SiO2OxidationSiSiO,selectivelyetched1SiO2Lithography and EtchingSiDopant atomsintroduced into exposed siliconSiOlon ImplantationsiSiO2Annealing and DiffusionDopantatomsdiffuseinto SiSi
Oxidation Lithography and Etching Ion Implantation Annealing and Diffusion
Quartz tubeSiWafersFlowcontrollerH,O or TCE(trichloroethylene)Resistance-heatedfurnaceN
Si + O2 → SiO2Dry Oxidation :Si +2H,0 → SiO2 + 2H,Wet Oxidation :101200°CdryPREdry1100°℃1.01000°CdryUswetA900°Cdry0010000.111900°Cwet(100)LE0.01101001.00.1Oxidation time (hr)
EXAMPLE : Two-step Oxidation(a) How long does it take to grow 0.1um of dry oxide at 1000 oC ?(b) After step (a), how long will it take to grow an additional0.2um of oxide at 900 oC in a wet ambient ?
Lithography(c) Development(a) Resist CoatingPositive resistNegative resistPhotoresistOxide(b) ExposureSSi(d) Etching and Resist StripDeep Ultraviolet LightOpticalPhotomask withLens systemopaque andclear patterns
Lithography