Fabrication of sub-micrometer Si spheres with atomic-scale surface smoothness using homogenized KrF excimer laser reformation system

Recently, microspheres have received increasing attention as optical microcavity resonators due to their high quality morphology dependent resonances (MDRs) [1]. Numerous applications have been realized by using microsphere MDRs. However, most of the research being conducted is based on noncrystalline materials such as glass [2] or polymers [3]. Since silicon is the dominating material in current integrated circuit industry, fabricating microspheres on a Si-based substrate with present electronic devices in a single chip are expected. The study contributes to compact and low-cost integrated devices for mass-market applications. Here, a novel technique using the homogenized KrF excimer laser reformation is presented as an alternative method for fabricating Si spheres.