Patent ID: 7517575

Claim:
A silver alloy reflective film comprising: silver; a total of 0.01-3 atomic % of X1; and a total of 6-20 atomic % of Y1, wherein the silver alloy reflective film comprises an enriched layer located in a region within 2 nm deep from the surface of the silver alloy reflective film, wherein X1 is enriched in the enriched layer at a higher concentration than the average concentration of X1 in the whole of the silver alloy reflective film, wherein X1 is at least one alloying element selected from the group consisting of Bi and Ge, wherein Y1 is at least one alloying element selected from the group consisting of Nd, Sn, In and Gd, and wherein the concentration of X1 in the enriched layer increases in a thickness direction from the surface of the silver alloy reflective film to a depth of 2 nm from the surface of the silver alloy reflective film.