纳米材料课件4.pdf

Scanning Probe Microscope(SPM)LithographyOr Scanning Probe Lithography(SPL)A Scanning Probe Microscope tip,such as an Atomic Force Microscope(AFM)or Scanning Tunneling Microscope(STM)tip,is used to locally modify a surface,much like a pen or knifeScanning Probe Lithography(SPL)Mechanical scratchingAnodization of Si surface Electrochemical decomposition of self-assembled monolayer Electrofield induced chemical reaction Electrochemical reaction in solution using protected STM tipsOptical or Optical-Assisted Lithography AFM Dip-Pen Nanolithography(DPN)Surface modification by STM tip with a voltage and current,line spacing is 3nmMechanical Modification of Surface with AFM TipLine pattern created by NSOM-based LithographySurface oxidation of silicon surface by STMAg line obtained by electrochemical reduction of Ag+in solution with STMSEM image of Chromium Lines created byDip-Pen NanolithographyDip-Pen Nanolithography(DPN)is an AFM lithography technique where molecules are transported from AFM tip to surface to form nanostructuresFrom Piner et.al,Science 283,661.Water meniscus spontaneously condenses between AFM tip and surface,which facilitates transport of the molecules from tip to surface.Deposition occurs due to surface affinity of the solutes.Previous efforts(by Chad Mirkin,NWU):serial patterning of alkanethiols on gold parallel patterning using several AFM tips patterning alkanethiol-based etch resistsPatterning hexamethyldithilathane on semiconductor surfacesDip-Pen NanolithographyRichard D.Piner,Jin Zhu,Feng Xu,Seunghun Hong,and Chad A.Mirkin,Science 1999 January 29;283:661-663.Multiple Ink Nanolithography:Toward a Multiple-Pen Nano-PlotterSeunghun Hong,Jin Zhu,and Chad A.Mirkin;Science 1999 October 15;286:523-525.A Nanoplotter with Both Parallel and Serial Writing CapabilitiesSeunghun Hong and Chad A.Mirkin;Science 2000 June 9;288:1808-1811.+SiliconSilicon+Silicon+Pt(IV)+4ePt(0)Silicon+AFM image of a platinum line drawn by the E-DPN method under the condition of relative humidity 40%with a voltage of 4 V and a translation speed of 5 nm/s.(a)A silver line drawn by E-DPN method with AgNO3 solution as the ink.Experimental conditions:relative humidity:42%,voltage:4V,translation speed:20nm/s.(b)A germanium line with the saturated solution of GeO2in 0.05 M NaOH as the ink,relative humidity:42%,voltage:5V,translation speed 100nm/s.(c)A palladium line using PdCl2as the precursor.Relativehumidity:38%,voltage:3.5V,scan speed:10 nm/s.(d)A copper square with CuCl2as precursor.Relative humidity:46%,voltage:3V,scan speed:50 nm/s.Factors that may affect the height and width of the fabricated features using the E-DPN technique:humidity scan speed applied voltage character of tip(shape and conductivity)property of the wafer(conductivity and surface property)amount of salts on tip property of metal salts50%46%41%Relative HumidityInk:saturated solution of GeO2in 0.05 M NaOHAFM image and height profile of two Pt lines drawn at different scan speed.Left line at 10 nm/s and right line at 20 nm/s.The voltage applied at the tip is 3V for both lines and the relative humidity is 43%.AFM images and height profiles of two Cu dots drawn at different voltage,top dot at 2.0V and bottom dot at 5.0V.Scan speed is 100 nm/s and the relative humidity is 50%.(a)The character V composed of platinum(left)and silicon oxide(right).The Pt line is drawn with a voltage of+4 V between the tip and the wafer and a scan speed of 10 nm/s.The SiO2line is created with a-10 V voltage to oxidize the surface and the scan speed is 50 nm/s.The relative humidity is 58%.(b)The same area of the wafer after heated at 500 C under the atmosphere of ethylene in argon for an hour.Au(III)+Si(0)Au(0)+Si(IV)Letters“DU”drawn at 10 nm/sec at 40%relative humidityUSING THE TINY WATER DROPLET AS A NANOMETER-SIZED REACTION VESSEL