Patent ID: 6507197
Filing Date: 2003-01-14
Classification: G01Q,Y10S

Abstract:
An electrostatic force microscope for measuring electrostatic force and film thickness of a sample under test having electrostatic charge on a surface thereof comprising:a) a detector comprising a cantilever arm having a tip formation at one end and located in spaced relation to the sample under test so that electrostatic force is induced at the tip formation due to electrostatic charge on the sample under test, the detector further comprising an electromechanical transducer on the cantilever arm and spaced from the tip formation; b) an optical system for transforming bending of the cantilever arm due to electrostatic force induced at the tip into an electrical signal output containing frequency components of the electrostatic force induced at the detector tip; c) a series combination of an AC bias voltage source and a DC bias voltage source connected to said transducer; and d) a detection circuit connected to the AC bias voltage source and to the output of the optical system for detecting the frequency component of the electrostatic force induced at the detector tip and the component corresponding to twice that frequency for obtaining a simultaneous measurement of both electrostatic force and film thickness of the sample under test.