Patent ID: 8126669

Claim:
A method, comprising: at least approximately describing a Jones pupil of a microlithographic projection exposure apparatus using an expansion into orientation Zernike polynomials; assessing the suitability of the microlithographic projection exposure apparatus on the basis of an expansion coefficient of at least one of the orientation Zernike polynomials in the expansion; and modifying the microlithographic projection exposure apparatus based on the assessment, wherein the orientation Zernike polynomials are defined as {right arrow over (W)} nmε =R n |m| Φ mε ; wherein R n m are radial polynomials given by R n m ⁡ ( r ) = ∑ s = 0 ( n - m ) / 2 ⁢ ( - 1 ) s ⁢ ( n - s ) ! s ! ⁢ ( 1 2 ⁢ ( n + m ) - s ) ! ⁢ ( 1 2 ⁢ ( n - m ) - s ) ! ⁢ r n - 2 ⁢ s with m, n, s being integers, m=−n, . . . , n and ε=0 or 1; and wherein Φ mε is given by Φ → m ⁢ ⁢ 0 = ( cos ⁢ m ⁢ ⁢ φ 2 - sin ⁢ m ⁢ ⁢ φ 2 ) , Φ → m ⁢ ⁢ 1 = ( sin ⁢ m ⁢ ⁢ φ 2 cos ⁢ m ⁢ ⁢ φ 2 ) or a linear combination thereof.