DEFECT DIAGNOSIS USING SIMULATION FOR IC YIELD IMPROVEMENT

Defects in integrated circuit wafers (10) are often difficult to diagnose, because patterned wafer inspections can only be done after certain wafer processing steps. Defect simulation is used to understand the relation between defects in the wafer (10) and the resulting wafer profiles. Defects such as particles (50) and bubbles (22) in the photoresist (28), for example, translate into a wide variety of defective profiles. Knowledge of the relation between defects and the defect profiles can assist in yield improvement efforts, since defects may be diagnosed by comparing simulated and observed defect profiles. From the simulated defect profiles, methods can be adapted to fix or correct observed defects.