Non-Destructive Optical Depth Inspection of Sub-Diffraction Limit Fine Holes (The fifth report)

Experiment verification based on modified Linnike microscopic interferometry

抄録

The importance of microstructure devices has been a valuable research topic, hampered in part by the quality control. One of the inspection factors for evaluating the quality is depth measurement for the fundamental and pervasive shape component microgroove. The conflict between the miniaturization of microstructures and diffraction limit restricts the application of conventional optical depth measurement. A novel optical inspection method was proposed to achieve the in-process depth measurement for diffraction limited microgrooves, which is characterized by non-destructive and high-throughput. In this paper, the modified Linnike microscopic interferometer system based on three identical objective lenses and reversibility principle of optical path was developed, and experiments for standard grating micro-grooves on silicon surface are carried out to demonstrate the feasibility of this optical depth measurement method.