AFM - atomic force microscopy
          AFM - atomic force microscopy
     A 'new' view of structure (1986)
     A 'new' view of structure (1986)
                     CD stamper
                      CD stamper                 AlGaN/GaN quantum well waveguide
                                                  AlGaN/GaN quantum well waveguide
                                                    surface atoms on Si single crystal
                                                    surface atoms on Si single crystal
                    polymer growth              See Vocabulary of Surface Crystallography, Journal of 
                    polymer growth              Applied Physics 35, 1306 (1964), by Elizabeth A. Wood
          AFM - atomic force microscopy
          AFM - atomic force microscopy
     How does the microscope work?
     How does the microscope work?
                                               laser          photodiode
                                               laser          photodiode
                                               diode
                                               diode
                                                        mirror
                                                        mirror
     Tip scans sample
     Tip scans sample
     Up and down movement of tip recorded 
     Up and down movement of tip recorded 
     by position sensing photodiode
     by position sensing photodiode
                                                Si N
                                                Si N
                                                  3  4
                                                  3  4
                                                 tip
                                                 tip
                                                        sample
                                                        sample
                                         
          AFM - atomic force microscopy
          AFM - atomic force microscopy
     How does the microscope work?
     How does the microscope work?
                                               laser          photodiode
                                               laser          photodiode
                                               diode
                                               diode
                                                        mirror
                                                        mirror
     Tip scans sample
     Tip scans sample
     Up and down movement of tip recorded 
     Up and down movement of tip recorded 
     by position sensing photodiode
     by position sensing photodiode
                                                Si N
                                                Si N
                                                  3  4
                                                  3  4
                                                 tip
                                                 tip
                                                        sample
                                                        sample
                                         
          AFM - atomic force microscopy
          AFM - atomic force microscopy
     How does the microscope work?
     How does the microscope work?
      Two modes of operation
      Two modes of operation                   laser          photodiode
                                               laser          photodiode
                                               diode
                                               diode
                                                        mirror
                                                        mirror
                                                Si N
                                                Si N
                                                  3  4
                                                  3  4
                                                 tip
                                                 tip
                                                        sample
                                                        sample
                                         
       AFM - atomic force microscopy
       AFM - atomic force microscopy
   How does the microscope work?
    How does the microscope work?
    Contact mode - short-range interactions (Å) - interatomic forces
    Contact mode - short-range interactions (Å) - interatomic forces
                            Tip: 5-20 nm radius, 10-25 m high, on 
                            Tip: 5-20 nm radius, 10-25 m high, on 
                               50-400 m cantilever beam
                               50-400 m cantilever beam