Semiconductor process flow

Mutha kuzimvetsa ngakhale simunaphunzirepo sayansi kapena masamu, koma ndizosavuta komanso zoyenera kwa oyamba kumene. Ngati mukufuna kudziwa zambiri za CMOS, muyenera kuwerenga zomwe zili m'nkhaniyi, chifukwa pokhapokha mutamvetsetsa ndondomekoyi (ndiko kuti, kupanga diode) mungathe kupitiriza kumvetsetsa zotsatirazi. Ndiye tiyeni tiphunzire za momwe CMOS iyi imapangidwira mu kampani yoyambira m'nkhaniyi (potengera njira yosapita patsogolo monga chitsanzo, CMOS ya ndondomeko yapamwamba ndi yosiyana mu kapangidwe ndi kupanga mfundo).

Choyamba, muyenera kudziwa kuti zowawa zomwe zimapeza kuchokera kwa ogulitsa (nsalu ya siliconkatundu) ndi mmodzimmodzi, ndi utali wozungulira wa 200mm (8-inchifakitale) kapena 300mm (12-inchifakitale). Monga momwe tawonetsera m'chithunzichi, ndizofanana ndi keke yaikulu, yomwe timatcha gawo lapansi.

Komabe, sikuli kwabwino kwa ife kuziwona mwanjira imeneyi. Timayang'ana kuchokera pansi ndikuyang'ana mawonekedwe ozungulira, omwe amakhala chithunzi chotsatira.

Kenako, tiyeni tiwone momwe mtundu wa CMOS umawonekera. Popeza ndondomeko yeniyeni imafuna masitepe zikwizikwi, ndilankhula za masitepe akuluakulu a chofufumitsa chosavuta cha 8-inch apa.

 

 

Kupanga Bwino ndi Inversion Layer:

Ndiko kuti, chitsimecho chimayikidwa mu gawo lapansi ndi ion implantation (Ion Implantation, pambuyo pake imatchedwa imp). Ngati mukufuna kupanga NMOS, muyenera kuyika zitsime zamtundu wa P. Ngati mukufuna kupanga PMOS, muyenera kuyika zitsime zamtundu wa N. Kuti mukhale omasuka, tiyeni titenge NMOS monga chitsanzo. Makina oyika ion amayika zinthu zamtundu wa P kuti zibzalidwe mu gawo lapansi mpaka kuya kwakuya, ndiyeno zimatenthetsa pa kutentha kwakukulu mu chubu cha ng'anjo kuti ayambitse ma ion awa ndikuwafalitsa mozungulira. Izi zimamaliza kupanga chitsime. Izi ndi momwe zimawonekera pambuyo pomaliza kupanga.

Pambuyo popanga chitsimecho, palinso njira zina zoyikira ion, zomwe cholinga chake ndikuwongolera kukula kwa mayendedwe apano ndi magetsi olowera. Aliyense akhoza kuyitcha kuti inversion layer. Ngati mukufuna kupanga NMOS, wosanjikiza wopindika amaikidwa ndi ma ions amtundu wa P, ndipo ngati mukufuna kupanga PMOS, wosanjikiza wopindika umayikidwa ndi ma ions amtundu wa N. Pambuyo pa kuikidwa, ndi chitsanzo chotsatira.

Pali zambiri zomwe zili pano, monga mphamvu, ngodya, ndende ya ion panthawi yoyika ion, ndi zina zotero, zomwe sizinaphatikizidwe m'nkhaniyi, ndipo ndikukhulupirira kuti ngati mukudziwa zinthuzo, muyenera kukhala wamkati, ndipo ayenera kukhala ndi njira yowaphunzirira.

