In-line High-Resistance Tungsten Plug Defect Monitoring with an Advanced e-beam System

摘要

In-line e-beam inspection is performed to detect dark voltage contrast (DVC) defects on normally bright W-plugs. Cross-sectional SEM and TEM in an FA lab verified that the different gray level values (GLV) of DVC defects are caused by different resistances of the W-plugs. We found that DVC defects with lower GLV (GLV1) are W-plugs that are open and almost open. DVC defects with GLV2 are caused by partially open W-plugs and in-plug voids.