Stacked-Spiral RF Inductor With Vertical Nano-Powder Magnetic Core in CMOS

This letter reports a novel concept of vertical stacked-spiral RF inductor with integrated nano-powder-magnetic-core in standard CMOS. A proof-of-concept design in a foundry 0.18 6-metal CMOS using a new post-CMOS backend process (CMOS+) is depicted. Measurement shows significant improvement in inductance of 35% and quality factor of 41% up to multi-GHz in prototype. An -density of 420 at 1.2 GHz is achieved. Limiting factors for the relatively low factor in the prototypes and improvement method are discussed.