Reactive Ion Etching (RIE) Reactive Ion Etching (RIE) and Deep Reactive Ion and Deep Reactive Ion Etching (DRIE)Etching (DRIE)Bryan Bryan Janaskie Janaskie & & Shuk Shuk Yin Yin ChukChukENEE 416ENEE 416November 11, 2007November 11, 2007zzDry EtchingDry EtchingMethodMethodzzPlasma etching Plasma etching combined with combined with sputteringsputteringzzEtchEtchdeepths deepths of of 10um10umzzEtch rate of up to Etch rate of up to 100 um/min100 um/minReactiveReactiveIon EtchingIon Etching(RIE)(RIE)QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.Etchant Etchant chemistrieschemistrieszzIsotropic: F based plasmaIsotropic: F based plasmazzAnisotropic: Anisotropic: Cl Cl and BRand BRQuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.Advantages of RIEAdvantages of RIEzzHighly AnisotropicHighly AnisotropiczzEnhanced structureEnhanced structurezzHigh resolutionHigh resolutionQuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.Disadvantages of RIEDisadvantages of RIEzzLowLowEtchEtchRateRatezzLow level of selectivityLow level of selectivityzzSurface damageSurface damagezzChemical/Physical balanceChemical/Physical balanceApplicationsApplicationszzSolar CellsSolar CellszzLaser diodesLaser diodeszzMEMsMEMsDeep Reactive Ion Etching Deep Reactive Ion Etching (DRIE)(DRIE)zzDry etch micromachining methodDry etch micromachining methodzzHigh density plasma (HDP)High density plasma (HDP)zzInductively couple plasma (ICP)Inductively couple plasma (ICP)zzCryoCryoProcessProcesszzBosch ProcessBosch ProcessCryoCryoProcessProcesszzSingle step processSingle step processzzEtch gas and Etch gas and passivationpassivationgas are released gas are released at the same time at the same time zzDone at cryogenic temperature (<Done at cryogenic temperature (<--110°C )110°C )Bosch Process Bosch Process zzDeveloped by German company Developed by German company --Robert Robert Bosch in 1994Bosch in 1994zzCycling twoCycling two--steps process altering steps process altering between deposition and etch stepsbetween deposition and etch stepszz11stst––standard isotropic plasma etchstandard isotropic plasma etchzz22ndnd––passivationpassivationlayer depositionlayer depositionAdvantages of DRIEAdvantages of DRIEzzVertical side wallsVertical side wallszzFine resolutionFine resolutionzzHigh aspect ratioHigh aspect ratiozzHigh etch rateHigh etch ratezzHigh selectivityHigh selectivityzzPrecisePreciseDisadvantages of DRIEDisadvantages of DRIEzzUse high plasma powerUse high plasma powerzzSingle wafer at a timeSingle wafer at a timezzSpecialized hardwareSpecialized hardwarezzExpensiveExpensiveDRIE ApplicationsDRIE ApplicationszzFew micrometers to 0.5mm in MEMSFew micrometers to 0.5mm in MEMSzzSensors and actuatorsSensors and actuatorszzPrinter headsPrinter headszzAccelerometer for air bagsAccelerometer for air bagszzCapacitor in DRAM memory circuitsCapacitor in DRAM memory
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