Yuav Ua Li Cas Fluoropolymer Exchangers Txhawb Kev ntub dej ntawm Silicon Nitride thiab Oxide hauv Fabs?

Nyob rau hauv semiconductor fabs, ob classic chemistry yog siv rau ntub etching: kub phosphoric acid rau tev silicon nitride, thiab hydrofluoric acid rau etch silicon oxide. Ob leeg yog nruj heev, yuav tsum muaj cov khoom siv hluav taws xob sib hloov uas yuav tsis corrode lossis pollute.

Cov txheej txheem ntub dej etching
Kev ntub dej ntub dej yog txheej txheem siv los xaiv tshem tawm cov ntaub ntawv los ntawm wafer nto hauv semiconductor fabrication. Ob hom etchants siv nyob rau hauv wafer fab ntub cov rooj zaum yog phosphoric acid (H3PO4) rau silicon nitride etching thiab hydrofluoric acid (HF) rau silicon oxide etching. Ob qho acids yog nruj heev thiab xav tau cov khoom siv hluav taws xob uas tuaj yeem tiv thaiv lawv cov teebmeem corrosive.

Nitride tshem tawm ntawm Phosphoric Acid Etching
Si 3N4 etching. Phosphoric acid feem ntau yog siv nyob rau hauv ib tug concentration ntawm 85% thiab rhuab mus rau 150-180 degree. Qhov kub thiab txias ua cim ntawm cov kua qaub feem ntau ua rau cov ntsiab lus ntawm PFA (perfluoroalkoxy) exchangers. Polytetrafluoroethylene (PTFE) tiv taus phosphoric acid tab sis nws qhov ntsuas kub siab tshaj plaws yog 110C yog li nws tsis haum rau daim ntawv thov kub no. Txawm li cas los xij, PFA exchangers tuaj yeem ua haujlwm tsis tu ncua ntawm qhov kub siab tshaj ntawm ~ 260℃thiab yog li tsim nyog rau kev tuav cov kub phosphoric acid yam tsis muaj kev puas tsuaj.

Hydrofluoric Acid Etching rau Oxide Stripping
HF etching feem ntau yog ua nyob rau hauv qhov kub thiab txias los yog kub me ntsis. PTFE thiab PFA yog qhov sib npaug zoo rau kev tswj hwm HF. PTFE siv ntau zaus vim nws tsis tshua kim thiab muab kev tiv thaiv txaus ntawm qhov kub thiab txias. Qhov teeb meem loj nrog HF etching tsis yog qhov kub thiab txias tab sis muaj peev xwm ntawm cov khoom siv los tiv thaiv kev ua phem ntawm HF. Ob leeg PTFE thiab PFA yog cov resistant rau HF, uas txhais tau hais tias lub tshav kub exchanger yuav tsis puas thiab yuav tsis kis tus txheej txheem etching.

Cov txiaj ntsig Fluoropolymer
PTFE thiab PFA kuj zoo heev rau ob qho tib si phosphoric acid thiab hydrofluoric acid, thiab yog li indispensable rau semiconductor etching txheej txheem. Kev siv cov ntaub ntawv no hauv fluoropolymer heat exchangers rau etching ntawm silicon nitride thiab oxides muab ntau yam zoo:

Corrosion Resistance: PFA thiab PTFE yog lig resistant rau corrosive los ntawm kub phosphoric acid thiab HF. Hlau exchangers yuav corrode sai, ua rau cov txheej txheem sib kis thiab ua tau wafer flaws.

Kev sib kis -Kev Ua Haujlwm Dawb: Fluoropolymers yog inert thiab tsis emit ions rau cov tshuaj thiab yog li ua kom cov txheej txheem etching huv si thiab khov kho. Cov kab mob kis tau los ntawm cov hlau tuaj yeem ua rau muaj qhov tsis zoo, ua rau cov khoom siv hluav taws xob fluoropolymer zoo heev rau etching silicon nitride thiab oxide.

Stable Temperature Control Fluoropolymer heat exchangers tswj qhov kub thiab txias kom zoo ib yam etch tus nqi. Qhov kev tswj qhov kub thiab txias no yog qhov tseem ceeb los xyuas kom meej homogeneous etching thoob plaws lub wafer, thiab tswj cov txheej txheem raug.

Kev xaiv cov khoom siv rau Hom Semiconductor Etchants
Etchant Temperature Range Recommended Heat Exchanger Materials
Phosphoric Acid (85%) 150-180℃PFA
Hydrofluoric Acid (HF) Chav Kub Kub PTFE, PFA
Nitric Acid (HNO3) Chav Temp. PTFE, PFA
Xaus
Kev kis kab mob-dawb thiab meej ntub ntub dej yog qhov tseem ceeb hauv kev tsim cov khoom siv hluav taws xob, thiab cov khoom siv hluav taws xob fluoropolymer, tshwj xeeb tshaj yog PTFE thiab PFA, yog qhov tseem ceeb rau txoj haujlwm no. Lawv muaj peev xwm tiv taus kub phosphoric acid thiab hydrofluoric acid, uas tso cai rau cov txheej txheem kub thiab tsis muaj hlau sib kis. Lub tshav kub exchanger cov ntaub ntawv nyob rau hauv semiconductor fabs raug xaiv raws li cov tshuaj aggressiveness ntawm etchants thiab purity yuav tsum tau ntawm cov txheej txheem. Cov fluoropolymer exchangers yog cov khoom nyiam rau nitride thiab oxide etching.