Deep high-aspect ratio Si etching for advanced packaging technologies

摘要

Deep high-aspect ratio Si etching (HARSE) has shown potential application for passive self-alignment of dissimilar materials and devices on Si carriers or waferboards. The Si can be etched to specific depths and; lateral dimensions to accurately place or locate discrete components (i.e lasers, photodetectors, and fiber optics) on a Si carrier. It is critical to develop processes which maintain the dimensions of the mask, yield highly anisotropic profiles for deep features, and maintain the anisotropy at the base of the etched feature. In this paper the authors report process conditions for HARSE which yield etch rates exceeding 3 (micro)m/min and well controlled, highly anisotropic etch profiles. Examples for potential application to advanced packaging technologies will also be shown.