Dielectric breakdown distributions for void containing silicon substrates

Distributions of gate oxide failure in various types of silicon substrate m aterials have been investigated for a wide range of oxide thicknesses. Sili con substrates containing various well-characterized void distributions alo ng with defect-free materials were tested using special low-series resistan ce capacitor structures. Results of both ramped field tests of variable ram p rate and constant field tests were performed and analyzed within the fram ework of Weibull statistics. Ramped field tests are not "time zero dielectr ic breakdown" tests as is commonly asserted. They can in fact be very usefu l in extrapolating time dependent failure. The same set of Weibull paramete rs can be used to describe both ramped field and constant field wearout tes ts if an appropriate model for the time dependent damage accumulation durin g the field ramp is used. There are implications for reliability predicatio n and the burn-in screening of device populations containing such defects. (C) 2001 Published by Elsevier Science Ltd.