Method for optimizing printing of a phase shift mask having a phase shift error

摘要

Optimizing printing of an image from an alternating phase shifting mask having a phase shift error is accomplished using off-axis illumination. By simulating the image using varying off-axis illumination parameters, optimized parameters are selected to compensate for the phase shift error. Once the off-axis illumination parameters are optimized, the image is shot. In addition, the method of varying off-axis illumination parameters to compensate for a phase shift error permits an alternating phase shifting mask to be shot at two different wavelengths.