Etching
1) Mus rau BSG
Silicon wafers tau ntxuav hauv lub tshuab ntxhua khaub ncaws los ntawm ntab rau hauv dej (nrog rau sab nraub qaum hauv kev sib cuag nrog cov kua qaub) kom tshem tawm BSG ntawm sab nraub qaum. Cov ntsiab lus tseem ceeb ntawm cov kua qaub yog 24.5% HF, thiab cov tshuaj tiv thaiv kab mob tseem ceeb suav nrog:
HF+SiO2 → SiF4+H2O
SiF4+HF → H2SiF6
Tom qab ntxuav nrog dej thiab ziab nrog rab riam cua, nws nkag mus rau cov txheej txheem tom ntej. BSG cov cuab yeej siv lub tshuab ntxuav yog ib qho khoom siv kaw ntom ntom uas suav nrog lub tank kua qaub, lub tank huv huv huv, thiab cov txheej txheem tsim tawm los tsim kom muaj qhov tsis zoo ntawm qhov chaw nyob hauv cov khoom siv thiab sau cov pa roj carbon monoxide.
Cov pa phem tseem ceeb hauv cov txheej txheem no suav nrog acidic khib nyiab roj (G4) uas muaj HF, uas tau sau los ntawm cov kav dej thiab xa mus rau cov kua qaub pov tseg cov roj siv ntauwd rau kev kho. High concentration acidic wastewater muaj hydrofluoric acid (W10) thiab cov kua qaub ntxuav cov dej khib nyiab (W11).
2) Rov qab etching
Txhawm rau txhim kho qhov cuam tshuam ntawm silicon wafer backside, lub nraub qaum ntawm silicon wafer yog polished nrog alkali thiab polishing tus neeg sawv cev.
Cov alkali polishing seem (6 kab) suav nrog cov qauv xws li kev ntxuav ua ntej, ntxuav dej, alkali polishing * 2, hydrogen peroxide tu (tso tseg), micro velvet (tso tseg), ntxuav dej ntshiab, tom qab ntxuav, ntxuav dej huv, ntxuav kua qaub * 2, dej ntshiab huv tom qab ntxuav cov kua qaub, qeeb rub ua ntej lub cev qhuav dej, ziab * 5, thiab lwm yam. Tag nrho cov txheej txheem ntawm rov qab etching yog txiav tawm, siv lub caj npab hloov mus rau xa cov khoom ua ntej ntxuav silicon wafers mus rau qhov chaw pub mis ntawm alkali polishing tshuab. Cov silicon wafers dhau los ntawm ntau yam corrosion thiab tu tso tsheb hlau luam nyob rau hauv lub automatic kaw alkali polishing tshuab los ntawm chais. Cov cuab yeej cia li tswj xyuas cov kua qaub, alkali tov, thiab dej ntshiab hauv txhua qhov module. Cov kua qaub thiab alkali tov nyob rau hauv lub tank yog pumped los ntawm pipelines, thiab cov dej khib nyiab hauv lub tank yog tawm tsis tu ncua.
3) Ua ntej ntxuav
Tom qab ua tiav, silicon wafer nkag mus rau hauv lub tank tu kom tshem tawm cov khoom seem ntawm cov organic thiab ua kom huv si ntawm silicon wafer nto, yog li txhim kho cov roj teeb hloov pauv mus rau qee yam. Raus lub loaded silicon wafers nyob rau hauv ua ntej tu, ntxiv dej ntshiab rau lub tank, thiab ntxiv ib tug tsim nyog npaum li cas ntawm NaOH tov los yog ntxuav kua (NaOH concentration yuav tsum yog {{0}}}.39%, H2O2 concentration yog xav tias yuav tsum yog 0.61%) raws li qhov piv rau qhov kub thiab txias (60 degree). Ua cov dej ntshiab huv tom qab ntxuav ua ntej. Kev ntxuav dej ntshiab yog tag nrho cov dej ntws los ntxuav, nqa tawm hauv chav sov li 100 vib nas this.
