Design and Experiment of Thermal Contact Sensor Detecting Defects on Si Wafer Surface

A deign study of a thermal-type contact sensor for the detection of small defects, the heights of which are less than 16 nm on the wafer surface, is described in this paper. The feasibility of the contact sensor, which would detect frictional heat generated at the contact with defects, was theoretically investigated focusing on the temperature rise of the sensor element. To investigate the temperature rise of the contact sensor due to the generated frictional heat, both the theoretical calculation with simple model of heat transfer and a simulation with a finite element model (FEM) was carried out. Relationship between the sensor size and the response of the temperature rise of the contact sensor was also investigated by using FEM simulation.