N’chifukwa chiyani kufunikira kupukuta?

Mu gawo la ndondomeko ya back-end,chikwama cha mkate (chokulungira cha silikonindi ma circuits kutsogolo) amafunika kuchepetsedwa kumbuyo musanadule, kuwotcherera ndi kulongedza kuti achepetse kutalika kwa phukusi, kuchepetsa kuchuluka kwa phukusi la chip, kukweza mphamvu ya kutentha kwa chip, magwiridwe antchito amagetsi, mphamvu zamakanika ndikuchepetsa kuchuluka kwa kudula. Kupukuta kumbuyo kuli ndi ubwino wochita bwino kwambiri komanso mtengo wotsika. Kwalowa m'malo mwa njira zachikhalidwe zodulira zonyowa ndi ion kuti zikhale ukadaulo wofunikira kwambiri wochepetsera kumbuyo.

Wafer woonda

Kodi kuonda bwanji?

Njira yayikulu yochepetsera wafer mu njira yachikhalidwe yopangira

Masitepe enieni achikwama cha mkateKuchepetsa kumafunika kumangirira wafer kuti ikonzedwe ku filimu yochepetsera, kenako kugwiritsa ntchito vacuum kuti igwire filimu yochepetsera ndi chip yomwe ili patebulo la wafer la ceramic lokhala ndi mapokoso, kusintha mizere yamkati ndi yakunja ya boti pakati pa malo ogwirira ntchito a gudumu lopukusira la diamondi looneka ngati chikho pakati pa wafer wa silicon, ndipo wafer wa silicon ndi gudumu lopukusira zimazungulira mozungulira nkhwangwa zawo kuti zigayidwe. Kupera kumaphatikizapo magawo atatu: kupukuta mopanda mphamvu, kupukuta bwino ndi kupukuta.

Wafer yochokera ku fakitale ya wafer imaphwanyidwa kumbuyo kuti ichepetse wafer kufika pa makulidwe ofunikira pakulongedza. Mukapera wafer, tepi iyenera kuyikidwa kutsogolo (Active Area) kuti iteteze dera la circuit, ndipo mbali yakumbuyo imaphwanyidwa nthawi yomweyo. Mukapera, chotsani tepiyo ndikuyezera makulidwe ake.
Njira zopukutira zomwe zagwiritsidwa ntchito bwino pokonzekera wafer wa silicon zikuphatikizapo kupukutira tebulo lozungulira,chokulungira cha silikoniKupera mozungulira, kupera mbali zonse ziwiri, ndi zina zotero. Ndi kupititsa patsogolo kwa zofunikira zapamwamba za ma wafer a silicon amodzi, ukadaulo watsopano wopera umaperekedwa nthawi zonse, monga kupera kwa TAIKO, kupera kwa makina a mankhwala, kupukuta ndi kupera kwa ma disc a planetary.

Kupera tebulo lozungulira:

Kusenda tebulo lozungulira (kusenda tebulo lozungulira) ndi njira yoyambirira yosenda yomwe imagwiritsidwa ntchito pokonza wafer wa silicon ndi kuchepetsa msana. Mfundo yake ikuwonetsedwa pa Chithunzi 1. Ma wafer a silicon amakhazikika pa makapu okoka a tebulo lozungulira, ndipo amazungulira motsatizana ndi tebulo lozungulira. Ma wafer a silicon okha sazungulira mozungulira mzere wawo; gudumu losenda limadyetsedwa mozungulira uku likuzungulira mwachangu, ndipo m'mimba mwake wa gudumu losenda ndi waukulu kuposa m'mimba mwake wa wafer wa silicon. Pali mitundu iwiri ya kusenda tebulo lozungulira: kusenda nkhope ndi kusenda nkhope. Posenda nkhope, m'lifupi mwa gudumu losenda ndi lalikulu kuposa m'mimba mwake wa wafer wa silicon, ndipo spindle ya gudumu losenda imadya mosalekeza motsatira njira yake ya axial mpaka yochulukirapo itakonzedwa, kenako wafer wa silicon imazunguliridwa pansi pa drive ya tebulo lozungulira; posenda nkhope, gudumu losenda limadya motsatira njira yake ya axial, ndipo wafer wa silicon imazunguliridwa mosalekeza pansi pa drive ya disk yozungulira, ndipo kusenda kumamalizidwa ndi kudyetsa mobwerezabwereza (reciprocation) kapena kudyetsa kokwawa (creepfeed).

