A composite arrangement has a substrate material with a main surface, a metal-insulator arrangement including a metal sheet with an insulation area on the main surface, and a magnetoresistive structure on the metal-insulator arrangement. Thereupon, a cover layer arrangement is heated, so that the same at least partially covers the magnetoresistive structure with a target thickness D, and finally the magnetoresistive structure is heated by light radiation with given wavelength λ. The absorbed portion of the emitted radiation depends on the actual thickness D′ of the cover layer arrangement and the wavelength λ, wherein the target thickness D of the cover layer arrangement is adjusted so that, if the cover layer deviates from the target thickness D in a range of ±20% with reference to the target thickness D, a change of the absorbed portion of the emitted radiation in the magnetoresistive structure of less than ±40% is caused.