Prediction of plasma charging induced gate oxide tunneling current and antenna dependence by plasma charging probe

Abstract

The SPORT charging probe has been used to monitor the plasma charging voltage evolution during a resist ashing step. The charging voltage rapidly increases when the etch is close to the end point. A modified model is also proposed to explain the oxide current flow during the ashing. From the direct measurement of the plasma I-V characteristic for charging and the thin oxide I-V characteristic, the antenna dependence of the electron fluence passing through the oxide and subsequent charging damage can be predicted. In general, this probe can be used as a fast diagnostic tool for characterizing and understanding the mechanisms behind plasma induced charging damage.