezantsi. Kodwa ngoku yonke i-wafer inje, kwaye sidinga kuphela indawo ethile ukuze sibe sisakhiwo "se-faucet". Ngoko ke kukho inyathelo elibaluleke kakhulu kuyo yonke inkqubo - ukuvezwa.
Siqala ngokusasaza umaleko we-photoresist kumphezulu we-wafer, kwaye iba ngolu hlobo.

Emva koko beka imaski echaziweyo (ipateni yesekethe ichaziweyo kwimaski) kuyo, uze ekugqibeleni uyikhanyise ngokukhanya kobude bexesha elithile. I-photoresist iya kusebenza kwindawo ekhanyiswe yimitha. Ekubeni indawo evalwe yimaski ingakhanyiswa ngumthombo wokukhanya, eli qhekeza le-photoresist alisebenzi.

Ekubeni i-photoresist esebenzayo kulula kakhulu ukuyihlamba lulwelo oluthile lwekhemikhali, ngelixa i-photoresist engasebenzanga ingenakuhlanjwa, emva kokukhanyiswa, ulwelo oluthile lusetyenziselwa ukuhlamba i-photoresist esebenzayo, kwaye ekugqibeleni iba ngolu hlobo, ishiya i-photoresist apho kufuneka igcinwe khona iPoly kunye neSiO2, kwaye isuse i-photoresist apho ingadingi kugcinwa khona.