Effect of static power dissipation in burn-in environment on yield of VLSI

Abstract

The leakage power is expected to inc ease with scaling of CMOS technology. The increased leakage is a strong function of the elev ted temperature and voltage stress. As a consequence, under the bum-in (BI) conditions the levated leakage power may cause increased post Burnin fallout. In this paper the impact elevated leakage and technology scaling in bum-in environment on post BI yield is analy ed. We have also shown that to maintain a constant post-BI yield loss, the burn-in tempe ature should go down by lO°C for each technology generation. We also show that at stati burn-in conditions, the die temperature is increased exponentially and range of optimal st essed voltage and temperature for fixed post bum-in yield loss is reduced significantly, whe CMOS technology is aggressively scaled down. 1: IntroductionBurn-in (BI) is an important test t chnique to weed out infant mortality from the main population.As a result, quality and eliability of outgoing Integrated Circuits (ICs) are improved. During the BI, ICs are subj cted to elevated voltage and temperature stress. As a consequence, the field and temperat re enhanced failure mechanisms are accelerated [1].Optimization of effectiveness of BI test has been the constant focus of quality and reliability engineers.As we scale the transistor to deep s b-micron regime, it's off state leakage increases significantly. A linear reduction in transis or threshold voltage with technology scaling, results in exponential increase in its leakage. This leakage is further increased under voltage and temperature stress conditions. High 1 akage causes further elevation in chip temperature and eventually leads to a positive feed ack. Therefore, handling the power dissipation, becomes an important consideration duing the burn-in. In this article, we investigate static power dissipation as a function of tern erature and voltage. The objective is to minimize the burn-in temperature and voltage, hile maintaining constant yield during the burn-in test for future technologies.