Wafer Cleaning Technology hauv Semiconductor Manufacturing

Wafer Cleaning Technology hauv Semiconductor Manufacturing

Kev ntxuav wafer yog ib kauj ruam tseem ceeb thoob plaws tag nrho cov txheej txheem tsim khoom semiconductor thiab yog ib qho tseem ceeb uas cuam tshuam ncaj qha rau kev ua haujlwm ntawm cov cuab yeej thiab cov khoom tsim tawm. Thaum lub sij hawm chip fabrication, txawm tias me ntsis kev kis kab mob tuaj yeem degrade cov yam ntxwv ntawm cov cuab yeej lossis ua rau tsis ua tiav. Yog li ntawd, cov txheej txheem ntxuav yog siv ua ntej thiab tom qab yuav luag txhua qhov kev tsim khoom kom tshem tawm cov kab mob ntawm qhov chaw thiab xyuas kom huv si wafer. Kev ntxuav kuj tseem yog kev ua haujlwm nquag tshaj plaws hauv kev tsim khoom semiconductor, suav txog kwv yees li30% ntawm tag nrho cov txheej txheem txheej txheem.

Nrog rau kev sib txuas txuas ntxiv ntawm kev sib koom ua ke loj heev (VLSI), cov txheej txheem no tau nce mus rau28nm, 14nm, thiab ntau dua, tsav tsheb ntau dua cov cuab yeej ceev, nqaim linewidths, thiab nce cov txheej txheem ntws. Cov nodes siab heev yog qhov muaj txiaj ntsig zoo rau kev sib kis, thaum qhov me me ntawm qhov loj me ua rau kev tu kom nyuaj dua. Yog li ntawd, tus naj npawb ntawm kev tu cov kauj ruam tseem nce ntxiv, thiab kev tu vaj tse tau ua ntau dua, qhov tseem ceeb dua, thiab nyuaj dua. Piv txwv li, 90 nm nti feem ntau xav tau txog90 cov kauj ruam tu, whereas 20 nm nti xav tau ib ncig215 cov kauj ruam tu. Raws li kev tsim khoom nce mus rau 14 nm, 10 nm, thiab cov pob me me, cov kev ua haujlwm tu yuav nce ntxiv.

Hauv essence,wafer tu yog hais txog cov txheej txheem uas siv tshuaj kho mob, gases, los yog lub cev txoj kev los tshem tawm impurities ntawm lub wafer nto. Cov kab mob xws li cov khoom, cov hlau, cov organic residues, thiab cov oxides ib txwm tuaj yeem cuam tshuam rau kev ua haujlwm ntawm cov cuab yeej, kev ntseeg siab, thiab tawm los. Kev tu vaj tse ua haujlwm ua "choj" ntawm cov txheej txheem sib txuas ua ke - piv txwv li, ua ntej tso thiab lithography, lossis tom qab etching, CMP (chemical mechanical polishing), thiab ion implantation. Feem ntau, wafer ntxuav tuaj yeem muab faib uantxuav ntub dejthiabqhuav tu.

Ntxuav ntub dej

Kev tu ntub dej siv cov kuab tshuaj los yog dej deionized (DIW) los ntxuav cov wafers. Ob txoj hauv kev tseem ceeb yog siv:

• Txoj kev immersion: wafers yog submerged nyob rau hauv lub tank ntim nrog cov kuab tshuaj los yog DIW. Qhov no yog txoj kev siv dav tshaj plaws, tshwj xeeb tshaj yog rau cov tshuab paub tab.

• Txau txoj kev: Cov kuab tshuaj los yog DIW yog txau mus rau rotating wafers kom tshem tawm impurities. Thaum immersion tso cai rau batch ua ntawm ntau wafers, tshuaj ntxuav tes tsuas yog ib tug wafer ib chamber tab sis muab kev tswj zoo dua, ua rau nws nce ntau nyob rau hauv advanced nodes.

Ntxuav kom qhuav

Raws li lub npe qhia, kev ntxuav kom qhuav zam cov kuab tshuaj los yog DIW, es tsis txhob siv cov pa roj los yog cov ntshav kom tshem tawm cov kab mob. Nrog rau kev thawb mus rau qib siab, kev tu kom qhuav yog qhov tseem ceeb vim nwssiab precisionthiab ua haujlwm zoo tiv thaiv cov organics, nitrides, thiab oxides. Txawm li cas los xij, nws xav taukev nqis peev ntau dua, kev ua haujlwm nyuaj dua, thiab kev tswj cov txheej txheem nruj dua. Lwm qhov zoo dua yog tias kev tu kom qhuav txo qhov ntim loj ntawm cov dej khib nyiab tsim los ntawm txoj kev ntub dej.

