QUANTITATIVE SURFACE-TOPOGRAPHY DETERMINATION BY NOMARSKI REFLECTION MICROSCOPY .1. THEORY

The Nomarksi differential interference contrast microscope is examined as a tool for determination of metallic mirror surface topography. This discussion includes the development of an optical model for the Nomarski system, an examination of the key results of the model's application to sloped sample surfaces, and recommended procedures for implementation. The functional relationship is developed between image intensity and the component of surface slope along the Nomarski shear direction, the fixed parameters in the Nimarksi system, and the adjustable phase shifts related to Nomarski prism position. Equations are also developed to allow the determination of surface slope from relative image intensity when sample reflectively is uniform and slopes are small.