ABSTRACT
The last two decades have shown an ever-increasing interest in higher precision and m iniaturization in a wide range of manufacturing activities. These growing trends have led to new requirem ents in machining, positioning control, and me trology down to nanom eter tolerances. Recent developments in silicon micromachining have made possible the fabrication of micromechanical elements of sizes typically ranging from 0.1 to 100 ,um [1-4]. Slots and apertures for some applications such as color TV, electron gun masks, and jet-engine turbines are made as small as 5 pm. Microcircuit elements of 0.5 to 1 pm are commonly m anufactured using X-ray or electron-beam
lithography [5]. In order to assess and control the quality of micromachined parts it has been necessary to develop new m easuring techniques, capable of effectively and accurately m easuring the dimensions, geometry, profile, and surface roughness of microholes, slots, very th in films, microspheres, steps, and grooves of different configurations in micromachined parts. These parts and features can be either checked for configuration and completeness, or m easured to determine ac tual sizes. Inspection and m easurem ent of these features raise the demand for special equipment some of which depends on entirely new principles.
