A micromachining post-process module with pattern transfer in deep cavities for RF silicon technology

In this paper a novel micromachining post-process module applied to the backside of processed wafers for the integration of radio frequency (RF) devices in silicon is presented. A specific characteristic of this module is the use of an optimized process for pattern transfer in and across 400 /spl square/m-deep etched cavities. The technology is described, and the potentials of this module are illustrated through the realization of several structures and devices such as trenches to reduce the crosstalk and sub-surface spiral inductors.