Study on Multi-Frequency Method for Electrostatic Force Microscopy in Air

Abstract

A detailed study of multi-frequency electrostatic force microscopy (MF-EFM) in air is presented. In the MF-EFM, the first eigenmode of the cantilever vibration is used for topographic imaging, while the second one is resonantly excited for the measurement of electrostatic force. Possible interferences between the two information channels are eliminated by using the lift mode and the two-pass mode. The lateral resolution of the microscopy is corroborated to be improved. The capabilities of the MF-EFM are demonstrated by characterizing a silicon wafer sample and by determining its local contact potential difference.

Keywords:

• Electrostatic force microscopy
• multi-frequency
• lateral resolution
• work function

Acknowledgments

The authors gratefully acknowledge financial support from: the Joint Fund of Guangdong Province and the Education Ministry, China (Grant No. 2010B090400123, 2011B 090400376), the National Natural Science Foundation of China (Grant No. 50871126), and the Science and Technology Program of Guangdong Province, China (Grant No. 2007B 010600066).