Reflective optical element and method for the production thereof

The invention relates to a reflective optical element, particularly for use in EUV lithography, for a working wavelength in the soft X-ray and extreme ultraviolet wavelength range, comprising a multi-layer system (20) made of at least two alternating materials (21, 22) having different real components of the diffraction index at the working wavelength, wherein a further layer (23) made of a nitride or carbide of the material (22) having the smaller real component is disposed preferably at at least one transition from the material (21) having the larger real component of the diffraction index to the material (22) having the smaller real component of the diffraction index. The material (22) having the smaller real component of the diffraction index is particularly preferably lanthanum or thorium. The layers (21, 22, 23) of at least one material are preferably applied using plasma for producing one of the previously indicated reflective optical elements.