Composite Glass-Silicon Substrates Embedded With Microcomponents for MEMS System Integration

This paper reports a novel composite glass-silicon substrate (CGSiS) embedded with microcomponents by a glass reflow process. Microcomponents including vias, electrodes, capacitors, inductors, and filters are designed. Highly doped silicon is taken as the conductive material of microcomponents. Glass reflow process is investigated to fabricate the CGSiS. Results show that the total thickness variations of three composite substrates by an improved planarization method are smaller than 10 μm. The surface roughness of silicon and glass after polishing is below 0.5 nm. The silicon conductivities of two composite substrates are 5.35 × 10-3 and 3.34 × 10
^-3
Ω · cm, respectively. Micropassives, vias, and electrodes are successfully embedded in the CGSiS. The CGSiS embedded with microcomponents shows great potential for MEMS 3-D integration.