Chithunzi 1, chithunzi cha ndondomeko yozungulira yopukusira tebulo (nkhope yolunjika)

Poyerekeza ndi njira yopera, kupukusa tebulo lozungulira kuli ndi ubwino wochotsa mwachangu, kuwonongeka pang'ono pamwamba, komanso kusinthasintha kwa automation. Komabe, malo enieni opera (kupukusa kogwira ntchito) B ndi ngodya yodulidwa θ (ngodya pakati pa bwalo lakunja la gudumu lopera ndi bwalo lakunja la wafer wa silicon) mu njira yopera imasintha ndi kusintha kwa malo odula a gudumu lopera, zomwe zimapangitsa kuti mphamvu yopera isakhazikike, zomwe zimapangitsa kuti zikhale zovuta kupeza kulondola kwa pamwamba (mtengo wapamwamba wa TTV), komanso kuyambitsa zolakwika mosavuta monga kugwa kwa m'mphepete ndi kugwa kwa m'mphepete. Ukadaulo wopera tebulo lozungulira umagwiritsidwa ntchito makamaka pokonza ma wafer a silicon a kristalo imodzi pansi pa 200mm. Kuwonjezeka kwa kukula kwa ma wafer a silicon a kristalo imodzi kwapereka zofunikira zapamwamba pa kulondola kwa pamwamba ndi kulondola kwa kayendedwe ka zida zogwirira ntchito, kotero kupukusa tebulo lozungulira sikoyenera kupukusa ma wafer a silicon a kristalo imodzi pamwamba pa 300mm.
Pofuna kukonza bwino ntchito yopera, zida zopera zamagetsi nthawi zambiri zimagwiritsa ntchito mawonekedwe a mawilo opera ambiri. Mwachitsanzo, mawilo opera opera ndi mawilo opera opera amakhala pazidazo, ndipo tebulo lozungulira limazungulira bwalo limodzi kuti limalize kupera kopera ndi kupera kopera pang'ono. Mtundu uwu wa zida umaphatikizapo G-500DS ya American GTI Company (Chithunzi 2).

Chithunzi 2, zida zopukusira tebulo lozungulira la G-500DS la Kampani ya GTI ku United States

Kupukusira kwa silicon wafer:

Pofuna kukwaniritsa zosowa za kukonzekera wafer wa silicon yayikulu komanso kukonza kumbuyo, komanso kupeza kulondola kwa pamwamba ndi mtengo wabwino wa TTV. Mu 1988, katswiri waku Japan Matsui adapereka njira yopukutira wafer wa silicon (in-feedgrinding). Mfundo yake ikuwonetsedwa pa Chithunzi 3. Wafer wa silicon imodzi yopangidwa ndi galasi ndi gudumu lopukutira la diamondi looneka ngati chikho lomwe limamatiridwa pa benchi logwirira ntchito limazungulira mozungulira nkhwangwa zawo, ndipo gudumu lopukutira limaperekedwa nthawi zonse motsatira njira ya axial nthawi yomweyo. Pakati pawo, m'mimba mwake wa gudumu lopukutira ndi lalikulu kuposa m'mimba mwake wa wafer wa silicon wokonzedwa, ndipo kuzungulira kwake kumadutsa pakati pa wafer wa silicon. Pofuna kuchepetsa mphamvu yopukutira ndikuchepetsa kutentha kopukutira, chikho chopukutira cha vacuum nthawi zambiri chimadulidwa kukhala mawonekedwe ozungulira kapena opindika kapena ngodya pakati pa spindle ya grinding wheel ndi suction cup spindle axis imasinthidwa kuti zitsimikizire kuti kugaya pakati pa gudumu lopukutira ndi wafer wa silicon kumalumikizidwa.

Chithunzi 3, Chithunzi cha ndondomeko yopukusira ya silicon wafer yozungulira

Poyerekeza ndi kupukusira tebulo lozungulira, kupukusira kozungulira kwa silicon wafer kuli ndi ubwino wotsatirawu: ① Kupukusira kamodzi kokha kumatha kukonza ma wafer akuluakulu a silicon opitilira 300mm; ② Malo enieni opukusira B ndi ngodya yodulira θ ndizokhazikika, ndipo mphamvu yopukusira ndi yokhazikika; ③ Mwa kusintha ngodya yopendekera pakati pa mzere wopukusira ndi mzere wa silicon wafer, mawonekedwe a pamwamba pa wafer imodzi ya kristalo ya silicon amatha kulamulidwa mwachangu kuti apeze kulondola kwa mawonekedwe a pamwamba. Kuphatikiza apo, malo opukusira ndi ngodya yodulira θ ya kupukusira kozungulira kwa silicon wafer alinso ndi ubwino wopukusira kwakukulu, makulidwe osavuta pa intaneti komanso kuzindikira ndi kuwongolera khalidwe la pamwamba, kapangidwe ka zida zazing'ono, kupukusira kosavuta kophatikizana ndi malo ambiri, komanso kugwira ntchito bwino kwambiri.
Pofuna kukonza bwino ntchito yopanga ndikukwaniritsa zosowa za mizere yopanga ma semiconductor, zida zopukutira zamalonda zomwe zimatengera mfundo ya silicon wafer rotary grinding zimagwiritsa ntchito kapangidwe ka multi-spindle multi-station, komwe kumatha kumaliza kupukutira kosalala ndi kupukutira bwino mu kukweza ndi kutsitsa kamodzi. Kuphatikiza ndi zinthu zina zothandizira, imatha kupukutira yokha ma crystal silicon wafers "ouma mkati/ouma" ndi "kaseti kupita ku kaseti".

