Patent ID: 6841786

Claim:
A method for compensating for unevenness, which comprises: providing a light-reflecting substrate having a carrier material, a front surface, a back surface, and at least one layer configured on the front surface, the layer at least partially forming a surface having an unevenness; providing a distance-measuring appliance and a radiation source for generating a light beam, an ion beam or an electron beam; defining an idealized plane substantially parallel to the front surface of the substrate; selecting a first position on the front surface of the substrate; at the first position, measuring a first value for a distance between the surface of the layer and the idealized plane using the distance-measuring appliance, the distance representing the unevenness; calculating a first radiation dose for the light beam, the ion beam or the electron beam as a function of the first value; and generating a local mechanical stress to compensate for the unevenness by locally irradiating a position on the back surface of the substrate with the first radiation dose of the light beam, the ion beam or the electron beam from the radiation source; the position on the back surface of the substrate located opposite the first position on the front surface.