In the next generation SAOP (Self-aligned Octuplet patterning) process, the line width and LWR (Line Width Roughness) measurement of lines with sub-10 nm is required. We have already proposed a novel method of line width and LWR measurement with sub-nanometer uncertainty by using FIB (Focused Ion Beam) processing, and TEM (Transmission Electron Microscope) images as reference metrology. In the previous report, we applied the method to SAQP features. A specimen of the SAQP FinFET line and space device is coated with carbon and cut horizontally into a thin planar sample by the FIB sampling system. The thin sample is observed by using planar-TEM. The average PSD of LWR of SAQP FinFET sample at the upper and lower positions calculated from planar-TEM images.
In this article, we apply the methodology to line width and roughness measurement of advanced features by SAOP process. The features are vertically or horizontally sliced as a thin specimen by FIB micro sampling system. LWR is calculated from the edges positions, and PSD (Power Spectrum Density) is analyzed for the reference metrology.
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