Tunnel effect sensor, suitable for determining the topography of a surface

摘要

A tunnel effect sensor, suitable for determining the topography of a surface, arm for exploring the profile of a surface of the sample by scanning it along two axes. The arm includes a tactile point that can be moved in a direction normal to the surface to be explored and a tunnel point near a tunnel electrode attached to the substrate. A control loop controls the distance between the tunnel point and its electrode. The position of the feeler arm is adjusted by means of the control loop and two actuators operating on the feeler arm in opposite directions. The feeler arm can therefore effect a virtual pivoting movement about the tunnel point. As a result, the sample-holder does not need to be moved along the measurement axis during measurements. Applications include atomic force microscopes.