Prediction of plasma charging induced gate oxide damage by plasma charging probe

The plasma processing induced wafer charging damage is predicted by the newly developed SPORT (Stanford Plasma On-wafer Real Time) charging probe. Such a probe can directly measure the spatial charging voltage built up on a wafer surface as well as the charging current from the plasma. Both antenna dependence of damage and charge fluence through a gate oxide due to charging can be calculated from the intersection between plasma I-V characteristic measured by the probe and intrinsic MOS I-V characteristic. This result agrees well with the real MOS capacitor damage data from O/sub 2/ plasma processing. Thus, given a fluence criteria, this methodology gives a means for predicting the minimum antenna ratio for observable damage.