Simultaneous measurement of surface geometry and material distribution by focusing ellipsotopometry

A new method for total surface measurement based on reflection ellipsometry is presented. By scanning the surface of the target under test with a focused laser beam, one can measure the surface topography and its material distribution simultaneously with high lateral resolution. Target topography is determined by ellipsometric measurement of local gradient angles gamma(x) and gamma(y) of the target's scanned surface elements. To identify the material, one measures the local complex refractive index n, too. The influence of beam focusing on the measurement results is discussed. We describe successful tests with various dielectric and metallic surfaces by use of He-Ne (632-nm) and He-Cd (442-nm) lasers.