An attenuated phase shift patterning device including a first component for reflecting radiation, and a second component for reflecting radiation with a different phase with respect to the radiation reflected from the first component, the second component covering at least a portion of the surface of the first component such that a pattern including at least one uncovered portion of the first component is formed for generating a patterned radiation beam in a lithographic apparatus in use, wherein the second component includes a material having a refractive index with a real part (n) being less than 0.95 and an imaginary part (k) being less than 0.04.