Advanced process characterization using light source performance modulation and monitoring

As DUV multi-patterning requirements continue to become more stringent, it is critical that all sources of lithography patterning variability are characterized and monitored. Advanced process characterization studies have been enabled using Cymer's novel technique to modulate Beam Divergence and Polarization, and Energy, Bandwidth, or Wavelength light source performance. These techniques have been instrumental in helping identify process sensitivities that enable proactive light source monitoring and excursion detection using SmartPulse (TM). Demonstration of the benefits of these technologies is provided through results from recent experiments at imec. Changes in patterning performance are characterized using top down CD-SEM metrology, enabling excellent correlation between optical parameters and on wafer attributes for typical patterning geometries. In addition, new results show that changes in laser beam parameter performance can have measurable wafer patterning and/or illumination impacts. Chipmakers can benefit from the use of this capability to perform proactive, comprehensive characterization of current and next generation process nodes.