A High-Efficiency Double-Side Silicon- Embedded Inductor for Integrated DC–DC Converter Applications

In this brief, a novel double-side silicon-embedded coreless inductor is proposed and demonstrated for integrated dc-dc converter applications. The inductor has double-side thick windings embedded into the silicon substrate and connected in parallel. Extremely large effective metal thickness of 300 μm can, therefore, be achieved. Consequently, the 0.8 mm
²
inductor fabricated shows a low dc resistance of 42 mΩ. A large inductance to dc resistance ratio of 0.4 nH/ mΩ is then achieved with an inductance over 16.1 nH. The calculated peak effective inductor efficiency is 96.1% for 1.8-0.85 V, 100 MHz dc-dc conversion.