A lithography mask includes a substrate, a reflective structure disposed over a first side of the substrate, and a patterned absorber layer disposed over the reflective structure. The lithography mask includes a first region and a second region that surrounds the first region in a top view. The patterned absorber layer is located in the first region. A substantially non-reflective material is located in the second region. The lithography mask is formed by forming a reflective structure over a substrate, forming an absorber layer over the reflective structure, defining a first region of the lithography mask, and defining a second region of the lithography mask. The defining of the first region includes patterning the absorber layer. The second region is defined to surround the first region in a top view. The defining of the second region includes forming a substantially non-reflective material in the second region.