The invention of the atomic force microscope (AFM) revolutionized the scientific world by providing researchers with the ability to make topographical maps of both conducting and non-conducting surfaces with nanometer resolution. As an alternative to optical AFM methods, thermal cantilevers have been investigated as a method to measure topography. This study reports the fabrication and testing of heated AFM cantilevers.
This study transfers a fabrication process first developed at Stanford University to the Georgia Institute of Technology micro-fabrication facility and fabricates six different heated AFM cantilever designs. Selective impurity doping of a silicon cantilever allows it to become electrically conductive with a resistive element near the cantilever free end. Voltage applied across the cantilever legs induces current flow through the cantilever that generates heat in the resistive element.
A deep understanding of the operational behavior and limits of the AFM cantilever is required to use the cantilever as an experimental tool. Characterization experiments determined the cantilever electrical resistance and temperature response. Experiments were conducted that electrically test heated AFM cantilevers at various system input voltages. Electrical and thermal responses of these cantilevers were compared against a theoretical model. The model utilizes heat transfer fundamentals and links the thermal response to the cantilever temperature-dependent electrical characteristics. Results of this study show that the fabricated heated AFM cantilevers have a tip with a radius of curvature as small as 20nm. Cantilever temperatures can exceed 700㠩n short pulses and, because the resistive heating element is also a temperature sensor, calibration of the cantilever temperature response is possible to within 1㮍
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/6890 |
| Date | 15 April 2005 |
| Creators | Wright, Tanya Lynn |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Format | 5769444 bytes, application/pdf |
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