Direct comparison of cross-sectional scanning capacitance microscope dopant profile and vertical secondary ion-mass spectroscopy profile

The scanning capacitance microscope (SCM) has been shown to be useful for quantitative 2D dopant profiling near the surface of silicon. An atomic force microscope is used to position a nanometer scale tip at a silicon surface, and local capacitance change is measured as a function of sample bias. A new feedback method has been recently demonstrated in which the magnitude of the ac bias voltage applied to the sample is adjusted to maintain a constant capacitance change as the tip is scanned across the sample surface.