Diffusion and resolution for chemically amplified resists

摘要

As discussed in the last edition of this column (MLW, May 2006), diffusion in conventional (nonchemically amplified) resists has a very predictable (and undesirable) impact on resolution. The effects of diffusion can be determined by convolving the prediffusion latent image with a diffusion "point-spread function" (DPSF), which for Fickean (constant diffusivity) diffusion is simply a Gaussian whose sigma is equal to the diffusion length.