Design for reliability

The advent of the ULSI era, and the continuing decrease of the critical dimensions of MOSFETs, has raised a number of issues concerning the prediction of device reliability, and the consequences for overall product reliability. The established practice has been to assure reliability at the end of the lengthy product cycle. However, to achieve a shorter time-to-market, product reliability concerns should be addressed at the design stage ("design for reliability"). Accordingly, the design and implementation of reliability simulation tools, which give a prediction of the susceptibility of an IC design to device failure mechanisms, is becoming critical. This paper reviews some of the reliability simulation tools that are currently available to industry. The capability of the most popular of these tools is described for a number of different reliability hazards. A topical reliability simulation issue is addressed, and a statistical validation, comparing measured and simulated degraded ring oscillator data, is presented.