Ukugeleza kwenqubo ye-semiconductor

Ungakuqonda noma ungakaze ufunde i-physics noma izibalo, kodwa ilula kakhulu futhi ifanele abaqalayo. Uma ufuna ukwazi okwengeziwe nge-CMOS, kufanele ufunde okuqukethwe kwalolu daba, ngoba kuphela ngemva kokuqonda ukugeleza kwenqubo (okungukuthi, inqubo yokukhiqiza ye-diode) ungaqhubeka nokuqonda okuqukethwe okulandelayo. Khona-ke ake sifunde ukuthi le CMOS ikhiqizwa kanjani enkampanini esungulwe kulolu daba (kuthatha inqubo engathuthuki njengesibonelo, i-CMOS yenqubo ethuthukisiwe ihlukile ngesakhiwo kanye nesimiso sokukhiqiza).

Okokuqala, kufanele wazi ukuthi ama-wafers atholwa yi-Foundry kumphakeli (isicwecwana se-siliconumphakeli) ngamunye ngamunye, anendawo engaba ngu-200mm (8-intshiimboni) noma 300mm (12-intshiifektri). Njengoba kuboniswe esithombeni esingezansi, empeleni kufana nekhekhe elikhulu, esiyibiza ngokuthi i-substrate.

Nokho, akulula ngathi ukukubheka ngale ndlela. Sibheka kusukela phansi kuya phezulu futhi sibheke umbono we-cross-sectional, okuba ngumfanekiso olandelayo.

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

 

 

Ukwenza kahle kanye ne-Inversion Layer:

Okusho ukuthi, umthombo utshalwa ku-substrate ngokufakwa kwe-ion (I-Ion Implantation, kamuva ebizwa ngokuthi imp). Uma ufuna ukwenza i-NMOS, udinga ukutshala imithombo yohlobo lwe-P. Uma ufuna ukwenza i-PMOS, udinga ukutshala imithombo yohlobo lwe-N. Ukuze kube lula kuwe, ake sithathe i-NMOS njengesibonelo. Umshini wokufakelwa kwe-ion ufaka izakhi zohlobo lwe-P ukuthi zifakwe ku-substrate ekujuleni okuthile, bese uzifudumeza ekushiseni okuphezulu kushubhu yesithando somlilo ukuze wenze la ma-ion asebenze futhi awasabalalise nxazonke. Lokhu kuqeda ukukhiqizwa komthombo. Yile ndlela ebukeka ngayo ngemva kokuqedwa kokukhiqizwa.

Ngemva kokwenza umthombo, kunezinye izinyathelo zokufakelwa kwe-ion, inhloso yazo ukulawula ubukhulu besiteshi samanje kanye ne-threshold voltage. Wonke umuntu angakubiza ngesendlalelo sokuguqula. Uma ufuna ukwenza i-NMOS, ungqimba oluguquguqukayo lufakwe ngama-ion ohlobo lwe-P, futhi uma ufuna ukwenza i-PMOS, isendlalelo sokuguqula sifakwe ngama-ion ohlobo lwe-N. Ngemva kokufakelwa, kuba imodeli elandelayo.

Kuningi okuqukethwe lapha, njengamandla, i-engeli, ukugxilwa kwe-ion ngesikhathi sokufakelwa kwe-ion, njll., okungafakiwe kulolu daba, futhi ngikholelwa ukuthi uma uzazi lezo zinto, kufanele ube umuntu wangaphakathi, futhi kufanele ube nendlela yokufunda.

 

Ukwenza i-SiO2:

I-Silicon dioxide (i-SiO2, kamuva ebizwa ngokuthi i-oxide) izokwenziwa kamuva. Enqubweni yokukhiqiza ye-CMOS, ziningi izindlela zokwenza i-oxide. Lapha, i-SiO2 isetshenziswa ngaphansi kwesango, futhi ubukhulu bayo buthinta ngokuqondile ubukhulu be-threshold voltage kanye nobukhulu besiteshi samanje. Ngakho-ke, abasunguli abaningi bakhetha indlela ye-oxidation yeshubhu yomlilo enekhwalithi ephezulu kakhulu, ukulawula ukushuba okunembe kakhulu, kanye nokufana okuhle kakhulu kulesi sinyathelo. Eqinisweni, kulula kakhulu, okungukuthi, ku-tube yesithando somlilo nge-oksijeni, izinga lokushisa eliphezulu lisetshenziselwa ukuvumela umoya-mpilo ne-silicon ukuba zisabele ngamakhemikhali ukuze zikhiqize i-SiO2. Ngale ndlela, ungqimba oluncane lwe-SiO2 lukhiqizwa ebusweni buka-Si, njengoba kuboniswe esithombeni esingezansi.

