【文章內(nèi)容簡介】 gure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaLens Capturing Diffracted LightUV0123412 34LensQuartzChrome Diffraction patternsMaskFigure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaEffect of Numerical Aperture on ImagingFigure Exposure lightLens NAPinhole masksImage resultsDiffracted lightGoodBadPoor169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaTypical NA Values for Photolithography ToolsTable 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaPhotoresist Reflective Notching Due to Light ReflectionsPolysiliconSubstrateSTISTIUV exposure lightMaskExposed photoresistUnexposed photoresistNotched photoresistEdge diffraction Surface reflectionFigure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaIncident and Reflected Light Wave Interference in Photoresist Standing waves cause nonuniform exposure along the thickness of the photoresist film.Incident waveReflected wavePhotoresist FilmSubstrateFigure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaEffect of Standing Waves in PhotoresistPhotograph courtesy of the Willson Research Group, University of Texas at AustinPhoto 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaAntireflective Coating to Prevent Standing Waves The use of antireflective coatings, dyes, and filters can help prevent interference.Incident wave Antireflective coatingPhotoresist FilmSubstrateFigure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaLight Suppression with Bottom Antireflective CoatingBARCPolysiliconSubstrateSTISTIUV exposure lightMaskExposed photoresistUnexposed photoresistFigure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaBARC PhaseShift Cancellation of Light(A) Incident lightPhotoresistBARC (TiN)AluminumC and D cancel due to phase difference(B) Top surface reflection(C)(D)Figure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaTop Antireflective CoatingIncident lightPhotoresistResistsubstrate reflectionsSubstrateIncident lightPhotoresistSubstrate reflectionSubstrateTop antireflective coating absorbs substrate reflections.Figure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaOptical LithographyResolution? Calculating Resolution? Depth of Focus? Resolution Versus Depth of Focus– Surface Planarity 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaResolution of FeaturesThe dimensions of linewidths and spaces must be equal. As feature sizes decrease, it is more difficult to separate features from each other.Figure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaCalculating Resolution for a given ?, NA and kLens, NAWaferMaskIlluminator, ?Rk = ????? ?? ??? R365 nm 486 nm365 nm 365 nm193 nm 257 nm193 nm 193 nmilineDUV k ? NAR =Figure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaDepth of Focus (DOF)+PhotoresistFilmDepth of focusCenter of focusLensFigure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaResolution Versus Depth of Focus for Varying NA ????? 2(NA)2DOF = PhotoresistFilmDepth of focusCenter of focus+Lens, NAWaferMaskIlluminator, ?DOF???? ? ?? ??? R DOF365 nm 486 nm 901 nm365 nm 365 nm 507 nm193 nm 257 nm 476 nm193 nm 193 nm 268 nmilineDUVFigure 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaPhotolithograhy Equipment? Contact Aligner? Proximity Aligner? Scanning Projection Aligner (scanner)? StepandRepeat Aligner (stepper)? StepandScan System 169。 2023 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Ju