A direct plasma etch approach to high aspect ratio polymer micromachining with applications in biomems and CMOS-MEMS

Abstract

A novel etching approach to high aspect ratio polymer micromachining is introduced. A switching chemistry utilizing oxygen as an etchant gas with a C4F8 passivation step has produced high aspect ratio polymer structures. Polymer layers have been bound to a mechanical silicon support, patterned and etched. The silicon is subsequently undercut creating suspended polymer membranes. The polymer microstructures have also been aligned with CMOS MEMS structures in a process compatible with post CMOS micromachining. All steps in the polymer micromachining and post CMOS release are compatible with standard MEMS processing equipment. This approach holds great promise for creating devices with CMOS electronics as sensors and actuators and aligned polymer microstructures serving as integrated fluidic conduits for bioMEMS and micro total analysis systems.