Patent ID: 8520190

Claim:
A method of evaluating an imaging performance of a projection optical system which projects a pattern of an original onto a substrate, the method comprising: a specifying step of specifying, by a computer, a polarization change of the projection optical system, which represents a relationship between a polarization state of light impinging on the projection optical system and the polarization state of the light exiting from the projection optical system; a first calculation step of calculating, by a computer, a value of a parameter having a correlation with the polarization change of the projection optical system specified in the specifying step; and a second calculation step of calculating, by a computer, an index value representing the imaging performance of the projection optical system in a state that the projection optical system has the polarization change specified in the specifying step, based on an amount of change in the index value representing the imaging performance of the projection optical system upon changing the value of the parameter by a unit amount, and the value of the parameter calculated in the first calculation step, wherein the parameter whose value is calculated in the first calculation step includes a phase of light passing through the projection optical system, the phase being calculated based on the polarization change of the projection optical system, wherein the polarization change of the projection optical system is expressed by a Jones matrix, and the value of the parameter is obtained based on an eigen value obtained by Pauli expansion of the Jones matrix, and wherein the value of the phase is obtained based on an eigen value obtained by Pauli expansion of the Jones matrix, and the phase is given by an arctangent function of the eigen value.