Modeling of the Cross-linking and the Diffusion Processes in a Negative Chemically Amplified Resist

A chemically amplified negative-type resist has proposed advantages of a negative tone imaging. However, a negative-image system has been analyzed virtually by using a positive-image simulation because the dark field of a positive-tone mask corresponds to the bright field of a negative-tone mask. In this paper, a new modeling method for the cross-linking and the diffusion processes is introduced for the lithography process of a negative resist. For random approaches, the gel formation model and the Monte Carlo method are described for negative resist. The simulated results for negative resists are in good agreement with the experimental results.