Semiconductor Dopant Profiling by Electrostatic Force Detection with AFM
Abstract: Atomic force microscopy (AFM) can be used not only as a tool for obtaining surface topography but also as a tool to investigate various electrical properties on semiconductor surfaces. It has been widely known that we can measure capacitance or spreading resistance using a conductive cantilever in contact to the sample surface. However, it is also possible to measure local electric properties such as surface potential or capacitance using dynamic-mode AFM. Recently, several researchers even succeeded in obtaining atomic-resolution surface potential images. In this paper, principles of the methods for investigation of local electric properties on semiconductor devices based on electrostatic force detection using dynamic-mode AFM are described. Current research trends in this research field and several examples of the local dopant profile measurement on semiconductor devices are also introduced.
Key words: semiconductor device, electrostatic force, dynamic-mode AFM, Kelvin-probe force microscopy, scanning capacitance force microscopy