Kupera mbali ziwiri:

Pamene silicon wafer yozungulira ikuphwanyika pamwamba ndi pansi pa silicon wafer, ntchitoyo iyenera kutembenuzidwa ndikuchitika pang'onopang'ono, zomwe zimachepetsa magwiridwe antchito. Nthawi yomweyo, silicon wafer yozungulira imakhala ndi zolemba zokopera (zokopedwa) ndi zopukutira (zolemba), ndipo sizingatheke kuchotsa bwino zolakwika monga kugwedezeka ndi kufooka pamwamba pa single crystal silicon wafer mutadula waya (multi-saw), monga momwe zasonyezedwera pa Chithunzi 4. Kuti athetse zolakwika zomwe zili pamwambapa, ukadaulo wopukutira mbali ziwiri (doublesidegrinding) unawonekera m'zaka za m'ma 1990, ndipo mfundo yake ikuwonetsedwa pa Chithunzi 5. Ma clamps amagawidwa mozungulira mbali zonse ziwiri amamangirira single crystal silicon wafer mu mphete yosungira ndikuzungulira pang'onopang'ono ndi roller. Mawilo awiri opukutira a diamondi ooneka ngati chikho ali mbali zonse ziwiri za single crystal silicon wafer. Amayendetsedwa ndi spindle yamagetsi yokhala ndi mpweya, amazungulira mbali zosiyana ndikudyetsa mozungulira kuti akwaniritse double-side double crystal silicon wafer. Monga momwe chithunzichi chikusonyezera, kupukusa mbali ziwiri kungachotse bwino kugwedezeka ndi kufooka pamwamba pa wafer imodzi ya kristalo ya silicon pambuyo podula waya. Malinga ndi momwe mzere wopukusa umakhalira, kupukusa mbali ziwiri kungakhale kopingasa komanso koyima. Pakati pawo, kupukusa mbali ziwiri kopingasa kungachepetse bwino mphamvu ya kusintha kwa wafer ya silicon chifukwa cha kulemera kwa wafer ya silicon pa mtundu wa kupukusa, ndipo n'zosavuta kuonetsetsa kuti momwe njira yopukusa mbali zonse ziwiri za wafer imodzi ya kristalo ya silicon ndi yofanana, ndipo tinthu tating'onoting'ono tomwe timapukusa ndi tchipisi topukusa sizophweka kukhala pamwamba pa wafer imodzi ya kristalo ya silicon. Ndi njira yabwino kwambiri yopukusa.

Chithunzi 4, "Kopera zolakwika" ndi zolakwika za chizindikiro cha kuwonongeka pakugaya kwa silicon wafer

Chithunzi 5, chithunzi cha njira yopukusira mbali ziwiri

Gome 1 likuwonetsa kufananiza pakati pa kupukutira ndi kupukutira mbali ziwiri za mitundu itatu yomwe ili pamwambapa ya ma wafer a silicon amodzi. Kupukutira mbali ziwiri kumagwiritsidwa ntchito makamaka popukutira ma wafer a silicon osakwana 200mm, ndipo kumakhala ndi phindu lalikulu la wafer. Chifukwa chogwiritsa ntchito mawilo opukutira okhazikika, kupukutira ma wafer a silicon amodzi a kristalo kumatha kukhala ndi mawonekedwe apamwamba kwambiri kuposa kupukutira mbali ziwiri. Chifukwa chake, kupukutira kozungulira kwa wafer wa silicon ndi kupukutira mbali ziwiri kumatha kukwaniritsa zofunikira pamtundu wa ma wafer a silicon a 300mm, ndipo pakadali pano ndi njira zofunika kwambiri zopukutira. Posankha njira yopukutira ya wafer wa silicon, ndikofunikira kuganizira mokwanira zofunikira za kukula kwa mainchesi, mtundu wa pamwamba, ndi ukadaulo wopukutira wafer wa wafer wa single-crystal silicon. Kuchepetsa kumbuyo kwa wafer kumatha kusankha njira yopukutira mbali imodzi yokha, monga njira yopukutira ya wafer wa silicon.

Kuwonjezera pa kusankha njira yopukusira mu silicon wafer grinding, ndikofunikiranso kudziwa njira zoyenera zogwiritsira ntchito monga kupanikizika kwabwino, kukula kwa tirigu wa grinding wheel, grinding wheel binder, grinding wheel speed, silicon wafer speed, grinding fluid viscosity ndi flow rate, ndi zina zotero, ndikupeza njira yoyenera yogwiritsira ntchito. Nthawi zambiri, njira yopukusira yogawanika kuphatikizapo rough grinding, semi-finishing grinding, finishing grinding, spark-free grinding ndi slow backward imagwiritsidwa ntchito kuti mupeze single crystal silicon wafers yokhala ndi processing efficiency, high surface flat and low surface disappeared.