A study of high-density embedded capacitor for silicon-substrate package

Rapidly growing performance and mixed-signal integration is driving the need for product component miniaturization in electronics applications. Embedded passive technology is a potentially attractive solution to replace discrete passives. Embedded capacitors are widely used for broad range of applications including filtering, tuning and power-bus decoupling in the substrate. Micro-Electron-Mechanical System (MEMS) process based on silicon and deep etching 3D patterns on silicon substrate is used. The fabrication process and properties of a semiconductor decoupling capacitor with high capacitance density is reported in this paper. Measurement results indicate that the capacitance density can reach 12nF/mm², which is 10-12 times that planar semiconductor capacitors, and that the decoupling frequency range is between from 10MHz to 3.2GHz.