Techniques of evaluating long term oxide reliability at wafer level

This paper discusses techniques of evaluating long term oxide reliability at the wafer level. These techniques are presently used in the development of high reliability oxide processes. The first technique involves a statistical analysis of the electric field distribution of MOS capacitor primary breakdown. The second technique consists of monitoring time dependent breakdowns of test capacitors during a short four second voltage accelerated stress test. Using an empirically derived voltage acceleration factor (10⁷/MV/cm) failure rates at nominal voltages can be accurately extrapolated from these voltage accelerated data. A discussion of how these techniques can be used to determine oxide reliability is presented.