Wafer burn-in (WBI) technology for RAM's

A simple and practical wafer burn-in (WBI) technology is described. This technology effectively screens reliability failures of random access memories on a wafer, prior to die-sorting. As a result, obtaining "known-good" RAM chips becomes much more realistic. Since most of the failures occurred during the WBI can be replaced by spare rows or columns, the product yield improves. The new WBI technology uses the conventional wafer prober and multi-chip probe card environment, and does not need any additional process steps which previous WBI proposals required. >