Patent ID: 9052337
Filing Date: 2015-06-09
Classification: B82Y,G01Q

Abstract:
1. A method for height control of a probe tip during imaging by dynamic tunneling force microscopy on a surface of a dielectric material, comprising: performing imaging by dynamic tunneling force microscopy; measuring a surface potential difference between the probe tip and a local region of a surface of the dielectric material with a lock-in amplifier to obtain a deviation signal; adjusting a feedback loop in response to the deviation signal to control a voltage applied to the probe tip to maintain electrical potential at the probe tip that is the same as an electrical potential at the local region of the surface of the dielectric material, thereby eliminating or reducing effects of surface potential variations on the surface of the dielectric material; monitoring or measuring oscillation frequency of a cantilever with respect to a set point, the cantilever supporting the probe tip; and adjusting the height of the probe tip in response to shifts in the oscillation frequency of the cantilever caused by height variation between the probe tip and the surface of the dielectric material during the imaging by dynamic tunneling force microscopy, to compensate for height variation between the probe tip and the surface of the dielectric material, thereby maintaining a constant oscillation frequency of the cantilever to maintain the height of the probe tip in relation to the surface of the dielectric material.