Inspection - checking whether connections and structures in chips are realised in the intended position - and testing - checking whether chips perform the desired function - are the operational parts of yield management and quality control. They contribute vitally to the profitability of any IC manufacturing company. Quality control by inspection directly supports the other factors of cost, productivity and on-time delivery.
TNO makes considerable R&D efforts to meet and anticipate the market needs pushed by the ever stricter demands of the semiconductor inspection roadmap. What is defined as a defect is entirely dependent on the application. But in all cases the margin of tolerance continues to shrink while the pressure on our clients regarding reliability, sensitivity, throughput and tool cost increases. Our research activities span the range of physical defect detection, from particles to process-induced defects, on patterned or blank substrates like wafers, masks, Printed Circuit Boards and Flat Panel displays. The challenge is to develop feasible tool concepts and prototypes, and to assist our clients in making their existing products meet the ever stricter specifications for the next generation of ICs.
TNO has over recent years acquired considerable expertise in the field of defect inspection. We use techniques such as scatterometric, ellipsometric, spectroscopic and fluorescent filtering. This has resulted in resolution and contrast enhancing measures, smart illumination concepts, selective noise-reduction and data-path improving measures. An additional strength is our ability to leverage our proficiency in semiconductor lithography, metrology, optics and applied laser technologies to defect inspection applications. We can draw on a wide set of facilities including in-house optical coating, prototyping facilities, laser laboratories for all UV and near-UV wavelengths and electron-optics test benches.