Optical critical dimension measurement for source/drain structures at advanced node

In modern IC industry, optical critical dimension (OCD) technique has been more and more applied, as one of the most import process control tools. In this work, OCD spectroscopy metrology was used to measure the profiles of 2-D sigma-shaped Source/Drain structures at advanced node. Due to the complexity of the samples, eighteen parameters were investigated and six floating parameters were set up to generate the spectra library. The results were compared with Transmission Electron Microscopy and reference OCD data. The stability of 15-day was evaluated. The results showed good performance of OCD metrology.