Abstract: A mask for use in a photolithographic process. The mask includes a plate or substrate having first and second opposite surfaces, a first image on the first surface of the substrate and a second image on the second surface of the substrate. When the mask is used in a photolithographic process, energy is reflected by the first image prior to entering the substrate and energy is reflected by the second image after passing through the substrate.

Abstract: A method for verifying reticle enhancement technique latent image sensitivity to mask manufacturing errors. The method includes the steps of revising a polygon based on mask CD distributions to provide a virtual mask, imaging the virtual mask to obtain response function statistical parameters, and comparing the statistical parameters to process tolerance requirements. Preferably, the method includes the steps of simulating an aerial and/or latent image of the virtual mask, calculating response functions based on the mask image simulation, collecting measurements and calculating statistical parameters based on the response functions, and comparing the statistical parameters with design rule requirements (i.e., for DI yield percentage for required mask manufacturing specification). The virtual mask is obtained by using mask CD distribution to induce statistical variations to layouts which have passed through the conventional OPC procedure.