Through-Glass Via (TGV) Fabrication in Quartz and D263 Glass Using Picosecond Laser Processing and Chemical Etching: AComparative Parametric Study

Through-glass vias (TGVs) enable vertical interconnections in 3D integrated circuits, MEMS packaging, and optoelectronic assemblies, but achieving consistent via quality across different glass types remains a fabrication challenge. This work investigates how pulse duration, focal position, and beam polarization affect TGV geometry in two compositionally distinct substrates: synthetic quartz and D263 alkali-containing silicate float glass. A quasi-Bessel beam delivered picosecond pulses at durations of 7 ps and 10 ps, while the focal position was stepped across six Z-axis offsets ranging from +0.3 mm to −0.2 mm. After laser modification, all samples were wet-etched in 10% hydrofluoric acid. For D263 glass only, beam polarization was additionally varied from linear to circular using a quarter-wave plate, allowing its influence on via depth, sidewall morphology, and taper angle to be evaluated. The two materials showed markedly different responses under identical processing conditions. Quartz responded more favorably to 10 ps pulses, producing deeper and more uniform vias with lower taper angles, whereas D263 performed better at 7 ps. Switching to circular polarization on D263 at 7 ps further improved etch depth by approximately 20% and reduced taper noticeably. These results offer practical parameter guidance for glass-composition-specific TGV fabrication in high-throughput interconnect manufacturing.