MEASUREMENT OF LINEAR NANOMETRIC DISTANCES BETWEEN SMOOTH PLANE-PARALLEL BODIES BY SCATTERED TOTAL INTERNAL-REFLECTION

Measurement of linear nanometric distances between perfectly smooth pl ane parallel surfaces by scattering evanescent waves of internally ref lected light is shown to be possible if one of the two surfaces is opt ically disseminative, that is, it either possesses a heterogeneous ind ex of refraction or it is capable of absorbing and re-emitting radiati on. Good agreement was obtained between the nominal 100 nm fly height of a magnetic recording slider and the 92 nm fly height measured by sc attered total internal reflection. This method is simpler and more inf ormative than interferometry or methods that employ the internally ref lected beam. (C) 1996 American Institute of Physics.