4) Alkali polishing thiab ntxuav
Lub alkaline polishing tank yog nruab nrog cov dej ntshiab, thiab qhov tsim nyog ntawm NaOH tov thiab polishing additives (NaOH tov yog li 1.6%, polishing agent concentration yog 0.97%) ntxiv. Tom qab ntawd, sab nraub qaum ntawm silicon wafer yog polished ntawm kev ua haujlwm kub ntawm 65 degree. Ntxuav nrog alkali ua ntej yaug nrog dej ntshiab. Cov tshuaj tiv thaiv uas tshwm sim thaum lub sij hawm pov tseg alkali yog raws li nram no:
Si+2NaOH+H2O=Na2SiO3+2H2↑
Kev ua haujlwm kub ntawm alkali ntxuav tank yog 65 degree, thiab lub sij hawm ntxuav alkali yog 220s.
5) Tom qab ntxuav thiab micro velvet ntau lawm
Ntxiv dej ntshiab rau lub tank, thiab ntxiv cov nqi tsim nyog ntawm NaOH tov thiab hydrogen peroxide (NaOH tov txog {{0}}}.55%, hydrogen peroxide concentration 0.25%) raws li qhov piv rau chav tsev kub tu. Tom qab ntxuav, ua cov dej ntshiab huv.
Cov tshuaj tiv thaiv uas tshwm sim thaum lub sij hawm micro velvet txheej txheem yog raws li nram no:
Si+2NaOH+H2O=Na2SiO3+2H2↑
6) Acid ntxuav
Tom qab kev ntxuav tom qab, cov kua qaub diluted ({{0}}.9% HCl thiab 0.23% HF) yuav tsum tau siv rau kev ntxuav kom huv. Kev ua haujlwm ntawm HCl yog txhawm rau tshem tawm cov seem ntawm NaOH, thaum lub luag haujlwm ntawm HF yog tshem tawm cov oxide txheej ntawm cov silicon wafer, ua rau nws ntau hydrophobic thiab tsim cov silicon complex H2SiF6. Los ntawm kev sib xyaw nrog cov hlau ions, cov hlau ions raug tshem tawm ntawm qhov chaw ntawm silicon wafer, txo cov hlau ion ntsiab lus thiab npaj rau kev sib txuas sib txuas. Ntxuav nrog dej ntshiab tom qab ntxuav cov kua qaub.
Cov tshuaj tiv thaiv uas tshwm sim thaum lub sij hawm pickling yog raws li nram no:
HCl+NaOH=NaCl+H2O
SiO2+6HF=H2SiF6+2H2O
Kev ua haujlwm kub ntawm lub tank pickling yog nyob rau hauv chav tsev kub, thiab lub sij hawm pickling yog tswj ntawm 100 vib nas this.
7) Qhuav
Hloov maj mam rub lub cev qhuav dej crystalline silicon wafer mus rau lub tank kom qhuav, thiab tshuab cua kub ntawm 90 degree nce thiab nqis ntawm lub wafer kom qhuav, siv hluav taws xob cua sov.
Nyob rau hauv cov lus saum toj no-hais rov qab etching txheej txheem, ua ntej tu, alkali polishing, thiab tom qab ntxuav cov txheej txheem ua kom muaj siab alkaline khib nyiab uas muaj sodium hydroxide (W12, W14, W16) thiab alkaline tu dej khib nyiab (W13, W15, W17). Cov txheej txheem ntxuav cov kua qaub ua kom muaj cov kua qaub ntau hauv cov dej khib nyiab uas muaj hydrochloric acid thiab hydrofluoric acid (W18) thiab cov kua qaub ntxuav cov dej khib nyiab (W19, W20). Kev ua haujlwm saum toj no yog nqa tawm hauv lub tshuab kaw alkali pov tseg. Cov txheej txheem ntxuav cov kua qaub yuav volatilize thiab tsim cov kua qaub pov tseg roj (G5) uas muaj HCl thiab HF, uas yuav raug sau los ntawm cov kav dej thiab xa mus rau cov kua qaub khib nyiab ntxhua khaub ncaws rau kev kho mob.
