Picomaster system supports top side alignment. In simax's unique portable optical module, a 5.2 megapixel monochrome camera is integrated, with a measurement resolution of 100 nm. The final alignment accuracy depends not only on the measurement resolution, but also on the quality of the alignment mark, the stability of the temperature and the correction of the system.
The alignment error can be less than 250 nm, but it must meet certain measurement requirements:
• Correct system calibration
• Temperature stability of system and substrate
• High quality alignment mark, minimum size 50 micron
• The alignment marks on the first layer are also processed by Picomaster system
The vernier structure is used for the top side alignment test, and the alignment accuracy is less than 100 nm.