Patent Number: 053717740
Section: claims

1. A method for imaging an X-ray lithography beamline from an X-ray source emitting an X-ray beam along a y axis and diverging along x and z axes, respectively, where the x, y and z axes are orthogonal to each other, comprising: providing a mirror having a reflecting surface reflecting the X-ray beam to an imaging plane orthogonal to the y axis and spaced from the mirror along the y axis;  determining the optical path function F from the source A to the image B by determining the optical path function from the source A to the mirror P, and from the mirror P to the image B, according to EQU F=AP+PB=((x.sub.A -x).sup.2 +(y.sub.A -y).sup.2 +(z.sub.A -z).sup.2).sup.1/2 +((x.sub.B -x).sup.2 +(y.sub.B -y).sup.2 +(z.sub.B -z).sup.2).sup.1/2  determining the partial derivatives of the optical path function F, .differential.F/.differential.x, .differential.F/.differential.y, .differential.F/.differential.z, wherein  determining a grid on said reflecting surface comprising a plurality of grid points; and  modifying the slope at said grid points such that the displacement of the reflected rays from the image line vanishes. 2. The method according to claim 1 comprising eliminating discontinuities in said reflecting surface by varying surface coordinates in z to smooth the surface. 3. The method according to claim 2 comprising modifying the surface recursively until it provides a smooth line image in the image plane along the x axis. 4. The method according to claim 3 comprising modifying the surface recursively according to ##EQU4## where n is the polynomial order, and c is the coefficient of the polynomials.