Introduction to Atomic force Microscopy Yanchun han
Introduction to Atomic Force Microscopy Yanchun Han
显微镜技术的发展 17世纪:光学显微镜:微米级,x,y二维 20世纪40年代:电子显微镜:SEM,TEM 5nmx,y二维 90年代:AFM三维,xy:2nm Z<0. 1 nm 优点:操作容易 样品准备简单 操作环境不受限制 分辨率高
显微镜技术的发展 17 世纪：光学显微镜：微米级， x, y二维 20世纪40年代：电子显微镜：SEM， TEM 5 nm, x, y二维 90年代: AFM: 三维，x,y: 2 nm Z<0.1 nm 优点: 操作容易 样品准备简单 操作环境不受限制 分辨率高
History of scanning Probe Microscope 1981 Heinrich Rohrer and Gerd Binnig develop the first scanning tunneling microscope (STM at IBM Zurich (Nobel Prize 1986) Atomic image of Si(7x7 oln this technique a sharp metal tip is positioned over the conducting sample. A small potential difference is then applied between the tip and the sample. Electrons"tunnel"through the Gap between the tip and the sample into the tip and vice versa oThe tip is then scanned across the surface of the sample. The signal that gets detected is the Tunnel Current oThe result is a Topographical image of atoms on a surface, achieved by recording the tip height at each location
History of Scanning Probe Microscope Atomic image of Si(7x7) 1981 Heinrich Rohrer and Gerd Binnig develop the first scanning tunneling microscope (STM) at IBM Zurich (Nobel Prize 1986) ⚫In this technique a sharp metal Tip is positioned over the conducting sample. A small potential difference is then applied between the tip and the sample. Electrons "tunnel"through the Gap between the tip and the sample into the tip and vice versa. ⚫The tip is then scanned across the surface of the sample. The signal that gets detected is the Tunnel Current ⚫The result is a Topographical image of atoms on a surface, achieved by recording the tip height at each location
AFM The Atomic Force Microscope(AFM)was developed from the Scanning Tunneling Microscope STM)in 1986 by Binning, Quate and Gerber. The limitation of the STMin only being able to image conducting materials was overcome by the Force Microscope This microscope neitherneeds the sample or the tip to be conductive,a huge development in the imaging of biological surfaces The two main Applications of aFm are Imaging and Force Distance curves With regards to imaging, the advances since 1986 have been astonishing. Atomic force Microscopy Provides quantitative, three dimensionalimages and surface measurements with extremely high resolution, which can be of the order of10 to 20 Angstroms Many surface structures have been revealed from the first images of lamellar materials in 1987, through to images of DNA, and proteinsin 1988
The Atomic Force Microscope (AFM) was developed from the Scanning Tunneling Microscope (STM) in 1986 by Binning, Quate and Gerber. The limitation of the STM in only being able to image conducting materials was overcome by the Force Microscope. This microscope neither needs the sample or the tip to be conductive,a huge development in the imaging of biological surfaces. The two main Applications of AFM are Imaging and Force Distance Curves. With regards to imaging, the advances since 1986 have been astonishing. Atomic Force Microscopy Provides quantitative, threedimensional images and surface measurements with extremely high resolution, which can be of the order of10 to 20 Angstroms. Many surface structures have been revealed from the first images of lamellar materials in 1987, through to images of DNA, and Proteinsin 1988. AFM
Scanning probe Microscopy(SPM) A family of microscopy forms where a sharp probe is scanned across a surface and some tip/sample interactions are monitored Scanning tunneling Microscopy (STM) Atomic Force Microscopy(AFM) · contact mode non-contact mode Tapping Mode(DFm) LiftMode Other forms of SPm ateral force Force modulation Magnetic or electric force · surface potential scanning thermal phase imaging Chemical force Nanoindentation/Scratch(IMHO) · Lithography
Scanning Probe Microscopy (SPM) A family of microscopy forms where a sharp probe is scanned across a surface and some tip/sample interactions are monitored Scanning tunneling Microscopy (STM) Atomic Force Microscopy (AFM) • contact mode • non-contact mode • TappingMode (DFM) • LiftMode Other forms of SPM • Lateral force • Force modulation • Magnetic or electric force • surface potential • scanning thermal • phase imaging • Chemical force • Nanoindentation/Scratch (IMHO) • Lithography
● The mu| tiMode microscope includes an optical detection head scanner, and microscope base. The com pact, rigid construction of the microscope gives it the mechanical stability and low noise needed for high resolution The microscope performs the full range of SPM techniques to measure surface characteristics including topography, elasticity, friction adhesion magnetic fields, and electrical fields
⚫The MultiMode microscope includes an optical detection head, scanner, and microscope base. The compact, rigid construction of the microscope gives it the mechanical stability and low noise needed for high resolution. ⚫The microscope performs the full range of SPM techniques to measure surface characteristics including topography, elasticity, friction, adhesion, magnetic fields, and electrical fields
.Atomic Force Microscopy Instrumentation Principle of Atomic Force Microscopy oModes of operation In Atom ic Force Microscopy .Applications of Atomic Force Microscopy
⚫Atomic Force Microscopy Instrumentation ⚫Principle of Atomic Force Microscopy ⚫Modes of Operation In Atomic Force Microscopy ⚫Applications of Atomic Force Microscopy
AFM原理 检测系统 ● The cantilever 扫描系统 ● The piezoscanner 反馈系统 ● The force sensor ● The feedback system laser diode mirron sensor output, 8c, F A⊥B cantilever position sensitive pong which deflects a probe tp photodetector scans sample surtace mearures deflect on af cantilever dc p robe ti urface 10-15 properties and causes ERROR unilever to deflect nen feedback loop controls t-ganpl paten computer controls sytem zoelectric performs data acquint on, alais scanner poritions sampl
AFM原理 检测系统 扫描系统 反馈系统 ⚫The cantilever. ⚫The piezoscanner. ⚫The force sensor. ⚫The feedback system
the main elements of the aFm ● Cantilever(+ Probe) ● Piezoscanner ● Laser beam source ● Photodiode detector ● Feedback systen photodiode (deflection detector) Mirror Laser beam Si gnal a Probe Path of tip Piez Feedback signal probe monitored 3-Dim ensional IMAGE
⚫Cantilever (+Probe) ⚫Piezoscanner ⚫Laser beam source ⚫Photodiode detector ⚫Feedback system the main elements of the AFM
检测系统 检测:悬臂的偏转或振幅的改变 检测方法:光反射法,光干涉法,隧道电 流法,电容检测法 激光光反射检测系统:探针,激光发生器 检测器
检测系统 检测：悬臂的偏转或振幅的改变 检测方法：光反射法， 光干涉法，隧道电 流法， 电容检测法 激光光反射检测系统：探针，激光发生器 检测器
