Optical spectral emission endpoint detection for passivation etch

As device integration and complexity escalates, Reactive ion etching (RIE) in radio frequency (RFT) glow discharges is perhaps the most popular means of achieving small geometry features. However, the complexity of the RIE process has prompted for accurate, reproducible endpoint detection methods and techniques. One commonly used non-destructive and non-invasive in situ plasma etching diagnostic method is optical spectral emission. To achieve accurate detection, errors triggering false detection signal has to be minimized. In this paper, we evaluate the correlation between etch rate uniformity and the effectiveness of endpoint detection in passivation etch process.