AFM University Introduction to Atomic Force Microscopy by Paul West

« Cover
« Foreward
« Chapter 1
 
1.1. History
1.2. Comparison
1.3. Enabling Nanotechnology
 « Chapter 2
 « Chapter 3
 « Chapter 4
 « Chapter 5
 « Chapter 6
 « Chapter 7
« Appendix A
« Appendix B
« Appendix C
« Appendix D
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Chapter 1
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was a result of horizontal forces on the probe caused when the probe encountered large features on the surface. This problem was first addressed by Becker2 in 1950 and later by Lee3. Both Becker and Lee suggested oscillating the probe from a null position above the surface to contact with the surface. Becker remarked that when using this vibrating profile method for measuring images, the detail of the images would depend on the sharpness of the probe.

In 1971 Russell Young4 demonstrated a non-contact type of stylus profiler. In his profiler, called the topographiner, Young used the fact that the electron field emission current between a sharp metal probe and a surface is very dependent on the probe sample distance for electrically conductive samples. In the topographiner, see (Figure 1-5), the probe was mounted directly on a piezoelectric ceramic used to move the probe in a vertical direction above the surface. An electronic feedback circuit monitoring the electron emission was then used to drive the piezoceramic and thus keep the probe sample spacing fixed. Then, with piezoelectric ceramics, the probe was used to scan the surface in the horizontal (XY) dimensions. By monitoring the X-Y and Z position of the probe, a 3-D image of the surface was constructed. The resolution of Young’s instrument was controlled by the instrument’s vibrations.


FIGURE 1-5 Schematic of the first non-contact mechanical profiler developed by Russel Young (Left). Light lever design developed by IBM for use in the AFM (Right).

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