On the generation and elimination of lonely poly-silicon crater-defects and their impacts on gate oxide integrity (GOI) in dual-gate technology

The various observations of poly-silicon (poly-Si) crater-defects and their impacts on the gate oxide integrity (GOI) in a dual-gate technology were first described. The electrochemical kinetics of selectively corroding poly-silicon has been elucidated for the first time in generating lonely crater-defects into the unnoticeable spots of damage due to the intermittent micro-arcing events during implantation. By largely shunting the electrochemical corrosion process in a weak electrolyte (HF), the crater-defects in poly-silicon have been eliminated for significantly improving the gate oxide integrity.