Model-based OPC for resist reflow process

In this paper, model-based optical proximity correction (OPC) software for thermal reflow is introduced and verified for its accuracy in comparison with experiment results due to pitch sizes. For its purpose, the resist reflow process (RRP) is modeled, and the OPE effects after development and thermal reflow are described by using the top view images. The sensitivity of the optimized parameters for contact hole and side wall angle of simulated profiles is analyzed using the response surface methodology (RSM). Through the quantization of sensitivity of these easy-to-optimized simulation parameters, lithography processes are quantified and compared between line-and-space and contact hole. By using the behavior model on the chip layout, the designed mask dimensions are changed due to the correction of the RRP image. The final profiles after the model-based OPC show that the optical proximity effects are reduced to an acceptable level even with the mask errors included.