Thermal treatment for optical proximity correction

For 32-nm technology node, thermal treatment is one of the process extension techniques with 193-nm ArF lithography equipment and chemically-amplified resist (CAR). However, it is difficult to use these techniques in the manufacture process because the optical proximity effect of thermal effects is quite severe. In this paper, thermal processes, such as softbake, post-exposure bake and thermal reflow, are described and modeled to investigate the property changes of a positive type, 193-nm CAR. The simulated results agree well with the experimental results. For the optical proximity correction (OPC) of the thermal effects, an orthogonal functional method is introduced. Due to contact hole (C/H) pattern, the underbake of post-exposure bake (PEB) and thermal reflow are performed for the 45-nm critical dimension (CD) by using the OPC simulated images, to demonstrate the possibility of controlling these thermal processes for the formation of 32-nm CD.