Dissolution rate analysis of ArF resists based on the percolation model

We investigated the dissolution properties of ArF-resist base polymers and ArF resist in order to study their development mechanism. We measured the d issolution rate of methacrylate copolymers and a resist as a function of th e hydrophilic unit content, and simulated dissolution phenomena by using pe rcolation theory. The obtained dissolution-rate curves had strong nonlinear dependence on hydrophilic unit content. In the simulation analysis, base m olecule diffusion through the hydrophilic path was modeled as particle diff usion through the percolation field. The diffusion constant was calculated by using conventional and modified diffusion models. We suggest a new varia ble to describe diffusion-path width in the modified model. The simulation results indicate that our model reproduced the experimental results better than the conventional model.