Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Yongshik ParkFebruary 13th, 2008EE C235/NSE C203Scanning Probe LithographyOutlineScanned Probe OxidationGenerating an Polymer “Resist” Layer using Scanning Probe LithographyHigh-Field Scanning Probe Lithography in HexadecaneCons and ProsConclusionsScanned Probe OxidationBegan at NIST in 1989Electrical bias between a conducting tip and a substrate induces a highly localized enhanced oxidation.Typical line width: 10~20nmJ. A. Dagata, Science, Vol. 270, 1995, pp1625-1626Scanned Probe Oxidation- ApplicationsFabrication of Si nanowireFabrication of single tunneling transistor(SET)J. A. Dagata, Science, Vol. 270, 1995, pp1625-1626Generating an Etch Resistant “Resist” Layer from Common SolventsAn organic electrolyte replaces water to generate an organic resist.Scan rate: 10um~20umDC BiasFluid CellSolvent vaporI. Suez, S. Backer, J. Frechet, Nano Letter, Vol. 5, No. 2, 2005, pp321-324Generating an Etch Resistant “Resist” Layer from Common SolventsThe height of n-octane: 2.5nm (40% higher than the case of water)After etching, the height of step: 8.5nmAfter generating n-octane patternsAfter etchingI. Suez, S. Backer, J. Frechet, Nano Letter, Vol. 5, No. 2, 2005, pp321-324High-Field Scanning Probe Lithography in Hexadecane - HydrophobocitySurface hydrophobocity determines the deposited material.Hydrophilic SiO2Hydrophobic n-octaneOxidation of the silicon surface occurs in the meniscus formed by the water dissolved in the fluid, with minimal effects on the reaction from the surrounding solventsI. Suez, M. Rolandi, S. Backer, A. Scholl, J. Frechet, Advanced Materials, Vol. 19, 2007, pp3570-3573High-Field Scanning Probe Lithography in Hexadecane - HydrophobocityEtching makes trenches on hydrophilic surface and tall posts on hydrophobic surface.On Hydrophilic surface On Hydrophobic surfaceAfter deposition(black)After etching(red)I. Suez, M. Rolandi, S. Backer, A. Scholl, J. Frechet, Advanced Materials, Vol. 19, 2007, pp3570-3573High-Field Scanning Probe Lithography in Hexadecane – PEEM analysisAlthough there are only small differences in features of the local spectra, carbon content information was obtained1st and 2nd peak: C=C double bond3rd peak: hybridized carbon atomsI. Suez, M. Rolandi, S. Backer, A. Scholl, J. Frechet, Advanced Materials, Vol. 19, 2007, pp3570-3573PEEM analysisAFM imageCarbon signal PEEMCons and ProsConsCan make nano patterns without optical apparatusCan control deposited material by hydrophobocity of the surfaceCan make arbitrary patterns by controlling the trajectory of AFM tipProsLow throughput: serial scan and low speedMultiple tipsSmall scan areaConclusionsScanning probe oxidation can make nanowire, SET, etc.By using an organic solvent, the organic material can be deposited on the surface.The hydrophobocity determines the deposited materialHydrophilic surface SiO2Hydrophobic surface hydrocarbonBy PEEM analysis, the deposited material on the hydrophobic surface has carbon
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