Abstract
Nano-imprint techniques have been expected for a following lithography technique of semiconductors because of the low costs, the simple process and the high resolution. However, there is a problem that thin resist film remains in the compressed area between a wafer and a mold through patterning process. The residual resist must be etched away precisely not to cause semiconductors performance defects. Hence, in order to apply the nano-imprint techniques to semiconductor manufacturing, a non-destructive inspecting technique to measure the residual resist thickness is required. Hence, we proposed a non-destructive inspecting method of thin film thickness based on the near-field optics. The principle is following that, firstly, a metal-coated fiber probe approaches the surface and is illuminated the tip of by laser to generate near-field light. Then we can inspect a thin film by using the near-field light. This method can be expected a high spatial resolution thanks to the fact that it depends an aperture size of fiber probes. In this paper, we observed response characteristics of near-field light to film thicknesses and confirmed the validity of the proposed method via FDTD simulation and fundamental experiments.
