Electrostatic force microscope1002202-50
A type of scanning probe microscope. It is a microscope that
the probe and measures the electrostatic force which works between the probe and the specimen, and
draws images based on the measurements.
The electrostatic force microscope is a kind of scanning probe
microscopes and measures the electrostatic force as a physical quantity. It is also called as
scanning capacitance microscope. When voltage V is applied between the probe and the measured
object, electrostatic force f working between them is proportional to the partial derivative of the
energy obtained by multiplying the square of the voltage with capacitance C between the probe and
the object, taken with respect to the perpendicular distance z. Hence, ｆ＝∂(C・V２/2)/∂z.
Therefore, if the voltage is kept a constant value, the capacitance can be obtained from the force
generated. At present, measurement with the resolution of 10-21 F at a bandwidth of 1 Hz is
possible. Moreover when the probe is grounded and the electrostatic force and the distance are
measured, the voltage can be obtained. Such method as providing electric charges and obtaining the
change in time from the change of the electrostatic force is also developed. Moreover, by measuring
capacitance while varying the bias voltage, the status of dopants, in a semiconductor can also be
known. Thus this apparatus is useful to know local electrical characteristics of micro circuitry.
Scanning tunneling microscope (STM)