ABSTRACT
The early failure-rate portion of the reliability curve is dominated by defects and shows a sharp reduction in failure rate with time. The reliability improvements are normally made through: defect elimination, lowering the intrinsic failure-rate, and making sure that wearout does not occur during the expected product lifetime. The stress and temperature dependence for this degradation rate is subject of reliability physics and is normally studied through the use of accelerated testing. The Weibull distribution seems to be the preferred distribution for plotting Ultra-large-scale-integrated-circuit (ULSI) failure mechanisms such as time-dependent dielectric breakdown data, an important ULSI failure mechanism which will be discussed in more detail shortly. To go from the empirically determined failure rate under accelerated conditions to a projected failure rate under normal operating conditions, the concept of an acceleration factor must be introduced. A clear understanding of the reliability physics for the new materials will be critically important for their successful and timely introduction into the semiconductor industry.
