SEM contour extraction application on OPC model of contact layer

There are many kinds of OPC test pattern in Contact (CT) layer, and different measurement methods are used to measure the model data, resulting in a large simulation error of y-direction rectangle type patterns in the model. We propose a new method to build OPC model of CT layer by using SEM image contour. In this work, the SEM image contour was extracted by Calibre SEMSuite™, and the measurements of the corresponding test pattern was calculated according to the image contour. The CD-SEM (critical dimension scanning electron microscope) measurement data of anchor point was used to calibrate the modeling data and then the OPC model was built. Compared with the model tuned by CD measurements, the simulation error of y-direction rectangle type patterns caused by measurement method is effectively reduced. Our experiments show that it is feasible to build a high precision OPC model of CT layer by using this method.