Overlay & Throughput Optimization

OPAL is one of the main modules in the OVALiS Suite. Based on production data received from exposure and metrology tools, it automatically and accurately calculates the effects of alternative on-product overlay settings. Therefore, OPAL really optimizes the three dimensions of the entire lithography process:

• Alignment settings
• Metrology settings
• APC settings

This multi-dimensional approach for determining the best on-product overlay settings makes OPAL the most powerful overlay optimization tool available. The method is also used for throughput enhancement, as it allows determining the minimum set of alignment & overlay marks required for acceptable overlay.

In a production environment, OPAL thus replaces time-consuming experiments and enables optimal overlay and throughput. OPAL can also be used in-line, to track and improve process stability. This in-line tracking leads to faster process stability and causes significant acceleration of the ramp-up phase of new technology nodes or products.

Results at a 300mm wafer fab showed astonishing on-product overlay improvements for several products and layers. They also showed that very significant throughput improvements, due to alignment & overlay mark layout optimizations, are realistic. OPAL is therefore indispensable for any leading-edge fab with the goal to optimize its process yields, and to introduce new technology nodes and products at the fastest possible pace.

Next OVALiS module: ONYX