METHOD AND APPARATUS FOR PERFORMING OPTICAL MEASUREMENTS OF LAYERS AND SURFACE PROPERTIES

摘要

The method and apparatus are capable of performing precise optical measurements of layers and surface properties (SB, SF) both transparent and also non-transparent substrates. A field stop aperture (11) in a confocal optical configuration is used to define the illumination area, and another aperture (13) is used to accept light reflected form the front (SF), or other surface, of a sample being analyzed, while blocking or rejecting the ghost reflection from the backside (SB) or other feature below the focal plane of the surface being analyzed.