Nanoimprint lithography (NIL) has developed from an emerging nano replication technology into a matured and industrially viable manufacturing technology. Since its invention in the mid 90s, it is now by far the fastest and most cost-efficient nano-replication method available on the market. One of the first industrial adaptations of nanoimprint lithography in manufacturing is to enhance light output of LED's [1,2] and it has been shown that the technology can be used for manufacturing with a high throughput and yield [3] but there are also many other applications with promise such as organic electronics [4] and magnetic media [5]. Obducat uses a IPS®/STU® manufacturing process where no hard materials touch each other during process sequence, see figure 1 (left). The IPS® material is flexible which allows the stamp to adjust to the curvature and roughness of the substrate, thereby giving a uniform residual layer on full wafer scale. This enables imprinting of several different types of wafers such as Ⅲ/V based wafers, flexible substrates, silicon substrates as well as lenses with a curved surface. Focusing on LED production, the wafers used are typically III/V semiconductor materials grown with epitaxial processes. These types of substrates suffer from growth defects like hexagonal spikes, v-pits, waferbowing, atomic steps and surface corrugations on a scale of few 10μm or even large islands of irregularities. The mentioned irregularities are particularly disturbing when NIL based processes are utilized to create patterns onto the wafer surface. The defects can have a height of several μm, which can cause large areas without nano-patterns, substrate breakage or as in the case where the stamp is applied directly onto the substrate, breakage of the stamp itself. Using the IPS®/STU® manufacturing process easily copes with this since no hard materials touch each other during the entire process sequence. Indeed, this is essential for high volume manufacturing where the imprinted nanostructures must have a consistent quality. This paper will show that NIL is the preferred technology to produce nanopatterns on GaN substrates used for producing LEDs. In addition, examples of other application areas such as organic electronics will also be shown.
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