Abstract
We report on a comprehensive study of the 3-D profile transformation process for microstructures on silicon-on-insulator (SOI) substrates. Using hydrogen annealing, single crystalline microspheres (1 μm radius), micropillars, and circular cantilever beams have been successfully demonstrated. The annealed Si exhibits a surface roughness of 0.26 nm. A theoretical model is presented for the mass transport process, and the parametric dependence on temperature and pressure is characterized. We have used this process to fabricate sub-micrometer single mode optical waveguides on SOI and achieved a very low optical loss of 0.2 cm -1 . © 2005 IEEE.