Novel Atomically Smooth Conformal Finishing Method for Ultra-Rapid Removal of Sub-Surface Damage and Stresses in SiC Mirrors

Silicon carbide (SiC) has long been recognized as an attractive mirror material due to its superior mechanical and thermal properties when compared to conventional optical materials. However, the extreme mechanical strength results in significant sub-surface damage (SSD) which needs to be removed by large area conformal polishing methods. The current state-of-the-art polishing methods are either typically very slow or introduce a high density of defects or large stresses. Sinmat plans to investigate a novel ultra-gentle and ultra-rapid Reactive Chemical Mechanical Planarization (RCMP) method to rapidly remove SSD and stresses from SiC mirrors. The polishing process is expected to be more than 100 times faster than that of current processes adopted in the industry, thereby resulting in significant time- and cost-savings. In the Phase I of this project, we plan to demonstrate the feasibility of this process to conformally, rapidly remove SSD in SiC substrates, whereas in Phase II we plan to integrate the process with figuring technologies leading to the development of precision SiC mirror in a rapid and scalable manner.