Optical Microscopy is a powerful yet often under utilized tool. The use of visible light to evaluate a sample can provide valuable information about a sample’s structure and composition. This technique alone can supply the information needed to solve the problem or direct the analyst along the most efficient path to gain additional information.

There are three common types of optical microscopy; brightfield illumination, darkfield illumination, and Nomarski. Brightfield illumination is the most commonly used mode. In this mode, light directly striking the surface is reflected based on the sample’s composition and topography. With darkfield illumination the center of the light cone is blocked allowing only light scattering along the surface at a low angle to illuminate the field of view. This method is good for viewing particles, edges, or other changes occurring on a sample’s surface. The third common type of optical microscopy, Nomarski imaging, is a form of interference contrast that uses polarized light passed through a prism to view the sample. Nomarski imaging is particularly useful for viewing shallow defects such as etch pits and cracks.

Silicon Cert Laboratories uses optical microscopy to inspect all submitted samples and will direct our customers along the most efficient course of analysis. SCL can provide digital images in a variety of formats from a full range of microscopes, and can provide dimension measurements using a toolmakers measuring microscope calibrated to a traceable standard.