Simultaneous irradiation of a substrate by multiple radiation sources

j j 1122IIji i j A method for configuring J electromagnetic radiation sources (J≧2) to simultaneously irradiate a substrate. Each source has a different function of wavelength and angular distribution of emitted radiation. The substrate includes a base layer and I stacks (I≧2) thereon. Pdenotes a same source-specific normally incident energy flux on each stack from source j. For simultaneous exposure of the I stacks to radiation from the J sources, Pis computed such that an error E being a function of |W−S|, |W−S, . . . , |W−S| is about minimized with respect to P=1, . . . , J). Wand Srespectively denote an actual and target energy flux transmitted into the substrate via stack i (i=1, . . . , I). The stacks are exposed to the radiation from the sources characterized by the computed P(j=1, . . . , J).