Eliminating polymer flake defects using an oxygen free chemistry

Catastrophic defect excursions existed in a plasma etch process due to polymer flaking. Several possible fixes such as an in-situ particle check and a Cl/sub 2/ plasma clean were investigated without effectively eliminating this yield limiting defect. This paper will describe how an oxygen free chemistry was adopted to eliminate the polymer flake defect. This process change eliminated polymer flake excursions, improved factory line yield by more than 1% and increased etcher availability by 15%.