Bandpass Filters for Semiconductor Laser-Based Inspection Systems

Bandpass filters for semiconductor laser-based inspection systems are designed to transmit selected laser wavelengths while reducing unwanted out-of-band light and background noise. In wafer inspection, defect detection, and optical metrology, these filters isolate the specific laser signal scattered or reflected from the semiconductor surface, ensuring accurate defect identification and surface analysis without interference from ambient lighting or secondary emissions.

Applications:

• Wafer surface inspection systems for isolating scattered laser light to detect particles, scratches, and micro-defects

• Optical metrology for measuring critical dimensions (CD) and thin-film thickness by filtering reflected laser signals

• Background noise and fluorescence rejection in automated optical inspection (AOI) setups to ensure sensor focus on the primary laser wavelength