Fabrication and Characterization of Wafer Level Three-Dimensional Silicon Lens

This study reported the silicon (Si) lenses with convex shape on 12 inch wafers by using the photoresist reflow method and grayscale lithography by Direct Write Laser (DWL), then transferred it to Si wafers by reactive ion etching (RIE) process. The reflow process was optimized for the condition of temperature and time to perform the suitable pattern for the AZ4562 photoresist. By adjusting the etching parameters, the proper etching selectivity of Si to photoresist is achieved and successfully fabricated the Si lenses on the 12 inch Si wafer.