SU-8 enhanced high power density MEMS inductors

Monolithic integration of DC-DC converters with on-chip inductors has emerged as a viable means to reduce size and increase transient performance for portable electronics applications. High-power-density inductors have been recognized as a barrier for such integration. In this paper, a CMOS-compatible process that is capable of fabricating on-chip inductors with low DC resistance and high power density is developed. A unique silicon molding technique is used to obtain thick electroplating layers for cores and windings. SU-8 is used as the isolation material between windings and cores. A pot-core inductor with a low-frequency inductance of 134 nH and a dc resistance of 9.1 mOmega has been demonstrated.