way of example one of the programs u201c solid c u201d and u201c prolith u201d already mentioned is used for the simulation prior to the simulation parameters 58 that characterize an exposure process 60 and a development process 61 of the wafer processing must be input into the program the exposure process 60 would typically be carried out by an exposure apparatus 62 which may still be in the development stage at the time of the simulation 56 in this case the parameters set as development aims should be input instead of actual parameters the exposure apparatus 62 contains for example a laser unit 64 for generating a laser beam 66 that images the structures on the mask by means of an optical arrangement usually in a manner reduced in size onto a silicon wafer 72 coated with a photoresist layer 70 during the simulation 56 the method steps of the exposure process 60 and of the development process 61 of the photoresist are simulated by calculations made with the aid of equations that describe the physical processes taking place at the end of the simulation 56 results data 74 are output see arrow 76 the results data 74 represent a resist pattern that essentially corresponds to a resist pattern 78 of the kind that might actually be produced with the aid of the exposure apparatus 62 and the development process 61 see arrow 80 elongate photoresist structures 82 84 and 86 corresponding in this order to the structures 14 16 and 18 remain on the silicon wafer 72 proceeding from the result data 74 further corrections of the layout data are often necessary see arrows 88 and 52 after one or more iterations result data suitable for the simulation of further method steps during the production of an integrated.