Vim li cas thiaj yuav PFA Sheath thinner ua tau phem dua nyob rau hauv qis qis -Nias Plasma Ib puag ncig Vim Ion Bombardment?

Tsawg-plasma teeb tsa siab siv rau semiconductor etching, plasma-enhanced chemical vapor deposition (PECVD), thiab deg activation immerse components in energetic ion bombardment. Ions (Ar + , O + , CF 3 + , thiab lwm yam) yog tsav hla lub plasma sheath peev xwm, feem ntau 100-1,000 V, thiab hu rau PFA nto nrog lub zog ntawm 50-500 eV ib ion. Thinner PFA sheaths (0.5-1.0 mm) tsis haum rau cov kev pabcuam plasma dua li cov ntaub tuab tuab (1.5-2.5 hli) vim tias cov ion bombardment erodes lub polymer nto txheej txheej los ntawm lub cev sputtering thiab tshuaj etching. Cov phab ntsa nyias nyias muaj cov khoom siv tsawg dua ua ntej nws mus rau cov tub ntxhais hlau. Qhov tseem ceeb tshaj, ion foob pob ua rau cov txheej txheem hloov pauv (10-100 nm sib sib zog nqus) nrog cov tshuaj hloov pauv thiab cov yam ntxwv ntawm lub cev. Cov txheej txheem hloov pauv no feem ntau yog permeable rau cov kab mob reactive, ua kom lub cev tsis zoo. Thicker PFA (2-3 mm) muaj sia nyob ntev dua hauv cov ntshav plasma, vim tias qhov kev yaig yog qhov sib txawv ntawm cov tuab (feem ntau 0.1-1.0 µm / hr, nyob ntawm qhov chaw plasma) thiab cov txheej txheem hloov pauv tsis ncav cuag ntawm phab ntsa. Sheaths ntawm 1.0 hli tuaj yeem ua tsis tiav tom qab 500-1,000 plasma teev, hos 2.5 hli sheaths tuaj yeem txhawb nqa 5,000-10,000 teev.

Cov txheej txheem Erosion los ntawm Ion Bombardment
Hauv qis-plasma siab (0.1-10 Torr) PFA lub rhaub dej txhim kho qhov tsis zoo ntawm tus kheej-kev tsis sib haum xeeb nrog rau qhov muaj peev xwm ntawm plasma, vim tias cov khoom siv hluav taws xob ntau dua li cov ions. Tus kheej tsis ncaj ncees (feem ntau 50-500 V rau RF plasmas, 100-1000 V rau DC plasmas) thawb cov ions zoo ntawm PFA nto. Cov ions hloov lub zog mus rau lub polymer thaum sib tsoo, ejecting atoms thiab molecules, nyob rau hauv ib tug txheej txheem hu ua lub cev sputtering. PFA sputter tawm los (atoms tshem tawm ib qho xwm txheej ion) hauv argon ntshav yog 0.5-2.0 ntawm ion energies ntawm 200-500 eV. Tus nqi yaig e=Y × J_ion × (M / (ρ × N_A)) qhov twg Y yog sputter tawm los, J_ion yog ion tam sim no ntom (mA / cm²), M yog qhov hnyav molecular, ρ yog qhov ceev. Rau ib txwm RF plasma (13.56 MHz, 100 W, 100 mTorr Ar), J_ion ~ 1-5 mA / cm^2, Y ~ 1.0, ua rau e ~ 0.2-1.0 µm/hr. Erosion hauv 1000 hr. 0.2-1.0 hli Lub 1.0 hli sheath poob 20-100% ntawm nws thickness, tab sis lub 2.5 hli sheath poob tsuas yog 8-40%.

Nyob rau hauv lub xub ntiag ntawm reactive gases (O₂, CF₄, SF₆, Cl₂) tshuaj etching yog ntxiv rau lub cev sputtering. Piv txwv li, PFA nto reacts nrog oxygen plasma los tsim cov volatile COF₂, CO₂ thiab HF. Tshuaj etch tus nqi yuav yog 2-10x siab dua lub cev sputtering. Lub 1.0 hli PFA sheath tuaj yeem eroded tag nrho hauv 200-500 teev hauv 50% O2 / 50% Ar plasma. Kev yaig tsis sib xws. Lub kaum ntse ntse erode sai sai (saib Tshooj 62), thiab qhov chaw uas fim lub plasma glow erode sai dua li qhov chaw ntxoov ntxoo. PFA phab ntsa ua 0.2-0.5 hli tuab, pinholes yog tsim thiab plasma hom mus rau hauv cov tub ntxhais hlau. Cov tub ntxhais yog raug rau reactive plasma thiab corrodes sai heev (Incoloy tsim volatile hlau fluorides nyob rau hauv fluorine raws li plasmas) ua rau muaj paug thiab cua sov tsis ua hauj lwm.

