Antireflective member, optical element, display device, method of making stamper and method of making antireflective member using the stamper

A stamper with a fine uneven surface structure, the stamper comprising:

• a base, including
• an aluminum layer, which includes at least 95 mass % of aluminum;
• and
• a porous alumina layer, which is arranged on the aluminum layer,
• wherein the porous alumina layer has a plurality of recessed portions, each having a stepped side surface, wherein
• some of the recessed portions are surrounded with three to six pointed raised portions, wherein
• a plurality of saddle portions, which are different from the plurality of raised portions and the plurality of recessed portions, are between the tops of adjacent raised portions, each saddle portion interconnecting the tops of two adjacent raised portions not via any recessed portion, and wherein
• the distance between two adjacent recessed portions and the distance between two adjacent pointed raised portions is at most 200 nm.