Tunnel effect sensor, particularly for measuring the topography of a surface

摘要

The detector comprises a fixed substrate (2), a displaceable sample support (P), and a feeler arm (6) suspended above the sample surface (S) in order to determine its surface profile by scanning. The arm (6) comprises a tactile point (9), which can be displaced normally to the surface (direction Z) and a point tunnel (10) placed adjacent to an electrode tunnel (4) within the substrate (2). A buckle regulates the distance separating the point tunnel (10) and its electrode (4). The position of the follower arm is controlled by a control loop and two actuators (3-6, 5-6) which act in contrary senses on the arm (6). Hence a virtual pivot movement occurs around the point tunnel and the sample needs only to be displaced along the measurement axis.