Kev ua tau zoo vs. Thickness hauv Plasma
Plasma Type Gas Composition Ion Energy (eV) Erosion Rate (micron/teev) Max Teev mus rau 0.5 mm Tseem tshuav (pib 1.0mm) Max Teev mus rau 0.5 mm Qhov seem (pib 2.5 mm) Pom zoo Min Thickness Inert (sputtering nkaus xwb) Ar, He 200–500 0.2–0.5 1,000–2,500 4,000–10,{12}} hli
Oxidising (chemical + sputter) O2, O2/Ar 100-300 0.5-2.0 250-1, 000 1,000-4,000 2.0 mm
Fluorocarbon (etching) CF4, CHF3, C4F8 200–500 1.0–5.0 100–500 400–2000 2.5 mm
Chlorine Cl₂, BCl₃ 100–300 0.3–1.0 500–1,500 2,000–6,000 2.0 mm
Siab-plasma ntom ntom (ICP) Txhua 500–1,000 2.0–10.0 50–250 200–1,000 3.0 mm (yog siv PFA)
Plasma w/ ion beam pab Ib qho 1,000–5,000 5.0–20.0 25–100 100–500 Tsis tsim nyog rau PFA
Atmospheric plasma (tsis muaj zog) Cua, N₂<50 <0.05 >10,000 >50, 000 1.0 mm tau
Permeation Enhancement thiab Surface Modification
Ion bombardment ua ntau tshaj li cov khoom siv tawm mus, nws hloov cov ciaj sia nyob ze - thaj av saum npoo. Ions tawg C-F daim ntawv cog lus thiab tsim cov dawb radicals uas hnov ​​​​mob nrog cov pa ambient. Cov txheej hloov pauv (feem ntau yog 10-}100 nm tuab) muaj qhov txo qis fluorine concentration (fluorine depletion), cov ntsiab lus oxygen ntau dua (los ntawm kev rov ua haujlwm nrog O2 lossis H2O) thiab qhov ntom ntom ntawm cov kab sib txuas ntau dua. Cov txheej txheem hloov pauv feem ntau yog permeable ntau dua rau cov hom reactive (xws li, atomic oxygen, fluorine radicals) dua li nkauj xwb PFA. Kev txhim kho permeability ceev kom degradation hauv qab ntawm qhov chaw. Rau lub nyias sheath (1.0 hli) hloov txheej yog 10-20% ntawm phab ntsa thickness tom qab 500 h, thaum rau ib tug tuab sheath (2.5 hli) nws tsuas yog 4-8%. Qhov tsis muaj kev cuam tshuam ntawm cov ntaub nyias nyias uas seem yuav nyias dhau los ua qhov cuam tshuam zoo. Cov txheej nyias nyias tuaj yeem ua ntxeem tau lossis nkig thiab tso cai rau plasma hom nkag mus rau hauv cov tub ntxhais, txawm tias tsis muaj kev yaig loj.

Kev paub dhau los nrog cov cuab yeej semiconductor plasma etch qhia tau hais tias PFA cov cua sov nrog 1.0 mus rau 1.5 hli phab ntsa siv raws li hauv -situ heaters (immersed hauv cov ntshav) poob tom qab 6 mus rau 12 lub hlis. Tib lub tshuab cua sov nrog 2.5-3.0 hli phab ntsa yuav kav 3-5 xyoo. Kev poob qis tsis yog kev puas tsuaj tab sis nce ntxiv. Deg roughening, ces pinhole tsim, ces hlau core fluorination (raws li pom los ntawm ntshav los yog dub discoloration ntawm lub Incoloy core . Cov hlau fluorides tsis yog -conductive thiab tej zaum yuav ua rau qhib Circuit Court tsis ua hauj lwm los yog spill tawm thiab paug wafers.

