High-Sensitivity Defect Inspection for Unpatterned Wafers via Integrating Dark-Field Scattering and Diffraction Phase...

Area of Science:

• Semiconductor Manufacturing
• Optical Metrology
• Materials Science

Background:

• Conventional wafer defect inspection methods lack sufficient sensitivity and reliability.
• Advanced semiconductor manufacturing demands higher precision in defect detection.

Purpose of the Study:

• To develop a novel dual-channel optical inspection system for enhanced wafer defect characterization.
• To improve the sensitivity and reliability of defect detection in unpatterned wafers.

Main Methods:

• Integration of dark-field scattering and diffraction phase microscopy into a single system.
• Simultaneous acquisition of dark-field intensity and phase gradient signals from defects.
• Experimental validation using polystyrene particles for limit of detection assessment.

Main Results:

• Achieved a limit of detection of 60 nm for wafer defects.
• Demonstrated improved sensitivity compared to single dark-field scattering systems.
• Maintained detection limits for small-scale defects in both lateral and vertical dimensions.

Conclusions:

• The proposed dual-channel system offers high sensitivity and reliability for unpatterned wafer defect inspection.
• This technology meets the stringent requirements of advanced semiconductor manufacturing.
• The integrated approach enables comprehensive defect characterization at the nanoscale.