Advances in Morphology Control of Through-Glass via Wet Etching for High-Performance Glass-Based Packaging

Through-glass vias (TGVs) are important high-aspect-ratio structures for glass-based advanced integration, and their wet-etching morphology significantly influences metallization quality, electrical performance, and reliability. This review establishes a process-morphology-performance framework to analyze morphology control strategies in TGV wet etching. Existing approaches are classified according to their morphology regulation mechanisms, including conventional hydrofluoric acid/buffered hydrofluoric acid etching, material modification, assisted etching, laser-induced selective etching, and hybrid strategies. The effects of these approaches on aspect ratio, sidewall roughness, sidewall verticality, dimensional uniformity, and defect formation are systematically discussed. Conventional HF/BHF etching exhibits high process maturity and low cost but is limited by isotropic dissolution and mass transport effects. Material modification and assisted etching improve local etching selectivity but remain dependent on glass composition and processing conditions. Laser-induced selective etching provides enhanced morphology control through localized structural modification. Future TGV fabrication requires integrated regulation of material modification, mass transport, and process monitoring to achieve precise via morphology optimization. This review provides guidance for selecting and optimizing wet-etching strategies for high-quality glass microstructure fabrication.