Process tool monitor

01/01/1999

Process tool monitor

The AIT II is a system for patterned process tool monitoring for 0.18-?m geometries and below, with bridge capability to 300-mm wafers. By making possible the immediate detection of process tool excursions, it minimizes the number of wafers exposed to out-of-control conditions. The system incorporates production-proven double-darkfield technology, which combines low-angle illumination with low-angle collection optics. This provides superior defect capture by suppressing color variation and grainy background noise, as well as increasing small particle sensitivity and providing surface selectivity to minimize detection of previous-layer defects. Improved collection optics optimize the system for CMP and etch process tool monitoring. Programmable spatial filters give good defect collection on array structures, while selectable polarization of the illumination beam provides increased sensitivity by minimizing process noise. AIT II can vary the die-to-die signal processing threshold and contrast levels for different areas of the device. KLA-Tencor Corp., San Jose, CA; ph 408/875-7039,

e-mail [email protected].