The Effect of Delay Between Dry Etch and Wet Clean Processing Steps on Cleaning of Post-Etch Residues

Abstract

The benefits of the integration of wet cleaning using short and controlled exposure times with plasma dry etch processes have been investigated. Selectivity for post-etch residue removal versus substrate loss and the effect of delay time between etch and clean processes are investigated for shallow trench isolation (STI) and hardmask-based poly-silicon gate applications, including screening of process windows. Several hypotheses about the underlying mechanisms are formulated and tested against the experiment.