This proposal is aimed at developing a full software solution for the next generation advanced optical metrology. Existing simulation tools cannot meet the current and future needs of scattering-based optical metrology for semiconductor manufacturing. Our proposed work will first focus on developing an enhanced RCWA-based simulation engine with advanced algorithms for fast convergence and stability, which can be applied to periodic and non-periodic 3D problems with arbitrary polarizations, structure profiles and material systems. A versatile and user-friendly CAD interface will also be developed based on the RSoft existing, industry-leading CAD technology for optoelectronics device simulation. Within the CAD, a 3D openGL display engine will be implemented for 3D data display and manipulation. Other potential methods, including FDTD, FEM and FMM, will also be investigated and implemented to address the full range of optical metrology applications. COMMERCIAL APPLICATIONS: The research and development effort in this proposal will create commercial design and simulation software for advanced optical metrology. The software can be used in the semiconductor manufacturing process for CD measurement, profile analysis, process monitoring, real-time and inline control. The software suite will provide a full-functional GUI and efficient and accurate algorithms for the above commercial applications. In addition, the same software suit can also be used in a broad range of other commercial application including (nano-) lithography, nano-photonic device, high-resolution optics, sub-wavelength surface grating devices, optical data storage, polarization sensitive devices, artificial dielectrics, three-dimensional displays, optical interconnection designs, spectroscopy, microlens arrays, spectral filtering, beamsplitting, and beamshaping