Cov txheej txheem ntub dej ntub

1. DIW (Deionized Dej) Ntxuav

DIW yog cov khoom siv tu ntau tshaj plaws hauv kev ntub dej. Tsis zoo li cov dej tsis tau kho, DIW muaj yuav luag tsis muaj cov khoom siv hluav taws xob, tiv thaiv corrosion, hluav taws xob hluav taws xob, lossis cov cuab yeej degradation. DIW feem ntau yog siv ob txoj hauv kev:

1. Direct wafer nto tu- Feem ntau ua nyob rau hauv ib leeg-wafer hom nrog chais, txhuam, los yog tshuaj tsuag nozzles thaum wafer tig. Ib qho kev sib tw yog electrostatic charge buildup, uas yuav ua rau muaj teeb meem. Txhawm rau txo qhov no, CO₂ (thiab qee zaum NH₃) tau yaj rau hauv DIW txhawm rau txhim kho kev coj ua yam tsis muaj kab mob wafer.

2. Rinsing tom qab tshuaj ntxuav- DIW tshem tawm cov kev daws teeb meem uas seem uas yuav ua rau lub wafer tsis zoo los yog ua kom cov cuab yeej ua haujlwm tsis zoo yog tias sab laug ntawm qhov chaw.

2. HF (Hydrofluoric Acid) Ntxuav

HF yog cov tshuaj zoo tshaj plaws rau kev tshem tawmCov txheej txheem oxide (SiO₂)ntawm silicon wafers thiab yog thib ob tsuas yog DIW hauv qhov tseem ceeb. Nws kuj dissolves txuas hlau thiab suppresses re-oxidation. Txawm li cas los xij, HF etching tuaj yeem roughen wafer nto thiab undesirably tua tej yam hlau. Txhawm rau daws cov teeb meem no, cov txheej txheem txhim kho dilute HF, ntxiv oxidizers, surfactants, lossis complexing agents los txhim kho kev xaiv thiab txo kev sib kis.

3. SC1 Cleaning (Standard Clean 1: NH₄OH + H₂O₂ + H₂O)

SC1 yog ib qho txiaj ntsig zoo thiab muaj txiaj ntsig zoo rau kev tshem tawmorganic residues, hais, thiab ib co hlau. Lub tshuab ua ke ua ke cov kev ua oxidizing ntawm H₂O₂ thiab cov nyhuv dissolving ntawm NH₄OH. Nws tseem ua rau cov khoom siv hluav taws xob los ntawm cov hluav taws xob hluav taws xob, thiab kev pab cuam ultrasonic / megasonic ntxiv txhim kho kev ua haujlwm. Txawm li cas los xij, SC1 tuaj yeem roughen wafer nto, yuav tsum tau ua tib zoo saib xyuas cov tshuaj sib piv, kev tswj qhov nro (ntawm surfactants), thiab cov neeg ua haujlwm chelating txhawm rau txo cov hlau rov qab.

4. SC2 Cleaning (Standard Clean 2: HCl + H₂O₂ + H₂O)

SC2 ntxiv SC1 los ntawm kev tshem tawmmetallic paug. Nws muaj zog complexation muaj peev xwm hloov oxidized hlau rau hauv soluble ntsev los yog complexes, uas yog rinsed tam sim ntawd. Thaum SC1 muaj txiaj ntsig zoo rau cov organic thiab cov khoom seem, SC2 yog qhov tseem ceeb tshwj xeeb rau kev tiv thaiv cov hlau adsorption thiab ua kom cov hlau tsis muaj paug.

5. O₃ (Ozone) Ntxuav

Kev tu ozone feem ntau yog siv rautshem tawm cov organic teeb meemthiabtshuaj tua kab mob DIW. O₃ ua raws li lub zog oxidant, tab sis tuaj yeem ua rau rov ua dua, yog li nws feem ntau ua ke nrog HF. Kev ntsuas kub zoo yog qhov tseem ceeb vim tias O₃ solubility hauv dej txo qis ntawm qhov kub siab dua. Tsis zoo li cov tshuaj tua kab mob chlorine (tsis tuaj yeem lees txais hauv cov khoom siv hluav taws xob), O₃ decomposes rau hauv oxygen yam tsis muaj kab mob DIW.

6. Organic Solvent Cleaning

Hauv qee cov txheej txheem tshwj xeeb, cov kuab tshuaj organic yog siv qhov kev tu tus qauv tsis txaus lossis tsis tsim nyog (xws li, thaum tsim oxide yuav tsum zam).

Xaus

Wafer ntxuav yog qhovfeem ntau rov ua kauj ruamnyob rau hauv semiconductor manufacturing thiab ncaj qha cuam tshuam tawm los thiab kev cia siab ntawm cov cuab yeej. Nrog kev txav mus losloj wafers thiab cov khoom siv me me geometry, qhov yuav tsum tau ua rau wafer nto huv si, tshuaj lom neeg lub xeev, roughness, thiab oxide thickness yog nce stringent.

Kab lus no tau tshuaj xyuas ob qho tib si paub tab thiab qib siab wafer tu thev naus laus zis, suav nrog DIW, HF, SC1, SC2, O₃, thiab cov txheej txheem organic hnyav, nrog rau lawv cov txheej txheem, qhov zoo, thiab kev txwv. Los ntawm ob qho tib sieconomic thiab ib puag ncig kev xav, kev txhim kho txuas ntxiv hauv wafer tu tshuab yog qhov tseem ceeb kom ua tau raws li qhov xav tau ntawm kev tsim khoom semiconductor siab heev.