Wafer scale integration of micro-optic and optoelectronic elements by polymer UV reaction moulding

A replication technique allowing for the wafer scale integration of microoptical elements is presented and illustrated by various examples. The technique is based on polymer UV reaction moulding using a modified contact mask aligner where mask and wafer are replaced by the replication tool and an arbitrary substrate (on top of which the microstructures are to be replicated), respectively. The technology takes advantage of the high precision and adjustment accuracy of photolithography equipment. The replication masters are nickel shims, etched Silicon wafers or uv-transparent fused silica tools. The latter ones allow for replication on opaque substrates. Additionally, polymer elements with unique properties can be obtained by the combination of replication and resist technology using partially transparent replication tools. Wafer scale hybrid integration of micro-optical subsystems is accomplished by replication of polymer elements like lenses, lens arrays, micro prisms etc, onto semiconductor wafers containing detectors or VCSELs, or, by combining micro-optical elements on both sides of a glass wafer. The use of thin layers of uv cured (crosslinked) polymers on inorganic substrates results in good thermal and mechanical stability compared to all-polymer devices.