A glass-based heterogeneous integrated structure with a back hole and its fabrication method

Abstract

This invention provides a glass-based heterogeneous integrated structure with back vias and its fabrication method. Back vias are designed on a heterogeneous integrated wafer. The heterogeneous integrated wafer includes a glass substrate and a piezoelectric crystal layer, or at least one heterogeneous thin film layer is bonded between the glass substrate and the piezoelectric crystal layer. The back vias are blind vias and / or through-holes, with the blind vias etched to reach the piezoelectric crystal layer or any heterogeneous thin film layer. Filler metal is sputtered into the back vias. Before etching the front piezoelectric crystal layer, a surface acoustic wave (SAW) filter pattern can be fabricated on the complete surface of the glass-based heterogeneous integrated wafer with back vias. After etching the piezoelectric crystal layer, the bottom of the filler metal is exposed on the surface of the glass-based heterogeneous integrated wafer. The SAW filter and the filler metal are then interconnected through photolithography, evaporation or sputtering, electroplating, etc. The blind vias can be arranged into a folded inductor, connected to the front device layer through the through-holes. This invention features better device heat dissipation, improved package design and mass production capabilities, higher integration density, and higher device Q-value.

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