 

Kupanga SiO2:

Silicon dioxide (SiO2, yomwe imatchedwa oxide) idzapangidwa pambuyo pake. Popanga CMOS, pali njira zambiri zopangira oxide. Pano, SiO2 imagwiritsidwa ntchito pansi pa chipata, ndipo makulidwe ake amakhudza mwachindunji kukula kwa magetsi a pakhomo ndi kukula kwa njira yamakono. Chifukwa chake, oyambitsa ambiri amasankha njira ya ng'anjo ya oxidation ya ng'anjo yokhala ndipamwamba kwambiri, yowongolera bwino kwambiri, komanso yofananira bwino pa sitepe iyi. Ndipotu, ndizosavuta, ndiko kuti, mu chubu la ng'anjo ndi mpweya, kutentha kwakukulu kumagwiritsidwa ntchito kuti mpweya ndi silicon zigwirizane ndi mankhwala kuti apange SiO2. Mwanjira iyi, gawo lochepa la SiO2 limapangidwa pamwamba pa Si, monga momwe tawonetsera pa chithunzi pansipa.

Inde, palinso zambiri zenizeni pano, monga madigiri angati omwe amafunikira, kuchuluka kwa mpweya wa oxygen kumafunika, kutalika kwa kutentha kumafunika, etc. Izi sizomwe tikuziganizira tsopano, ndizo mwachindunji kwambiri.

Mapangidwe a gate end Poly:

Koma sizinathe. SiO2 ikungofanana ndi ulusi, ndipo chipata chenicheni (Poly) sichinayambe. Kotero sitepe yathu yotsatira ndikuyika gulu la polysilicon pa SiO2 (polysilicon imapangidwanso ndi chinthu chimodzi cha silicon, koma makonzedwe a lattice ndi osiyana. ndi buku lotchedwa Semiconductor Physics Mukhoza kuphunzira za izo ndizochititsa manyazi ~). Poly ndi ulalo wofunikira kwambiri mu CMOS, koma gawo la poly ndi Si, ndipo silingapangidwe ndikuchita mwachindunji ndi gawo la Si monga kukula kwa SiO2. Izi zimafuna CVD yodziwika bwino (Chemical Vapor Deposition), yomwe imayenera kuchitapo kanthu m'malo opanda kanthu ndikuwongolera chinthu chomwe chapangidwa pawafa. Muchitsanzo ichi, chinthu chopangidwa ndi polysilicon, ndiyeno chimawombedwa pamtanda (apa ndiyenera kunena kuti poly imapangidwa mu chubu cha ng'anjo ndi CVD, kotero kuti kubadwa kwa polysilicon sikumachitidwa ndi makina oyera a CVD).

Koma polysilicon yopangidwa ndi njira iyi idzawomberedwa pamtengo wonsewo, ndipo zikuwoneka ngati izi pakagwa mvula.

 

Kuwonetsedwa kwa Poly ndi SiO2:

Pa sitepe iyi, mawonekedwe ofukula omwe tikufuna apangidwadi, okhala ndi poly pamwamba, SiO2 pansi, ndi gawo lapansi pansi. Koma tsopano chophika chonsecho chili chonchi, ndipo timangofunika malo enieni kuti tikhale mawonekedwe a "faucet". Chifukwa chake pali gawo lofunikira kwambiri panjira yonseyi - kuwonekera.
Timayamba kufalitsa wosanjikiza wa photoresist pamwamba pa chofufumitsa, ndipo chimakhala chonchi.

Kenaka ikani chigoba chofotokozedwa (chitsanzo cha dera chatanthauziridwa pa chigoba) pa icho, ndipo potsirizira pake muziziritsa ndi kuwala kwa kutalika kwake. The photoresist adzakhala adamulowetsa m'dera watsitsidwa. Popeza malo otsekedwa ndi chigoba sichiwunikiridwa ndi gwero la kuwala, chidutswa ichi cha photoresist sichimatsegulidwa.

Popeza adamulowetsa photoresist makamaka zosavuta kutsukidwa ndi enieni mankhwala madzi, pamene photoresist unactivated sangathe kutsukidwa, pambuyo walitsa, madzi enieni ntchito kutsuka ndi adamulowetsa photoresist, ndipo potsiriza zimakhala motere, kusiya photoresist kumene Poly ndi SiO2 ayenera kusungidwa, ndi kuchotsa photoresist kumene sikuyenera kusungidwa.