Method, computer program and apparatus for improving calibration of resist models used in critical dimension calculation

摘要

Improved calibration of a resist model used in critical dimension (CD) calculation is disclosed. A dose function is obtained based on optical tool to be used form the resist on a wafer. The dose function indicates the amount of energy in a resist. The dose function is convolved with a convolution kernel to obtain a modified dose function. The convolution kernel has variable diffusion lengths in different directions. The convolution kernel may include multiple Gaussian kernels each having variable diffusion lengths in different directions. The modified dose function is converted into a CD value which is compared with a target value. If necessary, the diffusion lengths of the Gaussian kernels are adjusted based on the comparison result.