NEAR-FIELD SCANNING OPTICAL MICROSCOPY AND SPECTROSCOPY FOR SEMICONDUCTOR CHARACTERIZATION

The applicability of near-field scanning optical microscopy (NSOM) for optical characterization of semiconductors is discussed. The NSOM tec hnique and some of its properties relevant to real-time in-situ measur ements are reviewed. Several optical characterization methods widely u sed in the far-field, including reflectance, reflectance-difference sp ectroscopy, Raman spectroscopy, ellipsometry, and carrier lifetime, ar e evaluated for their use with NSOM. Experimental data are included fo r some of these methods. It is concluded that several, but not all, of the standard optical characterization methods can be coupled with NSO M to provide higher spatial resolution. The applicability of NSOM real -time in-situ probe shares some of the problems of other proximal prob e methods, but offers enough new capabilities to warrant its applicati on.