A proposed process flow for a complete FinFET etch module is presented as well as experiments to ensure that the target films are etched uniformly with proper rate, selectivity and anisotropy. The proposed process flow was developed at RIT, designed to closely reproduce what the semiconductor industry uses for a Self-Aligned Double Patterning (SADP) process module while advancing RIT\u27s current cleanroom facility capabilities.
The etching experiment is proposed such that a sufficient degree of etch endpoint control can be achieved without a spectrophotometer for endpoint detection using the Magnetically Enhanced Reactive Ion Etching (MERIE) system at RIT. Without the proper etch data a number of critical steps would be incredibly difficult to control. Prior to this work across wafer etch non-uniformity was reported to be approximately 10% with a regular rate of 1400-1500A/min. This was improved through various means to a nonuniformity of \u3c 1% and a rate of 2200A/min on average. A way to achieve the mandrel etch and strip using gas ratios of 4:2:1::CF4:CHF3:C2F6 and 4:1::CHF3:C2F6, was derived, respectively
