OPERATING INSTRUCTIONS |

GENERAL INFORMATION
Inductively Coupled Plasma (ICP) etching is a technique which uses a radio frequency (RF) energy coupled into a low pressure gas by an inductive coil mounted on the outside of a quartz window. This technique allows fabrication of high aspect ratio silicon features with vertical sidewalls; The Cobra ICP etch sources produce a high density of reactive species at relatively low pressure values. DC bias can be applied to the substrate to increase directionality of ions into the substrate.

The CNI Fl DRIE etch system is a metal free system dedicated for silicon, silicon oxide, and silicon nitride etch. For other materials dry etch please use the Oxford PlasmaLab 80 ICP. The DRIE system uses the Bosch process which is a pulsed etching alternating repeatedly between two modes to achieve vertical pattern. The first mode is etching by SF6 followed by wall passivation which is achieved through polymerization of C4F8 on the side walls of the etched features, protecting it from further etching and allowing the next etch step to be directional. Available gases are: SF6, C4F8, CHF3, O2, Ar, N2, CF4, CH2F2, C2F6, and He.

For recipes and materials specific etch rate information you can view our process development file.

CONTACT INFORMATION
For additional information about the Oxford PlasmaPro 100 Cobra Fl DRIE, please contact the clean room staff at: cniCR@columbia.edu.