Cov lus pom zoo rau Plasma Service Design
Select the thickest PFA sheath that can be used for low-pressure plasma conditions, generally 2.5 to 3.0 mm. Thicker walls mean a longer erosion lifespan and a longer diffusion pathway for reactive substances. Trade is less heat transmission ( ΔT across sheath increases from 1.5 mm to 3.0 mm by 30 - 50 % , needing higher core temperature or larger surface area ) . For high power plasmas (>500 W, >500 eV ion zog) PFA tej zaum yuav tsis tsim nyog txawm hais tias cov thickness thiab lwm yam ntaub ntawv (quartz, alumina, los yog silicon carbide) yuav tsum tau tshawb xyuas . 1.5-2.0 hli PFA yog tsim nyog rau cov ntshav nrog ion energies <100 eV (xws li downstream plasma, tej thaj chaw deb plasma).

Kev tiv thaiv kev tiv thaiv ntxiv: (1) Tso lub hauv paus hlau thaiv (nrog qhov) nyob ib ncig ntawm lub rhaub kom ntes cov ions nquag ua ntej lawv ncav cuag PFA. Cov ntaub thaiv npog yuav tsum tsis txhob cuam tshuam nrog kev hloov pauv kub. (2) Tig lub rhaub kom ua rau lub ntsej muag sib luag rau cov kab hluav taws xob, yog li txo cov ion zoo. (3) Siv qhov hnyav dua molecular (qis MFI, saib Tshooj # 37) qib ntawm PFA nrog kev txhim kho corrosion kuj. (4) Rau fluorocarbon plasmas, xav txog npog PFA nrog nyias (0.1-0.2 hli) txheej ntawm PTFE los yog FEP, uas muaj ib tug qis sputter yield tshaj PFA (vim muaj fluorine ntau dua). Tsis muaj fluoropolymer tiv taus oxygen plasmas. Siv quartz lossis hlau.

Xaus: Thicker PFA ua haujlwm zoo dua hauv Plasma
Nyob rau hauv cov ntshav plasma uas tsis tshua muaj siab, lub thinner PFA txheej (0.5-1.5 hli) ua tau phem dua li cov ntaub qhwv tuab (2.5-3.0 hli) vim yog ion foob pob yaig (0.1-10 µm / teev) thiab kev hloov ntawm qhov chaw uas ua rau muaj kev nkag mus. Cov phab ntsa nyias nyias nthuav tawm cov tub ntxhais hlau ua ntej thiab cov txheej txheem hloov pauv sawv cev ib feem loj ntawm cov phab ntsa ntxiv. Lub neej xav tau ntawm tus qauv plasma etch sheath (200-500 eV ion zog, 0.5-2.0 um / teev yaig tus nqi) yog 500-2,000 teev rau 1.0 hli sheath thiab 2,000-10,000 teev rau 2.5 hli sheath ntev, 4-5 zaug Cov kws tsim qauv tsim PFA cov cua sov rau cov chav plasma yuav tsum siv cov phab ntsa tuab tshaj plaws (2.5 mus rau 3.0 hli) thiab lees txais cov cua kub qis dua lossis ntau dua qhov cua sov. Thinner barriers yog kev lag luam cuav. Lub tswv yim intuitive uas 'tsawg khoom=tsawg deterioration' yog cuav nyob rau hauv plasma. Nws yog tsav los ntawm yaig, tsis yog permeation los yog kub ntxhov. Kev yaig siv cov khoom tawm ntawm sab nraud mus rau sab nraud. Cov khoom siv ntau dua txhais tau tias nws yuav siv sij hawm ntev dua kom txog thaum cov tub ntxhais hlau raug. Rau plasma kev pab cuam hauv semiconductor fabs, 2.5 hli yam tsawg kawg nkaus PFA yog tus qauv. Lub 1.5 hli rhaub yog suav tias yog siv tau thiab tsim nyog tsuas yog rau lub sij hawm luv luv lossis qis zog plasma daim ntaub ntawv. Qhia cov thickness nrog cov plasma tshwj xeeb derating tsis. Tshawb xyuas phab ntsa thickness ntawm qhov tau txais kev tshuaj xyuas. Hauv plasma, tuab tsis zoo dua, nws yog qhov yuav tsum tau rau kev pabcuam txhim khu kev qha.