Pattern density tailoring for etching of advanced lithographic masks

1. Field of the Invention A method of preparing an x-ray mask comprising providing a substrate, and applying sequentially to a surface of the substrate i) an etch stop layer resistant to etchant for an x-ray absorber, and ii) an x-ray absorber layer. The method then includes removing a portion of the substrate below the layers to create an active region of the substrate above the removed portion of the substrate and an inactive region over remaining portions of the substrate, applying a resist layer above the absorber layer, and exposing a portion of the resist layer using electron beam irradiation and developing the resist layer to form a latent mask image over the active region of the substrate. The method then includes removing the exposed portion of the resist layer to leave a resist layer mask image over the active region of the substrate, and etching the absorber layer to leave an absorber layer mask image over the designated active region of the substrate while simultaneously removing the absorber layer from the inactive region to form, for example, an x-ray mask, on the substrate.