使用用于缺陷检验的激光功率控制的大粒子监控
By combining the main laser beam and the auxiliary laser beam and dynamically adjusting the laser power, the problems of particle ablation and wafer damage in laser scattering inspection tools are solved, achieving efficient detection and protection of small particles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KLA CORP
- Filing Date
- 2021-09-02
- Publication Date
- 2026-07-17
AI Technical Summary
Existing laser scattering inspection tools are prone to particle ablation and wafer damage when detecting small particles due to high laser power density, and it is difficult to dynamically adjust the laser power to avoid these problems.
A combination of a main laser beam and a secondary laser beam is used. The secondary laser beam detects particles before the main laser beam and reduces the power of the main laser beam. The power of the laser beam is gradually restored in a controlled manner to avoid ablation. An acousto-optic modulator or other modulator is used to modulate the power of the laser beam.
It effectively avoids particle ablation and wafer damage, improves detection capabilities, reduces the risk of damage to the wafer caused by laser power density, and achieves efficient detection of small particles.
Smart Images
Figure CN116018513B_ABST