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Wafer-level nanoimprint lithography (NIL) has increasingly become a key enabling technology to support new devices and applications across a wide range of markets. Leading manufacturers of augmented reality (AR) devices, optical sensors and biomedical chips are already utilizing NIL and realizing the benefits of this technology, including the ability to mass manufacture micro- and nano-scale structures down with a maximum degree of freedom for the device dimensions. Another key advantage of this replication based technology is, given by the fact that even complex structures which require precise and time consuming fabrication methods can be transferred to mass manufacturing in an efficient semiconductor manufacturing line. Additionally, for many devices especially for optical applications the replicated layer can be directly used as functional layer in the product. Today NIL is considered as decisive process step for a number of emerging products, including AR waveguides. With increasing volumes the scaling of the production lines is crucial for most economical implementation of NIL. In particular for scaling to production lines using 200mm or even 300mm wafer sizes, the whole process chain has to be established. This is in particular a focus for AR devices requiring highly complex structures with tight specifications. Thus best efforts for master fabrication are crucial to obtain best performing devices. For smaller substrates, typically full area masters are used to manufactured and used for the NIL process. However, as the masters are mainly fabricated by sequential processes the costs scale with the pattern area. For 200mm and 300mm it has been proven to be viable option to start with single high-quality devices and scale them by step and repeat (SR) NIL to fully populated waferscale masters and subsequently to use those for volume manufacturing on wafer-level. The wafer-level production itself requires then reliable replication of working stamps and wafer level nanoimprinting of these multiple devices on a single wafer. As a result it is key for the high volume manufacturing to have a thorough understanding of all required pattering and replications steps to enable these large area manufacturing lines.
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