Yiqiniso, kukhona nolwazi oluningi oluqondile lapha, njengokuthi mangaki amadigri adingekayo, ukuthi kungakanani ukugxila kwe-oksijini okudingekayo, isikhathi esingakanani izinga lokushisa elidingekayo, njll. Lokhu akusikho lokho esikucabangelayo manje, lezo zicacile kakhulu.

Ukwakhiwa kwe-gate end Poly:

Kodwa akukapheli. I-SiO2 ivele ilingane nentambo, futhi isango langempela (i-Poly) alikaqali okwamanje. Ngakho isinyathelo sethu esilandelayo ukubeka ungqimba lwe-polysilicon ku-SiO2 (i-polysilicon nayo yakhiwe isici esisodwa se-silicon, kodwa ukuhlelwa kwe-lattice kuhlukile. Ungangibuzi ukuthi kungani i-substrate isebenzisa i-silicon eyodwa ye-crystal futhi isango lisebenzisa i-polysilicon. Kukhona incwadi ebizwa ngokuthi i-Semiconductor Physics. Ungafunda ngayo. Kuyaphoxa~). I-Poly futhi iyisixhumanisi esibucayi kakhulu ku-CMOS, kodwa ingxenye ye-poly i-Si, futhi ayikwazi ukukhiqizwa ngokusabela okuqondile nge-Si substrate njengokukhula kwe-SiO2. Lokhu kudinga i-CVD yenganekwane (Chemical Vapor Deposition), okuwukusabela ngamakhemikhali ku-vacuum futhi kunciphe into ekhiqiziwe ku-wafer. Kulesi sibonelo, into ekhiqizwe i-polysilicon, bese iwa phezu kwe-wafer (lapha kufanele ngisho ukuthi i-poly ikhiqizwa ku-tube yesithando somlilo nge-CVD, ngakho-ke ukukhiqizwa kwe-poly akwenziwa umshini we-CVD ohlanzekile).

Kodwa i-polysilicon eyakhiwe ngale ndlela izokwenyuka kuyo yonke i-wafer, futhi ibukeka kanjena ngemva kwemvula.

 

Ukuvezwa kwe-Poly ne-SiO2:

Kulesi sinyathelo, isakhiwo esime mpo esisifunayo senziwe ngempela, sine-poly phezulu, i-SiO2 ngezansi, kanye ne-substrate phansi. Kodwa manje yonke i-wafer ifana nalokhu, futhi sidinga kuphela isikhundla esithile ukuze sibe isakhiwo "sompompo". Ngakho kunesinyathelo esibaluleke kakhulu kuyo yonke inqubo - ukuchayeka.
Siqala ukusabalalisa ungqimba lwe-photoresist ebusweni be-wafer, futhi iba kanje.

Bese ubeka imaski echaziwe (iphethini yesifunda ichazwe kumaski) kuyo, futhi ekugcineni uyikhanyise ngokukhanya kwe-wavelength ethile. I-photoresist izosebenza endaweni ene-radiated. Njengoba indawo evinjwe imaski ingakhanyiswa umthombo wokukhanya, lolu cezu lwe-photoresist alucushiwe.

Njengoba i-photoresist ecushiwe kulula kakhulu ukugezwa uketshezi oluthile lwamakhemikhali, kuyilapho i-photoresist engacushiwe ayikwazi ukugezwa, ngemva kokushiswa kwemisebe, uketshezi oluthile lusetshenziselwa ukugeza i-photoresist ecushiwe, futhi ekugcineni iba kanje, ishiya i-photoresist lapho i-Poly ne-SiO2 idinga ukugcinwa khona, futhi isuse i-photoresist lapho ingadingi ukugcinwa khona.