Metal assisted chemical etching (MaCE) is a promising technology for next generation microand nano- semiconductor fabrication, where noble metals are used as catalyst to anisotropically etch into bulk materials in solution. In this study, we report the first silicon vias (SV) with sub-100 nm diameter etched by MaCE. The distinct structure of thus fabricated SVs enables the successful copper filling from the bottom of the vias, which is manifested by scanning electron microscope (SEM) and energy dispersive X-ray spectroscope (EDS). The report demonstrates the applicability of nano-scale interconnection in 3D package from the view of fabrication. Also, this novel approach marks the significance in functional filling of semiconductor for nano-photonic devices as well as template-based synthesis of functional nanomaterials.