High resolution ellipsometric apparatus

摘要

In an ellipsometric apparatus, a laser is provided for generating a probe beam. The probe beam is passed through a polarization section to give the beam a known polarization state. The probe beam is then tightly focused with a high numerical aperture lens onto the surface of the sample. The polarization state of the reflected probe beam is analyzed. In addition, the angle of incidence of one or more rays in the incident probe beam is determined based the radial position of the rays within the reflected probe beam. This approach provides enhanced spatial resolution and allows measurement over a wide spread of angles of incidence without adjusting the position of the optical components. Multiple angle of incidence measurements are greatly simplified.