Nomarsky contrast microscopy, technique

Hie most important optical technique for examining semiconductor wafer surfaces is the differential interference contrast microscopy method of Nomarski (N-DIC). First described in 1952, DIG... 

A major advantage of optical microscopy techniques is the ease of sample preparation. Thin fibers, films, or membranes can be placed directly in an appropriate immersion oil on a glass slide and information regarding the crystalline or dispersed phases, orientation, birefringence, and so forth, can be readily determined (see Section 4.1.1). Sectioning (see Section 4.3.2) of thicker materials is routinely accomplished in very short times, on the order of 30 min or so, with steel or glass knives. Observations and measurements of spherulite sizes, local orientation in molded parts, and fiber orientation are also conducted with the optical microscope. Phase contrast and Nomarski techniques provide contrast in multiphase polymers. Small differences in refractive index are enough to make the dispersed phases distinct, so the... 

Another technique for crystallinity analysis is the measurement of pole figures. It is widely applied for thin films, LPE films, melt-processed polycrystalline samples with a noticeable texture (Goyal et al. 1993). In fig. 33, a good crystallinity of the Y123 LPE film is evidently obtained due to a specific growth mechanism, mentioned above (sect. 5.4), despite the large misfit between the film and the MgO substrate. Differential interference contrast (DIM or Nomarski) microscopy can be successfully applied to observe misorientation on flat ( mirror-like ) surfaces (Klemenz and Scheel 1993). 

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