A porous Si based novel isolation technology for mixed-signal integrated circuits

Abstract

A novel isolation technology for RF applications based on semi-insulating porous Si (PS) is demonstrated. RF cross-talk isolation of 70 dB at 2 GHz and -45 dB at 8 GHz has been demonstrated using PS trenches that provide complete isolation between neighboring regions of a p/sup +/ Si chip. On-chip spiral inductors of 6 nH fabricated over the PS regions have been demonstrated with Q/sub max/ /spl sim/29 at 7 GHz and a resonant frequency of over 20 GHz.