Scanning capacitance microscopy

It has since been adapted for use in combination with scanned probe microscopes for measuring other systems and materials with semiconductor doping profiling being the most prevalent.

The magnitude of this change in capacitance with the applied voltage gives information about the concentration of carriers (SCM amplitude data), whereas the difference in phase between the capacitance change and the applied, alternating bias carries information about the sign of the charge carriers (SCM phase data).

Because SCM functions even through an insulating layer, a finite conductivity is not required to measure the electrical properties.

Some applications of the SCM technique involve mapping the dopant profile in a semiconductor device on a 10 nm scale,[5] quantification of the local dielectric properties in hafnium-based high-k dielectric films grown by an atomic layer deposition method[6] and the study of the room temperature resonant electronic structure of individual germanium quantum dot with different shapes.

[7] The high sensitivity of dynamical scanning capacitance microscopy,[8] in which the capacitance signal is modulated periodically by the tip motion of the atomic force microscope (AFM), was used to image compressible and incompressible strips in a two-dimensional electron gas (2DEG) buried 50 nm below an insulating layer in a large magnetic field and at cryogenic temperatures.