Structural analysis of a Mo/Si EUV reflector by optical modeling

The performance of a multilayer extreme ultraviolet (EUV) reflector has direct bearing on the process throughput and the cost of new technology. Using measured data from a real, manufactured reflector, we intended, in this work, to show that the reflectivity of the Bragg reflector can be factorized by using structural parameters such as the d-spacing, density, inter-diffusion layers, and oxidation layer. This quantitative analysis of the reflectivity derived from the structural parameters can be utilized to optimize the optical properties of the existing Mo/Si system and to provide fundamental insights into the science involved in a Bragg EUV reflector.