Ultra-thin Bulk Silicon Thinning for Visible Light Probing with High Numerical Aperture Solid Immersion Lens Laser Imaging

Abstract

Visible Light Probing techniques are of mounting importance in improving the spatial resolution for increasingly miniaturized process technologies and demands of the sample preparation processes, precise control, and visible light metrology tools to obtain ultra-thinned samples. Current CNC contour milling processes are employed to prepare samples at $50\ \mu \mathrm{m}$ remaining silicon thicknesses to $\pm 5 \mu \mathrm{m}$ tolerances. In this work, a new process is proposed to significantly reduce process time and to prepare samples to tighter tolerances down to sub- $5\ \mu \mathrm{m}$ thicknesses compatible with Visible Light Probing techniques.