HR-AFM Manual
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File Type：pdf, Size：1020Kb
HR - AFM Users Guide V1.0 Definitions and Symbols The following terms and symbols are used in this document and also appear on the product where safety-related issues occur. General Warning or Caution [Image Def1: exclamation symbol] The exclamation symbol may appear in warning and caution tables in this document. Symbol designates an area where personal injury or damage to the equipment is possible. European Union CE Mark [Image Def2: CE symbol] The presence of the CE Mark on AFMWorkshop equipment means that it has been designed, tested and certified as complying with all applicable European Union (CE) regulations and recommendations. Warnings/Cautions/Notes The following are definitions of the warnings, cautions and notes that may be used in this manual to call attention to important information regarding personal safety, safety and preservation of the equipment, or important tips. WARNING Situation has the potential to cause bodily harm or death. CAUTION Situation has the potential to cause damage to property or equipment. NOTE Additional information the user or operator should consider. Contents 1. Introduction to Atomic Force Microscopy......................................................1-1 2. Introduction to the HR-AFM..........................................................................2-1 2.1 Stage.................................................................................................2-1 2.2 Computer..........................................................................................2-1 2.3 Ebox..................................................................................................2-2 2.4 Video Optical Microscope.................................................................2-2 3. Software.......................................................................................................3-1 3.1 Installation Procedure.............................................................................3-1 3.1.1 Gwyddion Image Analysis Software........................................3-1 3.2 AFM Control Software..........................................................................3-2 3.2.1 Pre-Scan Window.................................................................3-2 3.2.1.1 Modes ..........................................................................3-2 3.2.1.2 Resolution Modes.......................................................3-3 3.2.1.3 Laser Align.................................................................3-3 3.2.1.4 System Panel.........................................................3-3 3.2.1.5 Tune Frequency…………………………………….3-4 3.2.1.6 Manual Z Motor Control.............................................3-4 3.2.1.7 Automated Tip Approach...........................................3-5 3.2.2 Topo Scan Window...............................................................3-5 3.2.2.1 Image Windows.............................................3-6 3.2.2.2 Oscilloscope Windows...................................3-7 3.2.2.3 Z Feedback....................................................3-8 3.2.2.4 Display...........................................................3-9 3.2.2.5 Tip Retract.....................................................3-10 3.2.2.6 Scan..............................................................3-10 3.2.2.7 Scan parameters……………………………..3-10 3.2.3 Navigation area....................................................................3-10 3.2.4 Force Distance Curves..........................................................3-13 3.3 Workshop Video Software...........................................................3-14 4. Measuring Images with the HR-AFM............................................................4-1 4.1 Operating the Video Microscope.......................................................4-1 4.2 Preparing Samples............................................................................4-2 4.2.1 Exchanging Samples...............................................................4-2 4.3 Exchanging Probes...........................................................................4-3 4.4 Aligning the Light Lever Force Sensor.............................................4-4 4.4.1 Tips for Aligning the Light Lever Force Sensor......................4-4 4.5 Optically-Assisted Tip Approach.........................................................4-5 4.5.1 Performing Optically-Assisted Tip Approach..........................4-5 4.6 Contact Mode Imaging.......................................................................4-6 4.6.1 Pre-Scan Tab..........................................................................4-6 4.6.2 Topo Scan Tab.......................................................................4-8 4.7 Vibrating Mode Imaging......................................................................4-10 4.7.1 Pre-Scan Tab..........................................................................4-10 4.7.2 Topo Scan Tab.......................................................................4-12 5. Troubleshooting..............................................................................................5-1 5.1 Saturation of the Photo-Detector........................................................5-1 5.2 Sample Not Mounted Correctly..........................................................5-1 5.3 Probe Not Seated Correctly..............................................................5-1 5.4 Resonance Saturated........................................................................5-2 5.5 False Feedback................................................................................5-2 5.6 Scanner at End of Z Range..............................................................5-2 5.7 Defective Probe................................................................................5-2 6. High Resolution Imaging..............................................................................6-1 Appendix A. Setting Up the HR-AFM....................................................................A-1 A.1 Selecting a Location.........................................................................A-1 A.2 Setting Up the Optical Microscope...................................................A-1 A.3 Connecting the HR-AFM to the Cables............................................A-2 A.4 System Check..................................................................................A-3 A.5 Aligning the Video and HR-AFM Microscopes................................A-3 A.6 First Alignment of the Light Lever...................................................A-4 A.7 Installing the XYZ Piezoelectric Scanner........................................A-5 A.8 Levelling Sample Holder.................................................................A-5 A.9 Grounding the HR-AFM..................................................................A-5 Appendix B. HR-AFM Data Files..........................................................B-1 Appendix C. Calibration......................................................................................C-1 Appendix D. Noise Floor.......................................................................................D-1 Appendix E. Probes.............................................................................................E-1 Appendix F. Technical Information......................................................................F-1 F.1 Electronic Block Diagrams..............................................................F-1 F.2 Ebox and Modes Pin Assignments..................................................F-2 Appendix G. Optimizing GPID Parameters.........................................................G-1 Appendix H. Renaming National Instruments DAQ Device.................................H-1 Appendix I. Analyzing Force/Distance Curves....................................................I-1 1. Introduction to Atomic Force Microscopy In an AFM (atomic force microscope), a probe is scanned over a surface and the motion of the probe is monitored to create a three-dimensional image of the surface. These unique instruments are capable of measuring high-resolution images in both ambient air and liquids, accurately determine the dimensions of surface features of only a few nanometers in size. The three-dimensional motion of the sample (or probe) is generated by piezoelectric ceramics. These sensitive ceramics allow motions as small as a fraction of a nanometer. Typically, the sample (or probe) is moved in a raster pattern as the probe moves across the surface. [Image1.1: Light Lever] A light lever sensor is used for controlling the force of the probe on the surface while the sample is scanned. The light lever reflects a laser beam off the surface of a cantilever into a photo-detector. As the probe interacts with a surface, the cantilever deflects, and this motion is sensed by the photo-detector. With this light lever, measurement and control of forces as small as a pico-newton are possible. With such small forces, very small probes may be used. With micro-machining methods, probes can have diameters of only a few nanometers. [Image1.2: SEM image of AFM Probe] The light lever can be made more sensitive by vibrating the cantilever with a small piezoelectric ceramic. When the vibrating probe interacts with the surface, the amplitude of vibration may be monitored and used to control the probe's force on the surface. Modern atomic force microscopes include not only a probe and piezoelectric scanner, but additional hardware for bringing the probe rapidly into the proximity