In Line Electricalmonitor of Plasma-Enhanced Silicon Oxynitirde for 70-Nm Node or Beyond

In order to monitor plasma-enhanced SiON process for 70-nm-node, the Corona Oxide Silicon technology (Quantox XP) is implemented to detect the gate material characteristic besides optical metrology tool. H2 annealing following post-nitridation annealing (PNA) reduces the noise of the equivalent oxide thickness (EOT) and thereby increases the monitoring stability. Quantox parameters have good correlations (R square > 0.996) with process condition, which show excellent monitoring sensitivity and accuracy. The low variation of Jg index and EOT, which are 0.32% and 0.17% respectively, indicate good measurement repeatability. Since atomic airborne molecular contamination (AMC) affects the stability of measurement over time, the measurement window was set to 2-6 hour after the SiON process was completed. According to the monitoring sequence, the optical thickness should be measured before the Jg index and Ultra EOT was detected.