First Look at Across-chip Performance Variation Using Non Contact, Performance-Based Metrology

摘要

We report on the first non-contact, non-destructive performance measurements of embedded Ring Oscillators. Measurements are made on inside the die active area as early as Metal 1. A 90nm logic CMOS technology was used for this work. We have measured residual across-field performance variation separate from and of opposite sense to wafer uniformity. This effect cannot be extrapolated from scribe measurements.