Nyob rau hauv qhov chaw doping ntawm POPAID deposition
Cov txheej txheem POPAID yog cov txheej txheem tseem ceeb rau kev npaj phaj txheej los ntawm kev sib koom ua ke tunneling oxide txheej thiab doped crystalline silicon txheej.
Ua ntej, cov silicon wafer nkag mus rau hauv lub chaw thau khoom nyob rau hauv atmospheric tej yam kev mob, yog thauj mus rau hauv lub 300 degree preheating chamber, thiab ces nkag mus rau lub PO txheej txheem chamber. Nyob rau lub sijhawm no, O2 raug thauj mus rau cov roj sib cais los ntawm lub trachea, thiab yog qhib los ntawm RF fais fab mov rau ionize. Cov ions oxidize rau saum npoo ntawm silicon wafer, tsim ib txheej tunneling oxide; Tom qab ntawd cov silicon wafer dhau los ntawm kev hloov pauv thiab tsis muaj chamber thiab xa mus rau hauv chav them nyiaj. Qhov chaw them nyiaj tso rau ib qho tuab ntawm amorphous silicon nyob rau sab nraum qab ntawm lub substrate, thiab PH3 gas yog qhia thaum lub sij hawm deposition txheej txheem. Gaseous phosphine nkag mus rau hauv lub tshuab thiab zoo siab rau lub xeev ntawm phosphorus ions los ntawm 10kev thiab 0.5-2kev high-voltage xov tooj cua zaus. Ib qho hluav taws xob ncaj qha tam sim no tau ntxiv ntawm qhov chaw ion thiab hauv av, kom cov phosphorus ions tau txais lub zog los ntawm cov hluav taws xob hluav taws xob high-voltage. Lub beam dav yog 420mm, thiab tom qab ntawd cov silicon wafer hloov mus rau hauv qab ntawm lub nqaj. Thaum lub sij hawm tus txheej txheem ntawm cov atoms ntawm qhov them nyiaj ya mus rau lub substrate, lawv nqa P ions los yog hnov nrog P ions kom ua tau nyob rau hauv-situ phosphorus doping.
Qhov sib npaug ntawm cov tshuaj tiv thaiv tseem ceeb yog: PO+PAID＝POPAID
Plasma oxidation (PO): SiH4+O2 → SiO2
Plasma assisted in-site doping (PAID): Si (source) + PH3 → n-Si
Tom qab cov tshuaj tiv thaiv tiav lawm, nitrogen yog tshuab thiab cov ion raug txhaj rau hauv tus kheej-muaj adsorbent, nrog rau kev kho mob txog li 100%. Lub concentration ntawm phosphine ua ntej nkag mus rau hauv lub adsorption ntauwd yog 179.05ppm, thiab tsis pom PH3 tom qab adsorption. Qhov phiaj xwm no npaj yuav txuas cov pa tso pa tawm mus rau DA003 khib nyiab roj ntauwd rau kev kho mob thiab tawm mus. Nyob rau tib lub sijhawm, lub tuam txhab npaj yuav teeb tsa lub tswb tsis siv neeg rau phosphorus to nrog kev kuaj pom qhov txwv ntawm 0.1mg / m3.
Kev Ntsuam Xyuas Cov Txheej Txheem Kev Ua Kua Dej: Cov txheej txheem tseem ceeb hauv cov txheej txheem no yog Ar, PH3, thiab N2 tau qhia thaum lub sijhawm txheej txheem, uas tau sau los ntawm cov kav dej siab thiab xa mus rau cov kua qaub pov tseg roj txhuam cov pej thuam rau kev kho mob.